Abstract:
The present invention is directed to a polymeric bag having a reduced gauge portion extending generally across the width of the bag, wherein the reduced gauge portion allows that area of the polymeric bag to be stretched more easily. This invention is especially advantageous in the context of drawstring trash bags wherein the reduced gauge portion encompasses the hems.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to improvements in the construction and manufacture of polymeric bags. In particular, the present invention relates to improvements to trash bags. 
         [0004]    2. Description of the Related Art 
         [0005]    Polymeric bags are ubiquitous in modern society and are available in countless combinations of varying capacities, thicknesses, dimensions and colors. The bags are available for numerous applications including typical consumer applications such as long-term storage, food storage, and trash collection. Like many other consumer products, increased demand and new technology have driven innovations in polymeric bags improving the utility and performance of such bags. The present invention is an innovation of particular relevance to polymeric bags used for trash collection. 
         [0006]    Polymeric bags are manufactured from polymeric film produced using one of several manufacturing techniques that are well-known in the art. However, the two most common manufacturing methods for creating polymeric film are blown-film extrusion and cast-film extrusion. Both blown-film extrusion and cast-film extrusion offer certain advantages versus the other. The ultimate selection of a method of manufacture is often driven by considerations such as the desired properties for the final product as well as by financial considerations. 
         [0007]    In both blown-film extrusion and cast-film extrusion, an extruder is used to push molten polymeric material through a die. In the case of blown-film extrusion, the film during processing is tubular in shape. In cast-film extrusion, the film during processing is substantially flat. Certain dies also allow for the manufacture of polymeric films having multiple layers co-extruded through a single die. An early die designed to produce multi-layer blown-film tubes is described in U.S. Pat. No. 4,185,954 entitled Die for Extruding Tubes Composed of Plurality of Layers. Furthermore, other types of co-extrusion dies are available which allow for different polymer blends to be extruded through a single die to provide distinct sections across the width, or circumference, of the extruded film. Such dies, for example, may be used with polymer blends having different color additives to provide stripes in the extruded blown-film. 
         [0008]    As previously stated, the present invention relates to polymeric trash bags, which are available in several popular configurations such as drawstring trash bags and wave-cut trash bags, the latter of which have two or more flaps extending from the top of the bag. Both drawstring and wave-cut trash bags are popular among consumers and, given their popularity, recent innovations have attempted to improve the bags&#39; performance. 
         [0009]    One common complaint, which is applicable to many different types of trash bags, revolves around the tendency of the trash bag to fall into the trash can during use. Specifically, the top of the trash bag, which is placed over the top of the can, often has a tendency to fall into the trash can as the weight of the trash pulls the bag downward into the can. 
         [0010]    To address this issue, certain trash bags now provide features intended to enhance the ability of the bag to “grip” the outside of the trash can near the top of the trash can. With respect to drawstring trash bags, elastic drawstrings have been introduced which stretch outward and retract in order to grip the outside of a trash receptacle. However, the physical properties and strength of the panels comprising the trash bags, specifically the area near the top of the bag at or around the hem area, can make it difficult to stretch the mouth of the bag over the perimeter of the trash receptacle. 
         [0011]    One prior art attempt to address this problem is to provide perforations or notches near the upper corners of the bag thereby allowing the ends of an elastic drawstring to be separated from the bag proper and stretched over and around the upper opening of a trash receptacle. However, the perforations or notches result in large openings at the top of the bag when it is closed. Additionally, when compared with traditional drawstring trash bags, the perforations and/or notches in the bag can increase the risk that tears will propagate away from the cutouts when stress is placed on the bag. 
         [0012]    In view of the foregoing, it would be desirable to provide a trash bag that is easier to extend over the upper opening of a trash can, keeps the structural integrity of the bag intact, and overcomes challenges of the prior art. Additionally, it would also be desirable to provide a trash bag that effectively grips trash cans. The present invention addresses these and other needs. 
       SUMMARY OF THE INVENTION 
       [0013]    In one embodiment of the present invention, a trash bag is comprised of a first panel and a second panel joined along a first side edge, a second side edge, and a bottom edge. The top edge of the first panel and second panel defines an upper opening of the bag. The first panel has a normal thickness and further comprises a reduced gauge portion. The reduced gauge portion of the first panel has a thickness that is less than the normal thickness of the first panel. In some embodiments of the present invention, the reduced gauge portion of the first panel extends substantially across a width of the first panel. Additionally, the reduced gauge portion of the first panel may have a substantially uniform height. 
         [0014]    In certain embodiments of the present invention, the thickness of the reduced gauge portion may be less than or approximately equal to 80% of the normal thickness of the first panel. Furthermore, in some embodiments of the present invention, the thickness of the reduced gauge portion may be less than or approximately equal to 50% of the normal thickness of the first panel. Additionally, the second panel may also have a normal thickness with a reduced gauge portion of the second panel having a thickness that is less than the normal thickness of the second panel. 
         [0015]    In some embodiments of the present invention, a first hem is provided in the first panel with a first drawstring contained within the first hem. Additionally, a second hem may be provided in the second panel with a second drawstring contained within the second hem. In some embodiments, the first drawstring may be elastic or both the first and second drawstring may be elastic. Furthermore, in such embodiments, a reduced gauge portion of the first panel may be provided that includes substantially all of the first hem and may further include an area of the first panel below the first hem. Similarly, a reduced gauge portion of the second panel may be provided that includes substantially all of the second hem and may further include an area of the second panel below the second hem. 
     
    
     
       BRIEF DESCRIPTION OF THE RELATED DRAWINGS 
         [0016]    A full and complete understanding of the present invention may be obtained by reference to the detailed description of the present invention and certain embodiments when viewed with reference to the accompanying drawings. The drawings can be briefly described as follows. 
           [0017]      FIG. 1  provides a perspective view of a first embodiment of the present invention. 
           [0018]      FIG. 2  provides an elevation view of a panel used to construct the first embodiment of the present invention. 
           [0019]      FIG. 3  provides a perspective view of a second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0020]    The present disclosure illustrates several embodiments of the present invention. It is not intended to provide an illustration or encompass all embodiments contemplated by the present invention. In view of the disclosure of the present invention contained herein, a person having ordinary skill in the art will recognize that innumerable modifications and insubstantial changes may be incorporated or otherwise included within the present invention without diverging from the spirit of the invention. Therefore, it is understood that the present invention is not limited to those embodiments disclosed herein. The appended claims are intended to more fully and accurately encompass the invention to the fullest extent possible, but it is fully appreciated that certain limitations on the use of particular terms are not intended to conclusively limit the scope of protection. 
         [0021]    Referring initially to  FIG. 1 , a perspective view of drawstring trash bag  100  is shown according to one embodiment of the present invention. The drawstring trash bag comprises a first panel  102  and a second panel  104 , each panel being substantially rectangular in shape. The first panel  102  and second panel  104  are coupled along a first side edge  106 , a second side edge  108 , and a bottom edge  110  of the respective panels  102  and  104 . In some embodiments, the first panel  102  and second panel  104  may be formed from a single piece of polymeric film, folded to define a bottom edge  110  and sealed along the first side edge  106  and second side edge  108 . 
         [0022]    The unsealed top edge  112  of the respective panels  102  and  104  defines the upper opening of the drawstring trash bag. A pair of drawstrings  140  are disposed within hems  142  located proximate the top edge  112  of the respective first panel  102  and second panel  104 . The drawstrings  140  may be traditional high-density polyethylene drawstrings or, in some embodiments, may be elastic drawstrings. The drawstrings are generally loose within the hems  142  and sealed near the upper corners of the drawstring trash bag  100  by short seals  120  and  122 . Therefore, when the drawstrings  140  are pulled through the drawstring cutouts  144  of the bag  100 , the respective upper corners of the bag  100  are pulled together, facilitating closure of the bag. 
         [0023]    In the depicted embodiment of  FIG. 1 , the panels  102  and  104  of the drawstring trash bag  100  are primarily comprised of a polymer blend which generally comprises linear low density polyethylene (LLDPE) although other polyethylenes may be utilized as the primary component such as high density polyethylene (HDPE) or low density polyethylene (LDPE). Typically, the LLDPE comprises at least 80% of the polymer blend. The remaining 20% of the polymer blend may comprise additives to provide color for the final product, increased resistance to blocking, odor control, or other properties. 
         [0024]    To facilitate the drawstrings  140  in being stretched over certain trash receptacles while still keeping the structural integrity of the bag intact, a reduced gauge portion  150  generally extends across the width of the drawstring trash bag  100  and may generally encompass the hems  142  and may also encompass a small area below the hems  142  as well. The reduced gauge portion  150  has a thickness, or gauge, that is less than the remainder of the trash bag panels  102  and  104 . The thickness of the remainder of the trash bag panels  102  and  104  may be referred to herein as the normal gauge or normal thickness of the respective trash bag panels  102  and  104 . However, it is understood that the thickness of thin polymeric films may vary and that certain variations in thickness may be expected. Therefore, the gauge and thickness of a polymeric film is usually expressed in terms of an average thickness across a certain area. 
         [0025]    In a typical embodiment of the present invention as shown in  FIG. 1 , the reduced gauge portion  150  may have a thickness that is less than or equal to 80% of the normal thickness of the trash bag panels  102  and  104 . As an example, in a certain embodiment, the trash bag panels  102  and  104  may have a normal thickness of 1.0 mil while the thinner portion  150  may have a thickness of approximately 0.8 mil. Furthermore, it is contemplated that in certain other embodiments, the reduced gauge portion  150  may have a thickness equal to or less than 50% of the normal thickness of the trash bag panels  102  and  104 . Compared to a similar trash bag known in the prior art which has substantially uniform thickness, the reduced thickness of the reduced gauge portion  150  provides less resistance when stretching the mouth of the trash bag  100  over certain trash receptacles. 
         [0026]    In some embodiments of the present invention, the reduced gauge portion  150  may be comprised of the same polymer blend as the remainder of the trash bag panels  102  and  104 . For example, in many embodiments of the present invention the trash bag panels  102  and  104  may be comprised primarily of linear-low density polyethylene (LLDPE), which typically makes up over 80% of the polymer blend used for the trash bag panels  102  and  104 . IN certain embodiments, the reduced gauge portion  150  may comprise the same polymer blend, comprising at least 80% of LLDPE. However, in other embodiments of the present invention, the polymer blend of the reduced gauge portion  150  may be a modified polymer blend, different from the polymer blend used for the trash bag panels  102  and  104 . The modified polymer blend may have a lower modulus of elasticity than the remainder of the panels  102  and  104  facilitating the reduced gauge portion  150  of the drawstring trash bag  100  to be stretched over the outside of a trash receptacle. Additionally, the modified polymer blend may provide greater elastic recovery improving the grip of the drawstring trash bag  100  on the outside of the trash receptacle after being placed over it. It is contemplated that several different polymers may be used in the modified polymer blend, including but not limited to, linear low density polyethylene (LLDPE), low density polyethylene (LDPE), ethylene-vinyl acetate (EVA), ethylene-acrylic acid (EAA), very low density polyethylene (VLDPE), and ultra low density polyethylene (ULDPE). As an example, in some embodiments of the present invention, a modified polymer blend of the reduced gauge portion  150  may comprise at least 20% ULDPE or VLDPE. However, in certain preferred embodiments, the modified polymer blend may have at least 50% ULDPE or VLDPE. 
         [0027]    Referring now to  FIG. 2 , the first panel  102  is depicted to better illustrate the first panel  102  made with a reduced gauge portion  150 . The reduced gauge portion  150  is shaded to illustrate the portion of the first panel  102  which is thinner than the normal thickness for the remainder of the first panel  102 . In the depicted embodiment, the reduced gauge portion  150  of the first panel  102  encompasses the entire area of the hems  142  and extends slightly below the hem  142  as well. A person of ordinary skill in the art would understand that  FIG. 2  illustrates the first panel  102  wherein the drawstring cutout  144  has been provided but before providing a drawstring  140 . After providing the drawstring  140 , the upper portion of the first panel  102  would be folded downward over the drawstring  140  to form the hem  142  as shown in  FIG. 1 . 
         [0028]    Referring now to  FIG. 3 , another embodiment of the present invention is depicted. The embodiment depicted in  FIG. 3  is an improved drawstring bag  300  similar to the drawstring trash bag  100  of  FIG. 1 . Like the embodiment of  FIG. 1 , the reduced gauge portion  150  includes the hems  142  and extends slightly below the hems  142 . However, in this improved drawstring trash bag  300 , a first inner short seal  320  and a second inner short seal  322  are additionally provided to seal the drawstrings  140  and panels  102  and  104  together. The first inner short seal  320  and second inner short seal  322  effectively reduce the width of the upper opening of the improved drawstring bag  300 . 
         [0029]    As previously noted, the specific embodiments depicted herein are not intended to limit the scope of the present invention. Indeed, it is contemplated that any number of different embodiments may be utilized without diverging from the spirit of the invention. Therefore, the appended claims are intended to more fully encompass the full scope of the present invention.