Patent Publication Number: US-2021163182-A1

Title: Extended Hem Fold Drawstring Bag

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of currently pending U.S. patent application Ser. No. 14/883,680, filed Oct. 15, 2015, which is a continuation of currently pending U.S. patent application Ser. No. 13/688,369, filed Nov. 29, 2012, which is a continuation-in-part of now abandoned U.S. patent application Ser. No. 13/222,180, filed Aug. 31, 2011. These three aforementioned applications are incorporated by reference in their entirety into this application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     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. 
     2. Description of the Related Art 
     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. 
     Polymeric bags are manufactured from polymeric film produced using one of several manufacturing techniques well-known in the art. The two most common methods for manufacture of polymeric films are blown-film extrusion and cast-film extrusion. In blown-film extrusion the resulting film is tubular while cast-film extrusion produces a generally planar film. Regardless of the manufacturing method utilized, the present invention is generally applicable to drawstring trash bags typically manufactured from a continuous web of plastic film. Manufacturing methods for the production of drawstring bags from a web of material are shown in numerous prior art references including, but not limited to, U.S. Pat. Nos. 3,196,757 and 4,624,654, which are hereby incorporated by reference. 
     Drawstring trash bags are frequently used in connection with rigid containers. When used with a rigid container, it is common to fold the upper opening of a drawstring trash bag over the upper rim of the container to keep the upper opening of the bag accessible. Some rigid containers provide retaining devices to hold the upper opening of a drawstring bag in place while, in other instances, the drawstring bag may provide certain features or properties that facilitate keeping the bag in place on the container. The use of these rigid containers is particularly common in connection with 13-gallon drawstring bags typically used in the household or in an office environment. Rigid containers may also be used with larger bags, such as those commonly used for the collection of outdoor or yard waste. When drawstring bags are used with supporting rigid containers, the drawstring trash bag is often filled with trash and other debris until the capacity of the container or trash bag is reached. 
     After filling the drawstring bag with trash or debris, the bag and its contents are generally pulled out of the rigid container in one of several ways. Some consumers may prefer to pull the drawstrings taut, using the drawstrings to pull the bag and its contents out of the container. However, in many cases, consumers pull the bag out of the rigid container before pulling the drawstrings taut. In such cases, a consumer will typically grab the upper opening of the bag hem or, more commonly, the area immediately below the hem. As the consumer grabs the bag and pulls it out of the container, significant force can result in the area immediately below the hem due to the weight of the bag contents and the pulling action by the consumer, which can cause the plastic film to puncture or fail in this region of the bag—especially when the contents of the bag are particularly heavy. 
     Another aspect of prior art drawstring bags that may be subject to improvement is the tendency for the hems of drawstring bags to detach if there are even minor manufacturing defects. In particular, if the pressure or heat used to create the hem seal across the width of the drawstring trash bag is too great, the integrity of the drawstring trash bag may be endangered due to crystallization of the polymeric film along the hem seal. In these cases, when the drawstring trash bag is filled with trash or debris, the hem seal may fail causing the entire length of the hem, and the drawstring contained within the hem, to “zipper” or detach from the rest of the bag. The present invention may provide additional advantages by providing alternatives to traditional hem seals thereby overcoming the tendency of drawstring trash bags to fail in this manner. 
     In light of the foregoing, it would be desirable to provide a means for reinforcing the drawstring trash bag in the area immediately adjacent/below the hem area of the trash bag. The present invention represents a novel solution to address this need. 
     SUMMARY OF THE INVENTION 
     In at least one embodiment of the present invention, a thermoplastic bag has a front panel and a back panel. The front panel and back panel are generally joined along a first side edge, a second side edge, and a bottom edge of the respective front panel and back panel. The front panel also has a distal edge. A first overlap area comprises at least two layers of polymeric film below the upper opening of the thermoplastic bag. Furthermore, the at least two layers of polymeric film of the first overlap area are generally sealed together. 
     In some embodiments of the present invention, the thermoplastic bag may have a first hem immediately above the first overlap area. Additionally, a drawstring may be disposed within the first hem. In some embodiments, a first hem seal may be formed between the first hem and the first overlap area with the first hem seal extending generally from the first side edge of the thermoplastic bag to the second side edge of the thermoplastic bag. 
     In some embodiments, a first lower seal is located proximate the distal edge of the front panel and extends generally from the first side edge of the thermoplastic bag to the second side edge of the thermoplastic bag. In some such embodiments, the first lower seal is generally continuous while in other embodiments the first lower seal is intermittent. 
     In certain embodiments, the first overlap area has a height defined by a distance from a lower boundary of the first hem to the distal edge of the front panel with the height of the first overlap area being at least 1 inch. Additionally, in certain embodiments, the height of the first overlap area is less than 12 inches while in certain preferred embodiments the height of the first overlap area is in the range of 1.5 inches to 8 inches. 
     In certain embodiments, the at least two layers of polymeric film of the first overlap area are generally sealed together by a first plurality of lower seals extending between a lower boundary of the first hem to the distal edge of the front panel. Furthermore, the first hem seal may be formed between the first hem and the first overlap area with the first hem seal extending generally from the first side edge of the thermoplastic bag to the second side edge of the thermoplastic bag. The first plurality of lower seals may comprise a plurality of angular seals, each of the plurality of angular seals extending generally downwardly from the lower boundary of the first hem to proximate the distal edge of the front panel. Alternatively, the plurality of lower seals may extend generally from the first side edge of the thermoplastic bag to the second side edge of the thermoplastic bag and from the lower boundary of the first hem to a point proximate the distal edge of the front panel. In certain embodiments, the plurality of lower seals may comprise angular seals extending across the height of the overlap area while in other embodiments the plurality of lower seals may comprise a plurality of alternating smaller sealed areas. 
    
    
     
       BRIEF DESCRIPTION OF THE RELATED DRAWINGS 
       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. 
         FIG. 1  provides a perspective view of a first embodiment of the present invention. 
         FIG. 2  provides an elevation view of the front panel according to a first embodiment of the present invention. 
         FIG. 3  provides an elevation view of the back panel according to a first embodiment of the present invention. 
         FIG. 4  provides a cross section perspective view of a first embodiment of the present invention. 
         FIG. 5  provides a perspective view of a second embodiment of the present invention. 
         FIG. 6  provides an elevation view of a panel according to a second embodiment of the present invention. 
         FIG. 7  provides a perspective view of a third embodiment of the present invention. 
         FIG. 8  provides an elevation view of a panel according to a third embodiment of the present invention. 
         FIG. 9  provides a perspective view of a fourth embodiment of the present invention. 
         FIG. 10  provides an elevation view of a panel according to a fourth embodiment of the present invention. 
         FIG. 11  provides a perspective view of a fifth embodiment of the present invention. 
         FIG. 12  provides an elevation view of a panel according to a fifth embodiment of the present invention. 
         FIG. 13  provides a perspective view of a sixth embodiment of the present invention. 
         FIG. 14  provides an elevation view of a panel according to a sixth embodiment of the present invention. 
         FIG. 15A  provides an elevation view of a seventh embodiment of the present invention. 
         FIG. 15B  provides an enlarged elevation view of a portion of a seventh embodiment of the present invention. 
         FIG. 16  provides a perspective view of a panel according to a seventh embodiment of the present invention. 
         FIG. 17  provides an elevation view of an eighth embodiment of the present invention. 
         FIG. 18  provides a perspective view of a panel according to an eighth embodiment of the present invention. 
         FIG. 19  provides an elevation view of a ninth embodiment of the present invention. 
         FIG. 20  provides a perspective view of a panel according to a ninth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     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. 
       FIG. 1  provides a perspective view of a first embodiment of the present invention while  FIG. 2  and  FIG. 3  show a front and rear elevation of the same embodiment. Looking collectively at  FIGS. 1-3 , a drawstring trash bag  100  according to one embodiment is comprised of a front panel  102  and a back panel  104 , the front panel  102  and back panel  104  being substantially rectangular in shape and joined along a first side edge  110 , a second side edge  112 , and a bottom edge  114  to provide the body of the bag. The front panel  102  and back panel  104  may be formed from a single piece of polymeric film which is folded to define the bottom edge  114  and subsequently sealed along the first side edge  110  and second side edge  112 . However, other manufacturing configurations may be utilized in conjunction with the present invention. In certain embodiments, the front panel  102  and the back panel  104  are formed by plastic films that are substantially uniform in thickness, subject to standard manufacturing tolerances and variations, with an average thickness of between 0.4 mils and 4 mils for each panel  102 ,  104 . Moreover, in some embodiments, the average thickness of each of the respective panels  102 ,  104  is between 0.6 mil and 1.0 mil. Moreover, in certain preferred embodiments, the average thickness of each of the respective panels  102 ,  104  is between 0.75 mils and 1.0 mils. 
     In certain embodiments of the present invention, including the embodiment depicted in  FIG. 1 , the front panel  102  and back panel  104  of the drawstring trash bag  100  are comprised of a polymer blend, the polymer blend generally having linear low density polyethylene (LLDPE) as the primary component, but other polymers may be utilized including, but not limited to, other polyethylenes such as high density polyethylene (HDPE) or low density polyethylene (LDPE). Typically, the primary component of the polymer blend, such as linear low density polyethylene (LLDPE), will comprise at least 75% of the polymer blend. The remaining portion of the polymer blend may include additives including, but not limited to, coloring additives, anti-blocking agents, and/or odor control additives. 
     Looking briefly at  FIG. 4 , a cross-section view of one embodiment of the present invention, better illustrates certain aspects, features, and advantages of the present invention. In particular, an upper cross-section of a drawstring trash bag  100  is depicted although the thicknesses and dimensions are exaggerated to better illustrate the relation between the various parts of the particular embodiment. During manufacture of the drawstring trash bag, the distal edge  116  of the front panel  102 , i.e. the edge of the folded-over portion of the front panel  102  results from the fold-over defining the first hem  122  in the front panel  102  and a first drawstring  132  is disposed within the first hem  122 . Similarly, the distal edge  118  of the back panel  104  results from the fold-over defining the second hem  124  with a second drawstring  134  disposed in the second hem  124 . The upper boundaries of the hems  122 ,  124  define the upper opening  120  of the drawstring trash bag  100 . 
     The drawstrings  132 ,  134  may be comprised of traditional high-density polyethylene drawstrings or, in some embodiments, elastic or elastic-like polymeric components. The drawstrings  132 ,  134  are anchored to the front panel  102  and back panel  104  at the ends of the respective drawstrings  132 ,  134  near the first side edge  110  and second side edge  112 . In particular, the drawstrings  132 ,  134  are commonly anchored using short seals  136 ,  138  as shown in  FIGS. 1-3 , the short seals  136 ,  138  fusing both drawstrings  132 ,  134  with both the front panel  102  and the back panel  104 . Other than the anchor point, the drawstrings  132 ,  134  are generally loose within the hems  122 ,  124  enabling the drawstrings  122 ,  124  to be accessed and pulled through the respective drawstring cutouts  126 ,  128  centrally located between the first side edge  110  and second side edge  112 . Consequently, when the drawstrings  132 ,  134  are pulled through the drawstring cutouts  126 ,  128  of the drawstring trash bag  100 , the respective upper corners of the drawstring trash bag  100  are pulled together to facilitate closure of the bag. 
     Now looking at  FIGS. 1-4 , according to the depicted embodiment of the present invention the distal edges  116 ,  118  of the respective front and back panels  102 ,  104  are located a distance below the respective hems  122 ,  124 . Thus, the front panel  102  has an overlap area  142  that extends from the lower boundary of the first hem  122  to the distal edge  116  of the front panel  102 . In the same manner, the back panel  104  has an overlap area  144  that extends from the lower boundary of the second hem  124  to the distal edge  118  of the back panel  104 . Thus, for the front panel  102 , the overlap area  142  comprises two layers of polymeric film, and the hem overlap area  144  of the back panel  104  also comprises two layers of polymeric film according to the depicted embodiment. The length of the first overlap area  142  and the second overlap area  144  can be selected to be any length including a distance ending only slightly below the bottom boundaries of the respective hems  122 ,  124  or a distance that extends nearly to the bottom of the bag. However, in certain embodiments, it is desirable to provide a first overlap area  142  or second overlap area  144  of between 1 inch and 12 inches with a preferred range of 1.5 inches to 8 inches. 
     The overlap areas  142 ,  144  as shown in the depicted embodiments provide important benefits during use of the drawstring trash bag  100 . The primary benefit offered by the overlap areas  142 ,  144  is reinforcing the drawstring trash bag  100  in the areas immediately below the hems  122 ,  124 . As best illustrated by  FIG. 4 , it can be seen that the thickness of the polymeric film is essentially doubled in the overlap areas  142 ,  144  compared to the remaining area of the front panel  102  and back panel  104  below the overlap areas  142 ,  144 . The thicker overlap area  142 ,  144  is therefore expected to be stronger than the remainder of the bag. Thus, in the event that a consumer is carrying the bag or gripping the bag in one or both of the overlap areas  142 ,  144 , it is less likely that the drawstring trash bag  100  will puncture or tear in that particular area. By reducing the likelihood that the drawstring trash bag  100  will fail when a consumer grabs the drawstring trash bag  100  in the overlap areas  142 ,  144 , the drawstring trash bag  100  is more useful—especially when it contains heavier items or debris. 
     The depicted embodiment of  FIGS. 1-4  is illustrated as having hem seals  162 ,  164  extending the width of the drawstring trash bag  100 . Additionally, lower seals  172 ,  174  are provided in the respective panels  102 ,  104  proximate to the respective distal edges  116 ,  118 . By providing hem seals  162 ,  164  near the top of the overlap areas  142 ,  144  and lower seals  172 ,  174  near the bottom of the overlap areas  142 ,  144 , the two layers of plastic film comprising each overlap area  142 ,  144  are kept in close proximity, providing effectively a two-ply polymeric film of double thickness in the region of the overlap areas  142 ,  144 . For example, in the case of a front panel  102  and back panel  104  each having a nominal thickness of 0.7 mil, the overlap areas  142 ,  144  provide a thickness of roughly 1.4 mils, thereby providing a much stronger area for a consumer to grab, pull, and lift the trash bag. 
       FIG. 5  and  FIG. 6  depict a second embodiment of the present invention. Specifically,  FIG. 5  shows a perspective view of a drawstring trash bag  500  according to the disclosed embodiment with  FIG. 6  illustrating an elevation view of the front panel  102 . Although not expressly shown, a person of ordinary skill in the art would understand that the back panel  104  of the depicted embodiment could be constructed in the same manner as the depicted front panel  102  or in any other manner consistent with the present disclosure. 
     Looking at  FIG. 5  and  FIG. 6  together, the depicted embodiment of a drawstring trash bag  500  is very similar to the embodiment depicted earlier in  FIGS. 1-3  with the exception that instead of continuous lower seals extending across the width of the bag shown in the prior embodiment, in the depicted embodiment the lower seals  572 ,  574  are intermittent across the width of the drawstring trash bag  500 . The intermittent configuration of the seals facilitates the release of air that could potentially be trapped within the overlap areas  142 ,  144  during both manufacture and use of the drawstring trash bag  500 . 
       FIG. 7  and  FIG. 8  depict a third embodiment of the present invention. Specifically,  FIG. 7  shows a perspective view of a drawstring trash bag  700  according to the disclosed embodiment with  FIG. 8  illustrating an elevation view of the front panel  102 . Although not expressly shown, a person of ordinary skill in the art would understand that the back panel  104  of the depicted embodiment is constructed to be a mirror image of the front panel  102 , but could also be constructed in any other manner consistent with the present disclosure. 
     Looking at  FIG. 7  and  FIG. 8  together, the drawstring trash bag  700  lacks the transverse lower seals  172 ,  174  of previous embodiments and instead has lower seals  772 ,  774  comprised of a series of angular seals extending substantially across the entire height of the overlap areas  142 ,  144 , extending generally from the area below the hem seals  162 ,  164  down to a point just above the distal edges  116 ,  118  of the respective front panel  102  and back panel  104 . As with the hem seals  162 ,  164  and the lower seals  172 ,  174  of prior embodiments, the angular lower seals  772  join the overlap area  142  of the front panel  102  to the body portion of the same front panel  102 . Similarly, angular lower seals  774  bond the overlap area  144  of the back panel  104  to the body portion of the same back panel  104 . This configuration of the angular seals comprising the lower seals  772 ,  774  also facilitates the escape of any air trapped within the overlap areas  142 ,  144  during manufacture or use of the drawstring trash bag  700 . 
     A fourth embodiment of the present invention is shown in  FIG. 9  and  FIG. 10 , which discloses a drawstring trash bag  900  which again lacks the lower seals  172 ,  174  of previous embodiments and instead has lower seals  972 ,  974  comprised of a plurality of alternating smaller sealed areas, the individual sealed areas of lower seals  972  of the front panel  102  bonding the overlap area  142  of the front panel  102  to the body portion of the same front panel  102 . Similarly the individual sealed areas of the lower seals  974  bond the overlap area  144  of the back panel  104  to the body portion of the same back panel  104 . 
     A fifth embodiment of the present invention is shown in  FIG. 11  and  FIG. 12 , which is similar to the previously disclosed third embodiment. In this fifth disclosed embodiment, the drawstring trash bag  1100  has lower seals  1172 ,  1174  comprised of a series of sealed angular seals extending substantially across the height of the overlap areas  142 ,  144  down to a point just above the distal edges  116 ,  118  of the respective front panel  102  and back panel  104 . However, unlike previous embodiments, in this embodiment, traditional hem seals  162 ,  164  are omitted with the lower seals  1172 ,  1174  defining the bottom boundaries of the hems  122 ,  124 . 
     A sixth embodiment of the present invention is shown in  FIG. 13  and  FIG. 14 , which is similar in some aspects to the previously disclosed fourth embodiment. In this sixth disclosed embodiment, the drawstring trash bag  1300  has lower seals  1372 ,  1374  comprised of a plurality of alternating smaller sealed areas, the individual sealed areas of lower seals  1372  of the front panel  102  bonding the overlap area  142  of the front panel  102  to the body portion of the same front panel  102 . Similarly the individual sealed areas of the lower seals  1374  bond the overlap area  144  of the back panel  104  to the body portion of the same back panel  104 . Lower seals  1372 ,  1374  extend generally across the entire height of the overlap areas  142 ,  144  to a point just above the distal edges  116 ,  118  of the respective front panel  102  and back panel  104 . However, in the same manner as disclosed with respect to the fifth embodiment, traditional hem seals  162 ,  164  are omitted with certain lower seals  1372 ,  1374  defining the bottom boundaries of the hems  122 ,  124 . 
     A seventh embodiment of the present invention is shown in  FIG. 15A ,  FIG. 15B  and  FIG. 16 . In this seventh disclosed embodiment, the drawstring trash bag  1500  has a plurality of triangular embossed areas  1576 , each triangular embossed area  1576  comprising a plurality of embosses, preferably circular embosses. The triangular embossed areas  1576  extend substantially across the height of the overlap areas  142 ,  144  down to a point just above the distal edges  116 ,  118  of the respective front panel  102  and back panel  104 . In this particular embodiment, the triangular embossed areas  1576  are separated from one another by sets of sealed bands  1580 ,  1582 ,  1584 . Each set of sealed bands  1580 ,  1582 ,  1584  comprises a set of substantially parallel sealed areas extending across the overlap areas  142 ,  144 . The first set of sealed bands  1580  may extend in a direction generally parallel with the upper opening  120  and bottom of the bag. The second and third set of sealed bands  1582 ,  1584  are offset from one another, and the first set  1580 , by approximately 60 degrees. Each of the set of sealed bands  1580 ,  1582 ,  1584  seals the overlap areas  142 ,  144  to the respective panels  102 ,  104 . 
     An eighth embodiment of the present invention is shown in  FIG. 17  and  FIG. 18 . In this eighth disclosed embodiment, the drawstring trash bag  1700  has a plurality of parallelogram embossed areas  1776 , each parallelogram embossed area  1776  comprising a plurality of embosses, preferably circular embosses. The parallelogram embossed areas  1776  extend substantially across the height of the overlap areas  142 ,  144  down to a point just above the distal edges  116 ,  118  of the respective front panel  102  and back panel  104 . In this particular embodiment, the parallelogram embossed areas  1776  are separated by sealed bands  1780 . The sealed bands  1780  are substantially parallel to each other and extend across the overlap areas  142 ,  144 , preferably at an angle other than parallel to one of the sides  110 ,  112 , including the upper opening  120  or bottom  114 , of the drawstring trash bag  1700 . 
     A ninth embodiment of the present invention is shown in  FIG. 19  and  FIG. 20 . In this ninth disclosed embodiment, the drawstring trash bag  1900  has lower seals  1972 ,  1974  comprised of a series of curvilinear seals extending substantially across the height of the overlap areas  142 ,  144  down to a point just above the distal edges  116 ,  118  of the respective front panel  102  and back panel  104 . In this particular embodiment, the curvilinear seals  1972 ,  1974  are generally U-shaped with a narrowing along the middle of the U-shape. More importantly, the curvilinear lower seals  1972 ,  1974  are advantageous because the curvilinear edges of the respective seals  1972 ,  1974  reduce the likelihood of tears propagating. Like other previous embodiments, traditional hem seals are omitted with the lower seals  1972 ,  1974  defining the bottom boundaries of the hems  122 ,  124 . 
     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.