String zipper designs for slider-operated reclosable packaging
A reclosable package comprising a receptacle having a mouth, a string zipper joined to the receptacle at the mouth, the string zipper comprising first and second mutually interlockable zipper strips, and a slider mounted over the string zipper to cause the first and second zipper strips to separate when the slider is moved in one direction along the string zipper and to cause the first and second zipper strips to interengage each other when the slider is moved in an opposite direction along the string zipper. In one exemplary embodiment, the first flangeless zipper strip comprises two monohook elements, and the second flangeless zipper strip also comprises two monohook elements. In another exemplary embodiment, the first flangeless zipper strip comprises one monohook element and one double hook element, while the second flangeless zipper strip comprises three monohook elements.
This application is a continuation-in-part of and claims priority from U.S. patent application Ser. No. 10/401,365 filed on Mar. 27, 2003 and entitled “Reclosable Packaging Having Slider-Operated String Zipper”.
BACKGROUND OF THE INVENTIONThis invention generally relates to zippers for use in reclosable packaging, such as bags or pouches. In particular, the invention relates to string zippers for reclosable bags.
Reclosable bags are finding ever-growing acceptance as primary packaging, particularly as packaging for foodstuffs such as cereal, fresh vegetables, snacks and the like. Such bags provide the consumer with the ability to readily store, in a closed, if not sealed, package any unused portion of the packaged product even after the package is initially opened.
Reclosable bags comprise a receptacle having a mouth with a zipper for opening and closing. In recent years, many zippers have been designed to operate with a slider mounted thereon. As the slider is moved in an opening direction, the slider causes the zipper sections it passes over to open. Conversely, as the slider is moved in a closing direction, the slider causes the zipper sections it passes over to close. Typically, a zipper for a reclosable bag includes a pair of interengageable profiled closure strips that are joined at opposite ends of the bag mouth. The profiles of interengageable plastic zipper strips can take on various configurations, e.g. interlocking rib and groove elements having so-called male and female profiles, interlocking alternating hook-shaped closure elements, etc. Reclosable bags having slider-operated zippers are generally more desirable to consumers than bags having zippers without sliders because the slider eliminates the need for the consumer to align the interengageable zipper profiles before causing those profiles to engage.
In one type of slider-operated zipper assembly, the slider straddles the zipper and has a separating finger at one end that is inserted between the profiles to force them apart as the slider is moved along the zipper in an opening direction. The other end of the slider is sufficiently narrow to force the profiles into engagement and close the zipper when the slider is moved along the zipper in a closing direction.
In the past, many interlocking closure strips were formed integrally with the bag making film, for example, by extruding the bag making film with the closure strips formed on the film. Such constructions, however, were limited by the conditions required to extrude both the film and zipper together. To avoid such limitations, many bag designs entail separate extrusion of the closure strips, which are subsequently joined to the bag-making film, for example, by conduction heat sealing. These separate closure strips typically have flanges extending therefrom in such a way that the flanges can be joined to bag-making film in order to attach the closure strips to the film. Previous slider-operated, separately extruded zippers used flange-type constructions.
An alternative zipper design is the so-called flangeless or string zipper, which has substantially no flange portion above or below the interengageable closure profiles. In the case of a string zipper, the bag-making film is joined to the backs of the bases of the closure strips. String zippers can be produced at much greater speeds, allow much greater footage to be wound on a spool, thereby requiring less set-up time, and use less material than flanged zippers, enabling a substantial reduction in the cost of manufacture and processing.
There is a continuing need for new designs for reclosable bags that can be manufactured at low cost.
BRIEF DESCRIPTION OF THE INVENTIONThe present invention is directed to zipper improvements in reclosable packages that have a slider-operated string zipper attached to a receptacle, the slider being employed to open or close the string zipper for allowing or denying access to the interior volume of the receptacle.
One aspect of the invention is a reclosable package comprising: a receptacle comprising first and second walls, respective portions of the first and second walls forming a mouth that communicates with an interior volume of the receptacle; a string zipper comprising mutually interengageable first and second flangeless zipper strips, the first flangeless zipper strip having a back joined to the portion of the first wall, and the second flangeless zipper strip having a back joined to the portion of the second wall; and a slider mounted over the string zipper to cause the first and second flangeless zipper strips to separate when the slider is moved in one direction along the string zipper and to cause the first and second flangeless zipper strips to interengage each other when the slider is moved in an opposite direction along the string zipper, the slider comprising first and second sidewalls, the portions of the first and second walls joined to the first and second flangeless zipper strips passing between the first and second sidewalls of the slider, wherein the first flangeless zipper strip comprises a first monohook element, the second flangeless zipper strip comprises a second monohook element, and the first and second monohook elements interfere with each other during relative movement of the first and second zipper strips into and out of interengagement.
Another aspect of the invention is a reclosable package comprising a receptacle having a mouth, a string zipper joined to the receptacle at the mouth, the string zipper comprising first and second mutually interlockable zipper strips, and a slider mounted over the string zipper to cause the first and second zipper strips to separate when the slider is moved in one direction along the string zipper and to cause the first and second zipper strips to interengage each other when the slider is moved in an opposite direction along the string zipper, wherein the first flangeless zipper strip comprises a first monohook element, the second flangeless zipper strip comprises a second monohook element, and the first and second monohook elements interfere with each other during relative movement of the first and second zipper strips into and out of interengagement.
A further aspect of the invention is a reclosable package comprising a receptacle having a mouth, a string zipper joined to the receptacle at the mouth, the string zipper comprising first and second mutually interlockable zipper strips, and a slider mounted over the string zipper to cause the first and second zipper strips to separate when the slider is moved in one direction along the string zipper and to cause the first and second zipper strips to interengage each other when the slider is moved in an opposite direction along the string zipper, wherein the first flangeless zipper strip comprises a first backup element, a first monohook element and a double hook element, the first backup element and the first monohook element defining a first groove therebetween, and the second flangeless zipper strip comprises second, third and fourth monohook elements, the second and third monohook elements defining a second groove therebetween, the double hook element being received in the second groove, and the fourth monohook element being received in the first groove.
Yet another aspect of the invention is a reclosable package comprising a receptacle having a mouth, a string zipper joined to the receptacle at the mouth, the string zipper comprising first and second mutually interlockable zipper strips, and a slider mounted over the string zipper to cause the first and second zipper strips to separate when the slider is moved in one direction along the string zipper and to cause the first and second zipper strips to interengage each other when the slider is moved in an opposite direction along the string zipper wherein the first flangeless zipper strip comprises first and second backup elements and first and second monohook elements, the first backup element and the first monohook element defining a first groove therebetween, and the second backup element and the second monohook element defining a second groove therebetween; and the second flangeless zipper strip comprises third and fourth monohook elements, the third monohook element being received in the first groove, and the fourth monohook element being received in the second groove.
Other aspects of the invention are disclosed and claimed below.
BRIEF DESCRIPTION OF THE DRAWINGS
Reference will now be made to the drawings in which similar elements in different drawings bear the same reference numerals.
DETAILED DESCRIPTION OF THE INVENTION A reclosable package comprising a receptacle 2 and a flexible plastic string zipper 4 operated by manipulation of a slider 10 is shown in
The receptacle 2 may be made from any suitable film material, including thermoplastic film materials such as low-density polyethylene, substantially linear copolymers of ethylene and a C3-C8 alpha-olefin, polypropylene, polyvinylidene chloride, mixtures of two or more of these polymers, or mixtures of one of these polymers with another thermoplastic polymer. The person skilled in the art will recognize that this list of suitable materials is not exhaustive. The thickness of the film is preferably 2 mils or less. The receptacle 2 comprises opposing walls (only the front panel 2a is visible in
At its top end, the receptacle 2 has an openable mouth, on the inside of which is an extruded plastic string zipper 4. The string zipper 4 comprises a pair of interengageable zipper strips. One zipper strip 6 is visible in
The string zipper is operated by sliding the slider 10 along the zipper strips. As the slider moves across the zipper, the zipper is opened or closed. As shown in
The package shown in
A string zipper design in accordance with a first embodiment of the present invention is depicted in
The profiles of the lower portion of the string zipper 4 are constructed for effectively resisting opening separation from the interlocking engagement shown in
In accordance with the embodiment shown in
Hook flange 38 of rib 22 is of substantially greater mass, and thus greater stiffness, than the hook flange 36 of rib 22. The hook flange 44 of the hooked element 28 may also be provided with substantial mass, so that the engaged hook flanges 38 and 44 afford substantial resistance to separation due to internal forces generated within the receptacle of the package that tend to push the walls 2a and 2b apart. Further, to assist in the resistance to internal force separation of the hook flanges 38 and 44, the hooked element 28 has a curved profile, providing a concavity that receives hook flange 38 of rib 22, so that there is minimum stress tending to separate the hooked element 28 from the rib 22 when the wall 2b bows outwardly under internal pressure within the bag. Nevertheless, both of the hooked elements 28 and 30 are relatively resiliently flexible for enabling their relative movement past head 34 of rib 22 during zipper closure manipulation. After alignment of the profiled closure elements with the grooves therebetween as shown in
The upper portion of the string zipper 4 comprises a hooked element 32 projecting from the base 26 of the second flangeless zipper strip 8 and a hooked element 24 projecting from the base 20 of the first flangeless zipper strip 6. The distal end of hooked element 32 has a generally downwardly projecting hook flange 46, which engages a generally upwardly projecting hook flange 48 of hooked element 24. The hooked element 24 is disposed in back-to-back relation to hooked element 30 in a mutually supportive but separable relation. In addition, the first flangeless zipper strip 6 also comprises first and second backup flanges 50, 52 projecting substantially perpendicularly from the base 20 and respectively overlying the hooked elements 28 and 32 in backup relation. In effect, the hooked element 24 and the backup flange 52 define a groove that receives hooked element 32; and the rib 22 and the backup flange 50 define a groove that receives hooked element 28.
When maneuvering to close the string zipper 4, the hooked elements 24 and 32 assist in the zipper closing registration or aligning relation as shown in
Although the lower portion of the string zipper 4 is so constructed and arranged that there is efficient, substantially assured resistance against separation due to internal pressures within the receptacle of the package, and the upper portion of the string zipper, together with the lower portion will maintain an effective closure of the receptacle, opening of the receptacle when desired is easily effected by means of a slider 10, the closing end of which is seen in
To open the closed string zipper, the slider must be moved in an opening direction. During slider movement in the opening direction, the separating finger pries the zipper strips 6 and 8 apart with sufficient force to pull the interengaged profiled closure elements apart. When the hook flanges of flangeless zipper strip 6 clear the hook flanges of the second flangeless zipper strip 8, zipper strips are no longer interlocked and the zipper is open, as seen in
As seen in
As seen in
The slider may be made in multiple parts and welded together or the parts may be constructed to be snapped together. The slider may also be of one-piece construction. The slider can be made using any desired method, such as injection molding. The slider can be molded from any suitable plastic, such as nylon, polypropylene, polystyrene, acetal, polyketone, polybutylene terephthalate, high-density polyethylene, polycarbonate, or ABS.
A string zipper design in accordance with a second embodiment of the invention is shown in
The zipper strip 6 comprises a base 82 and first and second hooked elements 84 and 86 projecting from that base, each hooked element having a respective hook flange or detent 88 and 90 at its distal end. The zipper strip 8 comprises first and second hooked elements 70 and 72 projecting from the bottom and top respectively of a base 68. The hook flanges 88, 90 of hooked elements 84, 86 project away from each other; the hook flanges 74, 76 of hooked elements 70, 72 project toward each other. When the string zipper is closed (as depicted in
The flangeless zipper strip 6 shown in
The zipper design shown in
Different variations of a string zipper design in accordance with a third embodiment of the invention are shown in
In each of the variations depicted in
Each of the zipper designs shown in
The variation shown in
In both of the variations depicted in
The package in accordance with the fourth embodiment further comprises a slider 10′ (shown in
While the invention has been described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for members thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation to the teachings of the invention without departing from the essential scope thereof. For example, the zipper strips and frangible connection need not be extruded from the same plastic material. More specifically, the connection could be made of a material that is more brittle than the material used to form the zipper strips. Therefore it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
As used in the claims, the term “package” includes bags, pouches, and any other type of packaging in which a flexible plastic zipper can be incorporated. As used in the claims, the verb “joined” means fused, bonded, sealed, adhered, etc., whether by application of heat and/or pressure, application of ultrasonic energy, application of a layer of adhesive material or bonding agent, interposition of an adhesive or bonding strip, etc. As used in the claims, the term “string zipper” means a zipper comprising two interengageable zipper strips that have substantially no flange portions. As used in the claims, the term “monohook element” means a hook element having a single hook flange; the term “double hook element” means a hook element having two hook flanges directed oppositely; and the term “backup element” means an element not having any hook flanges.
Claims
1. A reclosable package comprising:
- a receptacle comprising first and second walls, respective portions of said first and second walls forming a mouth that communicates with an interior volume of said receptacle;
- a string zipper comprising mutually interengageable first and second flangeless zipper strips, said first flangeless zipper strip having a back joined to said portion of said first wall, and said second flangeless zipper strip having a back joined to said portion of said second wall; and
- a slider mounted over said string zipper to cause said first and second flangeless zipper strips to separate when said slider is moved in one direction along said string zipper and to cause said first and second flangeless zipper strips to interengage each other when.said slider is moved in an opposite direction along said string zipper, said slider comprising first and second sidewalls, said portions of said first and second walls joined to said first and second flangeless zipper strips passing between said first and second sidewalls of said slider,
- wherein said first flangeless zipper strip comprises a first monohook element, said second flangeless zipper strip comprises a second monohook element, and said first and second monohook elements interfere with each other during relative movement of said first and second zipper strips into and out of interengagement.
2. The package as recited in claim 1, wherein said first flangeless zipper strip further comprises a first backup element, said first backup element and said first monohook element defining a first groove therebetween, said first groove receiving a portion of said second monohook element when said first and second zipper strips are interengaged.
3. The package as recited in claim 1, wherein said second flangeless zipper strip further comprises a third monohook element, said second and third monohook elements defining a first groove therebetween, said first groove receiving a portion of said first monohook element when said first and second zipper strips are interengaged.
4. The package as recited in claim 3, wherein said first flangeless zipper strip further comprises a double hook element, said second flangeless zipper strip further comprises a fourth monohook element, and said third and fourth monohook elements define a second groove therebetween, said second groove receiving a portion of said double hook element when said first and second zipper strips are interengaged.
5. The package as recited in claim 3, wherein said second and third monohook elements comprise respective hook flanges that project in substantially the same direction, while said first monohook element comprises a hook flange that projects in a generally opposite direction.
6. The package as recited in claim 1, wherein said first flangeless zipper strip comprises a third monohook element, said second flangeless zipper strip comprises a fourth monohook element, and said third and fourth monohook elements interfere with each other during relative movement of said first and second zipper strips into and out of interengagement.
7. The package as recited in claim 6, wherein said first and third monohook elements are disposed between said second and fourth monohook elements.
8. The package as recited in claim 7, wherein said first and third monohook elements define a channel therebetween, and said second flangeless zipper strip further comprises an alignment element that projects into said channel when said first and second zipper strips are interengaged and that assists in aligning said first and second zipper strips with each other as they move toward each other and into interengagement.
9. The package as recited in claim 8, wherein said alignment element spreads said first and third monohook elements apart when said first and second zipper strips are interengaged.
10. The package as recited in claim 8, wherein said alignment element backs up said first and third monohook elements when said first and second zipper strips are interengaged.
11. The package as recited in claim 8, wherein said alignment element comprises a cylindrical portion and a stem portion, said cylindrical portion being connected to said base of said second flangeless zipper strip by said stem portion.
12. The package as recited in claim 6, wherein said second and third monohook elements comprise respective hook flanges that project in generally the same first direction, whereas said first and fourth monohook elements comprise respective hook flanges that project in generally the same second direction, said second direction being opposite to said first direction.
13. The package as recited in claim 6, wherein said first flangeless zipper strip further comprises first and second backup elements, said first backup element and said first monohook element defining a first groove therebetween, said first groove receiving a portion of said second monohook element when said first and second zipper strips are interengaged, and said second backup element and said third monohook element defining a second groove therebetween, said second groove receiving a portion of said fourth monohook element when said first and second zipper strips are interengaged.
14. The package as recited in claim 6, wherein said first and third monohook elements comprise respective hook flanges that project in generally the same first direction, whereas said second and fourth monohook elements comprise respective hook flanges that project in generally the same second direction, said second direction being opposite to said first direction.
15. The package as recited in claim 6, wherein said slider comprises a top wall connected to said first and second sidewalls, and a plow having one end connected to said top wall, said plow being inclined at an angle relative to said top wall that is not a right angle.
16. A reclosable package comprising a receptacle having a mouth, a string zipper joined to said receptacle at said mouth, said string zipper comprising first and second mutually interlockable zipper strips, and a slider mounted over said string zipper to cause said first and second zipper strips to separate when said slider is moved in one direction along said string zipper and to cause said first and second zipper strips to interengage each other when said slider is moved in an opposite direction along said string zipper, respective portions of said mouth passing between mutually opposing sidewalls of said slider, wherein said first flangeless zipper strip comprises a first monohook element, said second flangeless zipper strip comprises a second monohook element, and said first and second monohook elements interfere with each other during relative movement of said first and second zipper strips into and out of interengagement.
17. A reclosable package comprising a receptacle having a mouth, a string zipper joined to said receptacle at said mouth, said string zipper comprising first and second mutually interlockable zipper strips, and a slider mounted over said string zipper to cause said first and second zipper strips to separate when said slider is moved in one direction along said string zipper and to cause said first and second zipper strips to interengage each other when said slider is moved in an opposite direction along said string zipper, respective portions of said mouth passing between mutually opposing sidewalls of said slider, wherein said first flangeless zipper strip comprises a first backup element, a first monohook element and a double hook element, said first backup element and said first monohook element defining a first groove therebetween, and said second flangeless zipper strip comprises second, third and fourth monohook elements, said second and third monohook elements defining a second groove therebetween, said double hook element being received in said second groove, and said fourth monohook element being received in said first groove.
18. A reclosable package comprising a receptacle having a mouth, a string zipper joined to said receptacle at said mouth, said string zipper comprising first and second mutually interlockable zipper strips, and a slider mounted over said string zipper to cause said first and second zipper strips to separate when said slider is moved in one direction along said string zipper and to cause said first and second zipper strips to interengage each other when said slider is moved in an opposite direction along said string zipper, respective portions of said mouth passing between mutually opposing sidewalls of said slider, wherein:
- said first flangeless zipper strip comprises first and second backup elements and first and second monohook elements, said first backup element and said first monohook element defining a first groove therebetween, and said second backup element and said second monohook element defining a second groove therebetween; and
- said second flangeless zipper strip comprises third and fourth monohook elements, said third monohook element being received in said first groove, and said fourth monohook element being received in said second groove.
19. The package as recited in claim 18, wherein said first and second monohook elements define a channel therebetween, and said second flangeless zipper strip further comprises an alignment element that projects into said channel when said first and second zipper strips are interengaged and that assists in aligning said first and second zipper strips with each other as they move toward each other and into interengagement.
20. The package as recited in claim 19, wherein said alignment element spreads said first and second monohook elements apart when said first and second zipper strips are interengaged.
Type: Application
Filed: Nov 24, 2004
Publication Date: Apr 21, 2005
Inventor: Steven Ausnit (New York, NY)
Application Number: 10/998,108