Patent Publication Number: US-2020299033-A1

Title: Dust-free heat-shrinkable packaging article

Description:
BACKGROUND 
     For decades it has been known to provide loose dust, e.g., loose corn starch dust, on the inside and outside surfaces of a seamless heat shrinkable film tubing which is converted to heat shrinkable bags for the packaging of meat. In the manufacturing process, dust is applied to the inside of a thick, annular, seamless film “tape” immediately after it is extruded from an annular die, i.e., before the tape undergoes solid-state orientation to form the heat-shrinkable film tubing. The presence of dust on the inside surface of the tubing facilitates the manufacture of the heat-shrinkable film and subsequent film processing including (a) printing, (b) conversion to packaging articles, (c) processing of the resulting packaging articles on packaging machines, including opening and insertion of the product into the packaging article. 
     Dust is applied to the outside of the heat-shrinkable film tubing during conversion of the strand of heat-shrinkable film tubing into individualized packaging articles, e.g., bags, for example via sealing and cutting. The presence of the dust on the outside of the heat-shrinkable film tubing facilitates the subsequent handling of the individualized packaging articles during the process of filling the packaging article with a meat product. More particularly, the presence of dust on the outside surface of the individualized packaging articles lowers the film-to-film coefficient of friction, i.e., acts as a slip agent, i.e., lubricant, allowing the individualized packaging articles to readily slide and readily release from each other and from machine surfaces. 
     For example, when packaging meat products using a stack of bags in a box, the presence of dust on the outside surface of each of the individualized bags allows the top bag to be readily removed from the stack of bags for filling with product. Without dust on the outside of the bags, the top bag may adhere to the next bag (i.e., the bag immediately beneath the top bag) to a degree that the next bag moves off of the stack as the top bag is being removed from the stack and to a loading station. That is, the next bag may move partially or fully off the stack of bags as the top bag is moved to the loading station. This undesirable movement of the next bag could range from just slight movement off of the stack of bags, all the way to moving to the product loading station with the top bag. Without the dust on the outside of the bags, the movement of the top bag to the loading station would likely move the next bag at least out of alignment with the remaining bags of the stack, and part of the distance to the product loading station. Regardless of whether it is carried out manually or via automation, the removal of the top bag from the stack of bags, without substantial disturbance of the position of the next bag, is assisted by the dust on the outside surface of the top bag and the outside surface of the next bag. 
     Furthermore, in taped shingled bags, after a product is placed inside the downstream bag (i.e., a “first bag”) adhering to the tape(s), the presence of dust on the outside surface of all the bags adhered to the tape(s) allows the now product-containing first bag to be pulled off of the tape(s) with little or no disturbance of the next bag upstream (i.e., the “second bag”) on the tape(s), thereby facilitating the loading of the next product into the second bag. This facilitation of loading occurs for both manual and automatic product loading. The resulting loaded first bag can then be removed from the tape(s) and further processed either manually or automatically, including transport to a vacuum chamber where the atmosphere is evacuated from the bag while the product remains therein, with the bag then being closed with a heat seal, and with excess bag tubing cut off and discarded or recycled. Machinery and processes for vacuum packaging meat and other products place in heat shrinkable bags is described in U.S. Pat. No. 3,958,391 (Kujubu); U.S. Pat. No. 4,580,393 (Furukawa), and U.S. Pat. No. 4,640,081 (Kawaguchi et al.), each of which is hereby incorporated, in its entirety. 
     After the first bag on the tape(s) is loaded with product and removed from the tape(s) and forwarded for further packaging operations, the second bag is thereafter positioned for product loading, is thereafter opened, and is thereafter loaded with product, with the resulting loaded second bag thereafter being detached from the tape(s) and moved downstream for further packaging operations as with the first bag. The dust facilitates these packaging operations. 
     Dust on the inside surface of the tubing assists in the manufacture of the heat shrinkable film tubing. If dust is used to make a tubing in a process as schematically illustrated in  FIG. 1 , the dust is provided to the inside of the annular extrudate through a passageway through the center of the annular die. The dust is applied to the inside of the tubing immediately upon extrusion of the annular extrudate from the annular die. The annular extrudate emerging from the annular die is referred to herein as a “tape.” The annular tape is thick and is not yet solid-state oriented and therefore is not yet a heat-shrinkable film. The dust contacts the inside surface of the annular tape shortly after it emerges from the die. The annular tape is quenched by cooling liquid. Once quenched, the annular tape is collapsed into its lay-flat configuration. The annular tape in lay-flat configuration may thereby undergo additional optional processing while in tape form, e.g., irradiation, extrusion coating, etc. However, in the making of the heat-shrinkable film, the annular tape in lay-flat configuration is thereafter reheated to its softening temperature (e.g., via passage through a hot water bath at 85-90° C.), with the resulting softened annular tape thereafter passing through a first pair of nip rollers rotating at a surface speed of X meters per minute, following which the annular film is stretched both transversely by passage around a trapped bubble of air, and longitudinally by a second set of nip rollers rotated at a higher surface speed, e.g., X+Y meters per minute. The trapped air is present in an amount which forces the softened annular tape to open and expand transversely enough to cause a desired level of solid state transverse orientation. The relative surface speeds of the nip rollers, combined with the increased machine direction path length from the expansion around the trapped air bubble, produce a desired level of solid-state machine direction orientation. The opening of the softened tape is facilitated by the presence of the dust inside the softened tubing, as without the dust the tape may “block,” i.e., present substantial resistance to opening to allow the plug of air to expand the tape in the transverse direction. If the tape blocks, the solid state orientation process fails. Thus, the first reason for providing dust inside the tape is to allow for the opening of the softened tape at the start of the solid state orientation process. 
     After solid-state orientation, the resulting seamless, annular heat-shrinkable film tubing is collapsed into lay-flat configuration and wound up on a roll. This annular, heat-shrinkable film tubing in lay-flat configuration can thereafter be unrolled and converted, via cutting and sealing, into a plurality of bags or casings, i.e., into a plurality of packaging articles. During conversion of the heat-shrinkable film tubing into packaging articles (bags and casings), dust is added to the outside surface of the tubing, as described above. However, dust added to the inside the annular extrudate provides both enough dust to ensure that the softened tubing readily opens at the beginning of the solid-state orientation process, as well as enough dust to ensure that upon unwinding the wound-up lay-flat seamless heat-shrinkable film tubing followed by cutting and sealing operations to convert the film tubing to heat-shrinkable packaging articles, the resulting packaging articles readily open for subsequent operations for product insertion thereinto. It should be noted that the solid state orientation of the softened tape to form the heat shrinkable film tubing increases the surface area of the inside surface of the tubing by the amount of the total film orientation. For example, a tape subjected to a 3× transverse solid state orientation in combination with a 3× machine direction solid state orientation results in an interior surface area of the tubing which is nine times the interior surface area of the tape. The amount of dust fed inside the tape immediately after extrusion must be adequate to do more than merely allow the opening of the softened annular tape. That is, the amount of dust added must be adequate to prevent the blocking of the inside surface of the heat shrinkable film tubing to itself, so that the tubing can be opened for product insertion after the tubing is converted into a packaging product. 
     Although corn starch dust, and/or dust made from any other suitable material, provides the above-described slip and antiblock properties needed for the manufacture and use of the heat-shrinkable bags, during application of the dust to the outside of the tubing, dust escapes into the factory because the dust loses its adhesion to the outside surface of the tubing, as well as escapes from inside the tubing during conversion to packaging articles. The dust which escapes into the factory passes into whatever ambient environment the tubing or packaging article is in. The result is dust in the air and on the surfaces of air filters, equipment, building surfaces, etc. Moreover, as corn starch dust is nutritional, microbes can be sustained and multiply when provided with the dust as a food source. Dust also detracts from the aesthetic appearance of packaging articles before a meat product is placed inside the packaging article and the dust rinsed off the outside of the packaging article. Thus, it would be desirable to provide the tubing and packaging articles with the desired slip and antiblock properties without the use of dust. 
     Heat shrinkable film tubings which are dust-free but which have desirable slip and antiblock properties are known in the prior art. These prior art heat shrinkable film tubings have been used as packaging films, but have not been converted to heat-shrinkable bags and casings (comprising or made from seamless tubing) for the packaging of meat products. Rather, relative to heat-shrinkable bags and casings used for the packaging of meat and other products, these prior art heat-shrinkable films are manufactured as seamless tubings in order to provide the heat-shrinkable character, but the heat shrinkable film tubings are cut in the machine direction to open up the tubing to result in a flat film product which is wound up as a flat film and thereafter unwound and used as a flat film in various packaging applications. Moreover, these flat films have a total film thickness (before shrinking) of less than 1.6 mils. These prior art flat films have been used for the packaging of food and non-food items, and typically exhibit a free shrink at 85° C. of from 5 to 15% in the longitudinal direction (i.e., machine direction) and from 5 to 20% in transverse direction. 
     Moreover, as these prior art dust-free, heat-shrinkable flat films are not converted into packaging articles in the form of tubings in which the tubing is placed in lay-flat configuration with the lay-flat tubing having to be opened in order to be filled with product, these heat-shrinkable flat films are not subject to the same release requirements as are present in the manufacture and use of the heat-shrinkable bags described above. Rather, the only release requirements are in the unrolling of the flat film from a roll, which is different from and much less sensitive to blocking than the release requirements in the opening of a packaging article made from a tubing in lay-flat configuration, particularly a tubing in lay-flat configuration which has been on a roll and/or which has been passed through nip rollers in lay-flat configuration during film processing. 
     SUMMARY OF THE INVENTION 
     Heat-shrinkable packaging articles used for meat packaging have relatively thick heat seal layers comprising a polymeric composition of relatively low density. It has been discovered that the combination of slip and antiblock components used in prior art dustless heat-shrinkable films are inadequate to provide the antiblocking characteristics needed to provide openability to heat-shrinkable packaging articles for the packaging of meat, i.e., heat-shrinkable packaging articles comprising a multilayer, heat-shrinkable, film tubing in lay-flat configuration, the film tubing having an inside heat seal layer heat sealed to itself. This discovery confirms why commercially-available heat-shrinkable bags for packaging meat have dust on the inside and outside surfaces. The combination of slip and antiblock components used in the prior art dustless heat-shrinkable films does not need to meet the openability performance of packaging articles comprising a multilayer, heat-shrinkable, film tubing in lay-flat configuration in which a first lay-flat side is in contact with a second lay-flat side, because the prior art dustless heat-shrinkable films have not been used to make such packaging articles. Attempts to use the prior art dustless heat-shrinkable films to make packaging articles comprising the multilayer, heat-shrinkable, film tubing in lay-flat configuration have resulted in failure, as the packaging article blocked (i.e., would not open) under standard openability conditions. 
     In addition, the elimination of the use of corn starch dust, tapioca dust, etc. (i) reduces microbial growth by elimination of a food source (ii) provides a cleaner production area and improved working environment (iii) reduces contamination of equipment and sensors (iv) reduces the need for air filters (v) reduces wear on equipment, and (vi) lengthens the working life of heat sealing equipment (vii) reduces or eliminates air in rolls (viii) reduces or eliminates film creasing and feathered edges (ix) improves the consistency of the loading and handling of heat shrinkable film tubing and packaging articles made therefrom. 
     A first aspect of the invention is directed to a packaging article comprising a heat-shrinkable film tubing in lay-flat configuration. The heat-shrinkable film tubing has a first lay-flat side in contact with a second lay-flat side. The heat-shrinkable film tubing comprises a multilayer heat-shrinkable film comprising (A) an inside heat seal layer comprising a seal layer polymeric composition, and (B) an outside layer comprising an outside layer polymeric composition. The inside heat seal layer is heat sealed to itself. A first portion of the inside heat seal layer is on the first lay-flat side of the packaging article and a second portion of the inside heat seal layer is on the second lay-flat side of the packaging article, with the first portion of the heat seal layer being in contact with the second portion of the heat seal layer. The heat seal layer comprises a seal layer polymeric composition comprising polyolefin having an average density of less than 0.92 g/cm 3 . The inside heat seal layer has a thickness of at least 0.1 mil. The inside heat seal layer further comprises: (a)(i) antiblock particulates in an amount of at least 2000 ppm, based on total layer weight, the antiblock particulates having a mean particle size of at least 3 microns; (a)(ii) a fast-blooming release agent in the inside seal layer in an amount of at least 1200 ppm, based on total layer weight, the fast-blooming release agent comprising at least one member selected from the group consisting of erucamide, oleamide, lauramide, lauric diethanolamide, monoglyceride, diglyceride, glycerol monoleate, glycerol monostearate, and (a)(iii) a slow-blooming release agent in the inside seal layer in an amount of at least 1200 ppm, based on total layer weight, the slow-blooming release agent comprising at least one member selected from the group consisting of stearamide, bis-stearamide, ethylene bis-stearamide, stearyl stearamide, stearyl erucamide, erucyl erucamide, behanamide, ethylene bis-oleamide, oleyl palmitamide, stearate ester, sorbitan stearate, mono stearate, di stearate, tri stearate, sorbitan monolaurate, pentaerythritol stearate ester, polyglycerol stearate, zinc stearate, calcium stearate, magnesium stearate, sodium stearate, potassium stearate. The packaging article has an open end. The antiblock particulates, the fast-blooming release agent, and the slow-blooming release agent are present in the inside heat seal layer of the multilayer heat-shrinkable film in an amount so that the packaging article opens in a Standard Opening Test in which a strand of the multilayer heat-shrinkable film tubing has been stored in lay-flat configuration while wrapped around a core having a diameter of 8.9 cm for 7 days, with the strand of the multilayer heat-shrinkable film tubing being wound onto the core to a roll diameter of 50 cm, with the film being wound at a tension of 179 gm/cm of lay-flat tubing width, at a conclusion of which a portion of the tubing 2.54 cm from the core is converted into a packaging article while the tubing remains in lay-flat configuration. The resulting packaging article is provided with an open top having an open top edge transverse to a length of the tubing, with a lower lay-flat outside surface of the packaging article being in lay-flat contact with an upper horizontal surface of a support platform having a linear leading edge wider than a width of the packaging article and a length longer than the packaging article. The lower lay-flat outside surface of the packaging article is in adhered contact with the upper horizontal surface of the support platform by a pair of tapes each having a width of 6 mm and an adhesion to steel of at least 90 g/6 mm measured in accordance with AFERA 4001-ED.9/79, with each of the tapes running 1.5 inches from the linear leading edge of the packaging article in a direction perpendicular to the open top edge of the article. The tapes are located on the upper horizontal surface of the support platform such that each tape has a centerline placed at a position corresponding with 33.3% of a distance across the lay flat width of the tubing. The open top lip of the packaging article is parallel to and directly above the leading edge of the support platform. The packaging article opening up upon being simultaneously subjected to: (i) a 0.5 second burst of air delivered from a de Laval air nozzle having an air consumption of 28.9 Nm 3 /h (=17 scfm), the air nozzle being positioned along a center line inclined 15 degrees from the support platform, the air nozzle having a tip positioned 3 inches from the lip of the packaging article, with the air nozzle being aimed at the open top lip of the packaging article, and (ii) a 2 second flow of air from an air knife positioned parallel to and coincident with the support platform, the air knife having a discharge line 5.5 inches from the lip of the packaging article, the air knife having an air consumption of 76.5 Nm 3 /h (=45 scfm). 
     A second aspect is directed to a packaging article comprising:
         (A) a heat-shrinkable film tubing having an inside heat seal layer containing a seal layer polymeric composition, antiblock particulates, a fast-blooming release agent, and a slow-blooming release agent, and   (B) an outside layer comprising an outside layer polymeric composition as in the first aspect
 
wherein the outside layer has an outside surface having a peak coefficient of friction of less than 0.8, measured in accordance with ASTM D 1894, and the inside layer also has a peak coefficient of friction of less than 0.8, measured in accordance with ASTM D 1894.
       

     A third aspect is directed to a packaging article comprising:
         (A) a heat-shrinkable film tubing having an inside heat seal layer containing a seal layer polymeric composition, antiblock particulates, a fast-blooming release agent, and a slow-blooming release agent, and   (B) an outside layer comprising an outside layer polymeric composition as in the first aspect
 
wherein the outside layer comprising an outside layer polymeric composition, and wherein the outside layer has an outside surface having an instantaneous coefficient of friction of less than 0.6, measured in accordance with ASTM D 1894, and the inside layer also has an instantaneous coefficient of friction of less than 0.6, measured in accordance with ASTM D 1894.
       

     A fourth aspect is directed to an assembly comprising a set of imbricated packaging articles on two strands of tape. Each of the strands of tape has a tacky surface and an opposite surface free of tack. Each of the packaging articles is in accordance with the first or second or third aspects above. Each of the packaging articles has two overlying sides of substantially identical dimensions. Each of the packaging articles has one side secured to the tacky surface of both of said tapes. The open end of each of the packaging articles is in the same direction respecting the tapes as all of the other packaging articles in the set. Each successive packaging article adhered to the tapes is offset from the other packaging articles of the set and overlying the opening of an underlying packaging article. The tapes are spaced apart and parallel to one another. 
     A fifth aspect is directed to a process for packaging a plurality of individual meat products. The process comprises (A) placing each of the plurality of individual meat products into each of a corresponding plurality of individual packaging articles having an open top, each of the corresponding individual packaging articles being dust free and being in accordance with the first aspect, the second aspect, or the third aspect as set forth above, 1, to produce a plurality of partially packaged products including a first partially packaged product and a second partially packaged product, (B) moving a first platen into a loading zone, the first platen being in a state of continuous motion; (C) placing the first partially packaged product onto a first platen while the first platen is moving through the loading zone; (D)(d)(i) moving the first platen out of the loading zone while the first partially-packaged product remains on the first platen; and (D)(d)(ii) bringing a first vacuum chamber lid down over and into contact with the first platen to form a first vacuum chamber having the first partially packaged product therein while the first platen remains in continuous motion; (D)(d)(iii) evacuating the atmosphere from within the first vacuum chamber, including evacuating the atmosphere from within the first partially packaged product, as the first vacuum chamber continues to travel; (D) (d)(iv) sealing closed the individual packaging article of the first partially packaged product while the atmosphere remains evacuated from the first vacuum chamber to produce a first vacuum packaged product, as the first vacuum chamber continues to travel; (D)(d)(v) allowing atmosphere to re-enter the first vacuum chamber as the first platen, having the first vacuum packaged product thereon, continues to travel; (D)(d)(vi) separating the first vacuum chamber lid from the first platen, as the first platen continues to travel, and (D) (d)(vii) removing the first vacuum packaged product from the first platen, as the first platen continues to travel; (E) placing the second partially packaged product onto a second platen after the first platen has moved out of the loading zone and the second platen has moved into the loading zone; and (F)(f)(i) moving the second platen out of the loading zone while the second partially-packaged product remains on the second platen; (F) (f)(ii) bringing a second vacuum chamber lid down over and into contact with the second platen to form a second vacuum chamber having the second partially packaged product therein while the second platen remains in continuous motion; (F) (f) (iii) evacuating the atmosphere from within the second vacuum chamber, including evacuating the atmosphere from within the second partially packaged product, as the second vacuum chamber continues to travel; (F) (f) (iv) sealing closed the individual packaging article of the second partially packaged product while the atmosphere remains evacuated from the second vacuum chamber to produce a second vacuum packaged product, as the second vacuum chamber continues to travel; (F) (f) (v) allowing atmosphere to re-enter the second vacuum chamber as the second platen, having the second vacuum packaged product thereon, continues to travel; (F) (f) (vi) separating the second vacuum chamber lid from the second platen, as the second platen continues to travel, and (F) (f) (vii) removing the second vacuum packaged product from the second platen, as the second platen continues to travel. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic of a cross-sectional view of a heat shrinkable multilayer film. 
         FIG. 2  is a schematic of a process for producing a heat-shrinkable multilayer film tubing useful in making the packaging article, such as the film of  FIG. 1 . 
         FIG. 3  is a schematic of a heat-shrinkable end-seal bag made from the film tubing of  FIG. 1 . 
         FIG. 4  is a cross-sectional view of the bag of  FIG. 3 , taken through section  4 - 4  thereof. 
         FIG. 5  is a schematic of a heat-shrinkable side-seal bag also made from the film tubing of  FIG. 1 . 
         FIG. 6  is a cross-sectional view of the side-seal bag of  FIG. 5 , taken through section  6 - 6  thereof. 
         FIG. 7  is a schematic of a heat-shrinkable pouch, which also can be made from the film tubing of  FIG. 1 . 
         FIG. 8  is a transverse cross-sectional view of the heat-shrinkable pouch of  FIG. 7 , taken through section  8 - 8  thereof. 
         FIG. 9  is a longitudinal cross-sectional view of the heat-shrinkable pouch of  FIG. 7 , taken through section  9 - 9  thereof. 
         FIG. 10  is a schematic of a heat-shrinkable end-seal patch bag. 
         FIG. 11  is a cross-sectional view of the patch bag of  FIG. 10 , taken through section  11 - 11  thereof. 
         FIG. 12  is a schematic of a heat-shrinkable side-seal patch bag. 
         FIG. 13  is a cross-sectional view of the side-seal patch bag of  FIG. 12 , taken through section  13 - 13  thereof. 
         FIG. 14  illustrates a perspective view of a schematic of a “standard bag openability test apparatus.” 
         FIG. 15  illustrates a top view of the schematic of the standard bag openability test apparatus of  FIG. 14 . 
         FIG. 16  illustrates a side view of the schematic of the standard bag openability test apparatus of  FIG. 14 . 
         FIG. 17  illustrates an end-view of the schematic of the standard bag openability test apparatus of  FIG. 14 . 
         FIG. 18  illustrates a perspective view of the schematic of the standard bag openability test apparatus with an end-seal bag in lay-flat configuration thereon, i.e., ready for the openability test to be conducted. 
         FIG. 19  illustrates a top view of the schematic of the standard bag openability test apparatus with an end-seal bag in lay-flat configuration thereon, i.e., ready for the openability test to be conducted. 
         FIG. 20  illustrates a side view of the schematic of the standard bag openability test apparatus with an end-seal bag in lay-flat configuration thereon, i.e., ready for the openability test to be conducted. 
         FIG. 21  illustrates an end view of the schematic of the standard bag openability test apparatus with an end-seal bag in lay-flat configuration thereon, i.e., ready for the openability test to be conducted. 
         FIG. 22  illustrates a perspective view of the openability apparatus and bag of  FIG. 18  two seconds after openability testing is initiated, with the bag passing the openability test. 
         FIG. 23  illustrates a top view of the openability apparatus and bag of  FIG. 22 . 
         FIG. 24  illustrates a side view of the openability apparatus and bag  FIG. 22 . 
         FIG. 25  illustrates an end view of the openability apparatus and bag  FIG. 19 . 
         FIG. 26  illustrates a perspective view of the openability apparatus and bag of  FIG. 18  two seconds after openability testing is initiated, with the bag failing the openability test. 
         FIG. 27  illustrates a top view of the openability apparatus and bag  FIG. 26 . 
         FIG. 28  illustrates a side view of the openability apparatus and bag  FIG. 26 . 
         FIG. 29  illustrates an end view of the openability apparatus and bag  FIG. 26 . 
         FIG. 30  is a perspective view of an air nozzle to be used on the packaging article openability apparatus. 
         FIG. 31  is a perspective view of an air knife to be used on the packaging article openability apparatus. 
     
    
    
     DETAILED DESCRIPTION 
     As used herein, the term “film” is used in a generic sense to include plastic web, regardless of whether it is film or sheet. 
     As used herein, the term “package” refers to a product packaged in a packaging material, such as a film. 
     As used herein, the term “packaging article” refers to an article of manufacture which is suitable for use in the packaging of a product to be placed inside the packaging article. Bags and casings are examples of packaging articles which can be used for the packaging of meat products. The bag can be an end-seal bag, side-seal bag, L-seal bag, or pouch. The casing can be a seamless casing, or a backseamed casing. Backseamed casings include fin-seal casing, lap-seal casing, and butt-seal casing with backseaming tape. 
     As used herein, the phrases “seal layer”, “sealing layer”, “heat seal layer”, and “sealant layer”, refer to an outer film layer, or layers, involved in the sealing of the film to itself, another film layer of the same or another film, and/or another article which is not a film. It should also be recognized that in general, up to the outer 3 mils of a film can be involved in the sealing of the film to itself or another layer. With respect to packages having only fin-type seals, as opposed to lap-type seals, the phrase “sealant layer” generally refers to the inside film layer of a package, as well as supporting layers within 3 mils of the inside surface of the sealant layer, the inside layer frequently also serving as a food contact layer in the packaging of foods. 
     As used herein, the term “seal” refers to any seal of a first region of a film surface to a second region of a film surface, wherein the seal is formed by heating the regions to at least their respective seal initiation temperatures. The heating can be performed by any one or more of a wide variety of manners, such as using a hot wire, hot knife, heated bar, hot air, infrared radiation, ultrasonic sealing, etc. More preferably, the seal is formed by hot wire and/or hot knife. As is known to those of skill in the art, a static lap seal is another seal useful in forming a package from the film of the present invention. 
     As used herein, the phrase “a layer comprising a polymeric composition having a density of less than X g/cm 3 ” means that taking together all of the polymer(s) in the layer but not including the non-polymeric components in the layer, the density of the polymer(s) in the layer is averaged on a weight percent basis, with the resulting averaged value being less than 0.92 g/cm 3 . The same analysis applies for a density range. If different polymers are blended to make the polymeric composition from which the heat seal layer is made, the density of the polymeric composition is the density of the blend of polymers in the proportions in which they are blended. Solid materials such as antiblocking compounds are not included in determining the density of the first polymeric composition. For example, the density of the inside layer polymeric composition is weighted average of the densities of each of the polymer(s) present in the inside layer. 
     As used herein, the phrase “ . . . the film layer comprising . . . ,” refers to film layer which has the recited components throughout the cross-section of the layer, as well as on both outer principal surfaces of the layer. 
     As used herein, the term “tubing” refers to a seamless film tubing or a backseamed tubing in the form of a lap sealed tubing, a fin sealed tubing, or a butt sealed tubing having a backseaming tape. As used herein, with respect to film tubing and packaging articles made therefrom, the phrase “in lay-flat configuration” refers to a tubing or packaging article comprising a tubing that is in a flattened state with a first lay-flat side and a second lay flat side which are connected to one another along side edges which can be creased edges or sealed edges. 
     As used herein, the term “oriented,” when used relative to heat-shrinkable films and tubings, refers to a polymer-containing material which has been stretched while in the solid state, but at an elevated temperature (the orientation temperature), followed by being “set” in the stretched configuration by cooling the material while substantially retaining the stretched dimensions. Upon subsequently heating unrestrained, unannealed, oriented polymer-containing material to its softening point (i.e., the temperature at which solid state orientation was carried out), heat shrinkage is produced. More particularly, the term “oriented”, as used herein, refers to oriented films, wherein the solid state orientation can be produced in one or more of a variety of manners, including trapped bubble method and the tenter frame method. 
     As used herein, the phrase “orientation ratio” refers to the multiplication product of the extent to which the plastic film material is expanded in several directions, usually two directions perpendicular to one another. Expansion in the machine direction is herein referred to as “drawing”, whereas expansion in the transverse direction is herein referred to as “stretching”. For film tubings extruded through an annular die to form a seamless unoriented tubing, called a “tape,” stretching is obtained by heating the tape to its softening temperature followed by passing the tape over a trapped bubble of air to thereby “blow” the tape to produce transverse orientation in the making of the heat-shrinkable film. For such films, drawing is obtained by passing the film through two sets of powered nip rolls, with the downstream set having a higher surface speed than the upstream set, with the resulting draw ratio being the surface speed of the downstream set of nip rolls divided by the surface speed of the upstream set of nip rolls. The degree of orientation is also referred to as the orientation ratio, or sometimes as the “racking ratio,” which is the orientation in the machine direction (MD) multiplied by the orientation in the transverse direction (TD). 
     As used herein, the term “polymer” refers to the product of a polymerization reaction, and is inclusive of homopolymers, copolymers, terpolymers, etc. In general, the layers of a film can consist essentially of a single polymer, or can have still additional polymers together therewith, i.e., blended therewith. 
     As used herein, the term “copolymer” refers to polymers formed by the polymerization reaction of at least two different monomers. For example, the term “copolymer” includes the copolymerization reaction product of ethylene and an alpha-olefin, such as 1-hexene. However, the term “copolymer” is also inclusive of, for example, the copolymerization of a mixture of ethylene, propylene, 1-hexene, and 1-octene. 
     As used herein, a copolymer identified in terms of a plurality of monomers, e.g., “propylene/ethylene copolymer”, refers to a copolymer in which either monomer may copolymerize in a higher weight or molar percent than the other monomer or monomers. However, the first listed monomer preferably polymerizes in a higher weight percent than the second listed monomer, and, for copolymers which are terpolymers, quadripolymers, etc., preferably the first monomer copolymerizes in a higher weight percent than the second monomer, and preferably the second monomer copolymerizes in a higher weight percent than the third monomer, etc. 
     As used herein, copolymers are identified, i.e., named, in terms of the monomers from which the copolymers are produced. For example, the phrase “propylene/ethylene copolymer” refers to a copolymer produced by the copolymerization of both propylene and ethylene, with or without additional comonomer(s). 
     As used herein, terminology employing a “/” with respect to the chemical identity of a copolymer (e.g., “an ethylene/alpha-olefin copolymer”), identifies the comonomers which are copolymerized to produce the copolymer. As used herein, “ethylene alpha-olefin copolymer” is the equivalent of “ethylene/alpha-olefin copolymer.” 
     As used herein, the phrase “heterogeneous polymer” refers to polymerization reaction products of relatively wide variation in molecular weight and relatively wide variation in composition distribution, i.e., typical polymers prepared, for example, using conventional Ziegler-Natta catalysts. Heterogeneous polymers are useful in various layers of the film used in the present invention. Although there are a few exceptions (such as TAFMER®) linear homogeneous ethylene/alpha-olefin copolymers produced by Mitsui Petrochemical Corporation, using Ziegler-Natta catalysts), heterogeneous polymers typically contain a relatively wide variety of chain lengths and comonomer percentages. 
     As used herein, the phrase “homogeneous polymer” refers to polymerization reaction products of relatively narrow molecular weight distribution and relatively narrow composition distribution. Homogeneous polymers are useful in various layers of the multilayer film used in the present invention. Homogeneous polymers are structurally different from heterogeneous polymers, in that homogeneous polymers exhibit a relatively even sequencing of comonomers within a chain, a mirroring of sequence distribution in all chains, and a similarity of length of all chains, i.e., a narrower molecular weight distribution. Furthermore, homogeneous polymers are typically prepared using metallocene, or other single-site type catalysis, rather than using Ziegler Natta catalysts. 
     More particularly, homogeneous ethylene/alpha-olefin copolymers may be characterized by one or more methods known to those of skill in the art, such as molecular weight distribution (M w /M n ), composition distribution breadth index (CDBI), and narrow melting point range and single melt point behavior. The molecular weight distribution (M w /M n ), also known as polydispersity, may be determined by gel permeation chromatography. The homogeneous ethylene/alpha-olefin copolymers useful in this invention generally has (M w /M n ) of less than 2.7; preferably from about 1.9 to 2.5; more preferably, from about 1.9 to 2.3. The composition distribution breadth index (CDBI) of such homogeneous ethylene/alpha-olefin copolymers will generally be greater than about 70 percent. The CDBI is defined as the weight percent of the copolymer molecules having a comonomer content within 50 percent (i.e., plus or minus 50%) of the median total molar comonomer content. The CDBI of linear polyethylene, which does not contain a comonomer, is defined to be 100%. The Composition Distribution Breadth Index (CDBI) is determined via the technique of Temperature Rising Elution Fractionation (TREF). CDBI determination clearly distinguishes the homogeneous copolymers used in the present invention (narrow composition distribution as assessed by CDBI values generally above 70%) from heterogeneous polymers such as VLDPE&#39;s which are available commercially which generally have a broad composition distribution as assessed by CDBI values generally less than 55%. The CDBI of a copolymer is readily calculated from data obtained from techniques known in the art, such as, for example, TREF as described, for example, in Wild et. al., J. Poly. Sci. Poly. Phys. Ed., Vol. 20, p. 441 (1982). Preferably, the homogeneous ethylene/alpha-olefin copolymers have a CDBI greater than about 70%/a, i.e., a CDBI of from about 70% to 99%. Such homogeneous polymers exhibit a relatively narrow melting point range, in comparison with “heterogeneous copolymers”, i.e., polymers having a CDBI of less than 55%. Preferably, the homogeneous ethylene/alpha-olefin copolymers exhibit an essentially singular melting point characteristic, with a peak melting point (T m ), as determined by Differential Scanning Colorimetry (DSC), of from about 60° C. to 105° C. Preferably the homogeneous copolymer has a DSC peak T m  of from about 80° C. to 100° C. As used herein, the phrase “essentially single melting point” means that at least about 80%, by weight, of the material corresponds to a single T m  peak at a temperature within the range of from about 60° C. to 105° C., and essentially no substantial fraction of the material has a peak melting point in excess of about 115° C., as determined by DSC analysis. DSC measurements are made on a Perkin Elmer System 7 Thermal Analysis System. Melting information reported are second melting data, i.e., the sample is heated at a programmed rate of 10° C./min. to a temperature below its critical range. The sample is then reheated (2nd melting) at a programmed rate of 10° C./min. The presence of higher melting peaks is detrimental to film properties such as haze, and compromises the chances for meaningful reduction in the seal initiation temperature of the final film. 
     A homogeneous ethylene/alpha-olefin copolymer can, in general, be prepared by the copolymerization of ethylene and any one or more alpha-olefin. Preferably, the alpha-olefin is a C 3 -C 20  alpha-monoolefin, more preferably, a C 4 -C 12  alpha-monoolefin, still more preferably, a C 4 -C 8  alpha-monoolefin. Still more preferably, the alpha-olefin comprises at least one member selected from the group consisting of butene-1, hexene-1, and octene-1, i.e., 1-butene, 1-hexene, and 1-octene, respectively. Most preferably, the alpha-olefin comprises octene-1, and/or a blend of hexene-1 and butene-1. 
     Processes for preparing and using homogeneous polymers are disclosed in U.S. Pat. Nos. 5,206,075, 5,241,031, and PCT International Application WO 93/03093, each of which is hereby incorporated by reference thereto, in its entirety. Further details regarding the production and use of homogeneous ethylene/alpha-olefin copolymers are disclosed in PCT International Publication Number WO 90/03414, and PCT International Publication Number WO 93/03093, both of which designate Exxon Chemical Patents, Inc. as the Applicant, and both of which are hereby incorporated by reference thereto, in their respective entireties. 
     Still another genus of homogeneous ethylene/alpha-olefin copolymers is disclosed in U.S. Pat. No. 5,272,236, to LAI, et. al., and U.S. Pat. No. 5,278,272, to LAI, et. al., both of which are hereby incorporated by reference thereto, in their respective entireties. 
     As used herein, the term “polyolefin” refers to any polymerized olefin, which can be linear, branched, cyclic, aliphatic, aromatic, substituted, or unsubstituted. More specifically, included in the term polyolefin are homopolymers of olefin, copolymers of olefin, copolymers of an olefin and a non-olefinic comonomer copolymerizable with the olefin, such as vinyl monomers, modified polymers thereof, and the like. Specific examples include polyethylene homopolymer, polypropylene homopolymer, polybutene, ethylene/alpha-olefin copolymer, propylene/alpha-olefin copolymer, butene/alpha-olefin copolymer, ethylene/vinyl acetate copolymer, ethylene/ethyl acrylate copolymer, ethylene/butyl acrylate copolymer, ethylene/methyl acrylate copolymer, ethylene/acrylic acid copolymer, ethylene/methacrylic acid copolymer, modified polyolefin resin, ionomer resin, polymethylpentene, etc. Modified polyolefin resin is inclusive of modified polymer prepared by copolymerizing the homopolymer of the olefin or copolymer thereof with an unsaturated carboxylic acid, e.g., maleic acid, fumaric acid or the like, or a derivative thereof such as the anhydride, ester or metal salt or the like. It could also be obtained by incorporating into the olefin homopolymer or copolymer, an unsaturated carboxylic acid, e.g., maleic acid, fumaric acid or the like, or a derivative thereof such as the anhydride, ester or metal salt or the like. 
     As used herein, terms identifying polymers, such as “polyamide”, “polyester”, “polyurethane”, etc. are inclusive of not only polymers comprising repeating units derived from monomers known to polymerize to form a polymer of the named type, but are also inclusive of comonomers, derivatives, etc. which can copolymerize with monomers known to polymerize to produce the named polymer. For example, the term “polyamide” encompasses both polymers comprising repeating units derived from monomers, such as caprolactam, which polymerize to form a polyamide, as well as copolymers derived from the copolymerization of caprolactam with a comonomer which when polymerized alone does not result in the formation of a polyamide. Furthermore, terms identifying polymers are also inclusive of mixtures, blends, etc. of such polymers with other polymers of a different type. More preferably, however, the polyolefin is a the polymerization product of one or more unsubstituted olefins, the polyamide is the polymerization product of one or more unsubstituted amides, etc. 
     As used herein, the phrase “ethylene alpha-olefin copolymer”, and “ethylene/alpha-olefin copolymer”, refer to such heterogeneous materials as linear low density polyethylene (LLDPE), and very low and ultra-low density polyethylene (VLDPE and ULDPE); and homogeneous polymers such as metallocene-catalyzed EXACT® linear homogeneous ethylene/alpha olefin copolymer resins obtainable from the Exxon Chemical Company, of Baytown, Tex., and TAFMER® linear homogeneous ethylene/alpha-olefin copolymer resins obtainable from the Mitsui Petrochemical Corporation. All these materials generally include copolymers of ethylene with one or more comonomers selected from C 4  to C 10  alpha-olefin such as butene-1 (i.e., 1-butene), hexene-1, octene-1, etc. in which the molecules of the copolymers comprise long chains with relatively few side chain branches or cross-linked structures. This molecular structure is to be contrasted with conventional low or medium density polyethylenes which are more highly branched than their respective counterparts. The heterogeneous ethylene/alpha-olefin commonly known as LLDPE has a density usually in the range of from about 0.91 grams per cubic centimeter to about 0.94 grams per cubic centimeter. Other ethylene/alpha-olefin copolymers, such as the long chain branched homogeneous ethylene/alpha-olefin copolymers available from The Dow Chemical Company, known as AFFINITY® resins, are also included as another type of homogeneous ethylene/alpha-olefin copolymer useful in the present invention. 
     In general, the ethylene/alpha-olefin copolymer comprises a copolymer resulting from the copolymerization of from about 80 to 99 weight percent ethylene and from 1 to 20 weight percent alpha-olefin. Preferably, the ethylene/alpha-olefin copolymer comprises a copolymer resulting from the copolymerization of from about 85 to 95 weight percent ethylene and from 5 to 15 weight percent alpha-olefin. 
     As used herein, the phrases “inner layer” and “internal layer” refer to any layer, of a multilayer film, having both of its principal surfaces directly adhered to another layer of the film. 
     As used herein, the phrase “outer layer” refers to any film layer of film having less than two of its principal surfaces directly adhered to another layer of the film. The phrase is inclusive of monolayer and multilayer films. In multilayer films, there are two outer layers, each of which has a principal surface adhered to only one other layer of the multilayer film. In monolayer films, there is only one layer, which, of course, is an outer layer in that neither of its two principal surfaces is adhered to another layer of the film. 
     As used herein, the phrase “inside layer” refers to the outer layer, of a multilayer film packaging a product, which is closest to the product, relative to the other layers of the multilayer film. “Inside layer” also is used with reference to the innermost layer (which is also an outer layer) of a plurality of concentrically arranged layers extruded through one or more annular dies. The inside layer is also frequently referred to as the “seal layer” or as the “heat seal layer.” 
     As used herein, the phrase “outside layer” refers to the outer layer, of a multilayer film packaging a product, which is furthest from the product relative to the other layers of the multilayer film. “Outside layer” also is used with reference to the outermost layer of a plurality of concentrically arranged layers extruded through one or more annular dies. 
     As used herein, the phrase “machine direction”, herein abbreviated “MD”, refers to a direction “along the length” of the film, i.e., in the direction of the film as the film is formed during extrusion and/or coating. 
     As used herein, the phrase “transverse direction”, herein abbreviated “TD”, refers to a direction across the film, perpendicular to the machine direction. 
     As used herein, the phrase “free shrink” refers to the percent dimensional change in a 10 cm×10 cm specimen of film, when shrunk at 85° C. (=185° F.), with the quantitative determination being carried out according to ASTM D 2732, as set forth in the 1990 Annual Book of ASTM Standards, Vol. 08.02, pp. 368-371, which is hereby incorporated, in its entirety, by reference thereto. Free shrink measurements can be reported for the machine direction (“MD,” which is the direction in which the film is extruded), or the transverse direction (“TD”, which is perpendicular to the machine direction and directly across the direction in which the film is extruded), or as “total free shrink,” which is MD+TD, i.e., summed together. 
     The heat-shrinkable packaging article is made from a heat-shrinkable tubing. The heat-shrinkable tubing can be a seamless tubing or a backseamed tubing. A backseamed tubing is a tubing in which the film has a lengthwise seal to itself or a tape. If backseamed, the tubing can be formed with a fin seal, or with a lap seal, or the tubing film can be butt sealed to a backseam tape. 
     The heat-shrinkable tubing can be used to make a heat-shrinkable packaging article, such as a heat-shrinkable bag or a heat-shrinkable casing. Bag types include end-seal, side seal, pouch (i.e., U-seal), and L-seal (made by folding a flat film and providing a bottom seal and one side seal. The bag can have one or more patches adhered thereto. Casings can be seamless or backseamed, the latter including fin sealed, lap sealed, and butt sealed with a backseam tape. 
     The packaging article can be used for the packaging of a wide variety of products, it is especially useful for the packaging of meat products. Typical meat products include beef, pork, foul, fish, lamb, etc., and include fresh meat products and processed meat products, such as sausage. 
     If the outside layer of the film from which the bag is made contains only siloxane and/or a particulate antiblock, and does not contain fatty acid amides or waxes, it has been found that the adhesion of the patch film is much stronger than if a migratory slip agent or release agent, such as erucamide, is added to the outside layer of the bag. 
     The film used to make the packaging article is a heat-shrinkable multilayer film. The heat-shrinkable film can have a total thickness, before shrinking, of from 1.7 mils to 20 mils, or from 1.8 to 10 mils, or from 1.9 to 5 mils, or from 2 to 4 mils, or from 2 to 3 mils, or from 2 to 2.5 mils. 
     The film can have a total free shrink at 85° C. of at least 50% (measured in accordance with ASTM D 2732). The film can have a total free shrink at 85° C. of from 50% to 120%, or from 55% to 115%, or from 60% to 110%, or from 65% to 105%, or from 70% to 100%, or from 75% to 100%, or from 80% to 100%, or from 85% to 100%. 
     In an embodiment, the film tubing is made from a film of the following layer arrangement: 
     (inside) Seal/1 st  Bulk/1 st  Tie/O 2 -Barrier/2 nd  Tie/2 nd  Bulk/Abuse (outside) 
     In another embodiment, the film tubing is made from a multilayer film of the following layer arrangement: 
     (inside) Seal/1 st  Bulk/2 nd  Bulk/1 st  Tie/O 2 -Barrier/2 nd  Tie/2 nd  Bulk/Abuse (outside) 
     The film from which the heat shrinkable multilayer film tubing is made may be partially or wholly irradiated to induce crosslinking. In the irradiation process, the film is subjected to an energetic radiation treatment, such as corona discharge, plasma, flame, ultraviolet, X-ray, gamma ray, beta ray, and high energy electron treatment, which induce cross-linking between molecules of the irradiated material. The irradiation of polymeric films is disclosed in U.S. Pat. No. 4,064,296, to BORNSTEIN, et. al., which is hereby incorporated in its entirety, by reference thereto. BORNSTEIN, et. al. discloses the use of ionizing radiation for crosslinking the polymer present in the film. The extrusion coating process illustrated in  FIG. 2  (described below) allows various layers to be extruded and crosslinked before an irradiation-sensitive polyvinylidene chloride O 2 -barrier layer and other layers are extruded on top of the irradiated, crosslinked substrate portion of the multilayer film tubing, resulting in a stronger tubing film, whereas a full coextrusion of all the layers together, followed by irradiation, could result in degradation of the PVDC layer, causing a decrease in its oxygen barrier properties. 
     To produce crosslinking, a suitable radiation dosage of high energy electrons, preferably using an electron accelerator, with a dosage level being determined by standard dosimetry methods. Other accelerators such as a Van de Graaf generator or resonating transformer may be used. The radiation is not limited to electrons from an accelerator since any ionizing radiation may be used. The ionizing radiation can be used to crosslink the polymers in the film. Preferably, the film is irradiated at a level of from 2-15 MR, more preferably 2-10 MR. As can be seen from the descriptions of preferred films for use in the present invention, the most preferred amount of radiation is dependent upon the film composition, thickness, etc., and its end use. 
     The outside film layer is the outside layer of the heat-shrinkable film tubing used to make the heat-shrinkable packaging article. The outside layer contains an outside layer polymeric composition. The outside layer polymeric composition can comprise at least one member selected from the group consisting of polyolefin, ethylene/alpha-olefin copolymer, ethylene/unsaturated ester copolymer, ionomer resin, propylene/ethylene copolymer, polystyrene, polyamide, polyester, and polycarbonate. 
     The outside layer polymeric composition can have a density of less than 0.92 g/cc, or less than 0.915 g/cc, or less than 0.912 g/cc, or less than 0.910 g/cc, or less than 0.909 g/cc, or less than 0.908 g/cc, or less than 0.907 g/cc, or from 0.900 to 0.915 g/cc, or from 0.900 to 0.912 g/cc, or from 0.900 to 0.910 g/cc, or from 0.902 to 0.909 g/cc, or from 0.904 to 0.908 g/cc, or from 0.905 to 0.907 g/cc. 
     It is desirable to provide a dustless outside layer that not to block to itself, and that the outside surface of the packaging article has a low coefficient of friction. This can be accomplished by blending one or more fast-blooming or slow-blooming release agents (same as for the heat seal layer, described below), polysiloxane, and antiblock particulates into the outside layer. 
     The outside layer can comprise a slip agent. The slip agent can comprise at least one member selected from the group consisting of polysiloxane (including high molecular weight polysiloxane, and/or ultra-high molecular weight polysiloxane), erucamide, oleamide, stearamide, behenamide, oxidized polyethylene wax, glycerol monostearate, metallic stearate (e.g., calcium stearate, ethylene bis-stearamide), fatty acid amide, oxidized polyethylene, fatty acid ester, and fatty acid alcohol, and wax. The slip agent(s) may be present in the outside layer in a total amount of from 1,000 to 15,000 ppm, based on total weight of outside layer, from 1,500 to 12,000 ppm, from 2,000 to 10,000 ppm, from 2,000 to 8,000 ppm, from 2,000 to 6,000 ppm, from 2,500 to 5,000 ppm. 
     The use of polysiloxane and/or antiblock particulates in the outside layer is preferred over the use of release agents in the outside layer, as the release agents can interfere with printing of the outside layer. 
     It has been found that polysiloxane alone, or a combination of polysiloxane and antiblocking particulates, can provide the outside layer with desirable slip and antiblock properties, without adversely affecting printability and while providing relatively low haze. Polysiloxane alone, i.e., without antiblocking particulates and without release or slip aids, can suffice, and provide even lowerd haze while providing the packaging article with desired slip and antiblocking properties. Polysiloxane alone in the outside layer may be adequate for taped bags. For stacked bags, a combination of polysiloxane and antiblocking particulates can provide the packaging articles with the desired slip and antiblocking properties, and this combination enhances performance of the outside layers of the packaging article, and provides a readily printable outer surface for the packaging article. The presence of polysiloxane alone, or the combination of polysiloxane and antiblock particulates, can provide the packaging article with good machinability. 
     In an embodiment, polysiloxane is the only slip agent in the outside layer. The polysiloxane may be present in the outside layer in an amount of from 2,500 to 5,000 ppm, or from 3,000 to 4,000 ppm. 
     The outside layer can comprise antiblock particulates can have an average particle size of at least 3 microns (measured in accordance with ASTM D4664, or from 3μ to 25μ, or from 3μ to 15μ, or from 3μ to 12μ, or from 3μ to 9μ, or from 3.5μ to 6μ. The antiblock particulates can be present in the inside layer in an amount of from 1500-20,000 ppm, or from 2000-15,000 ppm, or from 2500 to 12,000 ppm, or from 4000-10,000 ppm, or from 6000-9000 ppm. 
     The outer layer may further comprise a printability enhancer comprising a polar polymer. Preferably, the polar polymer comprises at least one member selected from the group consisting of ethylene/ester/maleic anhydride terpolymer, ethylene/ester/glycidyl methacrylate terpolymer, and ethylene/acrylic acid copolymer. Preferably, the printability enhancer is present in the outer film layer in an amount of from about 1 to 25 percent, based on the weight of the outer film layer; more preferably, from about 2 to 20 percent; still more preferably, from about 5 to 15 percent; yet still more preferably, from about 5 to 10 percent. 
     The outside layer can have a thickness of at least 0.05 mil, or from 0.05 to 1.5 mils, or from 0.08 to 1 mil, or from 0.09 to 0.8 mil, or from 0.1 to 0.6 mil, or from 0.13 to 0.4 mil, or from 0.15 to 0.2 mil. 
     The heat seal layer is the inside layer of the heat-shrinkable film tubing. The heat seal layer can contain a heat seal polymeric composition comprising at least one member selected from the group consisting of polyolefin, ethylene/alpha-olefin copolymer, ethylene/unsaturated ester copolymer, ionomer resin, propylene/ethylene copolymer, polystyrene, polyamide, polyester, and polycarbonate. 
     The heat seal layer contains a seal layer polymeric composition having a density of less than 0.92 g/cc, or less than 0.915 g/cc, or less than 0.912 g/cc, or less than 0.910 g/cc, or less than 0.909 g/cc, or less than 0.908 g/cc, or less than 0.907 g/cc, or less than 0.906 g/cc, or less than 0.905 g/cc, or less than 0.904 g/cc, or less than 0.903 g/cc, or from 0.900 to 0.915 g/cc, or from 0.900 to 0.912 g/cc, or from 0.900 to 0.910 g/cc, or from 0.901 to 0.909 g/cc, or from 0.902 to 0.908 g/cc, or from 0.903 to 0.907 g/cc. 
     The inside seal layer also comprises antiblock particulates, a fast-bloom release agent, and a slow-bloom release agent, each of which are as described in various locations herein. Each of these components are blended into and extruded with the polymeric components present in the film. The antiblock particulates can be of any of the various compositions described herein. The antiblock particulates are present in the inside seal layer in an amount of at least 2000 ppm, based on total seal layer weight, or from 1,500 to 20,000 ppm, or from 2,000 to 15,000 ppm, or from 2,500 to 12,000 ppm, or from 4,000 to 10,000 ppm, or from 6,000 to 9,000 ppm. 
     The antiblock particulates have a relatively large mean (i.e., average) particle size, as determined by ASTM D4664. The antiblock particulates can have an mean particle size of at least 3μ, or from 3μ to 20μ, or from 3μ to 15μ, or from 3μ to 12μ, or from 3μ to 9μ, or from 3.5μ to 6μ. 
     The fast-blooming release agent comprises at least one member selected from the group consisting of erucamide, oleamide, lauramide, lauric diethanolamide, monoglyceride, diglyceride, glycerol monoleate, and glycerol monostearate. The fast-blooming release agent can be present in the inside seal layer in an amount of at least 1200 ppm, based on total layer weight, or from 2,000 to 20,000 ppm, or from 2,500 to 15,000 ppm, or from 3,000 to 12,000 ppm, or from 4,000 to 10,000 ppm, or from 5,000 to 9,000 ppm. 
     Alternatively, the fast-blooming release agent can have a single fatty acid chain that is either unsaturated or less than about C 16  in length, or both. Alternatively, the slow-blooming release agent can have a single fatty acid chain that is saturated and greater than C 16  in length, or multiple fatty acid chains that are saturated or unsaturated, with a total carbon chain length of at least C 20 . 
     The slow-blooming release agent comprises at least one member selected from the group consisting of stearamide, bis-stearamide, ethylene bis-stearamide, stearyl stearamide, stearyl erucamide, erucyl erucamide, behenamide, ethylene bis-oleamide, oleyl palmitamide, stearate ester, sorbitan stearate, mono stearate, di stearate, tri stearate, sorbitan monolaurate, pentaerythritol stearate ester, polyglycerol stearate, zinc stearate, calcium stearate, magnesium stearate, sodium stearate, potassium stearate. The slow-blooming release agent can be present in the inside seal layer in an amount of at least 1200 ppm, based on total layer weight, or from 2,000 to 20,000 ppm, or from 2,500 to 15,000 ppm, or from 3,000 to 12,000 ppm, or from 4,000 to 10,000 ppm, or from 5,000 to 9,000 ppm. 
     The heat seal layer can have a thickness of at least 0.1 mil, or from 0.15 to 5 mils, or from 0.18 to 4 mils, or from 0.2 to 2 mils, or from 0.1 to 1.5 mil, or from 0.2 to 1.1 mil, or from 0.25 to 1 mil; or from 0.3 to 0.8 mil, or from 0.35 to 0.7 mil, or from 0.35 to 0.6 mil, or from 0.4 to 0.6 mil, or from 0.4 to 0.6 mil, or about 0.47 mil. 
     The multilayer heat-shrinkable film can contain one or more intermediate layers between the inside film layer of the tubing and the outside film layer of the tubing. The intermediate layers can comprise one or more (i) O 2 -barrier layer, (ii) tie layers for adhering the barrier layer to the inside and/or outside film layers, and (iii) bulk layers for adding strength to the film. The O 2 -barrier layer may be made from at least one member selected from the group consisting of polyvinylidene chloride, ethylene/vinyl alcohol copolymer, polyamide, and polyester. The design and arrangement of the O 2 -barrier layer may be carried out to achieve any desired low level of oxygen transmission through the film, as known to those skilled in the art. 
     The one or more tie layer can include at least one member selected from the group consisting of ethylene/carboxylic acid copolymer, ethylene/ester copolymer, and anhydride-modified ethylene/alpha-olefin copolymer. Generally, tie layers are relatively thin, as their purpose is simply to provide a chemically compatible composition between two layers which otherwise do not bond with one another to a desired degree. 
     The one or more bulk layer can comprise at least one member selected from the group consisting of polyolefin, ethylene/alpha-olefin copolymer, ethylene/unsaturated ester copolymer, ionomer resin, propylene/ethylene copolymer, polystyrene, polyamide, polyester, and polycarbonate. Bulk layers are usually relatively thick, and/or are made from relatively strong polymers, as the purpose of bulk layers is to add strength, shrink (including free shrink as well as shrink force), puncture resistance, etc. to the film. 
     The antiblock particulates are hard particles that are provided to the inside layer and optionally to the outside layer. Although many of the particulates can be fully embedded within the thickness of the layer and thereby not affect the inside surface or the outside surface, at least some of the particulates protrude from the surface of the layer and cause the surface to be somewhat “rough,” with the protruding regions reducing the degree to which adjacent film surfaces adhere to one another, and allowing the film surfaces to readily slide over one another. 
     It has been found that for heat-shrinkable packaging articles having relatively thick seal layers made from relatively low density polymeric composition, relatively large antiblock particles (e.g., 3 micron and up) at relatively high loading (at least 2000 ppm, based on layer weight) are required in order for the tubing to be openable by a Standard Openability Test as described below. The antiblock particulates can have an average particle size of at least 3 microns (measured in accordance with ASTM D4664, or from 3μ to 25μ, or from 3μ to 15μ, or from 3μ to 12μ, or from 3μ to 9μ, or from 3.5μ to 6μ, layer o1AB Size: 3-25; 3-20, 3.2-15 microns; 3.5 to 10 microns; 4-7 microns; 4-6 microns; 4.5-5.5 microns. The antiblock particulates can be present in the inside layer in an amount of from 1500-20,000 ppm, or from 2000-15,000 ppm, or from 2500 to 12,000 ppm, or from 4000-10,000 ppm, or from 6000-9000 ppm. 
     The antiblock particulates can be made from natural silica, synthetic silica, silicate, diatomaceous earth, fumed synthetic silica, precipitated synthetic silica, gelled synthetic silica, sodium calcium silicate, and sodium calcium aluminum silicate, talc, kaolin, clay, mica, silicate, aluminum silicate, silicon dioxide, magnesium silicate, calcium silicate, calcium carbonate, and magnesium oxide. Antiblock particulates having a refractive index of 1.4-1.6, or 1.45-1.55 are preferred, as having a refractive index in this range results in a heat shrinkable film of lower haze than if a antiblock particulates with a refractive index outside this range are used. 
     If the tubing is to be printed, the dust is applied after the ink has been dried, but before windup. If the tubing is not to be printed, the tubing is unrolled immediately before conversion to bags, with dust being applied after unwinding but before conversion. The conversion of the dusted tubing (whether printed or unprinted) is carried out by sealing and cutting the tubing to form either end-seal bags or side-seal bags. The sealing can be carried out using an impulse type heat sealer. Cutting of the tubing to form discrete bags is carried out after sealing, using conventional film cutting methodologies. 
     For many uses, consumers and others place higher value on a packaging article exhibiting a low level of haze. Haze is determined by the level of clarity through the entire film thickness. Haze measurements, as reported herein, are determined using ASTM D1003-13. The heat-shrinkable film can have a haze level of less than 15%, or less than 12%, or less than 10%, or from 5% to 10%. 
     It has been found that the haze level exhibited by the heat-shrinkable film is somewhat proportional to the amount and type of antiblocking particulates used in the inside layer and the outside layer of the film tubing. In general, the higher the particulate level, the higher the haze level. The use of particulate materials having a refractive index of from 1.4 to 1.6, or from 1.45 to 1.55, helps to minimize the effect on haze from the antiblock particulates. It has been found that the use of relatively large particulates (average particle size of from 3μ to 10μ) in relatively controlled amounts (e.g., up to about 9,000 ppm, based on layer weight), allows a heat shrinkable film to be made that exhibits relatively high gloss while having desirable slip and antiblock and openability characteristics. 
     For many uses, consumers and others place higher value on a packaging article exhibiting a high level of gloss. Gloss is determined largely by the character of the outside surface of the packaging article. Gloss measurements, as reported herein, are specular gloss measurements obtained using ASTM D2457. 
     Providing the outside layer with release agents, antiblocking particulates, and slip agents can lower the gloss level exhibited by the packaging article. It has been found that the outside surface of the heat-shrinkable packaging article can exhibit relatively high gloss while at the same time possessing the desired antiblocking and slip properties, by providing the outside layer with polysiloxane alone, or with the combination of polysiloxane and antiblock particles. In this manner, the specular gloss can be at least 70% (measured per ASTM D2457), or at least 75%, or at least 78%, or at least 80%, or from 80% to 85%. 
     It is desirable for the outside layer of the packaging article to have a low coefficient of friction so that it readily slides relative to other packaging articles it is in contact with, without disturbing any other packaging article it may contact. This is particularly important when using imbricated bags on tapes or stacked bags in a box or other dispenser. 
     It is also desirable for the inside layer of the packaging article to have a low coefficient of friction relative to itself, as it is in contact with itself when the packaging article tubing is in its lay-flat configuration. This allows air to move freely between the lay-flat inside surfaces of the tubing, to prevent air from getting trapped or crushed during passage of the tubing through nip rollers, as is required during printing of the packaging articles as well as during converting of heat shrinkable film tubing into heat shrinkable packaging articles such as bags. 
     The coefficient of friction (COF) can be determined per ASTM D 1894, hereby incorporated by reference thereto, in its entirety. The inside and/or outside surfaces of the packaging article can have a peak value coefficient of friction of less than 0.8, or less than 0.7, or less than 0.6, or less than 0.5, or from 0.1 to 0.8, or from 0.1 to 0.7, or from 0.1 to 0.6, or from 0.1 to 0.5. The inside and/or outside surfaces of the packaging article can have an instantaneous value coefficient of friction of less than 0.6, or less than 0.5, or less than 0.4, or less than 0.3, or from 0.1 to 0.6, or from 0.1 to 0.5, or from 0.1 to 0.4, or from 0.1 to 0.3. 
     Although it is desirable to completely eliminate dust from the packaging article, dust can be provided to the inside of the tubing which is used to make the packaging article while the outside remains dustless, or dust can be provided to the outside of the packaging article while the inside is dustless. If dust is used on the inside or on the outside, the dust can comprise at least one member selected from the group consisting of corn starch, tapioca starch, potato starch, talc, and silica. 
       FIG. 1  illustrates a cross-sectional view of multilayer heat shrinkable film  20 . In the examples below, Film Nos. 1-11 have cross-sections which correspond with the layer number and arrangement illustrated in  FIG. 1 . Heat shrinkable film  20  has seven layers in which first layer  21  is an outer film layer which functions as an inside product-contact layer and heat seal layer. Second layer  22  functions as a first bulk layer. Third layer  23  functions as a first tie layer. Fourth layer  24  functions as an oxygen barrier layer. Fifth layer  25  functions as a second tie layer. Sixth layer  26  functions as a second bulk layer. Seventh layer  27  functions as an abuse layer. 
     Heat-shrinkable film tubing can be produced in accordance with a process schematically illustrated in  FIG. 2 . In the process illustrated in  FIG. 2 , solid polymer beads (not illustrated) are fed to a plurality of extruders  28  (for simplicity, only one extruder is illustrated). Inside extruders  28 , the polymer beads are forwarded, melted, and degassed, following which the resulting bubble-free melt is forwarded into die head  30 , and extruded through an annular die, resulting in tubing  32  which can be, for example, about 15 mils thick and which includes the seal layer, the first bulk layer and the first tie layer. Through a passageway inside of die head  30 , a continuous stream of cornstarch dust (C-3170 cornstarch obtained from Flint Group; see AB10 in Table 1, below) is injected into the interior of tubing  32 , at a rate so that the amount of corn starch powder deposited onto the inside surface of tubing  32  is adequate to prevent blocking of the tubing to itself both as the tubing is collapsed into lay-flat configuration as well as after biaxial orientation in the trapped bubble process, as described below. The amount of dust placed into the inside of the tubing can be, for example, about 95 milligrams per 100 square inches of the inside surface of the unoriented tubing  32 . Other types of dust which can be used include tapioca dust and potato starch dust, talc, and silica. 
     After cooling or quenching by water from cooling ring  34 , tubing  32  is collapsed by pinch rolls  36 , and is thereafter fed through irradiation vault  38  surrounded by shielding  40 , where tubing  32  is irradiated with high energy electrons (i.e., ionizing radiation) from iron core transformer accelerator  42 . Tubing  32  is guided through irradiation vault  38  on rollers  44 . Preferably, tubing  32  is irradiated to a level of from about 3 to 8 MR. 
     After irradiation, irradiated tubing  46  is directed through pinch rolls  48 , following which irradiated tubing  46  is slightly inflated, resulting in trapped bubble  50 . However, at trapped bubble  50 , the tubing is not significantly drawn longitudinally, as the surface speed of nip rolls  52  are about the same speed as nip rolls  48 . Furthermore, irradiated tubing  46  is inflated only enough to provide a substantially circular tubing without significant transverse orientation, i.e., without stretching. 
     Slightly inflated, irradiated tubing  50  is passed through vacuum chamber  54 , and thereafter forwarded through coating die  56 . Second tubular film  58  is melt extruded from coating die  56  and coated onto slightly inflated, irradiated tube  50 , to form two-ply tubular film  60 . Second tubular film  58  preferably comprises an O 2  barrier layer, which does not pass through the ionizing radiation. Further details of the above-described coating step are generally as set forth in U.S. Pat. No. 4,278,738, to BRAX et. al., which is hereby incorporated by reference thereto, in its entirety. 
     After irradiation and coating, tubing film  60  is wound up onto windup roll  62 . Thereafter, windup roll  62  is removed and installed as unwind roll  64 , on a second stage in the process of making the heat-shrinkable tubing film as ultimately desired. Tubular film  60 , from unwind roll  64 , is unwound and passed over guide roll  66 , after which two-ply tubular film  60  passes into hot water bath tank  68  containing hot water  70 . The now collapsed, irradiated, coated tubular film  60  is submersed in hot water  70  (having a temperature of about 185° F.) for a retention time of at least about 30 seconds, i.e., for a time period in order to bring the film up to the desired temperature for biaxial orientation. Thereafter, irradiated tubular film  60  is directed through nip rolls  72 , and bubble  74  is blown, thereby transversely stretching tubular film  60 . Furthermore, while being blown, i.e., transversely stretched, nip rolls  76  draw tubular film  60  in the longitudinal direction, as nip rolls  76  have a surface speed higher than the surface speed of nip rolls  72 . 
     As a result of the transverse stretching and longitudinal drawing, irradiated, coated biaxially-oriented blown tubing film  78  is produced, this blown tubing preferably having been both stretched in a ratio of from about 1:1.5-1:6, and drawn in a ratio of from about 1:1.5-1:6. More preferably, the stretching and drawing are each performed a ratio of from about 1:2-1:4. The result is a biaxial orientation of from about 1:2.25-1:36, more preferably, 1:4-1:16. While bubble  74  is maintained between pinch rolls  72  and  76 , blown tubing  78  is collapsed by rolls  80 , and thereafter conveyed through pinch rolls  76  and across guide roll  82 , and then rolled onto wind-up roll  84 . Idler roll  86  assures a good wind-up. 
     The resulting biaxially-oriented heat-shrinkable film tubing is thereafter unwound and converted into heat-shrinkable bags by sealing and cutting across the tubing. Optionally, the bags may have printing applied to the outside surface. During printing, the ink is applied to the tubing before the tubing is converted into bags. In addition to preventing the inside of the oriented film tubing from blocking to itself, the cornstarch dust present inside the film tubing also allows the tubing to slide against itself and allows air within the film tubing to move inside the tubing so that creasing of the tubing is reduced or eliminated as the tubing passes through nip rollers used in processing, including printing. 
     Furthermore, during conversion of the oriented film tubing into bags, the same cornstarch dust was applied to the outside of the tubing. The cornstarch dust was applied to the outside surface of the tubing at a level of about 95 milligrams per 100 square inches. The cornstarch dust can be applied using a metering roller or gravity feed. The cornstarch dust can be applied to only one side of the tubing while the tubing is in a lay-flat configuration. Thereafter, when the dusted heat-shrinkable film tubing is wound up to form a roll of tubing, the dust applied to the one lay-flat side transfers to the other lay-flat side while the first lay-flat side contacts the second lay-flat side in the roll of wound-up, dusted, heat-shrinkable film tubing. 
       FIG. 3  is a schematic of a heat-shrinkable end-seal bag  160  in lay-flat configuration. End-seal bag  160  is made from the heat-shrinkable film seamless tubing  162 .  FIG. 4  is a cross-sectional view of bag  160  taken through section  4 - 4  of  FIG. 3 . Viewing  FIGS. 3 and 4  together, bag  160  comprises bag film  162 , top edge  164  defining an open top, first bag side edge  166 , second bag side edge  168 , bottom edge  170 , and end seal  172 . 
       FIGS. 5 and 6  together illustrate heat-shrinkable side-seal bag  180  in lay-flat configuration.  FIG. 6  is a cross-sectional view of bag  180  taken through section  6 - 6  of  FIG. 5 . Side-seal bag  180  is also made from the heat-shrinkable film tubing as with the end-seal bag of  FIGS. 3 and 4 , but in making side-seal bag  180  the seamless tubing has been slit in the machine direction to form bag top  184 , and heat sealed across the tubing to make side seals  192  and  194 , with the machine direction orientation of the film  182  running transversely across side-seal bag  180 . Viewing  FIGS. 5 and 6  together, side-seal bag  180  is made from bag film  182  which is heat sealed to itself. Side seal bag  180  has top edge  184  defining an open top, folded bottom edge  190 , first side seal  192 , and second side seal  194 . 
       FIG. 7  illustrates pouch-type bag  66  made from sealing two separate pieces of flat film together. Pouch-type bag  66  has open top  68 , bottom heat seal  70  and bottom edge  72 , first side seal  74  and first side edge  76 , second side seal  78  and second side edge  80 . Together, first and second side seals  74  and  76  connect with bottom seal  70  to form a “U-shaped” seal connecting the two pieces of flat film together to form the pouch-type bag  66 . 
       FIGS. 7, 8, and 9  illustrate a pouch-type bag  266  made from sealing two separate pieces of flat film together. In  FIGS. 7, 8, and 9 , pouch  266  has open top  268 , bottom heat seal  270  and bottom edge  272 , first side seal  274  and first side edge  276 , second side seal  278  and second side edge  280 . Together, first and second side seals  274  and  276  connect with bottom seal  270  to form a “U-shaped” seal connecting the two pieces of flat film together to form the pouch-type bag  266 . 
       FIGS. 10 and 11  illustrate end-seal patch bag  206 , in lay-flat configuration. End seal patch bag  206  is a seamless tubular film  212  to which patches  214  and  216  are adhered. Bag  206  has end seal  210  and open top  208 . Each patch is confined to one lay-flat side of bag  206 , with end seal  210  being of the inside layer of tubular film  212  to itself. End seal  210  is not through either of patches  214  or  216 . In addition, patches  214  and  216  do not extend all the way to either of the folded lay-flat side edges of end-seal bag  206 . 
       FIGS. 12 and 13  illustrate side-seal patch bag  218 , in lay-flat configuration. Side-seal patch bag  218  is made up of folded bag film  220  to which are adhered first patch  230  and second patch  232 . Bag film  220  has seamless (i.e., folded) bottom edge  224 , open top  222 , first side seal  226 , and second side seal  228 , with each of side seals  226  and  228  being of the inside layer of the tubing to itself. Each of patches  230  and  232  are confined to a lay-flat side of bag  220 , with the patches not extending to either of side seals  226  or  228 , or to open top  222  or folded bottom  224 . 
     Additional patch bags are disclosed in the following US patent documents, each of which is hereby incorporated, in its entirety, by reference thereto: (A) U.S. Pat. Nos. 6,287,613; 6,383,537; 5,540,646; 5,545,419; 6,270,819; 6,790,468; 6,663,905; 6,296,886; 7,338,691; 5,534,276; 6,228,446; and 7,048,125. 
     It has been found that the “green strength” (i.e., strength of the adhesive bond between the patch film and the tubing within 15 minutes after the patch and tubing films contact one another with adhesive therebetween) is significantly enhanced by the presence of antiblocking particulates in the outside layer of the tubing film. For example, the outside layer of the heat-shrinkable film tubing can comprise antiblock particulates having an average particle size of from 3000 microns to 10,000 microns, with the antiblock particulates being present in the outside layer in an amount of from 3000 to 10,000 ppm. The result can be that the patch film is adhered to the outside surface of the film tubing with a green bond strength of at least 1 lb/in of patch width measured within 15 minutes of application of patch film to film tubing, versus 0.6 lb/in of patch width without the presence of the antiblock particulates. 
     Bag Openability Test: Apparatus and Set-Up 
       FIG. 14  illustrates a perspective view of a schematic of a Standard Bag Openability Test Apparatus  300 , which has horizontal bag platform  302  having top surface  304  for supporting a bag  310  in lay-flat configuration (See  FIGS. 18-21 ). Bag platform  302  is designed to be long enough and wide enough to provide full lengthwise and widthwise support to the longest bag to be tested for openability on test apparatus  300 . 
     Adhered to top surface  304  of bag platform  302 , extending rearward from front edge  306  of bag platform  302  in a direction perpendicular to front edge  306  of bag platform  302 , are a pair of bag-holding tapes  308 , each of which extends 1.5 inches down the length of the bag platform  302 . See  FIG. 15 . 
     Each of tapes  308  is secured “sticky side up” to the top surface of bag platform  302 , by applying glue or double stick tape beneath the backside of each of tape  308 , i.e., to hold tapes  308  down on top surface  304  of bag platform  302 . Each of bag-holding tapes  306  have a width of 6 mm, with the “sticky side” of the tapes having an adhesion to steel of at least 90 g/6 mm measured in accordance with AFERA 4001-ED.10/87. One such tape is BN  39  bag tape, obtained from Boston tapes S.p.A. of Sessa Aurunca, Italy. 
     The spacing between the two pieces of tape  308  is dependent upon the lay-flat width of the bag being tested. More particularly, centerlines running down the center of each of the two pieces of tape  308  are spaced apart a distance of one third of a total lay-flat width of the packaging article being tested. This arrangement is readily apparent in  FIG. 19 , in which tapes  306  are spaced apart by one third of the lay-flat width of bag  310 . 
     Outward of front edge  306  of bag platform  302  is mounting bracket  312  which has mounted thereon both air nozzle  314  and air knife  316 . Air nozzle  314  has a tip positioned along a centerline of the bag, the centerline being inclined 15° from horizontal. Air nozzle  314  has a tip positioned 3 inches from lip  318  of bag  310 . Air knife  316  has a top surface (i.e., surface oriented towards bag  310 ) which is coincident with bag platform  302  and an air discharge line parallel to, and 5.5 inches from, both front edge  306  and bag lip  318 . 
     Not illustrated in  FIGS. 14-21  are control solenoid valves and air conduits for providing 20.8 scfm of clean, dry compressed air at 100 psi to air nozzle  314 , and same for providing clean, dry compressed air to air nozzle  314  and air knife  316 . Also not illustrated in  FIGS. 14-21  is the compressor for generating the compressed air. 
     Conducting the Bag Openability Test 
     The Bag Openability Test is carried out by first storing a heat-shrinkable film tubing in lay-flat configuration while wrapped around an 8 cm diameter core for 7 days, with the strand of the multilayer heat-shrinkable film tubing being wound onto the core until a total diameter (core plus wound film) of 48 cm is achieved, with the film tubing being wound onto the core until a total diameter (core plus wound film tubing) of 19 inches is reached, with the film tubing being wound at a tension of 179 g/cm of lay-flat tubing width, at a conclusion of which the wound tubing is allowed to remain at ambient conditions for 7 full days, with the film tubing thereafter being unwound until the windings are 1 inch from the core. At that point a portion of the film tubing is removed and converted into end-seal bags and tested in accordance with the Bag Openability Test procedure, as set forth immediately below. 
     The packaging article, in lay-flat configuration, is then placed on the on top surface  304  of bag platform  302 , with the bag lip  318  being directly over the front edge  306  of bag platform  302 . The packaging article  310  has a lay-flat width of at least 3.5 inches and a lay-flat length of at least 4 inches. 
     The packaging article  310  is initially in its lay-flat configuration, with the lower lay-flat side being held down against top surface  304  of bag platform  302  by the pair of bag-holding tapes  308 , each of which extends 1.5 inches down the length of the packaging article. Each of the pair of tapes has a width of 6 mm and an adhesion to steel of at least 90 g/6 mm measured in accordance with AFERA 4001-ED.9/79. Each of the tapes runs for a length of 1.5 inches from the linear leading edge of the packaging article in a direction perpendicular to the open top edge of the packaging article, and each tape has a centerline placed at a position corresponding with 33.3% of a distance across the lay flat width of the packaging article, with the lip of the packaging article being parallel to and directly above the leading edge  306  of support member  302 . At this point there is no airflow through air nozzle  314  or air knife  316 , and the packaging article  310  on the test apparatus  300  appears as illustrated in  FIGS. 18, 19, 20, and 21 . 
     Once the packaging article is positioned on top surface  304  of platform  302  and held in place by tapes  308 , a first solenoid is activated to supply compressed air to air nozzle  314  and simultaneously a second solenoid is activated to supply compressed air to air knife  316 . The compressed air is supplied to the air nozzle for 500 milliseconds, at which time the first solenoid is closed, thereby shutting off further air to the air nozzle. The compressed air supplied to the air knife continues for 2 full seconds, after which time the second solenoid is closed, thereby shutting off further air to the air knife. 
     At the end of the two seconds of airflow through air knife  316 , the packaging article is deemed “openable” if it inflates with air, i.e., the article appears as illustrated in  FIGS. 22, 23, 24, and 25 . As is apparent ion  FIGS. 22-25 , if the article inflates, the lay-flat sides are separated by the airflow passing through air knife  316 . 
     On the other hand, if at the end of the two seconds of airflow through air knife  316  the packaging article  310  is deemed “not openable,” the article does not inflate with air, i.e., the article appears as illustrated in  FIGS. 26, 27, 28, and 29 . This appearance results if the inside layer of the tubing adheres to itself (i.e., “blocks”) to a degree that the airflow from the air nozzle followed by the air knife is inadequate to open the packaging article. 
       FIG. 30  is a perspective view of air nozzle  400  to be used with test apparatus  300 . Air nozzle  400  is commercially available as SILVENT 1011 stainless steel Laval nozzle. Air nozzle  400  has ⅛″ male thread, has central hole  402  that creates a concentrated, supersonic jet of air, and surrounding central hole  402  has six diverging slots  404  for generating a laminar air stream. Also surrounding central hole are six fins  406  which serve to prevent dead end static pressure from exceeding 210 kPa. The SILVENT 1011 Laval air nozzle can be obtained from Silvent AB. at Vevgatan 15, SE-504 64 Boras, Sweden. 
       FIG. 31  is a perspective view of air knife  420  to be used with test apparatus  300 . Air knife  420  is commercially available as Aluminium Strip Airmover SE150 from Brauer Clamps USA Inc of Warren, Mich. Air knife  420  uses the energy from a small volume of compressed air, supplied from a standard compressor, to amplify surrounding air to a high velocity, high volume, low pressure output airflow using the coanda effect. 
       FIG. 32  is a schematic of taped bag assembly  450  comprising bags  452 ,  454 ,  456  held in shingled set of imbricated bags (shingled bags, in overlapping relationship) held in place relative to one another by their adhesion to the adhesive side of parallel tapes  458  and  460 . Such imbricated bags assemblies  450  are provided in long strands containing hundreds or even thousands of bags, supplied to bag loading devices. Imbricated bags held by tapes, such as the two parallel tapes illustrated in  FIG. 32 , and the use of assemblies comprising such imbricated bags on tapes and their use in product loading devices, are disclosed in U.S. Pat. Nos. 3,587,843, 3,698,547, 4,032,038 and 4,076,122, each of which is hereby incorporated, in its entirety, by reference thereto. 
       FIG. 33  is a schematic illustration of a top view of rotary chamber vacuum machine  470  which has for decades been in use for the packaging of a wide variety of packaged meat products (not illustrated). A heat-shrinkable bag having a product therein (not illustrated) is placed on platen  472  which is in the product loading zone. Thereafter, chamber lid  474  rotates over and drops onto platen  472  as the vacuum chamber carousel assembly  476  rotates counterclockwise to position A, then B, then C, then D, then E, during which movement of platen  472  and chamber  474  the atmosphere is evacuated from within the chamber and from inside the bag, the bag is sealed closed and the excess bag length cut off and sucked away to a waste area. Then, at position F, the vacuum is released and air fills the chamber and chamber  474  lifts off platen  472  allowing the vacuum packaged product to be directed off of platen  474  and onto conveyor  478  for further processing, such as passage through a hot air tunnel (not shown) to shrink the bag film tight around the meat product. The counterclockwise rotary motion of vacuum chamber carousel assembly  476  is continuous throughout the process, as is the associated counterclockwise rotation of platen carousel assembly  480 . 
     Examples 
     Various films were produced in the form of multilayer heat-shrinkable film tubings, using the process illustrated in  FIG. 2 , described above. Although these tubings could have been converted into a variety of heat shrinkable packaging articles, such as end seal bags, side seal bags, and casings, the tubings were converted into packaging articles (i.e., end-seal bags as illustrated in  FIGS. 3 and 4 ), which were thereafter tested for openability. The structures of these films, including the layer arrangement, layer composition, and layer thicknesses, are provided in various tables below. The resins and other components utilized in these films are provided in Table 1, immediately below. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                   
                 Generic Resin Name 
                 Density 
                 Melt Index 
                   
               
               
                 Resin code 
                 Tradename 
                 {additional information} 
                 (g/cc) 
                 (dg/min) 
                 Supplier 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 SSPE 1 
                 AFFINITY ® 
                 Homogeneous 
                 0.900 
                 g/cc 
                 6.0 
                 Dow 
               
               
                   
                 PL 1281G1 
                 ethylene/octene 
               
               
                   
                   
                 copolymer 
               
            
           
           
               
               
               
               
               
               
            
               
                 SSPE 2 
                 AFFINITY ® 
                 Homogeneous 
                 0.902 
                 3.0 
                 Dow 
               
               
                   
                 PL 1850G 
                 ethylene/octene 
               
               
                   
                   
                 copolymer 
               
               
                 SSPE 3 
                 ENGAGE ® 
                 Homogeneous 
                 0.868 
                  0.50 
                 Dow 
               
               
                   
                 8157 
                 ethylene/octene 
               
               
                   
                   
                 copolymer 
               
               
                 SSPE 4 
                 EXCEED ® 
                 Homogeneous 
                 0.912 
                 3.8 
                 Exxon 
               
               
                   
                 3812 CB 
                 ethylene/hexene 
                   
                   
                 Mobil 
               
               
                 SSPE 5 
                 EXACT ® 
                 Homogeneous 
                 0.905 
                 4.5 
                 Exxon 
               
               
                   
                 3024 
                 ethylene/butene 
                   
                   
                 Mobil 
               
               
                   
                   
                 copolymer 
               
               
                 SSPE 6 
                 EXCEED ® 
                 Homogeneous 
                 0.912 
                 1.0 
                 Exxon 
               
               
                   
                 1012HJ 
                 ethylene/hexene 
                   
                   
                 Mobil 
               
               
                   
                   
                 copolymer 
               
               
                 SSPE 7 
                 EXCEED ® 
                 Homogeneous 
                 0.918 
                 4.5 
                 Exxon 
               
               
                   
                 4518PA 
                 ethylene/hexene 
                   
                   
                 Mobil 
               
               
                   
                   
                 copolymer 
               
               
                 VLDPE1 
                 XUS 
                 Very low density 
                 0.903 
                 0.5 
                 Dow 
               
               
                   
                 61520.15L 
                 polyethylene 
               
               
                 VLDPE2 
                 CV77525 
                 Very low density 
                 0.906 
                  0.45 
                 Westlake 
               
               
                   
                   
                 polyethylene 
                   
                   
                 Chemical 
               
               
                 VLDPE3 
                 CV77519 
                 Very low density 
                 0.906 
                 0.5 
                 Westlake 
               
               
                   
                   
                 polyethylene 
                   
                   
                 Chemical 
               
               
                 LLDPE 1 
                 DOWLEX ® 
                 Linear Low Density 
                 0.920 
                 1.1 
                 Dow 
               
               
                   
                 2045.03 
                 Polyethylene 
               
               
                 LLDPE 2 
                 LL 3003.32 
                 Heterogeneous 
                 0.9175 
                 3.2 
                 Exxon 
               
               
                   
                   
                 Ethylene/hexene 
                   
                   
                 Mobil 
               
               
                   
                   
                 copolymer 
               
               
                 LLDPE 3 
                 DOWLEX ® 
                 Linear low density 
                 0.920 
                 1.0 
                 Dow 
               
               
                   
                 2045.04 
                 polyethylene 
               
               
                 LLDPE 4 
                 CV77518 
                 Linear low density 
                 0.910 
                 2.0 
                 Westlake 
               
               
                   
                   
                 polyethylene 
                   
                   
                 Chemical 
               
               
                 LLDPE5 
                 CV77523 
                 Linear low density 
                 0.906 
                 0.5 
                 Westlake 
               
               
                   
                   
                 polyethylene with 18,000 
                   
                   
                 Chemical 
               
               
                   
                   
                 ppm antiblock &amp; 1150 
               
               
                   
                   
                 ppm slip 
               
               
                 LLDPE6 
                 SC74877 
                 Linear low density 
                 0.915 
                  0.75 
                 Westlake 
               
               
                   
                   
                 polyethylene with 7,000 
                   
                   
                 Chemical 
               
               
                   
                   
                 ppm antiblock 
               
               
                 znPEC 
                 PRO-FAX ® 
                 Ziegler Natta 
                 0.90 
                 2.0 
                 Lyondell 
               
               
                   
                 SR257M 
                 propylene/ethylene 
                   
                   
                 Basell 
               
               
                   
                   
                 copolymer 
               
               
                 ssPEC1 
                 VERSIFY ® 
                 Homogeneous 
                 0.891 
                 8.0 
                 Dow 
               
               
                   
                 3000 
                 propylene/ethylene 
               
               
                   
                   
                 copolymer 
               
               
                 ssPEC2 
                 VISTAMAXX 
                 Homogeneous 
                 0.874 
                 2.5 
                 Exxon 
               
               
                   
                 3020FL 
                 propylene/ethylene 
                   
                   
                 Mobil 
               
               
                   
                   
                 copolymer 
               
               
                 EVA 1 
                 ESCORENE ® 
                 Ethylene/vinyl acetate 
                 0.933 
                 3.5 
                 Exxon 
               
               
                   
                 LD 713.93 
                 copolymer (14.4% VA) 
                   
                   
                 Mobil 
               
               
                 EVA 2 
                 EB524AA 
                 Ethylene/vinyl acetate 
                 0.934 
                 3.5 
                 Westlake 
               
               
                   
                   
                 copolymer 
                   
                   
                 Chemical 
               
               
                   
                   
                 (14.5% vinyl acetate) 
               
               
                 EVA 3 
                 ATEVA ® 
                 Ethylene/vinyl acetate 
                 0.949 
                 6   
                 Celanese 
               
               
                   
                 2861A 
                 copolymer 
                   
                   
                 Chemicals 
               
               
                   
                   
                 (28% vinyl acetate) 
               
               
                 EVA 4 
                 ESCORENE ® 
                 Ethylene/vinyl acetate 
                 0.951 
                  5.75 
                 Exxon 
               
               
                   
                 LD 716.36 
                 copolymer 
                   
                   
                 Mobil 
               
               
                   
                   
                 (26.7% vinyl acetate) 
               
               
                 PVDC1 
                 SARAN ® 806 
                 Vinylidene chloride/ 
                 1.69 
                 — 
                 Dow 
               
               
                   
                   
                 methyl acrylate 
               
               
                   
                   
                 copolymer 
               
               
                 PVDC2 
                 IXAN ® 
                 Vinylidene chloride/ 
                 1.71 
                 — 
                 Solvin 
               
               
                   
                 PV910 
                 methyl acrylate 
               
               
                   
                   
                 copolymer 
               
               
                 FP 
                 IP-1121 
                 Fluoropolymer in LLDPE 
                 0.92 
                 2   
                 Ingenia 
               
               
                   
                   
                 (2% fluoropolymer) 
                   
                   
                 Polymers 
               
               
                 AB1 
                 KAOPOLITE ® 
                 100% Aluminum silicate 
                 2.62 
                 — 
                 Kaopolite 
               
               
                   
                 SF 
                 antiblock (0.7μ) 
                   
                   
                 Inc 
               
               
                 AB2 
                 SUPERFINE 
                 100% Silica - calcined 
                 2.3 
                 — 
                 Celite 
               
               
                   
                 SUPER 
                 diatomaceous earth (3.5μ) 
               
               
                   
                 FLOSS 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 AB3 
                 103228 
                 20 wt % Amorphous 
                 38 
                 lb/ft 3   
                 1.8 
                 Ampacet 
               
               
                   
                   
                 Silica in LLDPE (5μ) 
               
            
           
           
               
               
               
               
               
               
            
               
                 AB4 
                 SILTON ® 
                 100% Sodium 
                 1.05 
                 — 
                 Mitsui 
               
               
                   
                 JC-50 
                 aluminosilicate 
                   
                   
                 Chemical 
               
               
                   
                   
                 (5μ antiblock) 
               
               
                   
                   
                 (refractive index 1.50) 
               
               
                 AB5 
                 1000214-N 
                 70 wt % silica in LLDPE 
                 1.66 
                 — 
                 Ampacet 
               
               
                   
                   
                 (9μ) 
               
               
                 AB6 
                 IP1091 
                 25% Antiblock 
                 — 
                 — 
                 Ingenia 
               
               
                   
                   
                 (7.6μ) 
                   
                   
                 Polymers 
               
               
                 AB7 
                 MB25-502 
                 25 wt % high molecular 
                 0.94 
                 6.3 
                 Dow 
               
               
                   
                   
                 weight siloxane 
                   
                   
                 Corning 
               
               
                   
                   
                 Slip additive 
               
               
                 AB8 
                 ZEEOSPHERE 
                 100% Alkali-alumino- 
                 2.4 
                 — 
                 3M 
               
               
                   
                 W410 
                 silicate ceramic spheres 
               
               
                   
                   
                 (4μ antiblock) 
               
               
                   
                   
                 (refractive index 1.53) 
               
               
                 AB9 
                 ZEEOSPHERE 
                 100% Alkali-alumino- 
                 2.4 
                 — 
                 3M 
               
               
                   
                 W210 
                 silicate ceramic spheres 
               
               
                   
                   
                 (3μ antiblock) 
               
               
                 AB10 
                 C-3170 corn 
                 Corn starch* 
                 — 
                 — 
                 Flint 
               
               
                   
                 starch 
                 (13-15.5μ avg. part. size) 
                   
                   
                 Group 
               
               
                 AB11 
                 PM16815 
                 50% silica antiblock 
                 1.37 
                 — 
                 Techmer 
               
               
                 WAX1 
                 KEMAMIDE 
                 100% N,N′-ethylene-bis- 
                 0.995 
                 — 
                 PMC- 
               
               
                   
                 W-40 Prill 
                 stearamide wax 
                   
                   
                 Biogenix 
               
               
                 WAX2 
                 KEMAMIDE 
                 100% Erucamide wax 
                 0.8150 
                 81° C. mp 
                 PMC- 
               
               
                   
                 E Ultra Bead 
                   
                   
                   
                 Biogenix 
               
               
                 AB&amp;S1 
                 FSU 255E 
                 25.0 wt % diatomaceous 
                 1.08 
                 9   
                 Schulman 
               
               
                   
                   
                 earth silica (15μ) and 5.0 
               
               
                   
                   
                 wt % emcamide in 67.9 
               
               
                   
                   
                 wt % LDPE 
               
               
                 AB&amp;S2 
                 SYLOBLOC ® 
                 50 wt % Amorphous 
                 2.1 
                 — 
                 Grace 
               
               
                   
                 M150 
                 silica (5μ) with 50% 
                   
                   
                 Davison 
               
               
                   
                   
                 oleamide 
               
               
                 AB&amp;S3 
                 SYLOBLOC ® 
                 50 wt % Amorphous 
                 2.1 
                 — 
                 Grace 
               
               
                   
                 M250 
                 silica (5μ) with 50 wt % 
                   
                   
                 Davison 
               
               
                   
                   
                 erucamide 
               
               
                 AB&amp;S4 
                 100015 9-NP 
                 18 wt % amorphous silica 
                 1.028 
                 2.0 
                 Ampacet 
               
               
                   
                   
                 (5μ) with 3 wt % 
               
               
                   
                   
                 erucamide 
               
               
                 SLIP1 
                 MB50-802 
                 20-40 wt % silica 
                 \1.03 
                 8.0 
                 Dow 
               
               
                   
                   
                 50 wt % 
                   
                   
                 Corning 
               
               
                   
                   
                 UHMW Polysiloxane 
               
               
                   
                   
                 in 10-30 wt % LDPE 
               
               
                 SLIP 2 
                 A-2533 
                 5 wt % Erucamide 
                 0.92 
                 2.4 
                 Ampacet 
               
               
                   
                   
                 in 95 wt % LLDPE 
               
               
                 SLIP 3 
                 A-2142 
                 100 wt % 
                 — 
                 — 
                 Chemtura 
               
               
                   
                   
                 zinc stearate lubricant 
                   
                   
                 Corp 
               
               
                 EVA 2 
                 ESCORENE ® 
                 Ethylene/vinyl acetate 
                 0.950 
                  5.75 
                 Exxon 
               
               
                   
                 LD 761.36 
                 copolymer (26.7% VA) 
                   
                   
                 Mobil 
               
               
                   
               
               
                 particle size designation (in microns, μ) is average particle size determined per ASTM D4664 
               
               
                 *with additives: 0.9-1.0% calcium phosphate and silicon dioxide 
               
            
           
         
       
     
     Table 2, below, provides the structure and composition of Film No. 1, including the identities of the polymers used in the various layers, the arrangement of the layers, and the thickness of the layers. Film No. 1 was a prior art film produced in accordance with the process illustrated in  FIG. 2 , described above. The solid state orientation of the tape was carried out at about 3.6:1 in the machine direction and 3.6:1 in the transverse direction, for a total orientation ratio of about 13:1. The process included the addition of corn starch dust to the inside of the tape immediately upon extrusion, as well as the addition of corn starch dust to the outside of the lay-flat heat shrinkable film, as in the above description of  FIG. 2 . 
     
       
         
           
               
               
             
               
                   
                 TABLE 2 
               
             
            
               
                   
                   
               
               
                   
                 Layer 
               
               
                   
                 Film Tubing No. 1 (prior art dusted film tubing) 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 ComPosition 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 80% SSPE1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 20% LLDPE2 
                 30 EVA2 
                 EVA2 
                 PVDC1 
                 EVA4 
                 30 EVA2 
                 20 LLDPE3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 wt. % 
                 21.65 
                 38.96 
                 4.33 
                 9.09 
                 4.33 
                 12.99 
                 8.66 
               
               
                 Thickness 
                 0.43 mil 
                 0.78 mil 
                 .09 mil 
                 .18 mil 
                 .09 mil 
                 0.26 mil 
                 0.17 mil 
               
               
                   
               
            
           
         
       
     
     Film Tubing No. 2 Through Film Tubing No. 11 (Dustless Film Tubings) 
     Various additive compositions (ACs) were also prepared for use in the seal layer and/or the outer abuse layer, in order to eliminate the need for the use of dust, while maintaining the slip and antiblock properties of the film with dust thereon, as follows: 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Additive Compositions for Dustless Film Tubings 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Inside Layer 
                   
                   
                   
                   
                   
               
               
                   
                 Composition 
                 AC#1 
                 AC#2 
                 AC#3 
                 AC#4 
                 AC#5 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 AB1 
                   
                   
                 0.33 
                   
                   
               
               
                   
                 AB2 
                   
                   
                 1.25 
               
               
                   
                 AB3 
                   
                   
                   
                 12 
               
               
                   
                 AB4 
                   
                   
                   
                   
                 3.0 
               
               
                   
                 AB9 
                 0.7 
               
               
                   
                 WAX1 
                 3.29 
                 5 
                 3.50 
                   
                 3.5 
               
               
                   
                 WAX2 
                 1.35 
                   
                 4.50 
                   
                 3.5 
               
               
                   
                 SLIP2 
                   
                   
                   
                 8 
               
               
                   
                 SLIP3 
                 1.10 
               
               
                   
                 AB&amp;S2 
                 0.66 
               
               
                   
                 AB&amp;S3 
                 1.4 
               
               
                   
                 LLDPE2 
                 91.5 
                 95 
                 90.42 
                 20 
                 90 
               
               
                   
                 SSPE1 
                   
                   
                   
                 60 
                   
               
               
                   
                 Total (wt %) 
                 100 
                 100 
                 100 
                 100 
                 100 
               
               
                   
                   
               
            
           
         
       
     
     Heat-shrinkable Film Tubings No. 2 through No. 11 were also prepared by the process illustrated in  FIG. 2 , except that (i) no dust of any type was added either to the inside of the tape immediately upon extrusion, and (ii) no dust of any type was added to the outside of the resulting heat-shrinkable film tubing, even before or during conversion to heat-shrinkable packaging articles. Film Tubings No. 2 through No. 11 were prepared by conducting the solid state orientation of the tape at 3.6× in the machine direction and 3.6× in the transverse direction, for a total orientation ratio of about 13:1. Heat-shrinkable Film Tubing No. 2 through Film Tubing No. 11 were dust-free heat-shrinkable films which were provided with additives to the inside layer and/or outside layer in an effort to provide the resulting tubing and bags with the desired anti-blocking character (e.g., openability) and slip character, i.e., in an effort to provide the resulting heat-shrinkable film tubings and resulting packaging articles with anti-block and slip character comparable to bags with dust on the inside surface thereof and with dust on the outside surface thereof. 
     
       
         
           
               
               
             
               
                   
                 TABLE 4 
               
             
            
               
                   
                   
               
               
                   
                 Film Layer 
               
               
                   
                 Film Tubing No. 2 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 80% SSPE1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 20% AC#1 
                 30 EVA2 
                 EVA2 
                 PVDC1 
                 EVA4 
                 30 EVA2 
                 20 LLDPE3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 5 mils 
                 9 mils 
                 1 mil 
                 2 mils 
                 1 mil 
                 3 mils 
                 2 mils 
               
               
                   
               
            
           
         
       
     
     Film Tubing No. 2 opened before solid state orientation, but would not open after solid state orientation, because the inside layer of the oriented film tubing blocked to itself. 
     
       
         
           
               
               
             
               
                   
                 TABLE 5 
               
             
            
               
                   
                   
               
               
                   
                 Layer 
               
               
                   
                 Film Tubing No. 3 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 60% SSPE1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 38% AC #2 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 2% AB&amp;S 1 
                 30 EVA2 
                 EVA2 
                 PVDC1 
                 EVA4 
                 30 EVA2 
                 20 LLDPE3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 5 mils 
                 14 mils 
                 1 mil 
                 2 mils 
                 1 mil 
                 3 mils 
                 2 mils 
               
               
                   
               
            
           
         
       
     
     Film Tubing No. 3 readily opened before solid state orientation, but would not open after solid state orientation, because the inside layer of the oriented film tubing blocked to itself. Thus, the reported layer thickness is of the layers of the layers of the unoriented tubing. 
     
       
         
           
               
               
             
               
                   
                 TABLE 6 
               
             
            
               
                   
                   
               
               
                   
                 Layer 
               
               
                   
                 Film Tubing No. 4 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 80% SSPE1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 20% AC#3 
                 30 EVA2 
                 EVA2 
                 PVDC1 
                 EVA4 
                 30 EVA2 
                 20 LLDPE3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 0.43 
                 0.78 
                 0.09 
                 0.18 
                 0.09 
                 0.26 
                 0.17 
               
               
                   
               
            
           
         
       
     
     Film Tubing No. 4 opened both before solid state orientation and after solid state orientation. As the tubing could be opened after orientation (i.e., because the inside surface did not adhere to itself strongly enough to block), the reported layer thickness is of the layers of the heat-shrinkable film taken from the oriented film tubing. 
     
       
         
           
               
               
             
               
                   
                 TABLE 7 
               
             
            
               
                   
                   
               
               
                   
                 Layer 
               
               
                   
                 Film Tubing No. 5 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 60% SSPE1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 40% AC #4 
                 30 EVA2 
                 EVA2 
                 PVDC1 
                 EVA4 
                 30 EVA2 
                 20 LLDPE3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Targeted 
                 5 mils 
                 14 mils 
                 1 mil 
                 2 mils 
                 1 mil 
                 3 mils 
                 2 mils 
               
               
                 Thickness 
               
               
                   
               
            
           
         
       
     
     Film Tubing No. 5 blocked to such an extent that it would not open even before solid state orientation. As the tape tubing could not be opened even before solid state orientation (i.e., because the inside layer of the unoriented tape blocked to itself), the layer thickness numbers provided in Table 7 above are based on the rates of materials pumped through the annular die. 
     
       
         
           
               
               
             
               
                   
                 TABLE 8 
               
             
            
               
                   
                   
               
               
                   
                 Layer 
               
               
                   
                 Film Tubing No. 6 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 73% SSPE2 
                   
                   
                   
                   
                   
                   
               
               
                   
                 26% AC#3 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 1.33% AB&amp;S1 
                 30 EVA2 
                 EVA2 
                 PVDC1 
                 EVA4 
                 30 EVA2 
                 20 LLDPE3 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 0.43 
                 0.78 
                 0.09 
                 0.18 
                 0.09 
                 0.26 
                 0.17 
               
               
                   
               
            
           
         
       
     
     As with Film Tubing No. 4, Film Tubing No. 6 opened both before solid state orientation and after solid state orientation. As the tubing could be opened after orientation, the reported layer thickness is of the layers of the heat-shrinkable film taken from the oriented film tubing. 
     Openability Results: Film Tubing No. 1 Through No. 6 
     Data obtained from making Film No. 1 through Film No. 6 resulted in the finding that the size and amount of antiblock particulates provided in the inside layer, as well as the presence and amount of both the slow and fast blooming release agents in the inside layer, resulted in both (i) tape openability before solid state orientation, so that the shrink film production process could be run to completion, and (ii) a heat-shrinkable film tubing which could be wound up on a roll while in lay-flat configuration, and thereafter unrolled and converted into packaging articles which were openable by an Openability Test. Considering the results above for Film Tubings No. 1 through No. 6, only Film Tubing No. 4 and Film Tubing No. 6 were prepared in a manner which produced both (i) tape openability before solid state orientation and (ii) a heat-shrinkable film tubing which could thereafter be converted into openable packaging articles. 
     As all process factors remained substantially constant except the composition of the additives in the inside heat seal layer of the tubing, it is believed that the compositional differences between the various heat seal layers was responsible for the differences in openability data between Film Tubing Nos. 4 and 6 versus Film Tubing Nos. 2, 3, and 5. More particularly, the type and amount of antiblock and release agents was sufficient for Film Tubing No. 2 to open before solid state orientation, but not after solid state orientation. The fact that Film Tubing No. 3 opened before solid state orientation but not after solid state orientation confirmed that, relative to Film Tubing No. 2, roughly tripling the wt % and size (p) of the antiblock particulates (Film Tubing No. 3 vs. No. 2) in combination with halving fast-bloom release agent but roughly doubling the slow-bloom release agent (Film Tubing No. 3 vs. No. 2) did not provide the tubing with a combination of type and amount of antiblock particulates and release agents to produce a different openability result. In Film Tubing No. 5, elevating the amount of antiblock particulates even higher but eliminating the fast bloom release agent proved to prevent even the openability of the tubular tape, establishing the importance of the fast-bloom release agent in the inside layer of the tubing. 
     In contrast, Film Tubing No. 4 was openable at all stages (i.e., before orientation as well as after orientation and windup). Film Tubing No. 4 was provided with relatively high levels of both fast-bloom and slow-bloom release agents (9000 ppm and 7000 ppm, respectively), but with 2500 ppm antiblocking particulates having a size of 3.5μ. This combination of 3.5μ particle size at 2500 ppm together with the 9000 and 7000 ppm of the release agents provided improved openability over the somewhat different combination of additives present in Film Tubing Nos. 2 and 3. 
     Relative to the all-stage openability obtained with Film Tubing No. 4, the complete lack of openability for Film Tubing No. 5 revealed that eliminating the slow-bloom release agent in combination with decreasing the fast-bloom release agent to 1000 ppm while simultaneously increasing the antiblock to 9,600 ppm (from 2500 ppm for Film Tubing No. 4) and increasing the particle size from 3.5p (Film Tubing No. 4) to 5μ (Film Tubing No. 5), demonstrated the need for a substantial quantity of the fast-bloom release agent. Comparing the two-stage openability of Film No. 4 against the one-stage openability of Film Tubing No. 2 and No 3 further confirms the need for a substantial quantity of the fast-bloom release agent. 
     The openability data for Film No. 4 demonstrates that relatively high levels of both slow and fast blooming release agents in combination with a moderate amount of relatively large (3.5μ) antiblocking particulates produced openability at both stages in the making of a heat-shrinkable film tubing. Relative to Film Tubing No. 4, Film Tubing No. 6 was provided with even higher levels of both fast and slow blooming release agents, and about the same wt % of 3.5μ antiblock particulates plus about an equal wt % of 15μ particulates, with the openability of Film Tubing No. 6 confirming that the presence of even more release agents and antiblock particulates also generate the two-stage openability as found previously for Film Tubing No. 4. However, the haze level for Film Tubing No. 6 was significantly higher than the haze level measured for Film Tubing No. 4. See Table 14, below. 
     Further work to develop a two-stage openable tubing was carried out by making Film Tubing Nos. 7 through 11, as set forth below. Each of Film Tubing No. 7 through 11 varied only in the additive types and/or amounts provided to the inside heat seal layer of the film. Tables 9-13, below, provide the layer arrangement, layer composition, and layer thickness for each of Film Tubing Nos. 7 through 11. 
     
       
         
           
               
               
             
               
                   
                 TABLE 9 
               
             
            
               
                   
                   
               
               
                   
                 Film No. 7 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 72.5% SSPE1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 20% AB&amp;S1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 7.5% AB3 
                 30 EVA1 
                 EVA2 
                 PVDC1 
                 EVA3 
                 30 EVA1 
                 20 LLDPE1 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 0.43 mil 
                 0.78 mil 
                 0.09 mil 
                 0.18 mil 
                 0.09 mil 
                 0.26 mil 
                 0.17 mil 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 10 
               
             
            
               
                   
                   
               
               
                   
                 Film No. 8 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 74% SSPE1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 20% AB&amp;S1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 6% AB3 
                 30 EVA1 
                 EVA2 
                 PVDC1 
                 EVA3 
                 30 EVA1 
                 20 LLDPE1 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 0.43 mil 
                 0.78 mil 
                 0.09 mil 
                 0.18 mil 
                 0.09 mil 
                 0.26 mil 
                 0.17 mil 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 11 
               
             
            
               
                   
                   
               
               
                   
                 Film No. 9 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 80% SSPE1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 16% AB&amp;S1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 4% AB3 
                 30 EVAI 
                 EVA2 
                 PVDC1 
                 EVA3 
                 30 EVA1 
                 20 LLDPE1 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 0.43 mil 
                 0.78 mil 
                 0.09 mil 
                 0.18 mil 
                 0.09 mil 
                 0.26 mil 
                 0.17 mil 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 12 
               
             
            
               
                   
                   
               
               
                   
                 Film No. 10 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 80% SSPE1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 18% AB&amp;S1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 2% AB3 
                 30 EVAI 
                 EVA2 
                 PVDC1 
                 EVA3 
                 30 EVA1 
                 20 LLDPE1 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 0.43 mil 
                 0.78 mil 
                 0.09 mil 
                 0.18 mil 
                 0.09 mil 
                 0.26 mil 
                 0.17 mil 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
                 TABLE 13 
               
             
            
               
                   
                   
               
               
                   
                 Film No. 11 
               
               
                   
                 function 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Seal 
                 1 st  Bulk 
                 1 st  Tie 
                 Barrier 
                 2 nd  Tie 
                 2 nd  Bulk 
                 Abuse 
               
            
           
           
               
               
            
               
                   
                 compos. 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 80% SSPE1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 19% AB&amp;S1 
                 70 VLDPE1 
                   
                   
                   
                 70 VLDPE1 
                 80 SSPE2 
               
               
                   
                 1% AB3 
                 30 EVA1 
                 EVA2 
                 PVDC1 
                 EVA3 
                 30 EVA1 
                 20 LLDPE1 
               
               
                   
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                 Thickness 
                 0.43 mil 
                 0.78 mil 
                 0.09 mil 
                 0.18 mil 
                 0.09 mil 
                 0.26 mil 
                 0.17 mil 
               
               
                   
               
            
           
         
       
     
     The amounts of the fast-blooming release agent and the slow-blooming release agent were relatively flat for the heat seal layers of each of Film Tubing No. 7 through No. 11. More particularly, the amount of the fast-blooming release agent in the inside layer ranged from 8,100 ppm to 9,000 ppm, while the slow-blooming release agent ranged from 5,600 ppm to 7,000 ppm. In contrast, the amount of particulate antiblock was varied from a high of 17,500 ppm to a low of 4,375 ppm. The haze data for Film Tubing No. 7 through No. 11 revealed that a lower amount of antiblocking particulates produced a film exhibiting lower haze. Low haze is desirable as the film appears more transparent the lower the haze. See Table 14, below. 
     Table 14 further includes results for additional Film Tubing Nos. 12 through 17. In this set of examples, the same base film as used for Film Tubing Nos. 2 through 11 was again provided with different amounts of release agents and antiblock particulates. Although each of Film Tubing No. 12 through 17 exhibited two-stage openability, Film Tubing No. 16 and 17 exhibited “mild resistance” to opening, while Film Tubing Nos. 12 through 15 exhibited “substantial resistance” to opening. For Film Tubing Nos. 2 through 17, openability characterization was a subjective description based on a manually handling and blowing into the wound up tubing of the heat-shrinkable film. It was not carried out in accordance with the Openability Test described hereinbelow. 
     
       
         
           
               
             
               
                 TABLE 14 
               
             
            
               
                   
               
               
                 Inside Layer Results 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Inside 
                 Inside 
                   
                 Inside 
                 Inside 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 Primary 
                 WAX 2 
                 WAX 1 
                 Large 
                 layer 
                 layer 
                   
                   
                   
                   
                   
                   
                 COF 
                 COF Peak 
               
               
                   
                   
                 et/α- 
                 (ppm) 
                 (ppm) 
                 Antiblock 
                 AB2 
                 AB1 
                 Total 
                 Total 
                 Opened before 
                 Packaging 
                   
                   
                 Instantaneous 
                 Value 
               
               
                 Film 
                 Inside Layer 
                 olefin 
                 Fast 
                 Slow 
                 (ppm) 
                 (ppm) 
                 (ppm) 
                 Wax 
                 Antiblock ≥3.5μ 
                 solid state 
                 Article 
                 Haze 
                 Haze 
                 Inside-to- 
                 inside to 
                 Gloss 
               
               
                 No. 
                 composition 
                 (g/cm 3 ) 
                 bloom 
                 Bloom 
                 (5μ-15μ) 
                 (3.5μ) 
                 (0.7 μ) 
                 (ppm) 
                 (ppm) 
                 orientation 
                 Openability 
                 (%) 
                 Perform. 
                 inside 
                 inside 
                 (%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                  2 
                 80% SSPE1 
                 0.900 
                 3350 
                 8,800 
                 650 
                 1400 
                 0 
                 20,000 
                 5000 
                 1 st : YES 
                 1 st : YES 
                 1.32 
                 Good 
                 — 
                 — 
                 95 
               
               
                 (C) 
                 20% AC#1 
                   
                   
                   
                  (5μ) 
                 (3μ) 
                   
                   
                   
                 2 nd : YES 
                 2 nd : NO 
               
               
                  3 
                 60% SSPE1 
                 0.900 
                 1,000 
                 19,000 
                 5,000 
                 0 
                 0 
                 20,000 
                 5000 
                 YES 
                 NO 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 (C) 
                 38% AC#2 
                   
                   
                   
                 (15μ) 
               
               
                   
                 2% AB&amp;S1 
               
               
                  4 
                 80% SSPE1 
                 0.900 
                 9,000 
                 7000 
                 0 
                 2500 
                 660 
                 16,000 
                 2500 
                 YES 
                 YES 
                 6.12 
                 good 
                 — 
                 — 
                 96 
               
               
                 (W) 
                 20% AC#3 
               
               
                  5 
                 60% SSPE1 
                 0.900 
                 1,600 
                 0 
                 9600 
                 0 
                 0 
                 1.600 
                 9600 
                 NO 
                 NO 
                 — 
                 — 
                 — 
                 — 
                 — 
               
               
                 (C) 
                 40% AC#4 
                   
                   
                   
                  (5μ) 
               
               
                  6 
                 73% SSPE1 
                 0.900 
                 12,365 
                 9,100 
                 3325 
                 3250 
                 860 
                 21,465 
                 6575 
                 YES 
                 YES 
                 13.6 
                 poor 
                 — 
                 — 
                   80.6 
               
               
                 (W) 
                 26% AB&amp;S1 
                   
                   
                   
                 (15μ) 
               
               
                   
                 1.33% AB3 
               
               
                  7 
                 72.5% SSPE1 
                 0.900 
                 8991 
                 6993 
                 15040 
                 2497.5 
                 659.34 
                 15984 
                 18197 
                 YES 
                 YES 
                 11.6 
                 poor 
                 0.285 
                 — 
                 77 
               
               
                 (W) 
                 20% AB&amp;S 
               
               
                   
                 7.5% AB3 
               
               
                  8 
                 74% SSPE1 
                 0.900 
                 9000 
                 7000 
                 12000 
                 2500 
                 660 
                 16000 
                 15160 
                 YES 
                 YES 
                 11.4 
                 poor 
                 0.235 
                 — 
                 77 
               
               
                 (W) 
                 20% AB&amp;S1 
               
               
                   
                 6% AB3 
               
               
                  9 
                 80% SSPE1 
                 0.900 
                 7200 
                 5600 
                 8000 
                 2000 
                 528 
                 12800 
                 10528 
                 YES 
                 YES 
                 7.66 
                 fair 
                 0.228 
                 — 
                 83 
               
               
                 (W) 
                 16% AB&amp;S1 
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 8.46 
               
               
                   
                 4% AB3 
               
               
                 10 
                 80% SSPE1 
                 0.900 
                 8100 
                 6300 
                 4000 
                 2250 
                 594 
                 14400 
                 6844 
                 YES 
                 YES 
                 7.06 
                 good 
                 0.299 
                 — 
                 72 
               
               
                 (W) 
                 18% AB&amp;S1 
               
               
                   
                 2% AB3 
               
               
                 11 
                 80% SSPE1 
                 0.900 
                 8550 
                 6650 
                 2000 
                 2375 
                 627 
                 15200 
                 5002 
                 YES 
                 YES 
                 5.47 
                 good 
                 0.244 
                 — 
                 80 
               
               
                 (W) 
                 19% AB&amp;S1 
               
               
                   
                 1% AB3 
               
               
                 12 
                 80% SSPE1 + 
                 0.900 
                 1500 
                 4500 
                 500 
                 3000 
                 0 
                 6000 
                 3500 
                 YES 
                 YES** 
                 5.48 
                 good 
                 1 
                 1.99 
                 — 
               
               
                   
                 additives shown 
               
               
                 13 
                 80% SSPE1 + 
                 0.900 
                 1500 
                 6000 
                 500 
                 4000 
                 0 
                 7500 
                 4500 
                 YES 
                 YES** 
                 4.17 
                 good 
                 0.403 
                 0.977 
                 — 
               
               
                   
                 additives shown 
               
               
                 14 
                 80% SSPE1 + 
                 0.900 
                 6000 
                 4500 
                 1500 
                 3000 
                 0 
                 10500 
                 4500 
                 YES 
                 YES** 
                 8.05 
                 good 
                 1.640 
                 1.99 
                 — 
               
               
                   
                 additives shown 
               
               
                 15 
                 80% SSPE1 + 
                 0.900 
                 1500 
                 6000 
                 1500 
                 3000 
                 0 
                 7500 
                 4500 
                 YES 
                 YES** 
                 6.20 
                 good 
                 0.255 
                 0.491 
                 — 
               
               
                   
                 additives shown 
               
               
                 16 
                 80% SSPE1 + 
                 0.900 
                 6000 
                 4500 
                 1500 
                 3000 
                 0 
                 10500 
                 4500 
                 YES 
                 YES* 
                 8.12 
                 good 
                 0.425 
                 0.766 
                 — 
               
               
                   
                 additives shown 
               
               
                 17 
                 80% SSPE1 + 
                 0.900 
                 6000 
                 6000 
                 1500 
                 4000 
                 0 
                 12000 
                 5500 
                 YES 
                 YES* 
                 6.88 
                 good 
                 0.196 
                 0.385 
                 — 
               
               
                   
                 additives shown 
               
               
                   
               
               
                 *Opened: tubing initially opened, but with mild resistance to opening, i.e., not as readily as samples labeled as simply “opened” 
               
               
                 **Opened: tubing initially opened, but with substantial resistance to opening 
               
            
           
         
       
     
     Additional film tubings were prepared in an effort to discover what additive(s) were needed in the outside layer of the tubing to provide performance characteristics at least substantially equivalent to the use of dust on the outside of the film tubing. Dust on the outside of the film tubing enhances the release properties of the film (i.e., so that the film does not adhere to itself during unrolling and during handling of stacked bags and taped bags) and lowers the coefficient of friction of the outside surface of the film so that the film tubing, and packaging articles made therefrom, slide freely relative to equipment surfaces, etc., during further film processing, including during conversion of the tubing to packaging articles and subsequent processing of the packaging articles. 
     Table 15, below, provides composition and performance data pertaining to Film Tubing Nos. 19-31, each of which had an outside layer which was extruded with one or more slip or antiblock additives. Although no dust was added to the outside surface of any of Film Tubings 19-31, dust was added to the inside of Tubing Nos. 19-31 during their manufacture. 
     Among Tubing Nos. 19-31, haze ranged from a low of about 5% to a high of about 15%, with most of the films exhibiting from 6% to 11% haze. Gloss ranged from a low of about 45% to a high of about 78%. 
     
       
         
           
               
               
               
               
               
               
               
               
               
               
               
               
             
               
                 TABLE 15 
               
               
                   
               
               
                   
                   
                   
                 Antiblock 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 Film 
                 Composition 
                   
                 (ppm) in 
                 Blend 
                 Shrink 
                 Shrink 
               
               
                 Tubing 
                 of Tubing 
                 Slip Agent 
                 outside 
                 Density 
                 @185 F. 
                 @185 F. 
                 COF 
                 COF 
                 Gloss 
                 Haze 
               
               
                 No. 
                 Outside Layer 
                 (ppm) 
                 layer 
                 (g/cm 3 ) 
                 (L) 
                 (T) 
                 (instant) 
                 (Peak) 
                 (%) 
                 (%) 
                 Comments 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 18A 
                 SSPE5 80%/ 
                 200 
                 0 
                 0.906 
                 47.5 
                 50 
                 1.485 
                 Un- 
                 72.1 
                 3.51 
                   
               
               
                   
                 LLDPE319%/FP 1% 
                 fluoropolymer 
                   
                   
                   
                   
                   
                 defined 
               
               
                 19 
                 SSPE5 85%/SSPE6 
                 10,000 
                 4000 5μ 
                 0.910 
                 47.5 
                 50.5 
                 Un- 
                 Un- 
                 73.05 
                 7.85 
                 Ran well 
               
               
                   
                 11%/SLIP1 2%/AB3 2% 
                 polysiloxane 
                 silica 
                   
                   
                   
                 defined 
                 defined 
               
               
                 20 
                 SSPE5 85%/SSPE6 
                 900 
                 5400 5μ 
                 0.909 
                 44.5 
                 51 
                 0.281 
                 0.7575 
                 76.7 
                 6.485 
               
               
                   
                 12%/AB&amp;S4 3% 
                 Erucamide 
                 silica 
               
               
                 21 
                 SSPE5 80%/SSPE4 
                 10,000 
                 4000 5μ 
                 0.911 
                 46.5 
                 52.5 
                 0.993 
                 DIV/0! 
                 63.35 
                 7.385 
               
               
                   
                 16%/SLIP1 2%/AB3 2% 
                 polysiloxane 
                 silica 
               
               
                 18B 
                 SSPE5 80%/LLDPE3 
                 200 
                 0 
                 0.906 
                 47.5 
                 50.5 
                 1.48 
                 DIV/0! 
                 68.5 
                 5.05 
               
               
                   
                 19%/FP 1% 
                 fluoropolymer 
               
               
                 22 
                 Westlake 77523 
                 920  
                 14,400    
                 0.908 
                 45 
                 50.5 
                 0.396 
                 1.295 
                 76.1 
                 7.84 
               
               
                   
                 (loaded antiblock/ 
               
               
                   
                 slip) 80%/SSPE7 20% 
               
               
                 23 
                 LLDPE4 70%/Westlake 
                 10,000 
                 1400   
                 0.910 
                 44.5 
                 50.5 
                 0.2525 
                 0.7815 
                 68.65 
                 4.595 
               
               
                   
                 sc74877 20%/SSPE3 
                 Polysiloxane 
               
               
                   
                 8%/SLIP1 2% 
               
               
                 18C 
                 SSPE5 80%/LLDPE3 
                 200 
                 0 
                 0.906 
                 44 
                 51 
                 0.504 
                 0.8455 
                 77.9 
                 3.725 
               
               
                   
                 19%/FP 1% 
                 fluoropolymer 
               
               
                 24 
                 SSPE4 80%/SSPE3 
                 0 
                 6000 5μ 
                 0.908 
                 44 
                 51 
                 0.2185 
                 0.5985 
                 75.65 
                 5.23 
               
               
                   
                 17%/AB3 3% 
                   
                 silica 
               
               
                 25 
                 SSPE7 64%/ssPEC2 
                 0 
                 6000 5μ 
                 0.906 
                 45.5 
                 53.5 
                 0.107 
                 0.208 
                 42.45 
                 14.85 
               
               
                   
                 33%/AB3 3% 
                   
                 silica 
               
               
                 26 
                 SSPE4 67%/ssPEC1 
                 0 
                 6000 5μ 
                 0.909 
                 44.5 
                 52 
                 0.1755 
                 0.633 
                 75.8 
                 5.905 
               
               
                   
                 30%/AB3 3% 
                   
                 silica 
               
               
                 18D 
                 SSPE5 80%/LLDPE3 
                 200 
                 0 
                 0.906 
                 46 
                 51.5 
                 0.453 
                 0.937 
                 81.8 
                 3.635 
               
               
                   
                 19%/FP 1% 
                 fluoropolymer 
               
               
                 27 
                 znPEC 70%/SSPE5 
                 0 
                 6000 5μ 
                 0.905 
                 47 
                 51.5 
                 0.1475 
                 0.292 
                 65.5 
                 8.115 
               
               
                   
                 27%/AB3 3% 
                   
                 silica 
               
               
                 28 
                 znPEC 80%/Westlake 
                 0 
                 4000 5μ 
                 0.906 
                 43.5 
                 48.5 
                 0.1735 
                 0.2685 
                 72.2 
                 8.785 
                 Bad curl 
               
               
                   
                 SC74877 17%/AB3 3% 
                   
                 silica + 
               
               
                   
                   
                   
                 1190 add&#39;l 
               
               
                 29 
                 znPEC 90%/Westlake 
                 0 
                 4000 5μ 
                 0.905 
                 39.5 
                 49.5 
                 0.1725 
                 0.3325 
                 65.05 
                 9.84 
                 Bad curl 
               
               
                   
                 SC74877 7%/AB3 3% 
                   
                 silica+ 
               
               
                   
                   
                   
                 1190 add&#39;l 
               
               
                 18E 
                 SSPE5 80%/LLDPE3 
                 200 
                 0 
                 0.906 
                 47 
                 53 
                 0.604 
                 1.121 
                 86.8 
                 3.58 
                 Strange 
               
               
                   
                 19%/FP 1% 
                 fluoropolymer 
                   
                   
                   
                   
                   
                   
                   
                   
                 reading 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 (rev. values 
               
               
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                   
                 vs pilot run) 
               
               
                 30 
                 SSPE5 80%/LLDPE3 
                 10,000 
                 3600 5μ 
                 0.912 
                 44.5 
                 50.5 
                 0.569 
                 0.714 
                 72.25 
                 8.2 
                 Haze, bags 
               
               
                   
                 16%/AB&amp;S4 2%/ 
                 Polysiloxane 
                 silica 
                   
                   
                   
                   
                   
                   
                   
                 came apart, 
               
               
                   
                 SLIP1 2% 
                 600 
                   
                   
                   
                   
                   
                   
                   
                   
                 high static 
               
               
                   
                   
                 erucamide 
               
               
                 31 
                 SSPE4 61%/ssPEC2 
                 10,000 
                 4000 5μ 
                 0.903 
                 44.5 
                 52 
                 0.2565 
                 0.4515 
                 49.95 
                 10.9 
               
               
                   
                 35%/SLIP1 2%/AB3 2% 
                 polysiloxane 
                 silica 
               
               
                 32 
                 SSPE7 50%/ssPEC2 50% 
                 0 
                 0 
                 0.895 
                 46.5 
                 53 
                 0.0985 
                 0.251 
                 23.7 
                 26.4 
               
               
                   
               
            
           
         
       
     
     Film Tubing Nos. 33 through 41 were prepared entirely free of dust on either the inside of the tubing or the outside of the tubing. In each of these film tubings, a release agent and/or antiblock particulates were blended into each of the inside layer of the tubing and the outside layer of the tubing. The multilayer structures of Film Tubing Nos. 33-41 are provided in Table 16 through Table 24, below. Tables 16-24 include the composition and thickness of each layer. 
     
       
         
           
               
             
               
                 TABLE 16 
               
             
            
               
                   
               
               
                 Film Tubing No. 33 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 67 SSPE1 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 30ssPEC1 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 3 AB3 
               
               
                   
               
               
                 0.43 
                 0.78 
                 0.09 
                 0.06 
                 0.21 
                 0.07 
                 0.26 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 17 
               
             
            
               
                   
               
               
                 Film Tubing No. 34 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 80 SSPE1 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 17 SSPE3 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 3 AB3 
               
               
                   
               
               
                 0.43 
                 0.78 
                 0.09 
                 0.06 
                 0.21 
                 0.07 
                 0.26 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 18 
               
             
            
               
                   
               
               
                 Film Tubing No. 35 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 68.5 SSPE1 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 30 ssPEC1 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 3 AB5 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 19 
               
             
            
               
                   
               
               
                 Film Tubing No. 36 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 81.5 SSPE1 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 17 SSPE3 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.5 AB5 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 20 
               
             
            
               
                   
               
               
                 Film Tubing No. 37 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 67 SSPE1 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 30 ssPEC1 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.5 AB5 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.5 SLIP1 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 21 
               
             
            
               
                   
               
               
                 Film Tubing No. 38 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 80 SSPE1 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 17 SSPE3 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.5 AB5 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.5 SLIP1 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 22 
               
             
            
               
                   
               
               
                 Film Tubing No. 39 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 66.5 SSPE1 
               
               
                   
                   
                   
                   
                   
                   
                   
                 30 ssPEC1 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 1.5 AB5 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.0 SLIP1 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.0 FP 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 23 
               
             
            
               
                   
               
               
                 Film Tubing No. 40 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 79.5 SSPE1 
               
               
                   
                   
                   
                   
                   
                   
                   
                 17 SSPE3 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 1.5 AB5 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.0% SLIP1 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.0% FP 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 24 
               
             
            
               
                   
               
               
                 Film Tubing No. 41 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 79.5 SSPE5 
               
               
                   
                   
                   
                   
                   
                   
                   
                 17 LLDPE3 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 1.5 AB5 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.0% SLIP1 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.0% FP 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     In Film Tubing Nos. 33-41, each of the inside layers contained 20 wt % AC #5, which provided the inside layer with 7000 ppm fast-blooming release agent (erucamide), 7000 ppm slow-blooming release agent (bis-stearamide) and 6000 ppm of 5μ silica antiblock particulates. This blend was selected as providing two-stage openability without increasing haze to an undesirable level. 
     Film Tubing No. 35 and Film Tubing No. 36 exhibited tack together at converting and minor tack at loading. Film Tubing No. 37 and Film Tubing No. 38 provided zero tack/free hanging bags at converting and no rainbowing at hand loading. However, Film Tubing Nos. 37 and 38 had higher haze and lower gloss than Film Tubing Nos 35 and 36. 
     Table 25, below, provides a summary of the composition and various results obtained for Film Tubing Nos. 33-41. The haze values were affected by both the inside layer and the outside layer. The gloss and coefficient of friction values were determined by the characteristics of the outside layer alone. Low haze and high gloss are a desirable combination of properties. The results in Table 25 show the effects on haze and gloss and coefficient of friction as a function of the combination of slip and antiblock present in the outside and inside layers of Film Nos. 33-41, as well as for films A through H. 
     Additional Film Tubings Nos. 42 through 49 were prepared in the same manner as Film Tubing Nos. 33-41, except (i) dust was provided on the inside of the tubing during manufacture, and (ii) the composition of the outside layer was changed. The composition of the outside layer of the tubing for Film Tubing Nos. 42-49, and the gloss, haze, and other performance characteristics, are also provided in Table 25. 
     
       
         
           
               
               
               
               
               
               
               
               
               
               
               
               
               
             
               
                 TABLE 25 
               
               
                   
               
               
                   
                   
                   
                 Slip agents: 
                 Silica 
                 Main 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 Dustless 
                   
                 uhmw 
                 Antiblock 
                 et/α- 
                   
                   
                 Outside 
                 Outside 
               
               
                   
                 Outside/ 
                 Composition 
                 polysiloxane/ 
                 (ppm) In 
                 olefin 
                 Shrink 
                 Shrink 
                 surface 
                 surface 
               
               
                 Film 
                 Dustless 
                 of Tubing 
                 fluoropolymer 
                 outside 
                 density 
                 @195 F. 
                 @195 F. 
                 COF 
                 COF 
                 Haze 
                 Gloss 
               
               
                 No. 
                 Inside 
                 Outside Layer 
                 (ppm) 
                 layer 
                 (g/cm 3 ) 
                 (L) 
                 (T) 
                 (instant) 
                 (Peak) 
                 (%) 
                 (%) 
                 Clarity 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 33 
                 yes/yes 
                 67% SSPE4/30% 
                  0/0 
                 6000 5μ 
                 0.912 
                   
                   
                 Blocked 
                 Blocked 
                   
                   
                   
               
               
                   
                   
                 ssPEC1/3% AB3 
                   
                 silica 
               
               
                 34 
                 yes/yes 
                 80% SSPE4/17% 
                  0/0 
                 6000 5μ 
                 0.912 
                   
                   
                 Blocked 
                 Blocked 
               
               
                   
                   
                 SSPE3/3% AB3 
                   
                 silica 
               
               
                 35 
                 yes/yes 
                 68.5% SSPE4/30% 
                  0/0 
                 10,500 9μ 
                 0.912 
                 46 
                 51 
                 0.370 
                 0.918 
                 7.40 
                 81.7 
                 15.0 
               
               
                   
                   
                 ssPEC1/AB5 1.5% 
                   
                 silica 
                   
                   
                   
                   
                   
                   
                 81.6 
               
               
                 36 
                 yes/yes 
                 81.5% SSPE4/18.5% 
                  0/0 
                 10,500 9μ 
                 0.912 
                 46 
                 52 
                 0.273 
                 0.50 
                 14.9 
                 73.5 
                 5.6 
               
               
                   
                   
                 SSPE3/AB 5 1.5% 
                   
                 silica 
               
               
                 37 
                 yes/yes 
                 67% SSPE4/30% 
                 7500/0  
                 10,500 9μ 
                 0.912 
                 45 
                 52 
                 0.294 
                 0.436 
                 25.4 
                 68.2 
                 4.8 
               
               
                   
                   
                 ssPEC1/AB5 1.5%/ 
                   
                 silica 4,500 
               
               
                   
                   
                 SLIP1 1.5% 
                   
                 aadd&#39;l silica 
               
               
                 38 
                 yes/yes 
                 80% SSPE4/SSPE3/ 
                 7500/0  
                 10,500 9μ 
                 0.912 
                 44 
                 50 
                 0.354 
                 0.494 
                 17.6 
                 69.0 
                 4.7 
               
               
                   
                   
                 AB5 1.5%/SLIP1 1.5% 
                   
                 silica 4.500 
               
               
                   
                   
                   
                   
                 add&#39;l silica 
               
               
                 39 
                 yes/yes 
                 66.5% SSPE4/30% 
                 5000/200 
                 10,500 9μ 
                 0.912 
                 44 
                 52 
                 0.151 
                 0.306 
                 14 
                 70.2 
                 8.2 
               
               
                   
                   
                 ssPEC1/AB51.5%/ 
                   
                 silica 3,000 
               
               
                   
                   
                 SLIP1 1%/FP1% 
                   
                 add&#39;l silica 
               
               
                 40 
                 yes/yes 
                 79.5% SSPE4/SSPE3 
                 5000/200 
                 10,500 9μ 
                 0.912 
                 42 
                 52 
                 0.46 
                 0.569 
                 17.6 
                 70.4 
                 3.1 
               
               
                   
                   
                 /AB5 1.5%/SLIP1 
                   
                 silica 3,000 
               
               
                   
                   
                 1%/FP 1% 
                   
                 add&#39;l silica 
               
               
                 41 
                 yes/yes 
                 79.5% SSPE5/17% 
                 5000/200 
                 10,500 9μ 
                 0.905 
                 48 
                 54 
                 0.376 
                 0.497 
                 18.6 
                 54.0 
                 3.4 
               
               
                   
                   
                 LLDPE3/AB51.5%/ 
                   
                 silica 3,000 
               
               
                   
                   
                 SLIP1 1%/FP 1% 
                   
                 add&#39;l silica 
               
               
                 42 
                 yes/no 
                 SSPE5 80%/LLDPE3 
                 5500/200 
                 6,400 5μ 
                 0.905 
                 — 
                 — 
                 0.151 
                 0.312 
                 9.00 
                 79.8 
                 17.5 
               
               
                   
                   
                 15%/AB3 3.19%/SLIP1 
                   
                 silica 3,300 
               
               
                   
                   
                 1.13%/FP 1% 
                   
                 add&#39;l silica 
               
               
                 43 
                 yes/no 
                 SSPE5 80%/LLDPE3 
                 5500/200 
                 17,800 silica 
                 0.905 
                 — 
                 — 
                 0.136 
                 0.400 
                 11.4 
                 78.2 
                 18.0 
               
               
                   
                   
                 15%/AB11 2.87%/ 
               
               
                   
                   
                 SLIP1 1.13%/FP1% 
               
               
                 44 
                 yes/no 
                 SSPE5 80%/LLDPE3/ 
                 5500/200 
                 6,375 7.6μ 
                 0.905 
                 — 
                 — 
                 0.174 
                 0.311 
                 9.83 
                 76.4 
                 14.2 
               
               
                   
                   
                 2.55% AB6/SLIP1 
                   
                 silica 3,300 
               
               
                   
                   
                 1.13%/FP 1% 
                   
                 add&#39;l silica 
               
               
                 45 
                 yes/no 
                 SSPE5 80%/ LLDPE3/ 
                 7500/200 
                 3,000 7.6μ 
                 0.905 
                 — 
                 — 
                 0.178 
                 0.342 
                 17.8 
                 57.0 
                 9.1 
               
               
                   
                   
                 SLIP1 1.50%/AB6 
                   
                 silica 4,500 
               
               
                   
                   
                 1.2%/FP 1% 
                   
                 add&#39;l silica 
               
               
                 46 
                 yes/no 
                 SSPE5 80%/LLDPE3/ 
                 5500/200 
                 8,000 5μ 
                 0.905 
                 — 
                 — 
                 0.208 
                 0.398 
                 10.9 
                 78 
                 11.8 
               
               
                   
                   
                 AB3 4%/AB7 2.26%/ 
                   
                 silica 
               
               
                   
                   
                 FP 1% 
               
               
                 47 
                 yes/no 
                 SSPE5 80%/LLDPE3/ 
                 2750/200 
                 8,000 5μ 
                 0.905 
                 — 
                 — 
                 0.156 
                 0.337 
                 16.2 
                 61.0 
                 7.6 
               
               
                   
                   
                 AB3 4%/AB7 1.13%/ 
                   
                 silica 
               
               
                   
                   
                 FP 1% 
               
               
                 48 
                 yes/no 
                 SSPE5 80%/LLDPE3/ 
                   0/200 
                 8,000 5μ 
                 0.905 
                 — 
                 — 
                 0.208 
                 0.350 
                 23.2 
                 52.0 
                 5.2 
               
               
                   
                   
                 AB3 4%/AB11 1.13%/ 
                   
                 silica 5,500 
               
               
                   
                   
                 FP 1% 
                   
                 add&#39;l silica 
               
               
                 49 
                 yes/no 
                 SSPE5 80%/ LLDPE3/ 
                   0/200 
                 8,000 5μ 
                 0.905 
                 — 
                 — 
                 0.184 
                 0.386 
                 10.8 
                 77.8 
                 12.5 
               
               
                   
                   
                 AB11 0.565%/AB3 
                   
                 silica 2,750 
               
               
                   
                   
                 4%/FP 1% 
                   
                 add&#39;l silica 
               
               
                   
               
            
           
         
       
     
     Film Tubing Nos. 50-55 were also prepared in order to further assess the effects of various combinations of slip agents and antiblock particulates for use in the outside layer, in order to obtain the desired haze, gloss, and slip characteristics. Film Tubing Nos. 50-55 were 7-layer films of the same type as Film Tubing Nos. 2 through 32, and were prepared with dust added to the inside of the tubing during manufacturing. The results, including the composition of the additives in the outside layer, the haze, the gloss, the clarity, and the coefficient of friction, are provided in Table 26, below. 
     
       
         
           
               
               
               
               
               
               
               
               
               
               
             
               
                 TABLE 26 
               
               
                   
               
               
                   
                   
                 Slip agents: 
                 Silica 
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 uhmw 
                 Antiblock 
               
               
                   
                 Composition 
                 polysiloxane/ 
                 (ppm) in 
                 Main et/α- 
               
               
                 Film 
                 of Tubing 
                 fluoropolymer 
                 outside 
                 olefin density 
                 COF 
                 COF 
                 Haze 
                 Gloss 
               
               
                 No. 
                 Outside Layer 
                 (ppm) 
                 layer 
                 (g/cm 3 ) 
                 (instant) 
                 (Peak) 
                 (%) 
                 (%) 
                 Clarity 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 50 
                 80% SSPE5 /16.7% LLDPE3/ 
                 2000/200 
                 3000 5μ 
                 0.905 
                 0.3154 
                 0.462 
                 12.42 
                 71.34 
                 4.64 
               
               
                   
                 0.8% AB7/1.5% AB3 /1% FP 
                   
                 silica 
               
               
                 51 
                 80% SSPE5 /15.3% LLDPE3/ 
                 3000/200 
                 5000 5μ 
                 0.905 
                 0.129 
                 0.2886 
                 12.38 
                 72.08 
                 6.82 
               
               
                   
                 1.2% AB7/2.5% AB3 /1% FP 
                   
                 silica 
               
               
                 52 
                 80% SSPE5 /15.9% LLDPE3/ 
                 4000/200 
                 3,000 5μ 
                 0.905 
                 0.152 
                 0.2572 
                 8.54 
                 75.4 
                 11.64 
               
               
                   
                 1.6% AB7 /1.5% AB3/1% FP 
                   
                 silica 
               
               
                 53 
                 80% SSPE5 /14.7% LLDPE3/ 
                 2000/200 
                 7,000 5μ 
                 0.905 
                 0.1334 
                 0.2122 
                 10.746 
                 74.52 
                 17.18 
               
               
                   
                 0.8% AB7/3.5% AB3 /1% FP 
                   
                 silica 
               
               
                 54 
                 80% SSPE5 /13.9% LLDPE3/ 
                 4000/200 
                 7,000 5μ 
                 0.905 
                 0.1326 
                 0.2498 
                 9.466 
                 77.52 
                 17.54 
               
               
                   
                 1.6% AB7/3.5% AB3/1% FP 
                   
                 silica 
               
               
                 55 
                 80% SSPE5 /15.3% LLDPE3/ 
                 3000/200 
                 5,000 5μ 
                 0.905 
                 0.405 
                 0.5712 
                 7.684 
                 76.8 
                 20.04 
               
               
                   
                 1.2% AB7/2.5% AB3 /1% FP 
                   
                 silica 
               
               
                   
               
            
           
         
       
     
     Film Tubing Nos. 56 through 59 were prepared entirely free of dust on either the inside of the tubing or the outside of the tubing. In each of these film tubings, a release agent and/or antiblock particulates were blended into each of the inside layer of the tubing and the outside layer of the tubing. 
     The multilayer structures of Film Tubing Nos. 56-59 are provided in Table 27 through Table 30, below. Tables 27-30 include the composition and thickness of each layer. Film Tubing Nos. 56 through 59 each had inside layers containing 7000 ppm erucamide, 7000 ppm bis-stearamide, and 6000 ppm 5 micron silica antiblock particulates. Film Tubing Nos. 56 and 59 had outside layers with a polymer density of about 0.907 g/cc, while Film Tubing Nos. 57 and 58 had outside layers with a polymer density of about 0.914 g/cc. 
     Table 31 provides results for gloss and haze, as a function of slip agent type and amount and antiblock type and amount. 
     
       
         
           
               
             
               
                 TABLE 27 
               
             
            
               
                   
               
               
                 Film Tubing No. 56 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 80% SSPE5 
               
               
                   
                   
                   
                   
                   
                   
                   
                 13.9% LLDPE3 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 3.5% AB3 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.6% AB7 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.0% FP 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 28 
               
             
            
               
                   
               
               
                 Film Tubing No. 57 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 80 SSPE4 
               
               
                   
                   
                   
                   
                   
                   
                   
                 13.9 SSPE3 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 3.5 AB3 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.6% AB7 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.0% FP 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 29 
               
             
            
               
                   
               
               
                 Film Tubing No. 58 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 65.3 SSPE4 
               
               
                   
                   
                   
                   
                   
                   
                   
                 28.6 ssPEC1 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 3.5 AB3 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.6% AB7 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.0% FP 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 30 
               
             
            
               
                   
               
               
                 Film Tubing No. 59 
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 80 SSPE5 
               
               
                   
                   
                   
                   
                   
                   
                   
                 15.3 LLPE3 
               
               
                   
                 64 VLDPE2 
                   
                   
                   
                   
                 64 VLDPE3 
                 2.5 AB3 
               
               
                 80 SSPE1 
                 30 EVA2 
                   
                   
                   
                   
                 29.9 EVA2 
                 1.2% AB7 
               
               
                 20 AC#5 
                 6 SSPE3 
                 EVA2 
                 EVA4 
                 PVDC1 
                 EVA4 
                 6.1 SSPE3 
                 1.0% FP 
               
               
                   
               
               
                 0.42 
                 0.75 
                 0.08 
                 0.06 
                 0.20 
                 0.07 
                 0.25 
                 0.17 
               
               
                 INSIDE 
                   
                   
                   
                   
                   
                   
                 OUTSIDE 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
               
               
               
               
               
               
               
             
               
                 TABLE 31 
               
               
                   
               
               
                   
                   
                 Slip agents: 
                 Silica 
                 Main 
                 Av. Free 
                   
                   
                   
                   
                   
               
               
                   
                   
                 uhmw 
                 Antiblock 
                 et/α- 
                 Shrink @ 
                 Peak Load 
               
               
                   
                 Composition 
                 polysiloxane / 
                 (ppm) in 
                 olefin 
                 85 C. 
                 Impact 
                 Avg. 
                 Avg. 
                 Avg. 
                 Avg. 
               
               
                 Film 
                 of Tubing 
                 fluoropolymer 
                 outside 
                 density 
                 L/T 
                 Strength 
                 Haze 
                 Gloss 
                 Clarity 
                 Thickness 
               
               
                 No. 
                 Outside Layer 
                 (ppm) 
                 layer 
                 (g/cm 3 ) 
                 (%) 
                 (N) 
                 (%) 
                 (%) 
                 (%) 
                 (mils) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                   
                 0 
                 0 
                   
                 33/43 
                 231.84 
                 7.5 
                 78 
                 27.9 
                 2.12 
               
               
                 56 
                 80% SSPE5/13.9% LLDPE3/ 
                 4000/200 
                 7,000 5μ 
                 0.905 
                 34/43 
                 208.67 
                 9.6 
                 75 
                 20.3 
                 1.92 
               
               
                   
                 3.5% AB3/1.6% AB7/1%FP 
                   
                 silica 
               
               
                 59 
                 80% SSPE5/15.3% LLDPE3/ 
                 3000/200 
                 5,000 5μ 
                 0.905 
                 33/42 
                 215.29 
                 8.4 
                 80 
                 30.2 
                 1.88 
               
               
                   
                 2.5% AB3 /1.2% AB7/1% FP 
                   
                 silica 
               
               
                 58 
                 65.3% SSPE4/28.6% ssPEC1/ 
                 4000/200 
                 7,000 5μ 
                 0.912 
                 33/42 
                 193.94 
                 10 
                 76 
                 24.3 
                 1.88 
               
               
                   
                 3.5% AB3/1.6% AB7/1%FP 
                   
                 silica 
               
               
                 57 
                 80% SSPE4/13.9% SSPE3/ 
                 4000/200 
                 7,000 5μ 
                 0.912 
                 33/43 
                 188.31 
                 9.1 
                 76 
                 16.5 
                 1.94 
               
               
                   
                 3.5% AB3/1.6% AB7/1% FP 
                   
                 silica 
               
               
                   
               
            
           
         
       
     
     Film Tubing Nos. 56 through 59 each had inside layers containing 7000 ppm erucamide, 7000 ppm bis-stearamide, and 6000 ppm 5 micron silica antiblock particulates. Film Tubing Nos. 56 and 59 had outside layers with a polymer density of about 0.907 g/cc, while Film Tubing Nos. 57 and 58 had outside layers with a polymer density of about 0.914 g/cc. 
     Although the present invention has been described in connection with the preferred embodiments, it is to be understood that modifications and variations may be utilized without departing from the principles and scope of the invention, as those skilled in the art will readily understand. Accordingly, such modifications may be practiced within the scope of the following claims.