Patent Grant
8882349
1. Field of the Invention
The disclosed subject matter generally relates to reclosable fasteners with sliders particularly suited for thermoplastic bags and the like. Particularly, the disclosed subject matter relates to a track and slider configuration with increased strength and flexibility and reduced size.
2. Description of Related Art
Plastic bags are in widespread use in a varied and diverse number of household and commercial applications, especially in the food packaging industry. One advantage of plastic bags is their ease of opening and resealing. Some of these bags are reclosable via the use of a reclosable feature such as a reclosable fastener. In many bags, the fasteners can be opened and closed either by pressure or by the use of an auxiliary slider mechanism.
Generally, two types of such reclosable fasteners exist—(i) push to close (“PTC”) and (ii) zipper. The PTC fastener requires the application of an external force to open or close the engageable tracks, whereas the zipper fastener relies upon a slider for opening or closing the rib and groove elements. As such, the profile configuration of the reclosable track of a zipper fastener often differs from that of a PTC fastener.
In the manufacture of thermoplastic film bags, a pair of male and female fastener elements or tracks extend along the mouth of the bag and these male and female elements are adapted to be secured in any suitable manner to the flexible walls of the thermoplastic film bag. These elements may be integral marginal portions of such walls or the elements may be extruded separately and thereafter attached to the walls along the mouth of the bag. U.S. Pat. Nos. 5,007,143 and 8,087,826, each of which is incorporated by reference in its entirety, describe one type of zipper profile in which the cross-sectional shape of the zipper is such that the male and female elements can be engaged or closed by pressing the bottom together first, then rolling it closed toward the top. This configuration is referred to as a “rolling action” reclosable fastener.
Furthermore, various arrangements have been utilized heretofore to maintain auxiliary slider mechanisms on fasteners. One arrangement which has been used to prevent or inhibit the slider mechanism from going past the ends of the fastener and coming off of the bag is to incorporate opposing end termination clips at the ends of the fastener. The use of end termination clips, however, increases the cost of producing the bag as it requires an additional component on the bag and an additional piece of equipment in order to place the end termination clips on the bag. In addition, the placement of end termination clips on the ends of the fastener involves an additional processing step which may not be desirable when manufacturing speeds are important.
To avoid using end termination clips to prevent or inhibit the auxiliary slider mechanism from going past ends of the fastener, an alternative arrangement has been employed which involves shaping material from the fastener into opposing end stops or end stop structures which protrude from the fastener or zipper and engage the slider mechanism to prevent or inhibit it from going past the respective ends of the fastener. U.S. Pat. Nos. 7,267,856 and 7,669,307, each of which is incorporated by reference in its entirety, describe one technique to shape end stop structures by ultrasonically smashing the opposite ends of the male and female profiles of the fastener to form the protruding end stop structures.
However, there remains an opportunity to improve the seal strength of such conventional fasteners, yet provide a fastener with increased flexibility, for example to permit the fasteners to be easily opened and closed on overstuffed bags. Additionally, there remains an opportunity to provide a fastener with reduced size that can be formed using less material than conventional fasteners.
The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter includes a reclosable fastener assembly including a fastener having a pair of interlocking plastic tracks including a first track having a male profile and a second track having a female profile. The fastener has a height and a width when the first track and the second track are interlocked. The fastener assembly includes a slider slidably mounted to the pair of plastic tracks for movement between a closed position and an open position. The fastener assembly further includes at least one end stop located at an end of the fastener, the at least one end stop formed integrally from at least one of the first track and the second track. The end stop has a wedge shape with a first end, a second end, and a lateral extent, the first end being proximate the fastener and having a height no greater than the height of the fastener. The end stop has a decreasing height from the first end to the second end, and the lateral extent extending beyond the width of the fastener.
As embodied herein, the at least one end stop can include a first end stop formed integrally from the first track and a second end stop formed integrally from the second track. The first end stop and the second end stop can be free of a bond therebetween. Alternatively, the first end stop and the second end stop can be bonded together.
In some embodiments, the at least one end stop can include a single end stop formed integrally from both the first track and the second track. The height of the first end of the end stop can be less than the height of the fastener.
Furthermore, and as embodied herein, the pair of interlocking plastic tracks can define an axis, and the lateral extent can form an angle up to about 15 degrees relative to the axis. The pair of interlocking tracks can define an axis, and the end stop can have an upper surface angled relative to the axis.
In some embodiments, the end stop can be formed by at least one of ultrasonic welding, cold forming, thermal forming and injection molding. The end stop can include at least one of high density polyethylene, cyclic olefin copolymer, and low density polyethylene.
According to another aspect of the disclosed subject matter, a reclosable bag includes first and second opposing body panels fixedly connected to each other along a pair of sides and a bottom bridging the pair of sides and a reclosable fastener assembly extending along a mouth formed opposite the bottom. The reclosable fastener assembly includes a fastener comprising a pair of interlocking plastic tracks including a first track having a male profile and a second track having a female profile. The fastener has a height and a width when the first track and the second track are interlocked. The fastener assembly includes a slider slidably mounted to the pair of plastic tracks for movement between a closed position and an open position. The fastener assembly further includes at least one end stop located at an end of the fastener, the at least one end stop formed integrally from at least one of the first track and the second track. The end stop has a wedge shape with a first end, a second end, and a lateral extent, the first end being proximate the fastener and having a height no greater than the height of the fastener. The end stop has a decreasing height from the first end to the second end, and the lateral extent extending beyond the width of the fastener.
As embodied herein, the at least one end stop can include a first end stop formed integrally from the first track and a second end stop formed integrally from the second track. The first end stop and the second end stop can be free of a bond therebetween. Alternatively, the first end stop and the second end stop can be bonded together.
In some embodiments, the at least one end stop can include a single end stop formed integrally from both the first track and the second track. The height of the first end of the end stop can be less than the height of the fastener.
Furthermore, and as embodied herein, the pair of interlocking plastic tracks can define an axis, and the lateral extent can form an angle up to about 15 degrees relative to the axis. The pair of interlocking tracks can define an axis, and the end stop can have an upper surface angled relative to the axis.
In some embodiments, the end stop can be formed by at least one of ultrasonic welding, cold forming, thermal forming and injection molding. The end stop can include at least one of high density polyethylene, cyclic olefin copolymer, and low density polyethylene.
According to another aspect of the disclosed subject matter, a method of making a reclosable fastener assembly includes providing a fastener having a pair of interlocking plastic tracks including a first track having a male profile and a second track having a female profile, the fastener having a height and a width when the first track and the second track are interlocked. The method further includes slidably mounting a slider to the pair of plastic tracks for movement between a closed position and an open position. The method can further include forming at least one end stop at an end of the fastener, the at least one end stop formed integrally from at least one of the first track and the second track, the at least one end stop having a wedge shape with a first end, a second end, and a lateral extent, the first end being proximate the fastener and having a height no greater than the height of the fastener, the at least one end stop having a decreasing height from the first end to the second end, and the lateral extent extending beyond the width of the fastener.
In some embodiments, the method can further include forming a further end stop from the at least one of the first track and the second track, the further end stop formed in line with and proximate to the at least one end stop, and separating the at least one end stop from the further end stop. In this manner, the further end stop forms an end stop of a similarly configured but separate fastener.
Reference will now be made in detail to the present preferred embodiments of the application, examples of which are illustrated in the accompanying drawings. The reclosable fasteners and assemblies presented herein generally are intended for thermoplastic bags, although other similar or suitable uses are contemplated. In accordance with the disclosed subject matter, a reclosable fastener assembly is provided. The reclosable fastener assembly includes a fastener comprising a pair of interlocking plastic tracks including a first track having a male profile and a second track having a female profile. The fastener has a height and a width when the first track and the second track are interlocked. At least one end stop is located at an end of the fastener, the at least one end stop formed integrally from at least one of the first track and the second track. The end stop has a wedge shape with a first end, a second end, and a lateral extent, the first end being proximate the fastener and having a height no greater than the height of the fastener. The end stop has a decreasing height from the first end to the second end, and the lateral extent extending beyond the width of the fastener. The assembly further includes a slider slidably mounted to the pair of plastic tracks for movement between a closed position and an open position.
For purpose of explanation and illustration, and not limitation, a representative embodiment of a reclosable fastener in accordance with the application is shown in
With reference to
A slider 130 (as shown, for example, in
In accordance with the disclosed subject matter, and as shown in
As depicted in
End stop 150 can be formed by compressing an end portion of first track 110 and/or second track 120 to spread the material of the track laterally to form the lateral extent 156. In this manner, the height of at least a portion of end stop 150 is less than the initially undeformed or compressed portion of the first and second tracks 110, 120. As such, end stop 150 will have a height no greater than the height of fastener 100 defined by the first and second tracks 110, 120, and at least a portion of the end stop 150 will have a height less than the height of the fastener 100. In some embodiments, end stop 150 in its entirety can have a height less than the height of fastener 100. Furthermore, end stop 150 can have a height that varies along its length, such as decreasing from first end 152 to second end 154, as depicted in
As with the embodiment of
As shown in
Each end stop 350, 360 has a lateral extent 356, 366 extending beyond the width of fastener 300 defined by the first and second tracks 310, 320 when the first and second tracks 310, 320 are interlocked. As shown, for purpose of illustration, each end stops 350, 360 includes a lateral extent 356, 366, of increasing width from the first end 352, 362 to the second end 354, 364. As such, each end stop 350, 360 has a wedge shape, which can define an angle up to about 15 degrees relative to the axis α formed by the first and second tracks 310, 320. Thus, lateral extents 356, 366 of end stops 350, 360 can protrude from fastener 300 a distance adequate to engage the slider 130 and prevent the slider 330 from being moved beyond the respective ends of the fastener 300 and thus becoming disengaged from the fastener 300. In some embodiments, each lateral extent 356, 366 of end stops 350, 360 at a widest point can be up to 200% (e.g., about 0.20 inches) the width of the fastener 300 when the first and second tracks 310, 320 are interlocked, and particularly between about 170% to 200% of such width.
Furthermore, and as embodied herein, the wedge geometry of end stops 350, 360 can eliminate the need to bond end stops 350, 360 together. Rather, the movement of slider 130 proximate lateral extents 356, 366 of end stops 350, 360 urges end stops 350, 360 toward each other due to the wedge geometry of the lateral extents 356, 366.
End stops 350, 360 can be formed by compressing an end portion of first track 310 and second track 320 to spread the material of the track laterally to form the lateral extents 356, 366. In this manner, the height of at least a portion of end stops 350, 360 is less than the initially undeformed or compressed portion of the first and second tracks 310, 320. As such, end stops 350, 360 each will have a height no greater than the height of fastener 300 defined by the first and second tracks 310, 320, and at least a portion of the end stops 350, 360 can have a height less than the height of the fastener 300. In some embodiments, end stops 350, 360 each in its entirety can have a height less than the height of fastener 300. Furthermore, end stops 350, 360 each can have a height that varies along its length, such as decreasing from first ends 352, 362 to second ends 354, 364, respectively. For example, end stops 350, 360 can each be formed having an upper surface 358, 368 which can define an angle relative to axis α formed by first and second tracks 310, 320. In some embodiments, the angle formed by upper surface 358, 368 can be within a range of which can be up to about 0 to 15 degrees relative to axis α. In this manner, each end stop 350, 360 will have an increasing width or lateral extent 356, 366 from first end 352, 362 to second end 354, 364 with a decreasing height.
In accordance with another aspect of the disclosed subject matter, a method of making a reclosable fastener assembly is provided. The method includes providing a fastener comprising a pair of interlocking plastic tracks including a first track having a male profile and a second track having a female profile, the fastener having a height and a width when the first track and the second track are interlocked. The method further includes forming at least one end stop at an end of the fastener, the at least one end stop formed integrally from at least one of the first track and the second track, the at least one end stop having a wedge shape with a first end, a second end, and a lateral extent, the first end being proximate the fastener and having a height no greater than the height of the fastener, the at least one end stop having a decreasing height from the first end to the second end, and the lateral extent extending beyond the width of the fastener. The method can further include slidably mounting a slider to the pair of plastic tracks for movement between a closed position and an open position.
For purpose of illustration, reference is made to fastener assembly 10 of
Additionally, as illustrated in
First and second tracks 110, 120 and consequently the end stops 150 formed therefrom can include combinations of one or more of high density polyethylene, medium density polyethylene, polypropylene, a cyclic olefin copolymer, a high density material, or a high modulus material. As such, the end stops 150 of fastener 100 can be formed of high density polyethylene (HDPE), medium density polyethylene (MDPE), polypropylene (PP), a cyclic olefin copolymer (COC), a high density material, a high modulus material, and combinations or copolymers thereof.
For purpose of explanation and illustration, and not limitation,
The reclosable fastener assembly 10 is disposed along the mouth. As previously described, the reclosable fastener assembly 10 comprises first and second tracks 110, 120, which can be extruded separately and attached to the respective sides of the bag mouth, or alternatively, the first and second tracks 110, 120 can be extruded integral with the sides of the bag mouth. Slider 130 is shown in
The reclosable fastener 100 can have any suitable combination of the features described above. For example, the fastener 100 can include first and second tracks 110, 120 extending along the length of the top of the first and second opposing sides 210 and 220 with a single end stop 150 formed at each of the opposing ends of first and second tracks 110, 120, as described with regard to
While the present application is described herein in terms of certain preferred embodiments, those skilled in the art will recognize that various modifications and improvements may be made to the application without departing from the scope thereof. Thus, it is intended that the present application include modifications and variations that are within the scope of the appended claims and their equivalents. Moreover, although individual features of one embodiment of the application may be discussed herein or shown in the drawings of one embodiment and not in other embodiments, it should be apparent that individual features of one embodiment may be combined with one or more features of another embodiment or features from a plurality of embodiments.
In addition to the specific embodiments claimed below, the application is also directed to other embodiments having any other possible combination of the dependent features claimed below and those disclosed above. As such, the particular features presented in the dependent claims and disclosed above can be combined with each other in other manners within the scope of the application such that the application should be recognized as also specifically directed to other embodiments having any other possible combinations. Thus, the foregoing description of specific embodiments of the application has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the application to those embodiments disclosed.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5007143 | Herrington | Apr 1991 | A |
| 7267856 | Patel et al. | Sep 2007 | B2 |
| 7669307 | Patel et al. | Mar 2010 | B2 |
| 8087826 | Blythe et al. | Jan 2012 | B1 |
| Entry |
|---|
| U.S. Appl. No. 13/839,496, filed Mar. 15, 2013. |
| U.S. Appl. No. 13/841,054, filed Mar. 15, 2013. |
| Number | Date | Country | |
|---|---|---|---|
| 20140270588 A1 | Sep 2014 | US |
