Abstract:
A web for the manufacture of fluid filled units with a novel machine and process is disclosed. The web includes an elongate heat sealable, flattened plastic tube comprised of face and back imperforate layers. The layers are imperforately joined together along spaced side edges. The layers include superposed longitudinal lines of weakness disposed generally transversely midway between the side edges. The web has longitudinally spaced, pairs of transverse seals. Each transverse seal extends from a respective side edge to an end near but spaced from the longitudinal lines of weakness. The transverse seal pairs include transverse lines of weakness extending from one side edge to the other generally centrally of each seal in a longitudinal direction. The side edges, transverse seals and lines of weakness together delineating two oppositely oriented strings of pouches with each pouch having three imperforate sides and a centrally located fill opening at its fourth side. The transverse lines of weakness are spaced slightly more than one half the circumference of a cylindrical fluid fill nozzle used to fill the pouches such that the web closely surrounds the nozzle during pouch fluid filling.

Description:
RELATED APPLICATIONS 
     This application is a continuation application of U.S. application Ser. No. 11/252,365 filed on Oct. 17, 2005 for WEB FOR FLUID FILLED UNIT FORMATION which is a continuation application of U.S patent application Ser. No. 10/408,946 filed on Apr. 8, 2003 for WEB FOR FLUID FILLED UNIT FORMATION, now U.S. Pat. No. 6,955,846. 
    
    
     This invention relates to fluid filled units and more particularly to a novel and improved plastic web of interconnected pouches for use in a machine for, and with a process of, converting the pouches to fluid filled units. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. Re Nos. 36,501 reissued Jan. 18, 2000 and RE 36,759 reissued Jul. 4, 2000 respectively entitled “Method for Producing Inflated Dunnage” and “Inflated Dunnage and Method for its Production” and based on original patents respectively issued Sep. 3, 1996 and Dec. 2, 1997 to Gregory A. Hoover et al. (the Hoover Patents) disclose a method for producing dunnage utilizing preopened bags on a roll. The preopened bags utilized in the Hoover patents are of a type disclose in U.S. Pat. No. 3,254,828 issued Jun. 2, 1966 to Hershey Lerner and entitled “Flexible Container Strips” (the Autobag Patent). The preferred bags of the Hoover patents are unique in that the so called tack of outer bag surfaces is greater than the tack of the inner surfaces to facilitate bag opening while producing dunnage units which stick to one another when in use. 
     U.S. Pat. No. 6,199,349 issued Mar. 13, 2001 under the title Dunnage Material and Process (the Lerner Patent) discloses a chain of interconnected plastic pouches which are fed along a path of travel to a fill and seal station. As each pouch is positioned at the fill station the pouches are sequentially opened by directing a flow of air through a pouch fill opening to open and then fill the pouch. Each filled pouch is then sealed to create an hermetically closed, inflated dunnage unit. Improvements on the pouches of the Lerner Patent are disclose in copending applications Ser. No. 09/735,345 filed Dec. 12, 2000 and Ser. No. 09/979,256 filed Nov. 21, 2001 and respectively is entitled Dunnage Inflation (the Lerner Applications). The system of the Lerner Patent and Applications is not suitable for packaging liquids. Moreover, since the production of dunnage units by the process described is relatively slow, an accumulator is desirable. An improved accumulator and dispenser for receiving dunnage units manufactured by a dunnage unit formation machine is disclose in U.S. application Ser. No. 09/735,111 filed Dec. 12, 2000 by Rick S. Wehrmann under the title Apparatus and Process for Dispensing Dunnage. 
     Accordingly, it would be desirable to provide an improved system for filling pouches with fluid to produce dunnage or liquid filled units at high rates of speed. 
     SUMMARY OF THE INVENTION 
     The present invention is embodied in a plastic web which enhances the production of fluid filled units which may be dunnage units similar to those produced by the systems of the Lerner Patent and Applications but at greatly improved production rates. Specifically, a novel and improved unit formation web is disclose for use with a novel machine and process. The machine and process are claimed in a concurrently filed application by Hershey Lerner et al, Ser. No. 10/408,947. 
     The machine includes a rotatable drum having a spaced pair of cylindrically contoured surfaces. An elongated nozzle extends generally tangentially between and from the cylindrical surfaces. In use, the nozzle is inserted into the novel web at a transversely centered position as the web is fed upwardly and around the drum. The web has hermetically closed side edges and longitudinally space pairs of transverse seals. The seals of each pair are spaced a distance equal to slightly more than one half the circumference of the nozzle with which it is intended to be used. 
     Each transverse seal extends from an associated side seal toward the center of the web such that successive side seals and the associate side edge together define three sides of a pouch to be fluid filled. When the units being formed are dunnage, as the web passes over the nozzle, web pouches are inflated and the web is separated into two chains of inflated pouches as the nozzle assembly separates the web along longitudinal lines of weakness. 
     The chains are fed by the drum and metal transport belts successively under a plurality of heating and cooling shoes. Each shoe has a spaced pair of arcuate web transport belts engaging surfaces which are complemental with the cylindrical drum surfaces. The shoes are effective to clamp the transport belt and the web against the rotating drum as spaced sets of seals are formed to seal the air inflated pouches and convert the inflated pouches into dunnage units. The dunnage units are separated following their exit from the last of the cooling shoes. 
     Tests have shown that with pouches having four inch square external dimensions, dunnage units are produced at the rate of eight cubic feet per minute. This contrasts sharply with the machine of the Lerner Patents which produces dunnage units at the rate of three cubic feet per minute. 
     Accordingly the objects of the invention are to provide a novel and improved web for dunnage formation and a process of dunnage formation. 
    
    
     
       IN THE DRAWINGS: 
         FIG. 1  is an elevational view of the unit formation machine of the present invention; 
         FIG. 2  is a plan view of the machine of  FIG. 1  as seen from the plane indicated by the line  2 - 2  of  FIG. 1  showing a web being fed into the machine; 
         FIG. 3  is an enlarged sectional view of a heat shoe and a portion of the drum as seen from the plane indicated by the line  3 - 3  of  FIG. 1 ; 
         FIG. 3   a  is a further enlarged view of the shoe and the drum as seen from the same plane as  FIG. 3 ; 
         FIG. 4  is a view showing a dunnage embodiment of the machine with components which delineate a air flow path from a supply to and through the cooling shoes and then the inflation nozzle; 
         FIG. 5  is a perspective view of a section of the novel and improved Web; 
         FIG. 6  is a perspective view showing a section of a web as the web pouches are inflated and the web is separated into parallel rows of inflated pouches; 
         FIG. 7  is an enlarged plan view of a portion of the web including a transverse pair of heat seals; 
         FIG. 8  is a further enlarged fragmentary view of a central part of the web as located by the circle in  FIG. 7 ; 
         FIG. 9  is a perspective view showing a pair of completed fluid filled units following separation and as they exit the machine; and, 
         FIG. 10  is an enlarged view of a preferred support embodiment and a shoe which arrangement is for supporting the shoes in their use positions and for moving them to out of the way positions for machine set up and service. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     While the following description describes a dunnage formation system, it should be recognized the preferred embodiment of the machine is sterilizable so that beverages such as water and fruit juice may be packaged using the novel web, machine and process. 
     Referring now to the drawings and  FIGS. 1 and 2  in particular, a dunnage formation machine is shown generally at  10 . The machine includes a rotatable drum  12  which is driven by a motor  14  via a gear box  15  and a belt and pulley arrangement  16 ,  FIG. 2 . In the preferred and disclose arrangement, the drum is comprised of spaced annular disks  18 . 
     When the machine is in use a web  20  is fed from a supply, not shown. As is best seen in  FIG. 1 , the web  20  passes over a guide roll  22  and thence under a guide roll  24  to an inflation station  25 . The web  20  is fed around the disks  18  to pass under, in the disclose embodiment, three heat shoes  26  which shoes heat metal transport belts  27  to seal layers of the web. The heat softened web portions and the transport belts then pass under cooling shoes  28  which freeze the seals being formed. As the now inflated and sealed web passes from the cooling shoes individual dunnage units  30  are dispensed. 
     In practice the machine  10  will be housed within a cabinet which is not shown for clarity of illustration. The cabinet includes access doors with an electrical interlock. When the doors are open the machine may be jogged for set up, but the machine will not operate to produce dunnage units unless the doors are closed and latched. 
     The Web 
     Referring now to  FIGS. 5-9 , the novel and improved web for forming dunnage units is disclose. The web is formed of a heat sealable plastic such as polyethylene. The web includes superposed top and bottom layers connected together at spaced side edges  32 . Each of the side edges is a selected one of a fold or a seal such that the superposed layers are hermetically connected along the side edges  32 . 
     A plurality of transverse seal pairs  34  are provided. As best seen in  FIGS. 5-7 , each transverse seal extends from an associated side edge  32  toward a longitudinally extending pair of lines of weakness  35 . The longitudinal lines of weakness  35  are superposed one over the other in the top and bottom layers of the web and are located midway between the side edges. Each transverse seal  34  terminates in spaced relationship with the longitudinal lines of weakness which preferably are in the form of uniform, small perforations. The transverse seal pairs  34  together with the side edges  32  delineate two chains of centrally open side connected, inflatable pouches  37 . 
     As is best seen in  FIGS. 7 and 8 , transverse lines of weakness  36  are provided. The pouches are separable along the transverse lines  36 . Like the longitudinal lines of weakness  35  the transverse lines are preferably perforations but in contrast to the to the longitudinal line perforations each has substantial length. The perforations of the transverse lines  36 , in a further contrast with the perforations of the longitudinal lines  35 , are not of uniform dimension longitudinally of the lines. Rather, as is best seen in  FIG. 8 , a pair of small or short perforations  38  is provided in each line. The small perforations  38  of each pair are disposed on opposite sides of and closely spaced from the longitudinal lines  34 . Each transverse line of weakness also includes a pair of intermediate length perforations  40  which are spaced and positioned on opposite sides of the small perforations  38 . The intermediate perforations extend from unsealed portions of the superposed layers into the respective seals of the associated transverse seal pair. The remaining perforations of each line are longer than the intermediate perforations  40 . 
     The Machine 
     In the embodiment of  FIG. 1 , the disks  18  are mounted on a tubular shaft  42 . The shaft  42  is journaled at  44  for rotation driven by the belt and pulley arrangement  16 . The shaft  42  carries a stationary, tubular, nozzle support  45  which extends from around the shaft  42  radially outwardly. A nozzle assembly  46  is carried by a support arm  45 A,  FIG. 6 . The nozzle assembly  46  includes an inflation nozzle  48 . As is best seen in  FIG. 6 , the nozzle  48  is an elongated tube with a closed, generally conical, lead end portion  49 . The nozzle  48  when in use extends into the web at a central location transversely speaking. The web transverse lines of weakness are spaced slightly more than a one half the circumference of the nozzle so that the web layers fit closely around the nozzle to minimize leakage of air exiting side passages  51  of the nozzle to inflate the pouches  37 . 
     The nozzle assembly  46  includes a web retainer  50  which guides the web against the nozzle  48 . The retainer also functions to cause the web to be longitudinally split along the longitudinal lines of weakness  35  into two strips of inflated pouches. 
     As is best seen in  FIGS. 3 and 3A , each of the heat shoes  26  has a mirror image pair of heat conductive bodies  52 . The bodies  52  together define a cylindrical aperture  54 , which houses a heating element, not shown. Each heat body  52  includes a seal leg  55  having an arcuate surface substantially complemental with a cylindrical surface of an associated one of the disks  18 . In the disclose embodiment the disk surfaces are defined by thermally conductive silicone rubber inserts  18   s ,  FIG. 3A . In the embodiment of  FIGS. 3 and 3A , springs  56  bias the legs  55  against the transport belts  27  as the web passes under the heat shoes due to rotation of the drum  12  and its disks  18 . The cooling shoes  38  are mounted identically to the heat shoes. 
     Each cooling shoe  28  includes an expansion chamber  58 ,  FIG. 4 . An air supply, not shown, is connected to a chamber inlet  60 . Air under pressure is fed through the inlet  60  into the chamber  58  where the air expands absorbing heat and thus cooling the shoe. Exhaust air from the chamber passes through an exit  62 . Cooling shoe legs  63  are biased against the web to freeze the heat softened plastic and complete seals. 
     In the embodiment of  FIGS. 1-4  cooling shoe exhaust air then passes through a conduit  64  to the tubular shaft  42 . Air from the cooling shoes is fed via the conduit  64  and the shaft  42  to a passage  65  in the nozzle support  45 . The passage  65  is connected to the nozzle  48 . Thus air from the cooling shoes is directed to and through the nozzle  48  and the exit passages  51  into the pouches. 
     With the now preferred and sterilizable embodiment, cooling shoes  28 ′ as shown in  FIG. 10  are employed has a jacket  67  which surrounds a body having cooling fins shown in dotted lines in  FIG. 10 . An inlet  60 ′ is provided at the top of the jacket. Air flowing from the inlet passes over the fins cooling them and the exits from the bottom of the jacket. Each of the shoes  28 ′ is vented to atmosphere through an outlet  67 . The nozzle  48  is directly connected to a supply of fluid under pressure and the shaft  42  may be made of solid material. 
     A pair of hold down belts  66  are mounted on a set of pulleys  68 . The belts  66  are reeved around a major portion of the disks  18 . As is best seen in  FIGS. 3 and 3A , the belts  66  function to clamp portions of the web  20  against the disks on opposite sides of the shoe legs  55 . While test have shown that the machine is fully operable without the belts  66 , they are optionally provided to isolate pressurized air in the inflated pouches  37  from the heating and cooling shoes. 
     A fixed separator  69  is provided. As the inflated pouches approach the exit from the downstream cooling shoe the fixed separator functions to cam them radially outwardly sequentially to separate each dunnage unit from the next trailing unit along the connecting transverse line of weakness except for a small portion under the transport belts  27 . 
     A separator wheel  74  is provided,  FIG. 1 . The wheel  74  is rotated clockwise as seen in  FIG. 1  such that arms  76  are effective to engage completed dunnage units  30  sequentially to complete the separation of each dunnage unit from the web along its trailing transverse line of weakness  36 . Thus, the separator wheel is effective to tear the last small connection of each pouch which was under an associated one of the transport belts as the pouch was substantially separated by the fixed separator  69 . 
     In the embodiment of  FIG. 1 , each of the shoes  26 ,  28  is mounted on an associated radially disposed shaft  71 . Clamping arrangements shown generally at  72  are provided to fix each of the shafts  71  in an adjusted position radially of and relative to the drum  12 . As is best seen in  FIG. 3 , each shaft  71  carries a yoke  73 . The springs  56  span between yoke pins  75  and shoe pins  75  to bias the shoes against a web  20 . A cylinder  70  is provided for elevating a connected yoke and shoe for machine set up and service. 
     In the now preferred embodiment of  FIG. 10 , each shoe is pivotally mounted on an arm  78 . The arm is also pivotally mounted at  80  on a frame  82 . A cylinder  70 ′ spans between the arm and the frame for elevating the connected shoe for set up and service and for urging the shoes  28  into their operating positions. The heat shoes  26  are, in the now preferred arrangement, identically mounted. 
     Operation 
     In operation, the shoes are elevated by energizing the cylinders  70  of  FIGS. 1 and 4  or  70 ′ of  FIG. 10 . A web  20  is fed along a path of travel over the guide roll  22  and under the guide roll  24  and thence threaded over the inflation nozzle  48 . The web is then fed under the transport belts and the retainer  50 . As the machine is jogged to feed the web around the discs  18  and the heating and cooling shoes  26 , 28  the web is split by the nozzle support  55 . The split of the web is along the longitudinal line of weakness but the transverse lines of weakness remain intact at this time. Thus, the web portions at opposite ends of the small perforations  38  are of sufficient size and strength to avoid a longitudinal split of the web as the web is fed over the nozzle. Since the transverse seals of each pair are spaced only very slightly more than one half the circumference of the nozzle the web closely surrounds the nozzle to minimize air leakage when the pouches are inflated. 
     Next the heating and cooling shoes are elevated by actuating either the cylinders  70  or  70 ′. The web is then fed sequentially, and one at a time, under the heating shoes  26  and the cooling shoes  28 . Since the web has been split by the nozzle support  55 , there are in fact two parallel paths of travel each with an associated transport belt  27  and chain of side connected and inflated pouches. 
     Once the web has been fed around the drum to an exit location near the separator wheel  74  and the machine has been jogged until the operator is satisfied the feed is complete and the machine is ready the heat shoe elements will be energized. Air will be supplied to the cooling shoes  28  and the nozzle  48 . Next the motor  14  will be energized to commence machine operation. 
     As we have suggested, one of the outstanding features of the invention is that the web closely surrounds and slides along the nozzle. The close surrounding is assured by the transverse seals being spaced a distance substantially equal to one half the circumference of the nozzle  48 . Thus, the two web layers together delineate a nozzle receiving space which will closely surround an inserted nozzle. As the web advances the pouches  37  on opposed sides of the nozzle will be filled efficiently by fluid under pressure exiting the nozzle passages  51  in opposed streams. Where dunnage units are being formed the fluid will be air. The web is then split by the nozzle support into two chains of side connected and fluid filled pouches respectively traveling along associated ones of the two paths of travel. 
     Each of the chains is fed under spaced legs  55  of the heating shoes  26  to effect heat seals. As the web passes under cooling shoe legs  63  the seals are frozen and the pouches are separated along most of the length of transverse lines of weakness by the separator. Facile separation is assured by the long perforations because the remaining connections of the web across the transverse seals are short in transverse dimension and few in number. 
     When the pouches exit the last of the cooling shoes, they have been formed into finished dunnage units  30 . The finished units  30  are sequentially completely separated from the web by the arms  76  of the separation wheel  74 . 
     While the system as disclosed and described in the detailed description is directed to dunnage, again, as previously indicated, units filled with fluids other than air such as water and fruit juices can be produced with the same machine, process and web. 
     Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction, operation and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.