Patent Abstract:
A bag having an inwardly disposed seam is manufactured from a sheet of plastic bag material having two major surfaces and two parallel side edges. A first seam seals the two parallel side edges together at the same major surface with the side edges disposed inwardly of the tube to form the sheet of plastic bag material into a tube with internal flap portions extending interiorly of the tube. At least one seal across the tube is provided for forming at least a three-sided bag structure (and preferably two seals across the tube for forming a closed four-sided bag structure) whereby presstue in the interior of the bag acts against the internal flap portions disposed inwardly of the tube to enhance the sealing of the seam. The bag is filled at an opening defined along the opposite side edges of the seam facing inwardly of the tube.

Full Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     I hereby claim benefit under Title 35, United States Code, Section 119(e) of U.S. provisional patent application Ser. No. 60/300,591 filed Jun. 22, 2001 and 60/301,612 filed Jun. 27, 2001, and benefit under Title 35, United States Code, Section 120 of U.S. patent application Ser. No. 10/481,556 filed Jun. 11, 2002. This application is a continuation of the Ser. No. 10/481,556 application. The Ser. No. 10/481,556 application is currently pending. The 60/300,591 application, the 60/301,612 application and the Ser. No. 10/481,556 application are hereby incorporated by reference into this application. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable to this application.  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention  
         [0004]     This invention relates to plastic bags made from plastic sheeting such as those that may be used for packaging pet foods, foodstuffs and other bulk products. More specifically, this invention relates to the use of these plastic bags in a unique seamless configuration and the process of manufacturing them. This invention also relates to the use of these plastic bags in a unique system which provides for filling and sealing the bags with bulk contents such as pet foods, foodstuffs, concrete, plaster, and the like, in an automated process with a substantially dust-free environment.  
         [0005]     2. Description of the Related Art  
         [0006]     Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.  
         [0007]     Currently, most bags used for bulk contents are standard side-gusseted plastic bags, typically four to five mils thick and are filled from the top bag mouth, then sealed (or sewn closed) and palletized for shipping. Plastic bags of this variety are usually made from sheeting, as opposed to tubing and are highly desirable for bulk use such as packaging fertilizer, lawn maintenance products, seed bags, salt, kitty litter and so on. Generally speaking, these bags are put up in larger sizes to handle loads from as little as 5 pounds to as much as 100 pounds.  
         [0008]     The primary reason that sheeting is used to form these bags is that they may be expertly printed in up to 6 colors with process-tone print quality on all panels—front, back and the two sides and, at times, the top and bottom. To make a prior art bag, the printed sheeting is folded over and formed into a layflat tube, the open side edges are matched flush atop one another in the machine direction, lap-sealed (a continuous heat seal), gusseted on the sides, then cut and sealed along a bottom edge to form a bag. This type of high quality printing is restricted on tube-type bags since they are printed independently on the front and the back panels while in a two-sided layflat configuration, before being gusseted. Thus, print registration from front to back is extremely difficult to hold. In the outer portion of the layflat surfaces that become the front and rear gusset panels of the side gussets, it is commonly understood that print copy on the front panel of a gusset should not be attempted to be registered with print copy on the back panel of a side gusset. A further problem with printing tube stock is that the number of colors available to each independent surface is reduced. Since most printing presses have a maximum of 6 print stations (6 colors), there are only 6 color stations total that must be divided between the two surfaces, front and back. Thus, it is impossible to print 6-color process tone print quality on two sides, which would require a total of 12 stations: a set of 6 stations for each independent front and back surface.  
         [0009]     When manufacturing a prior art lap seal bag, the two open edges are matched and externally sealed with about a ¼″ “lap seal”, sealing the two matched edges together, thus forming a tube. When later gusseting the bag, this lap seal seam is usually registered on an outer gusset edge since it naturally points outward anyway. After gusseting, the bag is formed by heat sealing the bottom edge and cutting the top-open bag mouth. This is a fairly common manufacturing process used in industry today. The ¼″ lap seal seam that protrudes outward at the gusset edge may distort or interrupt the printing on the bag. Generally speaking, it is undesirable to print where a bag is going to be lap (heat) sealed, as the ink tends to build up on the lap sealer&#39;s heat elements when sealing along the printed film edges. But it is also undesirable to leave a lap seal strip unprinted and disrupt the continuity of attractive graphics. Thus, this becomes a predicament to the graphic artist, the bag manufacturer and the retailer.  
         [0010]     Most bags used with cement and concrete products and other heavy flowable contents are large multiwall paper bags with fill valves, like those commonly seen palletized in home improvement centers throughout the U.S. They typically contain products, such as 60# mortar and concrete mix and 94# cement and concrete mix, sold to consumers for use in home garden and yard applications. The chief reason paper valve bags are used for these applications is primarily due to per unit cost and productivity factors. Paper valve bags cost more than standard, top-loading plastic bags, but the paper bags are much faster to fill, thus substantially improving productivity and output. There has been some limited use of plastic valve bags made from a woven polypropylene—specially in Europe—that do not lower productivity. But in the U.S. and other countries where paper is still relatively inexpensive, the polypropylene valve bags cost quite a bit more. One of the main reasons they cost more than traditional polyethylene top loading bags is because the equipment used to manufacture them is extremely expensive—as much as ten times that of a standard plastic bag machine.  
         [0011]     As anyone experienced in the art knows, there are several problems associated with the prior art. In addition to the high cost, other disadvantages of paper packaging include the consumption of five times the storage space of plastic; the vulnerability of cement and concrete products stored in paper to weather conditions (especially rain), and the vulnerability of paper to pest infestations. In contrast, the superior environmental qualities of plastic are becoming commonly known to retailers and users throughout the country and would be desirable, if practical.  
         [0012]     Without question, if a plastic bag could be developed that could eliminate the external lap-sealed seam from sticking out and interrupting print graphics, it would be highly desirable in many applications. Moreover, if a plastic valve bag and system could be developed that could replace the multiwall paper bags cost effectively, without reducing productivity, it would be highly desirable. In fact, if a plastic valve bag were developed that could compete favorably with standard top-fill plastic bags, that too would be highly desirable.  
       BRIEF SUMMARY OF THE INVENTION  
       [0013]     A bag having an inwardly disposed seam is manufactured from a sheet of plastic bag material having two major surfaces and two parallel side edges. A first seam seals the two parallel side edges together at the same major surface with the side edges disposed inwardly of the tube to form the sheet of plastic bag material into a tube with internal flap portions extending interiorly of the tube. At least one seal across the tube is provided for forming at least a three-sided bag structure (and preferably two seals across the tube for forming a closed four-sided bag structure) whereby pressure in the interior of the bag acts against the internal flap portions disposed inwardly of the tube to enhance the sealing of the seam. The bag is filled at an opening defined along the opposite side edges of the seam facing inwardly of the tube. Preferably, at least one additional second seam is placed at the opening and configured at substantial right angles to the first seam. This second seam extends at least from the first seam, joining the side edges inwardly of the bag to form an internal flap portion for closing the opening responsive to pressure in the interior of the bag. The at least one additional second seam is angularly disposed with respect to the first seam to form an opening of variable cross-section, preferably tapering from a wide cross-section at the seam to the narrow cross-section interior of the bag. A tapered conduit having a smaller forward-most end and a larger rearward end is disposed within the opening of the decreasing cross-section from the first seam along the side edges into the interior of the tube. The bag opening is placed over the smaller forward-most end and held tight to the larger rearward end to fit snugly along a portion of the tapered conduit. The bag is filled through the tapered conduit. Air and dust from the filling process are vented. By providing pressure in the interior of the bag and withdrawing the conduit, the filled bag is sealed The variable cross-section opening is pulled from the bag interior to form a pouring spout for metered discharge of the bag contents.  
         [0014]     The problems associated with the prior art are overcome by the present invention. That is, the present invention eliminates the protruding lap seal seam and eliminates the requirement to seal atop the ink on printed surfaces. In appearance, it literally creates an attractive, seamless bag, that is friendlier and more forgiving to graphic artists, bag manufacturers and retailers.  
         [0015]     The present invention also discloses a new kind of valve bag that is suitable for cement and concrete by-products packaging, costs less than paper and will not sacrifice productivity. Furthermore, the valve bag may be manufactured in a method that allows the valve to be pulled out into a pour spout, which is ideal for many types of products such as seeds, fertilizer and some bulk food products.  
         [0016]     In addition, the present invention discloses a method of making the seamless bag and the valve bag that can actually decrease bag machinery costs, making the new method less costly than its traditional counterpart.  
         [0017]     The present invention accomplishes these objectives by turning the lap seal inside and thus sealing it along an internal edge with the use of a cantilevered lap sealing system. The cantilevered system is accompanied by an internal former that subsequently gussets the bag in a single internal operation. This method of making an internal lap seal also eliminates the need and cost of external post-gusseters.  
         [0018]     The most significant benefits of the unique manufacturing process, system and bag are elimination of the external lap seal, improved graphics, reduced equipment costs, fill valves suitable for filling with flowable contents, and dual-purpose valves that serve as a filling means and also as spouts. And most important, all of this can be accomplished without having a negative impact on the integrity of the product.  
         [0019]     The problems associated with the fill valve bags of the prior art are overcome by the present invention. The key to the solution is a high-productivity method that allows for immediate conversion of paper valve-bag filling systems to accommodate inexpensive plastic valve bag alternatives. The bag and system of the present invention accomplish that by using a method of affixing a plastic valve bag onto a unique fill nozzle in a high-productivity manner. As a result, the bag of the invention can outperform both paper filling processes and top-fill plastic bag filling processes.  
         [0020]     The present invention also discloses a means of creating a dust-free filling environment. The system is adaptable to several valve bag styles and may be automated as well.  
         [0021]     The present invention accomplishes these objectives by using a conical fill nozzle to which a valve bag firmly affixes itself. The fill nozzle also uses a narrowed tip to allow for easier insertion of the bag valve. The filling process may incorporate an air relief system that, in combination with the other attributes, creates not only a dust-free filling environment, but concentrates air and dust removal from the bag being filled to a single location behind the fill nozzle.  
         [0022]     The most significant benefits of the unique filling method are the ability to load as quickly as paper, dust containment, and automation potential. All of which is accomplished without having a negative impact on the integrity of the product, and may be used with polyethylene bags that cost less than present day paper or woven polypropylene bags.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:  
         [0024]      FIG. 1  is a plan view of a gusseted seamless bag, which can include two lap seals.  
         [0025]      FIG. 2  is a blown-up cross-sectional view of the gusseted film in the bag of  FIG. 1   FIG. 3  is a perspective view of the bag in  FIG. 1  with contents inside.  
         [0026]      FIG. 4  is a plan view of a valve bag of the present invention.  
         [0027]      FIG. 5  is a cross-sectional view of the gusseted film in the bag of  FIG. 4 .  
         [0028]     In  FIG. 6  bag is a perspective view of the top portion of the bag in  FIG. 3  after being filled and illustrating the closure of the valve sleeve.  
         [0029]      FIG. 7  is a plan view of a valve bag in which the valve doubles as a pour spout and also showing an anti-dimpling effect at the bag bottom.  
         [0030]      FIG. 8  is a perspective view of the bag in  FIG. 7  with the pour spout pulled out.  
         [0031]      FIG. 9  is a plan view of the bag in  FIG. 7  with an air ventilation system along the internal flap and with a die-cut handle.  
         [0032]      FIG. 10  is a top perspective view of the cantilevered manufacturing process.  
         [0033]      FIG. 11  is a perspective view of a tapered fill nozzle of the present invention.  
         [0034]      FIG. 12  is a plan view of a valve bag similar to that of the bag of  FIG. 1 .  
         [0035]      FIG. 13  is a perspective view of the bag in  FIG. 12  snugly mounted on the tapered fill nozzle of  FIG. 11 .  
         [0036]      FIG. 14  is a plan view of a variation on a valve bag also suitable for mounting on the tapered fill nozzle of  FIG. 11 .  
         [0037]      FIG. 15  is a perspective view of the tapered fill nozzle of  FIG. 11  with an air relief system.  
         [0038]      FIG. 16  is a perspective view of the bag in  FIG. 12  mounted in a magazine feed system that enables the user to quickly mount the bag onto a fill nozzle.  
         [0039]      FIG. 17  is a perspective view of a tapered fill nozzle, with a mounted valve bag and a U-shaped bag retaining means.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0040]     In  FIG. 1 , bag  10  has top  12 , a bottom  14 , left- and right-side gussets  16  and  16 ′, respectively, with left- and right-side center gusset creases  18  and  18 ′, respectively. Extending inward approximately ⅛″ to ¼″, or a little more, from left-side center gusset crease  18  are internal flap edges  20  and  22  (the latter not shown as it lies directly underneath internal flap edge  20 ). Internal lap-sealed portion  24  (shaded portion) is the narrow strip of material that lies in between left-side center gusset crease  18  and internal flap edges  20  and  22  and runs continuously from bag top  12  to bottom  14 . As viewed, the lap-sealed portion  24  lies inside of bag  10  adjacent to left-side center gusset crease  18 , and the lap seal defining left-side center gusset crease  18 . With the lap seal facing inward, inside the bag, the outer surface of the bag has no ridges or seals pointing outward, as would be the case with prior art.  
         [0041]     In  FIG. 2 , bag  10  is illustrated as having a front panel  26 , a rear panel  28 , a left-front-side gusset panel  30 , a left rear side gusset panel  32 , a left-side center gusset crease  18 , a right-front-side gusset panel  34 , a right rear side gusset panel  36  and a right-side center gusset crease  18 ′. In between left-side center gusset crease  18  and internal flap edges  20  and  22  is internal lap-sealed portion  24 . This lap-sealed portion may be a strip as narrow as ⅛″ or may be wider. For the economy of using fewer raw materials, the narrow seal is preferred, unless of course, a wider, stronger seal were preferred due to heavier contents. It is easy to see that with the lap seal&#39;s disposition being inside the bag, the outer surfaces appear to be seamless, with no outwardly protruding edges or seals. Lap sealing in this method naturally produces a center gusset crease, albeit, the crease may also be positioned elsewhere on the bag, for instance, on the right-side gusset or on a front or rear panel.  
         [0042]     In  FIG. 3  bag  10  has been filled with a flowable material and sealed at the top edge  12 . Left-side center gusset crease  18  is one continuous crease formed by the internal lap-sealed portion  24  (the latter not shown since it is inside bag  10 ). The outer appearance of center gusset crease  18  looks much like that of any other side gusset crease commonly seen in standard tube-type bags, that is, one clean, continuous fold.  
         [0043]     In  FIG. 4  bag  40  has atop  42 , a bottom  44 , left- and right-side gussets  46  and  46 ′, respectively, with left- and right-side center gusset creases  48  and  48 ′, respectively. Both bag top  42  and bottom  44  are sealed forming bag  40  into a pillow-like bag when filled. Extending inward from left-side center gusset crease  48  are internal flap edges  50  and  52  (the latter not shown as it lies directly underneath internal flap edge  50 ). Internal lap-sealed portion  54  (shaded portion) is a narrow sealed strip that lies adjacent to left-side center gusset crease  48  and spaced from internal flap edges  50  and  52 , but runs continuously only from bag bottom  44  up to point  56 , where it stops. Valve opening  58  is the unsealed portion that lies along left-side center gusset crease  48  in between point  56  and bag top  42 , and is suitable for allowing entry of a fill nozzle much like those used to fill standard paper valve bags. With valve opening  58  positioned at the center gusset crease, it is easy and natural for the user to find the valve opening  58  of bag  40  and mount it on a fill nozzle. In between lap-sealed portion  54  and valve opening  58 , and internal flap edges  50  and  52 , lie internal flap portions  60  and  62  (the latter not shown as flap portion  62  lies directly under flap portion  60 ) that run continuously from bag top  42  to bag bottom  44 . Typically, internal flap portions  60  and  62  may extend inward, inside bag  40 , about  2 ″ to  3 ″ depending upon bag size, but could certainly be more or less. Horizontal seal  64  begins at point  56  and runs approximately horizontally into internal flap portions  60  and  62 . The area in between horizontal seal  64  and sealed bag top  42  forms a valve sleeve  65 , which sleeve, along with valve opening  58 , typically measures about the same overall circumference, or slightly greater, as an existing prior art fill nozzle. Thus, valve opening  58  and valve sleeve  65  may be mounted onto a fill nozzle with a reasonably snug fit, preventing leakage as the bag is filled, and subsequently collapsing upon itself after filling, so that the flowable material contained inside will not leak out. The intention of the present invention is not to specify the width of the internal flap portions that allow the formation of a valve sleeve, but to illustrate the concept as one that is viable with present day flowable filling machinery that use fill nozzles. The internal flap portion as shown is an integral portion of the same sheeting that has formed the internal flaps and the bag. It may also be accomplished by inserting a separate internal flap portion and sealing it to the bag top and to the internal lap seal  54  below point  56 . Or, it may even be accomplished in much the same way, but with an external lap seal instead of an internal lap seal. Either manner could serve the same purpose. However, having the internal portion as a continuous part of the sheeting is the preferred manufacturing process, even though it requires using a bit more film and a bit more raw material. This manufacturing process may be improved upon by cutting away the unused internal flap portions that lie below the horizontal seal  64  and recycling that unused portion.  
         [0044]     In  FIG. 5 , bag  40  is illustrated as having a front panel  66 , a rear panel  68 , a left-front-side gusset panel  70 , a left rear side gusset panel  72 , a left-side center gusset crease  48 , a right-front-side gusset panel  74 , a right rear side gusset panel  76  and a right-side center gusset crease  48 ′. In between left-side center gusset crease  48  and internal flap edges  60  and  62  is valve opening  58 . The internal lap-sealed portion  54  is not shown as it lies directly below open valve portion  58  and is much like that of internal lap seal  24  of  FIG. 2  in that it may be a strip as narrow as ⅛″ or wider. Valve sleeve  65  lies inward of valve opening  58 . Horizontal seal  64 , though not shown, defines the lower extremity of valve sleeve  65 . As shown valve sleeve  65  is made from integral portions of internal flap edges  60  and  62 . Alternatively, it may be an attached sleeve portion sealed to a top edge and the internal lap seal as described in  FIG. 4 .  
         [0045]     In  FIG. 6 , the top of bag  40  has been filled with flowable contents and takes on its natural parallelepiped or cubic disposition predetermined, in the most part, by the bag&#39;s dimensions. As seen, bag  40  includes a sealed top  42 , a front panel  66 , a left-front-side gusset panel  70 , a left rear side gusset panel  72  and a left center gusset crease  48 , which is in an unfolded disposition since bag  40  is filled with flowable contents. Upon filling with flowable contents, bag  40  has formed a top  78 , which is made up of the two upper portions of front panel  66  and rear panel  68  (see  FIG. 5 ), with valve opening  58  now positioned inside the upper folded left-side gusset region  80  and closed off. Upon filling with contents, valve sleeve  65  closes back upon itself into a layflat configuration, thus not allowing the flowable contents to escape, or leak out. The formation into a cubic disposition causes valve sleeve  65  to close upon itself and also to pull downward and outward thus causing a small stress dimple  69  at the junction of bag top  42  and internal flap edges  50  and  52  (not shown). Once palletized, bag  40  would be placed flat upon rear panel  68 , thus making top  78  an “end” of the rectangular cube. It is important to note that the closure phenomena explained herein is even stronger in its palletized disposition since the pressure from the contents pushes outward on the valve sleeve, creating a more secure closure of the valve sleeve and valve opening.  
         [0046]     In  FIG. 7 , the structure of bag  90  is much like that of bag  40  in  FIG. 4  with a top  92 , a bottom  94 , left- and right-side gussets  96  and  96 ′, respectively, with left- and right-side center gusset creases  98  and  98 ′, respectively. Both bag top  92  and bottom  94  are sealed forming bag  90  into a pillow-like bag when filled. Extending inward from left-side center gusset crease  98  are internal flap edges  100  and  102  (the latter not shown as it lies directly underneath internal flap edge  100 ). Internal lap-sealed portion  104  (shaded portion) is a narrow sealed strip that lies adjacent to left-side center gusset crease  98  and spaced from internal flap edges  100  and  102 , and runs continuously from bag bottom  94  up to point  106 , where it stops. An improvement is made at point  106  by rounding the lap-sealed edge as it joins horizontal seal  114 , thus eliminating a potential stress location and also making valve opening  108  easier to mount on a fill nozzle. Valve opening  108  lies along left-side center gusset crease  98  in between point  106  and bag top  92 , and is suitable for allowing entry of a fill nozzle much like those previously described. In between lap-sealed portion  104  and valve opening  108 , and internal flap edges  100  and  102 , lie internal flap portions  110  and  112  (the latter not shown as flap portion  112  lies directly under flap portion  110 ) that run continuously from bag top  92  to bag bottom  94 . Beginning at point  106  and running approximately horizontally into the internal flap portions  110  and  112 , is horizontal seal  114  defining valve sleeve  115 , which in combination with valve opening  108 , is mountable on a fill nozzle. Top perforation line  116  is located on internal flaps  110  and  112 , near the top of valve sleeve  115 , adjacent to bag top  92 , and bottom perforation line  118  is located near the bottom of internal flap portions  110  and  112  adjacent to bag bottom  94 . Top perforation line  116  is sufficiently easy to tear so that a user may reach in and pull outward on the prefabricated valve sleeve  115 , thus forming a pour spout as illustrated in  FIG. 8 . Top perforation line  116  also serves to eliminate the stress dimple (shown as  69  in  FIG. 6 ) at the top region, when it tears free upon filling with flowable contents. Likewise, when bottom perforation line  118  tears free upon filling with flowable contents, there will be no stress dimple along the bottom sealed edge either. Stress dimples do not appear to affect the integrity of the bag strength quality in most applications, but might if the bags were filled with extremely heavy contents and the internal flaps extend far into the bag. In other words, the narrower the internal flap, the less significant the stress dimple. Using perforations at the top and bottom regions of the internal flaps and eliminating the stress dimples also improves the outward appearance, since there is no distortion along a top or bottom sealed edge. Alternatively, creating a top pour spout or eliminating stress dimples can be achieved by placing cut lines on the internal flaps instead of top or bottom perforations. A perforation line also doubles as a means to maintain the integrity of the web of film as it moves along in the manufacturing process, whereas a cut line may tend to allow some web distortion. The perforation or cut line may also extend outward, past the internal flap and into the gusset panels to the outermost bag edges With this design, the spout tends to become larger.  
         [0047]     In  FIG. 8 , bag  90  is filled with flowable contents and sits upright much like the bag in  FIG. 6 . Valve sleeve  115  has been pulled outward and perforation line  116  (see  FIG. 7 ) has severed, forming pour spout  120 . Pour spout  120  was valve sleeve  115  when in its internal position (see  FIG. 7 ), and is defined by top edges  122  and  122 ′, and a bottom edge  124 . Top edges  122  and  122 ′ were the edges of valve sleeve  115  at perforation line  116  when the sleeve was in its internal position. Bottom edge  124  is horizontal seal  114 , which has been extracted from the interior of the bag to form a pour spout base. The pour spout size is determined by the overall height (or size) of the valve sleeve. Valves used in many common nozzle filling applications are about 4″ to 4.5″ in circumference, and when pulled out to form a spout, make a workable pour spout. Pull-out pour spouts as defined herein also include those that are part of an internally attached portion that is not part of an internal flap.  
         [0048]     In  FIG. 9 , bag  140  is much like those in  FIG. 4  and  FIG. 7  with a top  142 , a bottom  144 , left- and right-side gussets  146  and  146 ′, respectively, and left- and right-side center gusset creases  148  and  148 ′, respectively. Both bag top  142  and bottom  144  are sealed, forming bag  140  into a pillow-like bag when filled. Extending above bag top  142  are handle portions  143  and  147  (the latter not shown because it lies directly underneath handle portion  143 ), which portions have centrally located die-cut handles  145  and  149  (also not shown because die cut  149  is cut upon handle portion  147  and lies directly below die cut handle  145 ). Handle portions  143  and  147  are contiguous sections of film connected to front panel  151  and rear panel  153  (the latter not shown because it lies directly below front panel  151 ). Extending inward from left-side center gusset crease  148  are internal flap edges  150  and  152  (the latter not shown because it lies directly underneath internal flap edge  150 ). Internal lap-sealed portion  154  (shaded portion) is a narrow sealed strip that lies adjacent to left-side center gusset crease  148 , is spaced from internal flap edges  150  and  152 , and runs continuously from bag bottom  144  up to point  156 , then stops. A second internal lap-sealed portion  155  is adjacent to internal flap edges  150  and  152 , is spaced from left-center gusset crease  148 , runs parallel to lap-sealed portion  154 , and ends at point  157  where it joins horizontal seal  164 . Throughout second internal lap-sealed portion  155  are intermittent breaks  167  in the seal to allow air passage. These breaks typically are as narrow as 1/32″ to as great as ¼″. In addition, intermittent breaks  169  are positioned throughout internal lap-sealed portion  154 . In between internal lap-sealed portion  154  and second internal lap-sealed portion  155  lies a mostly sealed-in internal region  160  created by the internal flaps themselves, bounded by four seals-bottom seal  144 , internal lap seals  154  and  155  and horizontal seal  164  with breaks at  167  and  169  as previously described. When bags of the present invention are filled with flowable materials, it may be desirable to have a means to allow entrapped air to escape from portions other than the valve sleeves and valve openings. Thus, breaks  167  in second internal lap seal  155  allow air to escape into the sealed-in internal region  160  and, subsequently, out through breaks  169  in lap seal  154 . This is a tortuous path because sealed-in internal portion  160  is collapsed upon itself. Such a tortuous path is desirable in many cases since it will help prevent, or completely eliminate leakage of the flowable contents. A tortuous path may also be created by having perforation holes in the mostly sealed-in portion instead of having breaks in second lap seal  155 . In such a bag, the handled top is suitable for carrying and transporting as well as serving as a means to assist in pouring flowable Contents from the pour spout (as illustrated in  FIGS. 7 and 8 ). It may be made in any variety of styles and sizes. While not essential, the air relief means serves as a means of allowing air trapped inside during the filling process to escape from inside the bag, and allows the bag to breathe in order to avoid condensation build-up.  
         [0049]     In the top view of  FIG. 10 , layflat film sheet  170  moves between rollers  172  and  174  (the latter not shown because it lies directly under roller  172 ). The pressure exerted between rollers  172  and  174  holds film  170  in its layflat disposition. Upon leaving rollers  172  and  174 , layflat sheet  170  begins a fold-over process as it wraps around cantilever arm  176 . Cantilever arm  176  is secured to base  178  and protrudes forward toward the tube-to-be-formed, which, at its extremity, is mounted with an internal former  180 , an edge turning device  182  and internal lap sealer  184 . Two gusseting fins  186  and  188  are located on the outside of former  180 . As layflat sheet  170  folds over, which is accomplished by any number of prior art means, film edge  190  turns under until it is matched with film edge  192 . The edges move together into edge turning device  182 , thus turning the two matched film edges  190  and  192  inward, pointing inside the tube-to-be-formed. The two inside film edges  190  and  192  then move to internal lap sealer  184 , are sealed together in an internal disposition and, as may be required for the various bag styles previously discussed, may include the interruption of seals to create valve openings or air relief breaks. At location  194  a tube has been formed from the film, and the gusseting operation is completed by the internal former  180  and the two external gusset fins  186  and  188 , as the film passes by. Rollers  196  and  198  (the latter not shown because it lies directly under roller  196 ) maintain the newly gusseted film  200  in its predetermined gusseted disposition for further processing downstream.  
         [0050]     The forming of the tube to create two turned-in matched edges for further internal lap sealing, may be accomplished in a number of ways. The novelty of what is revealed herein is not the exact methodology of doing this, but the requirement to do so on a cantilevered means. Internal formers are known in prior art, but have not been used in accordance with a cantilever process as described herein. The internal forming operation, may be achieved by the internal former being an integral part of the cantilever/lap sealing system, or the internal former may be independent of the sealing operation. But the internal sealing must be accomplished in a cantilevered fashion, regardless of whether the cantilever extends out 5 inches or 5 feet.  
         [0051]     In  FIG. 11 , tapered fill nozzle  210  is an extended hollow tube connected to the filling equipment (not shown) at its rear entry point  212 . The front tube portion  214  of fill nozzle  210  tapers to a smaller diameter than at rear entry point  212 , and ends with a pointed tip  216 , suitable for easy insertion into a valve bag. Exit point  218 , from which flowable material will flow into a bag when mounted on fill nozzle  210 , is set back from pointed tip  216 . Typically this type of fill nozzle has about a 2″-2.5″ ID and is about  18 ″ long for concrete products filling applications. The nozzle may be substantially smaller for small bags, or substantially larger for larger bags or bulkier flowable materials. For durability, fill nozzles are usually made of steel, but may be made of most any other type of material, such as plastic or aluminum, that can be formed into a tubular shape. As will be illustrated, the use of a tapered fill nozzle may include a nozzle that is tapered only along the front portion, a mid portion or a rearward portion, depending upon how far onto the fill nozzle a bag is to be mounted.  
         [0052]     In  FIG. 11 , valve bag  230  has a top  232 , a bottom  234 , and left- and right-side gussets  236  and  236 ′, respectively, with left- and right-side center gusset creases  238  and  238 ′, respectively. Both bag top  232  and bottom  234  are sealed forming bag  230  into a pillow-like bag when filled. Extending inward from left-side center gusset crease  238  are internal flap edges  240  and  242  (the latter not shown because it lies directly underneath internal flap edge  240 ). Internal lap-sealed portion  244  (shaded portion) is a narrow sealed strip that lies adjacent to left-side center gusset crease  238  is spaced from internal flap edges  240  and  242 , and runs continuously only from bag bottom  234  up to point  246 , then stops. Valve opening  248  is the unsealed portion that lies along left-side center gusset crease  238  in between point  246  and bag top  232 , and is suitable for allowing entry of the fill nozzle shown in  FIG. 12 . In between lap-sealed portion  244  and valve opening  248 , and internal flap edges  240  and  242 , lie internal flap portions  250  and  252  (the latter not shown because flap portion  252  lies directly under flap portion  250 ) that run continuously from bag top  232  to bag bottom  234 . Typically, internal flap portions  250  and  252  extend inward about 2″ to 3″ inside bag  230 , depending upon bag size, but could certainly extend to a greater or lesser depth. Beginning at point  246  and running approximately horizontally, but tapering upward into the internal flap portions  250  and  252  is horizontal tapered seal  254 . The area in between horizontal seal  254  and sealed bag top  232  forms a tapered valve sleeve  255 , which sleeve along with valve opening  248  snugly fits around the front tapered portion  214  of the fill nozzle of  FIG. 11 . Valve opening  248  and valve sleeve  255  may be mounted onto a standard fill nozzle with a snug fit, or onto a tapered fill nozzle such as that of  FIG. 1  with an even greater secure, snug fit, thus preventing the flowable material from spilling out during the filling process (which is frequently a high-pressure operation). This tapered fit also keeps air and its accompanying flowable material dust particles from escaping, such as that which accompanies cement and concrete byproducts. A tapered valve sleeve as described herein clearly works best in combination with a tapered fill nozzle, as it will seat itself along the entire valve surface to the tapered nozzle surface underneath. However, the tapered valve sleeve is also an improvement when used with existing non-tapered fill nozzles.  
         [0053]     In  FIG. 13 , bag  230  is mounted onto fill nozzle  210  by pulling valve opening  248  over pointed tip  216 , pulling forward (direction of arrows) and seating valve sleeve  255  securely on tapered front tube portion  214  (as illustrated now lies directly under valve sleeve  255 ). The tapered valve sleeve  255  of the present invention will typically be tapered at the same degree as the tapered fill nozzle front portion, which means both would have about the same circumference dimensions at any given point along the valve sleeve or fill nozzle, once the valve sleeve has been mounted on the fill spout. These matching tapers provide an extremely tight fit and can virtually eliminate the escape of even the smallest dust particles. As shown, horizontal tapered seal  254  provides the matched tapers that ensure the tight fit on front tube portion  214  so that the exit point  218  lies just past internal flap edge  240 , which also defines the innermost edge of valve seal  255  at curved dotted line  241 . When valve sleeve  255  is withdrawn from fill nozzle  210 , it subsequently collapses upon itself, back into its layflat disposition, so that the flowable material contained inside will not leak back out. The intention of the present invention is not to specify the length and width of the tapered valve sleeve or the fill nozzle, but to illustrate the concept that the matched circumferences of the two tapered elements provide unique, valuable dynamics: 1) the superior securing of a tapered valve on a fill nozzle; 2) elimination of flowable material leakage during the fill process; and 3) elimination of dust contamination in the work environment.  
         [0054]     In  FIG. 14 , plastic valve bag  260  has a top  262 , a bottom  264 , and left- and right-side gussets  266  and  266 ′, respectively, with left- and right-side outside gusset folds  268  and  268 ′, respectively. Both bag top  262  and bottom  264  are sealed forming bag  260  into a pillow-like bag when filled. Situated in from the left-side outer gusset fold is an overlapping edge  270  that extends outward from internal flap edge  272 . Overlapping edge  270  has all adjacent lap-sealed portion  274  (shaded portion), a narrow sealed strip that runs continuously from bag bottom  264  up to point  276 , then stops. Valve opening  278 , the unsealed portion of overlapping edge  270 , lies in between point  276  and sealed bag top  262 , and is suitable for allowing entry of a fill nozzle like that of  FIG. 11 . In between lap-sealed portion  274  and valve opening  278 , and internal flap edge  272 , lies external flap portion  280  and internal bag wall portion  282  (not shown because it lies directly below external flap portion  280 ). External flap portion  280  and internal bag wall portion  282  run continuously from bag top  262  to bag bottom  264 . Typically, internal flap edge  272  extends inward from overlapping edge  270 , about 2″ to 3″ (inside bag  260 , depending upon bag size, but could certainly extend to a greater or lesser depth. Horizontal seal  284 , begins at point  276  and runs approximately horizontally, but tapers upward into internal bag wall portion  282 . The area between horizontal tapered seal  284  and sealed bag top  262  forms a tapered valve sleeve  285 . The tapered sleeve, along with valve opening  278 , typically measures about the same overall circumference, at any given point, as the circumference along the front tapered portion of a fill nozzle as described in  FIG. 13 . Thus, valve opening  278  and valve sleeve  285  mount onto fill nozzle  210  with a highly snug fit, much like that of the bag described in  FIGS. 12 and 13 , with the same results of setting a secure fit of the valve on the fill nozzle, preventing leakage of flowable materials during the filling process, and eliminating the escape of flowable material dust particles. Again, the intention of the present invention is not to specify the width of the internal bag wall portion or external flap portions that allow the formation of a valve sleeve, but to illustrate the concept as one that is viable with present day flowable filling machinery that uses fill nozzles.  
         [0055]     Moreover, the location of the overlapping edge may be all the way out to the left-side outer gusset edge, or further inward. The overlapping edge may even be rotated about to be positioned on one of the inner gusset panels or at a center gusset crease. This type of valve may also be created by inserting a separate internal flap portion, or portions, and sealing it (or them) to a bag top (such as  262 ) and to a lap seal (such as  274  below point  276 ) In such a case there would be no need to have an internal bag wall portion. Either manner serves the same purpose. However, having the internal bag wall portion as a continuous part of the sheeting is the preferred manufacturing process for this style of bag. This manufacturing process may be improved upon by cutting away the unused internal flap portions that lie below the horizontal tapered seal  84  and recycling those unused portions. The use of this type of valve bag generally works well on the fill nozzle of the present invention. Valve bags of this variety with the valve openings positioned in the side gusset panels, and preferably at the center gusset crease, tend to be preferred overall as it is easier to find the valve opening and they have a stronger construction because the suspending of the bag and valve on the fill nozzle is more balanced and uses equal film material plies (two) on each side of the valve sleeve.  
         [0056]     In  FIG. 15 , tapered fill nozzle  290  is similar to that of  FIG. 11  and is an extended tube connected to the filling equipment (not shown) at its rear entry point  292 . The front tube portion  294  of fill nozzle  290  is not tapered and ends at exit point  298 , where flowable material flows into a subsequently mounted bag. Securely positioned around front portion  294  and exit point  298  is a second, larger, tapered tube  300  with a pointed tip  296 , suitable for easy insertion into a valve bag. Air space  302 , which allows the escape of air and dust upon pressurized filling operations, is located around the outer surface of front portion  294  and the inner surface of tapered tube  300 . With a bag mounting on fill nozzle  290 , as in  FIG. 13 , any entrapped air and its accompanying dust exits in the direction of the arrows, the venting being placed back and away from the location of the workers loading bags onto the nozzles. Typically this type of fill nozzle combination has about a 2″-2.5″ ID and a length of about  18 ″ for concrete products filling applications. This fill nozzle combination may be substantially smaller for small bags or substantially larger for larger bags or bulkier flowable materials. For durability, this combination could be made of steel, but may be made of most any type of material, such as plastic or aluminum, that can be formed into a tubular shape. The principle that is illustrated here is one that provides for an air escape so that during the filling process, any air that is used in the high pressure filling operations will not be captured and contained within the bag, such as happens in the fill processes typically used with cement and concrete products. With a high-pressure filling method in combination with the secure tight fit of the valve sleeve on a tapered nozzle, some form of air relief is desirable. The method of the invention primarily eliminates the need to have ventilation in plastic bags so that trapped air may subsequently escape. Further, the method directs the air and dust escape route backward into a concentrated area where it can be recaptured with a vacuum system and put back into the raw material silos. This concentrated air and dust escape means can also be accomplished by having an air relief tube inserted inside a fill nozzle, such as that of  FIG. 11 . Thus, the present invention provides a means of allowing for a concentration of air and dust to escape in a direction away from the front side of the nozzle where an individual is working as he/she mounts the bags and bag valves on the fill nozzle or is monitoring an automated process. For most applications having a high degree of dust levels and air pressure utilization in the fill process, this nozzle is the preferred version.  
         [0057]     In  FIG. 16 , magazine holder  410  has a left side  412 , a right side  414  (not shown as it opposes left side  412 ), a bottom panel  416  (not shown), a front panel  420  and a rear panel  418  (not shown as it opposes front panel  420 ), with valve bag pack  422  (consisting of bags of one of the styles previously disclosed) set vertically within the magazine holder. Bag pack  422  is positioned within the magazine holder with all the underlying valve openings and valve sleeves registered inside the center gusset crease, (not shown) in the upper front corners  434 . Adjacent to edge  424  and running substantially along front panel  420  is open slot  426  that allows for removal of a forward-most bag. As illustrated, forward-most bag  428  is partially extracted from magazine  410 . Extracting a bag may be accomplished by several means. First, a worker may grasp forward-most bag  428  with his hand at the upper front corner  430 , pull it forward (arrow direction) and out through open slot  426  and subsequently mount the underlying valve opening  432  and valve sleeve  434  on a nearby fill nozzle  436 . Another means of extraction would be by the use of two suction cups that affix themselves to the front and rear bag panels (one to each panel) at the upper front corner  430  thus, grasping the opposing panels at the upper front corner  430 . In combination, the two suction cups pull the side gusset panels slightly open and then pull the bag forward and onto the fill nozzle. Other grasping operations may be used as well; the general principle is to have bags mounted in a conveniently positioned magazine for subsequent manual or mechanical extraction. Furthermore, the magazine may be positioned at a slight tilt so that gravity causes the bags to stay in an upright disposition. Or, a simple spring-loaded plunger means may serve the same purpose. The magazine may also be loaded from the side instead of the top. In addition, the bags may be maintained in a horizontal disposition prior to being placed in a vertical disposition on a fill nozzle.  
         [0058]     In  FIG. 17 , tapered fill nozzle  440  has a valve bag  442  mounted thereon much like any of the bags and fill nozzles described herein. Bag  442  is held in place with pressure-actuated retaining means  444 , which, when actuated by electric eye  446 , moves downward, pins and maintains the secure fit of bag  442  on nozzle  440 . Retaining means  444  is “U-shaped” at base  445  so it fits the contour of the bag on the fill nozzle and faces back at an angle, so that a worker may conveniently place his/her hands at the top of bag  442  at top forward point  448  while retaining means  444 , when actuated, pins down bag  442  at top rear point  450  out of the way of a worker&#39;s fingers and hands. In front of retaining means  444  is safety stop  452  that prevents the workers fingers or hands from going past as he/she slides the bag  442  onto fill nozzle  440 . Typically retaining means  444  is metal with a rubber base. The safety stop is made of a somewhat flexible material, such as a hard rubber.  
         [0059]     The spirit of the present invention is to improve existing filling operations of flowable materials while enhancing dust control and improving productivity. Without question, there could be variations and modifications that may be considered, all of which would be considered as falling under the scope of the present invention.  
         [0060]     As of the time of the filing of this PCT application, actual bags incorporating the invention have been built. Typical lay flat dimensions of this bag include a 10 inch width and a 21 inch length. On the side opposite the opening, the bag has a 2-inch inwardly extending seam. On the side having the opening, the bag has a 5-inch seam. The aperture of the bag is about 5 lineal inches in the lay flat configuration. The actual performance of the bag is quite surprising. When fabricated from thick plastic material, the bag can be blown full of air and seals itself. Further, once the bag has sealed itself, a 200-pound man can stand on the bag and the air inside the bag will not escape! The reader will understand that the above dimensions can be varied by simple trial and error.  
         [0061]     In the following claims, the term “seam” will be reserved for joinder of the two parallel side edges of the tube material at the same major surface to form a joinder of the bag material. The term “seal”-will refer to any joinder of the bag material, including a seam.  
         [0062]     What has been described and illustrated herein is a preferred embodiment of the invention along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention, which is intended to be defined by the following claims (and their equivalents) in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Any headings utilized within the description are for convenience only and have no legal or limiting effect.

Technology Classification (CPC): 1