BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, FIG. 1 is a side view of a polystyrene bag having a blended polyethylene zipper;
FIG. 2 is a side view of a second embodiment of a polystyrene bag having a blended polyethylene zipper;
FIG. 3 is a third embodiment of a polystyrene bag having two zippers located thereon; and
FIG. 4 is a partial end view of the bag of FIG. 1 showing the zipper in a closed position.
DESCRIPTION OF A PREFERRED EMBODIMENT
In FIG. 1, a thermoplastic bag 2 is made from a polystyrene material and a zipper 4 is made from a blended polyethylene material. The zipper 4 is welded to the bag 2. The polystyrene is a polystyrene resin that contains additives and the polyethylene is a blend of polyethylene that enables the zipper to be welded to the bag. Preferably, the polystyrene resin is a styrene-butadiene copolymer. Chevron Phillips product K-resin, DK13 (a trademark) is a suitable polystyrene. The blended polyethylene is a low density polyethylene with a metallocene sealing membrane. Preferably, the metallocene sealing member is co-extruded onto a blended polyethylene base layer. A suitable blended polyethylene zipper is manufactured by Presto Products (a trademark). The polystyrene film from which the bag is made provides a clear, glossy bag with good physical properties such as good tear strength and puncture resistance. The polystyrene material of the bag and polyethylene material of the zipper must be sufficiently compatible to enable the zipper to be welded to the bag. The bag 2 has a gusset 6 along a bottom portion thereof. The top of the bag 2 has a tearaway portion 8 located above the perforated line 10. The tearaway portion 8 has openings 12 therein. The openings can be used to hang several of the bags 2 from a holder (not shown). The zipper 4 is located beneath the tearaway portion 8. In FIG. 2, a bag 14 has a zipper 4 located near a top 16 with a retention portion located below a sealing line 20. The retaining portion 18 has openings 12 therein. The tearaway position 8 is a header.
In FIG. 3, the bag 22 is similar to the bag 2 shown in FIG. 1 except that the bag 22 has two zippers 4 located adjacent to one another. The same reference numerals are used in FIGS. 1 to 3 to describe those components that are identical.
In FIG. 4, there is shown a partial end view of the zipper 4 mounted in a bag 24 having a front side 26 and a rear side 28. The zipper 4 has two projections 30, 32 that are sized and shaped to removably fit within two receptacles 34, 36. The two projections 30, 32 are fixed to the front side 26 and the two receptacles 34, 36 are fixed to the rear side 28. The projection 32 is much larger than the projection 30 and fits snugly within the receptacle 36. The projection 30 fits more loosely in the receptacle 34. The receptacles 34, 36 each have a movable membrane 38 thereon that flexes to open when the projections 30, 32 are inserted into the receptacles 34, 36 and the zipper 4 is then in a closed position that is shown in FIG. 4. When the projections 30, 32 are located outside of the receptacles 34, 36, the zipper 4 is in an open position (not shown). The smaller projection 30 and receptacle 34 are easier to close and open than the larger projection 32 and the receptacle 36. The projections 30, 32 are mounted on a zipper moiety 40 on the front side 26 and the receptacles 34, 36 are mounted on a zipper moiety 42 on the rear side 28 on the bag 24. The zipper 4 is reopenable.
The zipper moieties can be designed to fit snugly or loosely together or the zipper moieties can be designed to permanently close the opening between the zipper moieties when the zipper moieties are closed. When the opening is permanently closed, the bag cannot be opened without noticeably damaging the bag by making a hole in one of the sides or by damaging or cutting the zipper moieties. Further, a zipper can have only one projection on one zipper moiety and one receptacle on the corresponding zipper moiety. A zipper can have more or fewer than two projections and receptacles. The zipper is not limited to the design shown in FIG. 4. Various sizes, shapes and types of zippers can be used.
As shown in FIGS. 1 to 3, polystyrene bags using polyethylene zippers as shown in the drawings can be of various designs. In addition to the designs shown in FIGS. 1 to 3, numerous other designs will also be suitable. For example, a polystyrene bag can have a zipper or zippers located along a lower portion of the bag and a zipper or zippers located along an upper portion of the bag. The zippers of a bag can be reopenable or they can be designed to be permanently closed as soon as they are closed for the first time.
The bag shown in FIG. 2 can have perforations located above the zipper to make the bag easier to open. A bag can have one zipper along a top of the bag and one zipper along a bottom of the bag. Reopenable zipper(s) can be used on the same bag as permanently closed zipper(s). The gussets shown are optional and can be used on any bag as desired. A zipper can extend completely across the bag or only partially along the bag. The shape of the bags can also vary.
Patent Application
20080069484
