The present invention relates to reclosable plastic bags and, in particular to a zipper strip for use in the manufacture of such bags.
As reclosable plastic bags become increasingly more popular as primary packaging for food stuffs and other commodities, the need has arisen for more complex closures such as those featuring slider operated fasteners that can be used to manufacture more sophisticated packages. For example, certain foods require hermetic packaging. Accordingly, the closure is required to carry a hermetic seal, either above or below the interlocking elements of the zipper to insure the integrity of the package. In many applications the closure is required to provide for tamper resistance or, at least evidence any tampering. This may be accomplished by providing a rupturable membrane or peel seal either above or below the interlocking elements or a header surrounding the zipper interlocking elements which must be ruptured to gain access to the package contents. Another desirable feature for many packages is the provision of a hang tag to enhance the display of the package.
Heretofore, the closures and packaging techniques were required to be more or less custom designed to provide the particular features required. This customized packaging is inherently expensive and the need has arisen for a universal closure which, with relatively minimum alteration and expense can be used in a wide variety of applications.
In view of the above, it is a principal object of the present invention to provide a zipper strip, particularly one having an associated slider, which, with relatively slight modifications in the method of its attachment can provide a wide range of features to a resultant package.
A further object is to provide such a strip which, may relatively easily be modified, as required to provide desired features to a resultant package.
A still further object is to provide such a zipper strip that may readily be utilized in existing form, fill and seal equipment.
The above and other beneficial objects and advantages are attained in accordance with the present invention by providing an improved zipper strip having a base member from which first and second profiles extend upwardly. Each of the profiles comprises an arm having one of a set of interlocking members attached. The base member including a first web extending between the arms; a second web, outboard of the first arm; and a third web, outboard of said second arm. One or both surface of the webs may be coated and/or the webs may be perforated to thereby impart desired characteristics to the package formed with the zipper.