Patent Publication Number: US-8118489-B2

Title: Bag

Description:
BACKGROUND 
     Among their many applications, it is known to use thermoplastic bags as disposable liners for trash canisters. The trash canisters are typically made from a rigid material like plastic or metal. The bags intended to be used as liners for such refuse containers are typically made from low-cost, pliable or flexible thermoplastic material. When the receptacle is full, the thermoplastic liner actually holding the trash may be removed for further disposal and replaced with a new liner. 
     When being utilized as a trash canister liner, it is important that the bag be secured in a manner that the bag can extend vertically within the canister so that items placed into the canister fall and collect at the bottom of the bag. Additionally, it is important that the bag does not unsecure or release itself with respect to the trash receptacle so as to fall into the trash receptacle. To avoid this problem, the open circumference of the bag is often folded over the lip or rim of the trash canister and may be tied thereto in order to retain the bag to the trash canister. However, tying knots into liner bags in order to secure them to the canister is an inconvenient and time consuming process. 
     Therefore, it is desirable to develop a simpler and quicker method of securing trash bag liners to trash canisters. It is also desirable to facilitate the interaction between an elastic securing material and the relatively inelastic film substrate to secure a trash bag liner to a trash canister. It is also desirable to implement the securing method in such a manner that it is inexpensive and may be facilitated in a high speed manufacturing environment. 
     BRIEF SUMMARY 
     A thermoplastic bag intended to be used as a trash receptacle liner may be made from a first sidewall of thermoplastic material overlaid and joined to a second sidewall of the same or similar material to provide an interior volume. To provide an opening for accessing the interior volume, a top edge of the first sidewall may remain un-joined to a corresponding top edge of the second sidewall. When the bag is laid flat, the first and second sidewalls may lay adjacent one another with the first and second top edges extending adjacent and parallel to each other. When inserting the bag into a trash receptacle, the first and second sidewalls may be pulled apart from each other to open the opening and expand the interior volume. To close the opening when, for example, disposing of the liner bag, the bag may include a draw-tape that may be accommodated in a hem formed about the opening along either or both of the un-joined first and second top edges. 
     To assist in securing the bag to the trash canister, the bag includes an elongated elastic strap or strip, the length of which may stretch and contract. The elastic strap may be attached only by its first end to a first attachment point associated with the first sidewall and by its second end to a second attachment point associated with the opposing second sidewall. In various embodiments, the ends of the elastic strap may be attached to the draw-tape, to the inner surface of the first or second sidewalls proximate the top opening, or to the outer surfaces of the first and second sidewalls proximate the opening. The intermediate portion of the elastic strap may remain unattached or loose and may extend across the bag opening. Because the elastic strap is only attached at two attachment points associated with the first and second sidewalls, the relaxed or contracted elastic strap will not cause the sidewall material to bunch or constrict together when the bag is laid flat and the first and second top edges are adjacent one another. 
     However, the length of the elastic strap when relaxed or contracted may be less than the maximum width of the opening when the first and second sidewalls are pulled apart to open the bag. When the bag is inserted or installed in a trash canister, the elastic strap may stretch or flex to allow the first and second top edges providing the opening to be folded over the rim of the canister. The elastic strap may then contract or relax due to its elastic or resilient characteristics to provide a gripping force about the periphery of the canister thereby securing the bag to the canister. 
     The bag with an elastic strap may be produced by a high speed manufacturing process that processes continuous sheet-like webs of thermoplastic material into the finished bag via automated equipment. The process may include equipment that folds the edges of the web to provide hems and that introduces the draw-tape into the hems. Additionally, the process may direct a continuous strip or pre-cut strips of elastic material to the web and may intermittently or discontinuously attach the strips to the draw-tape or proximate the hems. Additional processing steps may be included to produce the finished bag. 
     A possible advantage of the thermoplastic bag having the elastic strap is that it may better secure itself to the refuse container and may resist falling into the container. Another possible advantage is that the elastic strap may be attached in such a way that, in its relaxed state, it does not bunch or constrict the sidewall material when the bag is laid flat. These and other possible advantages and features of the disclosure will become apparent from the description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a thermoplastic bag adapted for use as a trash receptacle liner which includes an elastic strap attached to a draw tape accommodated in a hem formed about the opening of the bag. 
         FIG. 2  is a front elevational view of the bag of  FIG. 1  illustrating the bag as laid flat with the opposing sidewalls adjacent one another. 
         FIG. 3  is a cross-sectional view taken along line  3 - 3  of the bag of  FIG. 1  illustrating the draw-tape accommodated in the hem. 
         FIG. 4  is a partial top plan view of the bag of  FIG. 1  illustrating the elastic strap attached to the draw-tape and extending across the opening. 
         FIG. 5  is a generalized top plan view of the bag of  FIG. 1  depicting lengths and dimensions of the bag opening and the attached elastic strap. 
         FIG. 6  is a perspective view of the bag of  FIG. 1  inserted into a trash canister with the opening folded about a rim of the canister and the elastic strap securing the bag to the canister. 
         FIG. 7  is a perspective view of another embodiment a thermoplastic bag adapted for use as a trash receptacle liner which includes an elastic strap attached to a draw tape accommodated in a hem formed about the opening of the bag. 
         FIG. 8  is a cross-sectional view taken along line  8 - 8  of  FIG. 7 . 
         FIG. 9  is a perspective view of the bag of  FIG. 7  inserted into a trash canister with the opening folded about a rim of the canister and the elastic strap securing the bag to the canister. 
         FIG. 10  is a perspective view of another embodiment of a thermoplastic bag adapted for use as a trash receptacle liner including an elastic strap attached to an inner surface of a hem accommodating a draw tape. 
         FIG. 11  is a partial top plan view of the bag of  FIG. 10  illustrating the elastic strap attached to the inner surface of the hem and extending across the opening. 
         FIG. 12  is a perspective view of the bag of  FIG. 10  inserted into a trash canister with the opening folded about a rim of the canister and the elastic strap securing the bag to the canister. 
         FIG. 13  is a cross-sectional view of another embodiment. 
         FIG. 14  is a perspective view of another embodiment of a thermoplastic bag adapted for use as a receptacle for a trash canister liner including an elastic strap attached to an outer surface of a hem accommodating a draw tape. 
         FIG. 15  is a cross-sectional view taken along line  15 - 15  of  FIG. 14  illustrating the draw tape accommodated in the hem and the elastic strap extending across the hem. 
         FIG. 16  is a perspective view of the bag of  FIG. 14  inserted into a trash canister with the opening folded about the rim of the canister and the elastic strap securing the bag to the canister. 
         FIG. 17  is a cross-sectional view of another embodiment. 
         FIG. 18  is a perspective view of another embodiment of a thermoplastic bag adapted for use as a liner for a trash canister including an elastic strap attached to an inner surface of the bag sidewalls below a hem accommodating a draw tape. 
         FIG. 19  is a partial top plan view of the bag of  FIG. 18  illustrating the elastic strap attached to the inner surface of the bag sidewalls and extending across the opening. 
         FIG. 20  is a perspective view of the bag of  FIG. 18  inserted into a trash canister with the opening folded about a rim of the canister and the elastic strap securing the bag to the canister. 
         FIG. 21  is a perspective view of another embodiment of a thermoplastic bag adapted for use as a trash canister liner including an elastic strap attached to the outer surface of the bag sidewall below a hem accommodating a draw tape. 
         FIG. 22  is a cross-sectional view taken along line  22 - 22  of  FIG. 21  illustrating the draw tape accommodated in the hem and the elastic strap extending across the bag opening. 
         FIG. 23  is a perspective view of the bag of  FIG. 21  inserted into a trash container with the opening folded about a rim of the container and the elastic strap securing the bag to the container. 
         FIG. 24  is a partial top view of another embodiment. 
         FIG. 25  is a perspective view of another embodiment. 
         FIG. 26  is a cross-sectional view taken along line  26 - 26  in  FIG. 25 . 
         FIG. 27  is a partial top view of another embodiment. 
         FIG. 28  is a cross-sectional view taken along line  28 - 28  in  FIG. 27 . 
         FIG. 29  is a perspective view of another embodiment. 
         FIG. 30  is a partial top view of the bag in  FIG. 29 . 
         FIG. 31  is a perspective view illustrating a patterned thermoplastic material that may be used for the bag sidewalls, the material being formed to have a stretchable or yieldable characteristic, the material being in the un-stretched condition. 
         FIG. 32  is a perspective view similar to that of  FIG. 31 , illustrating the thermoplastic material as stretched out. 
         FIG. 33  is a schematic representation of a high speed manufacturing process for producing thermoplastic bags of the foregoing type. 
         FIG. 34  is a schematic representation of another embodiment of a manufacturing process. 
     
    
    
     DESCRIPTION 
     Referring to  FIGS. 1 and 2 , a thermoplastic bag  100  may be used as a liner for trash receptacles and refuse containers. The bag  100  may be made from a first sidewall  102  and an opposing, second sidewall  104  that may be overlaid and may be joined to the first sidewall to define an interior volume  106  for holding trash. In the illustrated embodiment, the first and second sidewalls are rectangular in shape, but in other embodiments may have other suitable shapes. The first and second sidewalls  102 ,  104  may be joined together along a first side edge  110 , a second side edge  112  spaced apart from the first side edge, and a bottom edge  114  that extends between the first and second side seals. The sidewalls  102 ,  104  may be joined along their edges by any suitable joining process such as, for example, heat sealing in which the thermoplastic material bonds or melts together. Other sealing or joining processes may include ultrasonic methods and adhesive. 
     The first and second sidewalls  102 ,  104  may be made of flexible or pliable thermoplastic material formed or drawn into a smooth, thin-walled web or sheet. Examples of suitable thermoplastic materials may include polyethylenes, such as, high density polyethylene, low density polyethylene, linear low density polyethylene, very low density polyethylene, polypropylene, ethylene vinyl acetate, nylon, polyester, ethylene vinyl alcohol, or ethylene-methyl acrylate, and may be formed in combinations and in single or multiple layers. When used as a garbage can liner, the thermoplastic material may typically be opaque but may also be transparent, translucent, or tinted. Furthermore, the material used for the sidewalls may be a gas impermeable material and may include other features such as being treated with deodorants and/or disinfectants as is sometimes desirable in the production of trash can liners. 
     To access the interior volume  106 , the top edges  120 ,  122  may remain un-joined to provide an opening  124 . The un-joined top edges  120 ,  122  may be separated or pulled apart to open the bag  100 . To close the opening  124  when, for example, disposing of a filled liner bag, the bag may include one or more draw tapes  130 ,  131  along the opening. The draw tapes  130 ,  131  may be accommodated within first and second hems  132 ,  134  formed along the respective first and second top edges  120 ,  122 . The draw tapes  130 ,  131  may each be an elongated elastic tape of flexible, thermoplastic material which may be pulled to cinch closed the opening  124 . 
     Referring to  FIGS. 1 and 3 , to form the first hem  132 , a hem flap  140  that is an extension of the first sidewall material is folded back into the interior volume  106  about the first top edge  120  and attached to an interior surface of the first sidewall  102  at a first hem seal  142 . The folded over first hem flap  140  provides an enclosed channel or hem through which the draw tape  130  may freely extend. In another embodiment, the hem flap may be folded toward the exterior of the sidewall and may be attached to the exterior surface of the sidewall. The draw tape  130  may extend through the first hem  132  from the first side edge  110  to the second side edge  112  and may be fixedly attached to the sidewalls at the sealed together first and second side edges. The second hem  134  is likewise formed by folding a second hem flap  144  back into the interior volume and attaching the second hem flap to an interior surface of the second sidewall  104  at a second hem seal  146 . A second draw tape  131  is accommodated in and extends through the channel provided by the second hem  134 . To access the first and second draw tapes  130 ,  131 , notches  148  are disposed through the first and second hems  132 ,  134  about mid-length along the first and second top edges  120 ,  122 . Pulling the draw tapes through the notches  148  will constrict the top edges  120 ,  122  thereby drawing closed the opening  124 . 
     To assist in securing the bag  100  to a trash receptacle or canister, the bag may include an elongated elastic strap  150  attached at attachment points associated with the first and second sidewalls  102 ,  104 . The elastic strap  150  may be located proximate the opening  124  and may work in conjunction with the first and second top edges  120 ,  122  to hold the bag to the receptacle as described below. The elastic strap  150  may be made from a stretchable, elastic material that may be stretched or expanded in length and may resiliently contract back to its relaxed length. Examples of elastic materials may include rubber, polypropylene, polyethylene, isoprene, isobutylene, polyurethane (such as, spandex), and combinations thereof. 
     Referring to  FIG. 4 , in the present embodiment, the elongated strap  150  may be attached by its first end  152  to the draw tape  130  accommodated in the first hem  132  and by its second end  154  to the draw tape  131  accommodated in the second hem  134 . An intermediate portion  156  of the elastic strap  150  may remain loose and may extend across the opening  124 . In some embodiments, the elastic strap may be exclusively attached at the first and second ends to the respective first and second sidewalls. 
     To attach the ends of the elastic strap  150  to the draw tapes  130 ,  131 , as illustrated in  FIGS. 1 and 4  there are disposed through the first and second hems  132 ,  134  a respective first aperture  160  and a second aperture  162 . As illustrated, the apertures  160 ,  162  may be generally rectangular windows that expose the draw tape. In other embodiments, the apertures may have other shapes, such as, circular, oval, square, triangle, hexagonal, other polygons, asymmetric shapes, or other shapes. In other embodiments, the apertures  160 ,  162  may extend through both sides of the hem. In other embodiments, the apertures  160 ,  162  may be notches, such as, notches  1260 ,  1262  in  FIGS. 29-30 . In other embodiments, the aperture  160  may have a different shape than the aperture  162 . The apertures may expose the draw tape without substantially destroying the channel formed by the hems  132 ,  134 . The first end  152  of the elastic tape can be inserted into the first aperture  160  and attached to the first draw tape  130  by, for example, adhesive or heat sealing. The second end  154  of the strap  150  is inserted through the second aperture  162  and likewise attached to the second draw tape  131 . The intermediate portion  156  of the elastic strap  150  passes through the apertures  160 ,  162  and may traverse the opening  124  between the top edges  120 ,  122 . 
     The length of the elastic strap  150  when contracted or relaxed and the location of the attachment points may be selected so that the strap is normally situated between the first and second sidewalls  102 ,  104  within the opening  124 . For example, referring to  FIG. 5 , the attachment point  170  associated with the first sidewall  102  may be a distance  174  from the first side edge  110  of the bag. For example, the distance  174  may have a first range from about 1 inches (2.54 cm) to about 10 inches (25.4 cm), a second range from about 3 inches (7.62 cm) to about 7.5 inches (19.05 cm), and a third range from about 4.5 inches (11.43 cm) to about 5.5 inches (13.97 cm). In one embodiment, the distance  174  may be about 5 inches (12.7 cm). The second attachment point  172  associated with the second sidewall  104  may be a distance  175  from the first side edge  110 . The distance  175  may have the same dimensional information as distance  174 . In one embodiment, the distance  175  may be the same as distance  174 . In other embodiments, the distance  175  may be different than the distance  174 . 
     The relaxed length of the elastic strap  150  from the attachment point  170  to the attachment point  172  may be less than the sum of the distance  174  and the distance  175 . In one embodiment, the strap, when relaxed, may not extend to the side edge  110 , but the strap  150  may be situated within the opening  124 . For example, as illustrated in  FIG. 5 , when the strap  150  is directed or oriented toward the first side edge  110 , the strap  150  may have a relaxed distance  176  from the first attachment point  170  to an apex point  178  at which the strap folds back on itself and runs toward the second attachment point  172 . The distance  176  may be less than the distance  174  and the distance  175 . The distance  176  may have a first range from about 0.5 inches (1.27 cm) to about 10 inches (25.4 cm), a second range from about 0.75 inches (1.91 cm) to about 4 inches (10.16 cm), and a third range from about 1.25 inches (3.18 cm) to about 1.75 inches (4.45 cm). In one embodiment, the distance  176  may be about 1.5 inches (3.81 cm). 
     The bag may have a width  179 . The width  179  may have a first range from about 8 inches (20.32 cm) to about 40 inches (101.6 cm), a second range from about 23 inches (58.42 cm) to about 31 inches (78.74 cm), and a third range from about 23 inches (58.42 cm) to about 25 inches (63.5 cm). In one embodiment, the width  179  may be about 24 inches (60.96 cm). 
     A possible advantage of configuring the relaxed length of the strap to be less than the sum of the distances between the attachment points and the side edge is that, when the bag is laid flat on one of its sidewalls, the strap is situated within the opening between the sidewalls. This may simplify packaging and distribution of the bag. Another possible advantage is that because the strap is only attached at its first and second ends and intermediate portion remains loose, the strap will not bunch or constrict the relatively inelastic sidewall material when the bag is laid flat. Hence, the bag as laid flat may have the appearance as illustrated in  FIG. 2 . 
     The elastic characteristic of the elastic strap  150 , however, will allow a user to stretch the strap outward proximate to or beyond the first side edge  110 . Referring to  FIG. 6 , this may enable the first and second top edges  120 ,  122  delineating the opening to be folded over or wrapped around the rim  182  of a trash receptacle  180 . For example, the combined length of the first and second top edges  120 ,  122  may be greater than the distance about the rim  182  of the receptacle  180  so that the top edges may be folded over the rim. The bag  100  may be partially inserted into the trash receptacle  180  and the opening provided by the first and second top edges  120 ,  122  is turned inside out and over the rim  182 . This folding and turning action stretches the elastic strap  150  to become commensurate with the side edge  110  as the strap is moved outward and over the receptacle rim  182 . The tension on the elastic strap  150  is then released allowing the strap to contract and the strap pulls the draw tapes  130 ,  131  about the perimeter of the receptacle  180 . The elastic strap may provide a gripping force for holding the bag to the receptacle and the bag may resist falling into the receptacle when large or heavy objects are placed or dropped into the bag. The location of the attachment points of the elastic strap and the degree of elasticity of the strap material may control the distance the strap may be stretched and the gripping force provided, and those factors may be adjusted or varied accordingly. 
     Referring to  FIGS. 7 ,  8 , and  9 , another embodiment of a bag  200  is shown. The bag  200  may be similar to bag  100  except that the strap  250  may be attached to the draw tapes  230 ,  231  through apertures  260 ,  262  in the outside portion of the hems  232 ,  234 . The intermediate portion  256  of the strap  250  may run over and about the first and second edges  220 ,  222  to traverse the opening  224 . Referring to  FIG. 7 , the total length of the elastic strap  250  between the first and second attachment points  270 ,  272  may be less than the sum of the distance  274  between the first attachment point  270  of the first end  252  and the first side edge  210  and the distance  275  between the second attachment point  272  of the second end  254  and the first side edge  210 . Accordingly, the elastic strap when relaxed may not extend to the first side edge  210  of the bag. 
     Referring to  FIG. 7 , the strap  250  may have a distance  276  from the first attachment point  270  to an apex point  278 . The distance  274  may have the same dimensional information as distance  174 . The distance  275  may have the same dimensional information as distance  175 . The distance  276  may have the same dimensional information as distance  176 . 
     The elastic characteristic of the elastic strap  250 , however, will allow a user to stretch the strap outward proximate to or beyond the first side edge  210 . Referring to  FIG. 9 , this may enable the first and second top edges  220 ,  222  delineating the opening to be folded over or wrapped around the rim  282  of a trash receptacle  280 . For example, the combined length of the first and second top edges  220 ,  222  may be greater than the distance about the rim  282  of the receptacle  280  so that the top edges may be folded over the rim. The bag  200  may be partially inserted into the trash receptacle  280  and the opening provided by the first and second top edges  220 ,  222  is turned inside out and over the rim  282 . This folding and turning action stretches the elastic strap  250  to become commensurate with the side edge  210  as the strap is moved outward and over the receptacle rim  282 . The tension on the elastic strap  250  is then released allowing the strap to contract and the strap pulls the draw tapes  230 ,  231  about the perimeter of the receptacle  280 . The elastic strap may provide a gripping force for holding the bag to the receptacle and the bag may resist falling into the receptacle when large or heavy objects are placed or dropped into the bag. 
     In other embodiments of the bag, the elastic strap does not need to be attached to the draw tape to function in the foregoing manner. For example, referring to  FIGS. 10 ,  11  and  12 , there is illustrated another embodiment of a thermoplastic bag  300  intended for use as a trash receptacle liner that is equipped with an elastic strap  350 . Referring to  FIGS. 10 and 11 , the thermoplastic bag  300  may have a first sidewall  302  and a second sidewall  304  of pliable thermoplastic material that are overlaid and joined to each other to provide an interior volume  306 . The first and second sidewalls  302 ,  304  may be rectangular in shape and may be joined along a first side edge  310 , a second side edge  312 , and a bottom edge  314 . The first and second side edges may be joined by, for example, heat sealing. To access the interior volume  306 , the first and second top edges  320 ,  322  of the respective sidewalls  302 ,  304  may remain un-joined to delineate an opening  324 . To close the opening  324 , first and second draw tapes  330 ,  331  may be positioned in respective first and second hems  332 ,  334  formed along the first and second top edges  320 ,  322 . The draw tapes  330 ,  331  may be drawn or pulled through notches  348  disposed through the hems  332 ,  334  to constrict the opening  324 . 
     The elastic strap  350  may be provided as an elongated strip or length of elastic material that enables the strap to stretch and contract. Referring to  FIG. 11 , the strap  350  may be attached at a first end  352  to an attachment point  370  associated with the first sidewall  302  and at its second end  354  to a second attachment point  372  associated with a second sidewall  304 . In the present embodiment, the first end  352  is attached to the inwardly folded hem flap that provides the first hem  332  and the second end  354  attaches to the inwardly folded hem flap of the second hem  334 . The intermediate length  356  of the elastic strap  350  traverses the opening  324  between the first and second top edges  320 ,  322 . 
     The length of the elastic strap  350  and the location of the attachment points may be selected so that the strap normally is situated within the bag opening  324  between the first and second top edges  320 ,  322 . For example, the first attachment point  370  may be a distance  374  from the first side edge  310 . The second attachment point  372  may be a distance  375  from the first side edge  310 . The elastic strap  350  may have a distance  376  from the first attachment point  370  to an apex point  378  at which the strap folds back and is directed toward the second attachment point  372 . The distance  376  may be less than the distance  374  and the distance  375  so that the strap does not extend to the first side edge  310 . The relaxed length of the strap  350  from the attachment point  370  to the attachment point  372  may be less than the sum of the distance  374  and the distance  375 . The distance  374  may have the same dimensional information as distance  174 . The distance  375  may have the same dimensional information as distance  175 . The distance  376  may have the same dimensional information as distance  176 . 
     The elastic characteristic enables the elastic strap to stretch outwardly proximate to or beyond the first side edge to facilitate inserting and securing the bag to a trash receptacle. Referring to  FIG. 12 , when the bag  300  is inserted into the receptacle  380  and the first and second top edges  320 ,  322  are folded over the receptacle rim  382 , the elastic strap  350  stretches to become commensurate with the first side edge  310  of the bag. The tension on the elastic strap is then released causing the strap  350  to recover or contract while pulling the first and second hems  332 ,  334  about the perimeter of the receptacle  380 . This elastic pulling force secures or holds the bag to the receptacle. 
     In another embodiment, the attachment points may be at the hem seals. Referring to  FIG. 13 , the bag  400  may be similar to bag  300  except that the first attachment point  470  of the first strap end  452  of the strap  450  may be at the hem seal  442  on the first sidewall  402  and the second attachment point  472  of the second strap end  454  may be at the hem seal  446  on the second sidewall  404 . 
     In other embodiments, the elastic strap can be attached to the bag so as to be situated outside the interior volume. For example, referring to  FIGS. 14 , and  15 , a thermoplastic bag  500  may include first and second thermoplastic sidewalls  502 ,  504  overlaid and joined to one another to provide an interior volume  506 . The sidewalls  502 ,  504  may be joined along a first side edge  510 , a second side edge  512 , and a bottom edge  514 . The interior volume  506  may be accessible via an opening  524  delineated by un-joined first and second top edges  520 ,  522  of the respective first and second sidewalls  502 ,  504 . To close the opening  524 , the bag  500  may include first and second draw tapes  530 ,  531  positioned in respective first and second hems  532 ,  534  formed along the first and second top edges  520 ,  522 . The draw tapes  530 ,  531  may be drawn or pulled through notches  548  disposed through the hems  532 ,  534  to close the opening  524 . 
     The elastic strap  550  may be length or strip of elastic material that may stretch and contract. The elastic strap  550  may be attached by a first end  552  to the exterior of the first sidewall  502  at the first hem  532  and at a second end  554  to the exterior of the second sidewall  504  at the second hem  534 . The intermediate portion  556  of the elastic strap  550  runs over and about the first and second top edges  520 ,  522  to traverse the opening  524 . Referring to  FIG. 14 , the total length of the elastic strap  550  between the first and second attachment points  570 ,  572  may be less than the sum of the distance  574  between the first attachment point  570  of the first end  552  and the first side edge  510  and the distance  575  between the second attachment point  572  of the second end  554  and the first side edge  510 . Accordingly, the elastic strap when relaxed may not extend to the first side edge  510  of the bag. 
     Referring to  FIG. 14 , the strap  550  may have a distance  576  from the first attachment point  570  to an apex point  578 . The distance  574  may have the same dimensional information as distance  174 . The distance  575  may have the same dimensional information as distance  175 . The distance  576  may have the same dimensional information as distance  176 . 
     Referring to  FIG. 16 , the elastic characteristic allows a user to stretch the elastic strap  550  to and beyond the first side edge  510  when installing the bag  500  in a trash receptacle  580 . As illustrated, the elastic strap  550  stretches when the first and second top edges  520 ,  522  are folded over the receptacle rim  582 . The strap  550  may then contract and may pull the hems  532 ,  534  about the perimeter of the receptacle  580  and may secure the bag to the receptacle. Because the elastic strap  550  is attached to the exterior of the bag  500 , the strap may be located between the folded-over sidewall and the receptacle  580 . 
     In another embodiment, the attachment points may be at the hem seal. Referring to  FIG. 17 , the bag  600  may be similar to bag  500  except that the first attachment point  670  of the first strap end  652  of the strap  650  may be at the hem seal  642  on the first sidewall  602  and the second attachment point  672  of the second strap end  654  may be the hem seal  646  on the second sidewall  604 . 
     Referring to  FIGS. 18 and 19 , there is illustrated another embodiment of a thermoplastic bag  700  intended for use as a trash receptacle liner. The bag may include overlapping first and second sidewalls  702 ,  704  that may be joined together along first and second side edges  710 ,  712  and a bottom edge  714  to provide an interior volume  706 . The interior volume  706  may be accessible via an opening  724  provided by the un-joined first and second top edges  720 ,  722  of the respective side walls. To close the opening, a draw tape  730  may be positioned in a hem  732  formed along the top edge  720  of the first sidewall  702  and a second draw tape  731  may be positioned in a second hem  734  formed along the top edge  722  of the second sidewall  704 . The draw tapes  730 ,  731  may be drawn through notches  748  disposed through the first and second hems  732 ,  734 . 
     The elastic strap  750  may be an elongated strip of elastic material that may be attached at a first end  752  to a first attachment point associated with the first sidewall  702  and at a second end  754  to a second attachment point associated with the second sidewall  704  such that an intermediate portion  756  extends across the opening  724 . In the present embodiment, the attachment points are located below the first and second hems  732 ,  734 . For example, the first end  752  of the strap  750  is attached to an inner surface of the first sidewall  702  below where the flap of the first hem  732  seals to the inner surface. The second end  754  is attached below the second hem  734  on the opposite second sidewall  704 . The elastic strap is situated within the opening  724 . The relaxed length of the strap and location of the attachment points may be selected so that the strap does not extend all the way to the first side edge  710 . The distance  774  may have the same dimensional information as distance  174 . The distance  775  may have the same dimensional information as distance  175 . The distance  776  may have the same dimensional information as distance  176 . 
     Referring to  FIG. 19 , the first attachment point of the first strap end  752  may be located a distance  758  below the hem  732 . The distance  758  may have a first range from about 0 inches (0 cm) to about 30 inches (76.2 cm), a second range from about 0 inches (0 cm) to about 1 inch (2.54 cm), and a third range from about 0.25 inches (0.64 cm) to about 0.75 inches (1.91 cm). In one embodiment, the distance  758  may be about 0.5 inches (1.27 cm). The second attachment point of the second end  754  may be located a distance  760  below the second hem  734 . The distance  760  may have the same dimensional information as distance  758 . The distance  758  may be the same as distance  760 . In other embodiments, the distance  758  may be different than the distance  760 . 
     Referring to  FIG. 19 , the first attachment point  770  may be a distance  774  from the first side edge  710 . The second attachment point  772  may be a distance  775  from the first side edge  710 . The strap  750  may have a distance  776  from the first attachment point  770  to an apex point  778 . The relaxed length of the strap  750  from the attachment point  770  to the attachment point  772  may be less than the sum of the distance  774  and the distance  775 . The distance  774  may have the same dimensional information as distance  174 . The distance  775  may have the same dimensional information as distance  175 . The distance  776  may have the same dimensional information as distance  176 . 
     Referring to  FIG. 20 , the elastic characteristic allows the strap to stretch and contract when installing the bag  700  as a liner in a trash receptacle  780 . Specifically, when the first and second top edges  720 ,  722  are folded over the rim  782 , the elastic strap  750  may stretch outward to be commensurate with the first side edge  710 . The elastic strap  750  may then partially recover or contract to pull the sidewalls  702 ,  704  about the perimeter of the trash receptacle  780 . This may help hold the bag to the receptacle and may prevent the bag from falling into the receptacle. 
     Referring to  FIGS. 21 and 22 , there is illustrated another embodiment of a thermoplastic bag  800  intended for use as a trash receptacle liner with an elastic strap for securing the bag to the receptacle. The bag  800  may include first and second sidewalls  802 ,  804  that may be overlaid and joined to each other along a first side edge  810 , a second side edge  812  and a bottom edge  814  to provide an interior volume  806 . The top edges  820 ,  822  of the respective first and second sidewalls may remain un-joined to provide an opening  824  through which the interior volume  806  may be accessed. To close the opening, a draw tape  830  may be positioned in a first hem  832  formed along the top edge  820  of the first sidewall  802  and a second draw tape  831  may be positioned in a second hem  834  formed along the top edge  822  of the second sidewall  804 . The draw tapes  830 ,  831  may be drawn through notches  848  disposed through the first and second hems  832 ,  834 . 
     The elastic strap  850  may be formed as an elongated strip of elastic material that may be attached by a first end  852  to a first attachment point associated with the first side wall and at second end  854  to a second attachment point associated with the second sidewall. In the illustrated embodiment, the first and second ends  852 ,  854  are attached to the exterior of the sidewalls  802 ,  804  generally below the first and second hems  832 ,  834 . The intermediate portion  856  of the strap extends over and around the first and second top edges  820 ,  822  to cross over the opening  824 . As described above, the relaxed length of the elastic strap and the distance between the attachment points and the sidewall may be selected so that the strap does not normally extend to the side edge  810 . 
     Referring to  FIG. 22 , the attachment points of the first end  852  may be a distance  858  below the hem  832 . The distance  858  may have a first range from about 0 inches (0 cm) to about 5 inches (12.7 cm), a second range from about 0 inches (0 cm) to about 1 inch (2.54 cm), and a third range from about 0.25 inches (0.64 cm) to about 0.75 inches (1.91 cm). In one embodiment, the distance  858  may be about 0.5 inches (1.27 cm). The second attachment point of the second end  854  may be located a distance  860  below the second hem  834 . The distance  860  may have the same dimensional information as distance  858 . The distance  858  may be the same as distance  860 . In other embodiments, the distance  858  may be different than the distance  860 . 
     Referring to  FIG. 21 , the first attachment point  870  may be a distance  874  from the first side edge  810 . The second attachment point  872  may be a distance  875  from the first side edge  810 . The strap  850  may have a distance  876  from the first attachment point  870  to an apex point  878 . The relaxed length of the strap  850  from the attachment point  870  to the attachment point  872  may be less than the sum of the distance  874  and the distance  875 . The distance  874  may have the same dimensional information as distance  174 . The distance  875  may have the same dimensional information as distance  175 . The distance  876  may have the same dimensional information as distance  176 . 
     Referring to  FIG. 23 , the elastic characteristic of the elastic strap  850  enables the strap to stretch when the bag  800  is installed on a trash receptacle  880 . More specifically, the strap  850  may stretch or expand to become commensurate with the first side edge  810  when the first and second top edges  820 ,  822  are folded over the rim  882  of the receptacle. The elastic strap  850  may then relax or contract to pull the first and second side walls  802 ,  804  about the perimeter of the trash receptacle and may hold the bag to the receptacle. 
     In other embodiments, the first attachment point of one embodiment may be used with the second attachment point of another embodiment. For example in one embodiment, the elastic strap may have a first attachment point  170  of  FIG. 5  and a second attachment point  372  of  FIG. 11 . In another example, an elastic strap may have a first attachment point  170  of  FIG. 5  and a second attachment point  572  of  FIG. 14 . 
     Referring to  FIG. 24 , another embodiment of a bag  900  is shown. The bag  900  may be similar to bag  100  in  FIG. 4  except that the second end  954  of the strap  950  may be attached to the hem  934  at attachment point  972 . The attachment point  972  may be similar to the attachment point  372  in  FIG. 11 . The strap  950  may be attached at a first end  952  to an attachment point  970  associated with the first sidewall  902 . The first end  952  may be attached to the draw tape  930  at attachment point  970 . The first end  952  may be attached to the inside of the draw tape  930 . The draw tape  930  may be accommodated in the first hem  932 . The hem  932  may include an aperture  960  to expose the draw tape  930 . The strap  950  may be attached at a second end  954  to an attachment point  972  associated with a second sidewall  904 . The second end  954  may be attached to second hem  934 . The second end  954  may be attached to the inside of the second hem  934 . The intermediate length  956  of the strap may traverse the opening  924 . The elastic strap  950  when relaxed may not extend to the first side edge  910 . The elastic characteristic of the elastic strap  950  may allow a user to stretch the strap  950  outward proximate to or beyond the first side edge  910 . The elastic strap  950  may provide a gripping force for holding the bag to the receptacle. The bag  900 , including the strap  950  and the location of the attachment points, may have the same dimensional ranges and information as the bag  100  including the strap  150  and the locations of the attachment points, such as, distances  174 ,  175 ,  176 ,  179 . 
     Referring to  FIGS. 25 and 26 , another embodiment of a bag  1000  is shown. The bag  1000  may be similar to bag  200  in  FIG. 7  except that the second end  1054  of the strap  1050  may be attached to the draw tape at attachment point  1072 . The attachment point  1072  may be similar to the attachment point  172  in  FIG. 1 . The strap  1050  may be attached at a first end  1052  to an attachment point  1070  associated with the first sidewall  1002 . The first end  1052  may be attached to the draw tape  1030  at attachment point  1070 . The first end  1052  may be attached to the outside of the draw tape  1030 . The draw tape  1030  may be accommodated in the first hem  1032 . The hem  1032  may include an aperture  1060  to expose the draw tape  1030 . The strap  1050  may be attached at a second end  1054  to an attachment point  1072  associated with a second sidewall  1004 . The second end  1054  may be attached to the draw tape  1031  at attachment point  1072 . The second end  1054  may be attached to the inside of the draw tape  1031 . The draw tape  1031  may be accommodated in the second hem  1034 . The hem  1034  may include an aperture  1062  to expose the draw tape  1031 . The intermediate length  1056  of the strap may traverse the opening  1024 . The elastic strap  1050  when relaxed may not extend to the first side edge  1010 . The elastic characteristic of the elastic strap  1050  may allow a user to stretch the strap  1050  outward proximate to or beyond the first side edge  1010 . The elastic strap  1050  may provide a gripping force for holding the bag to the receptacle. The bag  1000 , including the strap  1050  and the location of the attachment points, may have the same dimensional ranges and information as the bag  100  including the strap  150  and the locations of the attachment points, such as, distances  174 ,  175 ,  176 ,  179 . 
     Referring to  FIGS. 27 and 28 , another embodiment of a bag  1100  is shown. The bag  1100  may be similar to bag  400  in  FIG. 13  except that the second end  1154  of the strap  1150  may be attached to the hem  1134  at attachment point  1172 . The attachment point  1172  may be similar to the attachment point  372  in  FIG. 11 . The strap  1150  may be attached at a first end  1152  to an attachment point  1170  associated with the first sidewall  1102 . The first end  1152  may be attached to the hem  1132  at attachment point  1170 . The first end  1152  may be attached to the hem seal  1142 . The strap  1150  may be attached at a second end  1154  to an attachment point  1172  associated with a second sidewall  1104 . The second end  1154  may be attached to the second hem  1134 . The second end  1154  may be attached to the inside of the second hem  1134 . The intermediate length  1156  of the strap may traverse the opening  1124 . The elastic strap  1150  when relaxed may not extend to the first side edge  1110 . The elastic characteristic of the elastic strap  1150  may allow a user to stretch the strap  1150  outward proximate to or beyond the first side edge  1110 . The elastic strap  1150  may provide a gripping force for holding the bag to the receptacle. The bag  1100 , including the strap  1150  and the location of the attachment points, may have the same dimensional ranges and information as the bag  100  including the strap  150  and the locations of the attachment points, such as, distances  174 ,  175 ,  176 ,  179 . 
     Referring to  FIGS. 29-30 , another embodiment of a bag  1200  is shown. The bag  1200  may be similar to bag  100  in  FIG. 1  except that that the apertures  1260 ,  1262  may be notches. The strap  1250  may be attached at a first end  1252  to an attachment point  1270  associated with the first sidewall  1202 . The first end  1252  may be attached to the draw tape  1230  at attachment point  1270 . The first end  1252  may be attached to the inside of the draw tape. The draw tape  1230  may be accommodated in the first hem  1232 . The hem  1232  may include an aperture  1260  to expose the draw tape  1230 . The aperture  1260  may be a notch. The notch may be open at the top of the hem  1232 . The strap  1250  may be attached at a second end  1254  to an attachment point  1272  associated with a second sidewall  1204 . The second end  1254  may be attached to the draw tape  1231  at attachment point  1272 . The second end  1254  may be attached to the inside of the draw tape. The draw tape  1231  may be accommodated in the second hem  1234 . The hem  1234  may include an aperture  1262  to expose the draw tape  1231 . The aperture  1262  may be a notch. The notch may be open at the top of the hem  1234 . The intermediate length  1256  of the strap may traverse the opening  1224 . The elastic strap  1250  when relaxed may not extend to the first side edge  1210 . The elastic characteristic of the elastic strap  1250  may allow a user to stretch the strap  1250  outward proximate to or beyond the first side edge  1210 . The elastic strap  1250  may provide a gripping force for holding the bag to the receptacle. The bag  1200 , including the strap  1250  and the location of the attachment points, may have the same dimensional ranges and information as the bag  100  including the strap  150  and the locations of the attachment points, such as, distances  174 ,  175 ,  176 ,  179 . 
     In other embodiments, the strap  1250  may be attached to the outside of one or both of the draw tapes. In other embodiments, the notches may have different shapes, such as, a circular notch, an oval notch, a square notch, a triangular notch, a hexagonal notch, other polygon shaped notches, asymmetric shaped notches, or other shapes of notches. In other embodiments, the aperture  1260  may have a different shape than the aperture  1262 . The notches may be used with any of the embodiments described herein, as appropriate. 
     The bag may include additional features to facilitate its use as a trash receptacle liner. For example, a patterning may be imparted or embossed to all or part of the thermoplastic sidewalls to provide the bag with a stretchable or yieldable characteristic so that the bag may accommodate large or bulky items. Examples of such patterns and similar features are disclosed in U.S. Pat. No. 6,139,185; U.S. Publication No. 2004/0134923; U.S. Pat. No. 6,394,651; U.S. Pat. No. 6,394,652; U.S. Pat. No. 6,150,647; U.S. Pat. No. 6,513,975; and U.S. Pat. No. 6,695,476, each of which is herein incorporated by reference in its entirety. 
     Referring to  FIGS. 31 and 32 , the pattern  1300  may be formed as a plurality of stretchable or strainable networks in which the normally planar, sheet-like thermoplastic material of the first and second sidewalls may be bunched together in a series of parallel wrinkles or creases. These include a plurality of first regions  1302  that may correspond to the planar sheet of the sidewall and a plurality of second regions  1304  formed as rib-like elements that may protrude from the plane of the first regions and that may appear bunched or contracted together when in an un-tensioned state illustrated in  FIG. 31 . When a pulling force  1306  is applied as indicated in  FIG. 32 , the rib-like second regions may be able to unbend or geometrically deform so that the first and second regions may become substantially co-planar with each other. This un-bunching action may stretch or elongate the pattern thereby adding to the overall area of the sidewalls. Thus, the bag may expand or increase in volume when large or bulky items are inserted into it and come into contact with the sidewalls. This stretching and yielding of the sidewalls may help absorb and dissipate the force otherwise created by the inserted object thereby improving the toughness and durability of the bag. The thermoplastic material into which the pattern  1300  is imparted may demonstrate shape memory causing the first and second regions to return to the geometry of the un-tensioned state illustrated in  FIG. 31  when the applied forces are removed. 
     Bags of the aforementioned type may be produced in a high speed, automated manufacturing process such as that illustrated in  FIG. 33 . The illustrated manufacturing process  1400  may include automated equipment and arranged stations that may convert continuous sheet-like webs of planar, thermoplastic material into the finished bags. The webs may initially be provided in roll of thermoplastic sheet material. For example, a first web  1401  of flexible thermoplastic material may be unwound from a first roll  1402  and movingly directed along a machine direction  1406  by the processing equipment. When unwound, the first web  1401  may have a first side edge  1410  and a second side edge  1412  that define a width  1414  that may be perpendicular to the machine direction  1406 . 
     To provide the enclosed interior volume of the finished bag, the web  1401  may be folded in half orthogonally about the machine direction  1406  by a folding operation  1420 . When folded in half, the first and second side edges  1410 ,  1412  may be moved adjacent to each other. The width  1424  of the folded web  1401  may be half of the width  1414  of the unfolded web. Moreover, once folded, the center of the web  1401  provides an outer edge  1422  that may correspond to the bottom edge of the finished bag. In another embodiment, the roll  1402  may have a pre-folded web and the folding operation is not necessary. 
     The process may include equipment that provides for installing the draw tapes within the hems. For example, in a hem-forming operation  1430 , the adjacent edges  1410 ,  1412  of the web may be folded inwardly parallel to the machine direction  1406  to provide the channel-like hems. The draw tape may be formed from a continuous strip  1432  of thermoplastic material that is unwound from a roll  1434  and directed by appropriately placed rollers  1436  to run parallel to the machine direction  1406  and between the folded over edges  1410 ,  1412  of the web  1401 . A plurality of elongated elastic straps  1440  may be provided and may be attached by their ends to the advancing web  1401  by an attachment operation  1442 . Depending upon the embodiment being made, apertures may be provided in one or more hems so that the elastic strap may be attached to one or more draw tapes. Additionally, notches  1444  may be disposed into the web to expose the installed strip  1432  that will become the draw tape. 
     To provide the side edges of the finished bag, side seals  1450  may be formed into the web  1401  at intermittent spaces along the web and may be perpendicular to the machine direction  1406 . The spaced apart seals may be symmetrical and identical to each other. The seals  1450  may be formed as generally straight, continuous lines that extend between the aligned edges  1410 ,  1412  and the edge  1422  of the folded web. To form the seals, the advancing web  1401  may be directed through a sealing operation  1452  in which heated bars or rollers may be pressed against the web to form heat seals in the thermoplastic material. The sealing operation may also fixedly attach together the thermoplastic web and the draw tape that is accommodated in the folded-over side edges  1410 ,  1412  corresponding to the hems. In another embodiment, the elastic straps  1440  may be attached to the web after the sealing operation  1452  has been completed. 
     After forming the side seals  1450 , the web  1401  may be directed through a perforating operation  1454  in which perforations  1456  are made at the side seals  1450 . In another embodiment, the web may be folded one or more times before the web is perforated. Thus, individual bags  1480  may be detached from the web  1401  at the perforations  1456 . The individual bags  1480  which are attached to each other may be directed into a roll  1482 . The roll  1482  may be placed in a box or bag for sale to a customer. The user may then detach the bags from the roll along the perforations  1456 . 
     In another embodiment, referring to  FIG. 34 , the individual bags  1490  may be detached and separated from the other bags on the processed web by a cutting operation  1492 . In another embodiment, the web may be folded one or more times before the web is cut. The individual bags  1490  may be packaged for distribution. For example, the bags  1490  may be wound into a roll  1494  for packaging and distribution. For example, the roll  1494  may be placed in a box or bag for sale to a customer. The bags  1490  may be interleaved prior to winding into the roll  1494 . In another embodiment, the bags  1490  may be positioned in a box or bag, and not onto the roll  1494 . The bags  1490  may be interleaved prior to positioning in the box or bag. 
     Additional equipment may be included for applying patterns to the thermoplastic web as discussed above. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein may be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     Exemplary embodiments are described herein. Variations of those embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor(s) expect skilled artisans to employ such variations as appropriate, and the inventor(s) intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.