Patent Publication Number: US-2002005244-A1

Title: Disposable liner

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
     [0001] The present application is a divisional application of co-pending application No. 09/302,107, filed on Apr. 29, 1999, the entire disclosure of which are specifically incorporated by reference herein. 
    
    
     
       BACKGROUND OF INVENTION  
       [0002] 1. Technical Field  
       [0003] The present invention relates in general to a package article and more specifically to a disposable liner made of plastic or the like material, of the type which is suitable for use in a meat packaging facility for holding meat and the like.  
       [0004] 2. Background  
       [0005] As is known in the meat packaging industry, animal carcasses are transported to a meat processing and packaging plant for processing. At this location, the carcasses are processed so that the desired and valuable meat of the animal is separated away from other bodily components, such as bone, organs, and bodily fluids to name a few. This separation process generally involves the use of cutting devices which act to cut the meat away from the carcass so that the meat can be transported for further processing. Further processing of the meat may involve making additional cuts into the meat, cleaning the meat, and packaging the meat for further transportation to additional facilities which market the product to consumers.  
       [0006] Because the desired meat portion of the animal carcass only comprises a portion of the carcass itself, the meat must be stripped from the carcass and placed in containers for transportation and further processing. More specifically, the meat portion of the carcass is stored in containers separate from the containers which hold the animal waste products which include bodily fluids such as blood and fluid waste products such as urine. The meat portion itself also contains bodily fluids, such as blood, and typically, the meat is placed in large cardboard containers which are lined with a plastic liner. The plastic liner is designed to catch and hold the meat so that the meat may be isolated, packaged and finally transported for disposal. One notably disadvantage of conventional plastic liners used in the cardboard containers is that the blood from the meat tended to accumulate and settle on the bottom of the cardboard container resulting in a great amount of stress being applied to the bottom seal of the liner. As the blood accumulates, it finds the weakest point of the plastic liner and leaks out causing a major mess. The reason for the leakage problem is that the conventional liners used in the meat packing have an inherently weak bottom seal. Thus, the weight and volume of the meat itself and the associated blood places a stress upon the seal and it gives way and leakage occurs.  
       [0007] In order to overcome this problem, the meat packing industry has tried to use double liners in the cardboard containers. These efforts have proved largely unsuccessful and add unnecessary cost because of the two fold increase in liners per a given cardboard container. Thus, there is a need for a plastic liner for use in cardboard containers used in the meat packing industry for holding meat and its blood after the animal has been slaughtered.  
       SUMMARY OF INVENTION  
       [0008] The present invention comprises a plastic liner for use in containers which are used in the meat packing industry to hold meat after the animal has been slaughtered. A plastic liner blank is provided and a pair of side gussets are formed therein. The pair of side gussets comprise vertical gussets which travel the length of the plastic liner blank. In accordance with the present invention, the depth of the each gusset is such that there is only a minimal distance between the gussets after they are formed in the plastic liner blank. Preferably, the distance between the gussets is about 1-2 inches and more preferably about 1 inch. After forming the side gussets, the plastic liner blank is folded in half along a center line resulting in one of the side gussets being folded onto the other side gusset. After folding the plastic liner blank in this manner, the plastic liner blank is generally in the form of a rectangle and preferably the width of an individual side gusset substantially represents the width of the rectangle.  
       [0009] Individual plastic liners are formed from the plastic liner blank by introducing the plastic liner blank into a device which intermittently provides a seal at predetermined locations of the plastic liner blank. Preferably, the seal is formed by applying heat and pressure along a line which causes the layers of the plastic liner blank to bond to another. In addition, a perforated separation line is provided adjacent the seal and this permits individual plastic liners to be separated from one another by grasping one end of the plastic liner and separating it from the rest along the perforated line.  
       [0010] The present invention presents a plastic liner designed to catch and hold animal meat so that the meat is easily transportable for further processing and/or packaging. More importantly, the present construction of the plastic liner offers a strong bottom seal which does not include an inherently weak bottom seal which is associated with prior art liners for use in the meat packing industry. The bottom seal is a leak-proof seal due to the seal having a substantially uniform thickness. Thus, the present invention eliminates the leakage of blood from the bottom seal and is more cost effective than current practices.  
       [0011] The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. 
     
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
     [0012] Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:  
     [0013]FIG. 1 illustrates a conventional two sided gusseted article of the prior art;  
     [0014] FIGS.  2 - 3  show an assembly step for forming the two sided gusseted article of FIG. 1; and  
     [0015] FIGS.  4 - 7  show the progressive preferred assembly steps used in forming a plastic liner in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION  
     [0016] Referring to FIG. 1, in which a conventional plastic liner is generally indicated at  10 . Plastic liner  10  has a first open end  12  and an opposite sealed second end  14 . At second end  14 , a seal  16  extends the width of plastic liner  10  and serves to close second end  14 . Adjacent seal  16  is a perforated separation line  18  which permits plastic liner  10  to be easily removed from adjacent material in which a plurality of plastic liners  10  are formed. As is known in the art, upon separating plastic liner  10  along perforated separation line  18  at second end  14 , the adjacent material is opened along perforated separation line  18  to form what is now an open end for an adjacent plastic liner  10 ′.  
     [0017] Turning now to FIGS.  1 - 3 , plastic liner  10  includes a pair of side gussets  20 . As shown in FIG. 2, plastic liner  10  is formed from a plastic liner blank  22 . Plastic liner blank  22  also includes a central line  24  which marks the approximate center of plastic liner blank  22 . When the pair of side gussets  20  are formed in plastic liner blank  22 , inner edge lines  26  are created and partially define the pair of side gussets  20 . Central line  24  and inner edge lines  26  are substantially parallel to one another. Inner edge lines  26  of gussets  20  are formed so that each of inner edge lines  26  does not extend closely to central line  24 . In other words, there is a distance A between inner edge lines  26  of plastic liner blank  22  and a distance B between each of edge lines  26  and central line  24 .  
     [0018] After forming the pair of side gussets  20 , seal  16  is formed at second end  14  by conventional sealing techniques resulting in second end  14  being closed. Perforated separation line  18  is also formed in plastic liner blank  22  by conventional techniques. Plastic liner  10  suffers from the associated deficiency that when plastic liner  10  is sealed, the distance A shown in FIG. 3 comprises a double thickness seal due to the lack of any gussets  20  being located within this region. The outermost regions of plastic liner  10  include a quadruple thickness seal because of the presence of gussets  20 . Consequently, seal  16  is not uniform because of this difference in thickness along the width of the material forming plastic liner  10 . This results in an inherently weak seal  16  due to the non-uniform thickness of seal  16 . At this inherently weak region, seal  16  has a tendency to leak.  
     [0019] Referring now to FIGS.  4 - 7  which show the progressive preferred assembly steps used in forming a plastic liner in accordance with the present invention. As best shown in FIG. 7, an individual plastic liner of the present invention is generally indicated at  100 . Plastic liner  100  comprises a liner for use in a receptacle, e.g. container, and is particularly intended for use as a liner for containers used in the meat packing industry to collect the meat portion of a carcass during a slaughtering process. In an exemplary and preferred embodiment, plastic liner  100  is formed of polyethylene and has a thickness of about 3 mil. It being understood that this is an exemplary material and exemplary thickness and it is within the scope of the present invention that other suitable materials may be used having varying thicknesses.  
     [0020] Now returning to FIGS.  4 - 7 . FIG. 4 shows a plastic liner blank  102  in an initial form as a plastic film tube  103  having a diameter of about 98 inches. As shown in FIG. 5, a gusset  104  is provided on opposing sides of plastic film tube  102 . Gusset  104  comprises a V-shaped tuck including a first surface  108  and a second surface  110  which generally face one another and converge at an inner edge line  112  to form gusset  104 . When gussets  104  are formed in plastic liner blank  102 , a pair of outer gusset edges  114  are formed which oppose one another and outer gusset edges  114  may be brought together to form the generally rectangular plastic liner blank  102  shown in FIG. 5. Outer gusset edges  114  form the open ended outer part of the V-shaped gusset  104 . When gussets  104  are formed in plastic liner blank  102 , plastic liner blank  102  no longer takes the form of tubular member  103  and may lie flush against a surface to form a generally rectangular plastic liner blank  102 . Plastic liner blank  102  has a minimal central area  116  extending between gussets  104 , wherein central area  116  is a non-gusseted region. It being understood that gussets  104  are vertical gussets which run the entire length of plastic liner blank  102 . In this second position, shown in FIG. 5, the width of each gusset  104  is approximately 24 inches, thereby the width of the rectangular plastic liner blank  102  of FIG. 4 is about 49-50 inches (partially defined by 2 gussets at 24 inches). In this one exemplary embodiment, central area  116  is approximately 1 to 2 inches in width. Thus, the distance between gussets  104  is minimal and in an exemplary embodiment is about 1-2 inches.  
     [0021] In FIG. 5, plastic liner blank  102  is folded along a generally central fold axis  118  of plastic liner blank  102  resulting in one of gussets  104  being folded over on top of the other of gussets  104 . In this configuration, outer gusset edges  114  are generally stacked on one another to define one side edge of the folded plastic liner blank  102 . The opposite side edge of the folded plastic liner blank  102  is defined by central fold line  118  in central area  116 . As shown in FIG. 6, the plastic liner blank  102  generally is still in the form of a rectangle having a width which is {fraction (1/2 )} of the width of plastic liner blank  102  in FIG. 5 prior to the folding procedure shown in FIG. 6. In the exemplary embodiment, the width of folded plastic liner blank  102  is about 25 inches. Central region (not shown) has a width which sufficiently permits the folding of one gusset  104  over onto the other gusset  104 . Consequently, the pair of side gussets  104  are formed so that the inner edge lines  112  of gussets  104  are substantially parallel and adjacent to central region  116  of plastic liner blank  102 . When plastic liner blank  102  is folded along central fold line  118  so that one of gussets  104  is folded on top of the other of gussets  104 , only a minor amount of the central region is visible because of it having a reduced and minimal width. Central fold line  118  defines one side edge of the individual plastic liners  100 .  
     [0022] The folded plastic liner blank  102  is then subjected to a conventional bag machine which forms individual plastic liners  100  from plastic liner blank  102 . In an exemplary embodiment, plastic liner blank  102  is about  196  inches long and individual plastic liners  100  are about 96 inches in length. It being understood that these lengths are merely exemplary in nature and plastic liner  102  may have a variety of lengths which permit individual plastic liners  100  having predetermined lengths to be formed from plastic liner blank  102 . As is known, a conventional bag machine makes seal  16  at a predetermined location by typically applying heat and pressure to this predetermined location to form seal  16  in plastic liner blank  102 . One conventional sealing device involves the use of a hot knife apparatus which introduces heat and pressure along seal line  16  at the predetermined location thereby forming seal  16  by evenly sealing across the width of folded plastic liner blank  102  shown in FIG. 5. This sealing process is continued at predetermined intervals along the length of plastic seal blank  102  so that a plurality of individual seals  16  are formed in plastic liner blank  102 . Each individual seal  16  is formed by bonding all of the folded material comprising plastic liner blank  102  together by application of heat and pressure to form seal  16 . Each individual seal  16  is substantially parallel to one another. At the same time that folded plastic liner blank  102  is sealed along seal line  16 , perforated separation line  18  is formed adjacent to each seal  16 . Both seal  16  and perforated separation line  18  define individual plastic liners  100  and perforated separation lines  18  permit an individual plastic liner  100  to be removed from plastic liner blank  102 . This also permits the sealed and perforated plastic liner blank  102  to be used in a dispenser which conveniently stores plastic liner blank  102  and permits an individual plastic liner  100  to be separated therefrom and disposed in the container.  
     [0023] Unlike conventional liners, plastic liner  100  of the present invention is folded along central fold line  118  prior to the sealing of plastic liner  100 . Thus, the sealing of plastic liner  100  seals the gusseted regions on top of one another and provides a reinforced seal  16  having a substantially uniform thickness. It has been found that plastic liner  100  of the present invention presents an article designed to catch and hold animal meat in a leak-proof manner so that the meat is easily transportable for further processing and/or packaging. More importantly, the present construction of plastic liner  100  offers a strong, leak-proof bottom seal which does not include an inherently weak bottom seal  16  which is associated with prior art liners for use in the meat packing industry. This is partly because of the folding action along center fold line  118  prior to the sealing of plastic liner  100 . More specifically, a better seal  16  is formed in accordance with the present invention because seal  16  is of a substantially uniform thickness throughout the width of plastic liner  100 . This results because the central region  116  between gussets  104  is minimal and thus seal  16  comprises an eight folded material seal  16  due to folded gussets  104 . Because gussets  104  are folded on one another prior to sealing, seal  16  has a substantially uniform thickness along its length. Because the thickness of seal  16  is uniform, the inherently weak point of the prior art is eliminated. Thus, the present invention eliminates the leakage of blood from the bottom seal and is more cost effective than current practices. The type of seal used as the bottom seal of the present invention is known as a star seal configuration.  
     [0024] While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.