High strength plastic bag

Information

  • Patent Grant
  • 6702460
  • Patent Number
    6,702,460
  • Date Filed
    Friday, March 22, 2002
    22 years ago
  • Date Issued
    Tuesday, March 9, 2004
    20 years ago
Abstract
A high strength plastic bag is formed from two sheets of polymeric material. The sheets are folded, machined, and heat sealed to form a receptacle portion, a flap for covering an opening to the receptacle portion, and a handle having three layers of polymeric material for improved strength. The bag includes a tamper-indicating closure and has a high friction coefficient to prevent sliding of stacked bags.
Description




FIELD OF THE INVENTION




This invention relates to plastic bags, and more particularly to a high strength plastic bag.




BACKGROUND OF THE INVENTION




Plastic bags have been widely used to contain various articles. Such plastic bags include tamper-indicating bags, which have been used to secure sensitive or valuable items during transit. These tamper-indicating bags have often been used to transfer money in the form of paper money, checks, or coins. The use of plastic bags to transfer coins presents several problems, however. For example, when plastic bags are used to accommodate more than a small number of coins, the bags need to be strong so they do not rupture under the weight of the coins. To make carrying the bag easier, the plastic bags require a means for grasping the bag. Prior plastic bags having handles to permit a user to grasp the bags are limited with respect to the amount of coins which may be contained in the bag because the heavy weight of a large number of coins tends to tear the bag at the handle. Furthermore, conventional plastic bags are susceptible to sliding against one another, making it difficult to stack the bags atop one another.




There is thus a need for a high strength plastic bag which may be used to contain and transport coins, and which overcomes the drawbacks of prior art plastic bags.




SUMMARY OF THE INVENTION




The present invention provides a high strength plastic bag which may be used to contain and carry heavy items, such as coins. The bag is formed from two sheets of polymeric material which have been, folded, die stamped, and heat sealed to create a receptacle portion, a handle portion, and a flap portion. The handle portion of the bag includes an aperture which permits a user to grasp the bag and comprises three sheets of high strength polymeric material that have been joined with heat seals to provide added strength to the handle.




The flap portion of the bag covers an opening to the receptacle and may be sealed over the opening with a tamper-evident adhesive to secure the bag. In one aspect of the invention, the flap portion further includes a removable receipt which may be detached from the bag for record keeping purposes. In another aspect of the invention, a second removable receipt is formed on the handle portion of the bag.




In yet another aspect of the invention, the bag is formed from polymeric material having a high friction coefficient so that the bags may be stacked atop one another without slipping.











The features and objectives of the present invention will become more readily apparent from the following Detailed Description taken in conjunction with the accompanying drawings.




BRIEF DESCRIPTION OF THE DRAWINGS




The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention.





FIG. 1

is a perspective view of an exemplary plastic bag of the present invention;





FIG. 2

is a cross-section of the bag shown in

FIG. 1

, taken along lines


2





2


; and





FIG. 3

is a cross-section of the bag of

FIG. 2

, depicting the bag in a sealed condition with first and second receipts detached from the bag.











DETAILED DESCRIPTION




Referring to

FIGS. 1-3

, there is shown an exemplary plastic bag


10


of the present invention. The plastic bag


10


is formed from two sheets of plastic material


12


,


14


. The first sheet


12


is folded in an overlapping manner and heat sealed to form an interior compartment. First sheet


12


is also folded together with the second sheet


14


to form a handle for carrying the bag


10


. As formed, the bag


10


includes a receptacle portion


16


, a handle portion


18


, and a flap portion


20


. The receptacle portion


16


of the bag


10


is formed by folding the first sheet


12


over itself to form a first folded edge


22


and first and second overlapping layers


24


,


26


. When the side edges


28


,


30


of the folded sheet are heat sealed, the first and second layers


24


,


26


of the first sheet


12


form a compartment


32


defined by the sealed edges


28


,


30


and the first folded edge


22


. The interior of the compartment


32


may be accessed by an opening


33


created by the unsealed free edge


34


of the second layer


26


.




The handle and flap portions


18


,


20


of the bag


10


are formed by folding the first layer


24


of the first sheet


12


back over itself to create a second folded edge


36


whereby the free edge


38


of the first layer


24


extends beyond the free edge


34


of the second layer


26


. The second plastic sheet


14


is inserted between the folds of the first layer


24


of the first sheet


12


so that at least part of the handle portion


18


comprises three layers of plastic. The handle portion


18


further includes an aperture


40


formed through the three layers of the handle portion


18


at a distance from an end of the bag


10


. In an exemplary embodiment, the aperture


40


is formed a distance of approximately 2½ to 4 inches from an end of the bag


10


. In another exemplary embodiment, the aperture


40


is formed at least approximately 3 inches from an end of the bag


10


. The aperture


40


is surrounded by a heat seal around its perimeter. Upper and lower heat seals


42


,


44


above and below the aperture


40


join the three layers of plastic material.




The second sheet


14


of the handle is a polymeric sheet which has been developed for strength and heat sealability. It can be formed from standard polyolefins, blends or coextrusions. In an exemplary embodiment, the second sheet has inner and outer layers formed from a blend of linear low density ethylene and metalocene and a stiffening middle layer, such as high density polyethylene (HDPE).




The flap portion


20


extends over the opening


33


formed by the free edge


34


of the second layer


26


of the first sheet


12


to form a closure for the bag. In the exemplary embodiment shown, the bag


10


is provided with an adhesive


46


applied to the second layer


26


of the first sheet


12


near the opening


33


created by the free edge


34


, whereby the flap


20


may be bonded to the second layer


26


to seal the bag


10


. A release liner


47


may be provided over the adhesive


46


to protect the adhesive


46


from contamination and to prevent premature bonding prior to sealing the bag


10


. In an exemplary embodiment, the adhesive


46


is a tamper-indicating adhesive and the bag


10


is printed with tamper-indicating ink near the opening


33


, as described more fully in U.S. Pat. No. 6,196,716 to Geyer, herein incorporated by reference in its entirety. After the bag


10


is sealed as described above, the tamper-indicating adhesive


46


provides an indication of when the flap portion


20


has been opened the first time. In this manner, the plastic bag


10


provides a secure means for containing sensitive or valuable items.




The plastic bag


10


further includes one or more receipt portions


48


,


50


which may be removed from the bag


10


for record keeping purposes. In the exemplary embodiment shown, the bag


10


includes two receipt portions


48


,


50


which may be removed from the bag


10


. A first receipt portion


48


is removably attached to the handle portion


18


of the bag


10


, and a second receipt portion


50


is removably attached to the flap portion


20


of the bag


10


. In the exemplary embodiment, the receipt portions


48


,


50


are formed by perforations


51


,


53


formed on the bag


10


a distance from the edges


36


,


38


of the handle and flap portions


18


,


20


to create a removable strip of plastic material. Ink or other visible material may be applied to the bag


10


to create viewable areas


52


for marking the bag


10


with indicia


54


. Such markable areas


52


are particularly useful on the receptacle and receipt portions


16


,


48


,


50


, but may be applied to any portion of the bag


10


as desired.




A high strength plastic bag


10


as described above may be formed from two sheets of plastic material


12


,


14


according to the following exemplary method. The first sheet


12


of polymeric material is folded to form a first folded edge


22


and first and second overlapping layers


24


,


26


whereby the first layer


24


extends beyond a free edge


34


of the second layer


26


. A second sheet


14


of polymeric material is positioned on a portion of the first layer


24


of the first sheet


12


, at a distance from the free edge


34


of the second layer


26


. The first layer


24


of the first sheet


12


is folded over the second sheet


14


and a portion of the second layer


26


of the first sheet


12


to sandwich the second sheet


14


between the folds of the first layer


24


, forming a second folded edge


36


and a flap


20


which covers the free edge


34


of the second layer


26


.




The first and second side edges


28


,


30


of the first folded sheet


12


are heat sealed to define an interior compartment


32


between the first and second overlapping layers


24


,


26


of the first sheet


12


and an opening


33


to the interior compartment


32


at the free edge


34


of the second layer


26


. The first sheet


12


of polymeric material is perforated near the second folded edge


36


to define a first removable receipt


48


. The first sheet


12


of polymeric material is perforated near the edge


38


of the flap


20


to define a second removable receipt


50


. An aperture


40


is formed through the folds of the first layer


24


of the first sheet


12


and through the second sheet


14


sandwiched between the folds of the first sheet


12


, at a distance of at least three inches from the perforation defining the first removable receipt


48


. The first and second sheets


12


,


14


are heat sealed around the perimeter of the aperture


40


and at locations


42


,


44


above and below the aperture


40


.




Indicia


54


may be printed on any portion of the plastic bag


10


either before or after formation of the bag


10


. In an exemplary embodiment, ink


60


is applied to portions of the first sheet


12


near the side edges


28


,


30


and the opening


33


formed by the free edge


34


of the second layer


26


of the first sheet


12


. The ink


60


applied in these areas prevents the flap portion


20


of the bag


10


from sealing against the bag


10


when the bag


10


is machined.




While the present invention has been illustrated by the description of the various embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in anyway limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of applicant's general inventive concept.



Claims
  • 1. A plastic bag having a high strength handle, comprising:a receptacle portion having first and second opposing walls, said first and second walls joined substantially around the perimeters of said walls to define an interior cavity for receiving articles and an opening permitting access to said interior cavity; a handle portion having an aperture whereby user may grasp said handle portion; a flap portion integral with said receptacle portion and proximate said opening, said flap portion extending over said opening to form a closure for said opening; said handle portion further comprising first and second outer plastic layers and an interior plastic layer sandwiched between said first and second outer layers; upper and lower lateral heat seals above and below said aperture, respectively, and a heat seal around said aperture; a tamper-indicating adhesive disposed on said receptacle portion proximate said opening to bond said flap portion over said opening to seal the bag; a first receipt portion frangibly attached to said handle portion above said heat seal; and a second receipt portion frangibly attached to said flap portion and having a printed area.
  • 2. The bag of claim 1 wherein said handle portion is located at a distal end of said bag and said aperture is located at least approximately 3 inches inboard of said end of said bag.
  • 3. The bag of claim 1 wherein said first receipt is a discrete strip of material formed by perforating the bag proximate a distal end of said bag.
  • 4. The bag of claim 1 wherein said second receipt is a discrete strip of material formed by perforating the bag proximate a distal end of said flap portion.
  • 5. The bag of claim 1 wherein the entire bag is formed from two sheets of polymeric material which are folded, die cut, and heat sealed to form said individual receptacle, handle, flap, and receipt portions.
US Referenced Citations (4)
Number Name Date Kind
5908243 Hanning Jun 1999 A
6190043 Diplock Feb 2001 B1
6196716 Geyer Mar 2001 B1
6431752 Diplock Aug 2002 B1
Foreign Referenced Citations (4)
Number Date Country
0 430 558 Feb 1994 EP
2238291 May 1991 GB
2238292 May 1991 GB
002250011 May 1992 GB
Non-Patent Literature Citations (1)
Entry
Sample and photographs of plastic retail security bag, first produced circa 1999-2000.