Reclosable Bag Having a Repulpable Zipper

This application is a continuation-in-part application of U.S. patent application Ser. No. 17/965,581 (filed 13 Oct. 2022), which claims priority to U.S. Provisional Application No. 63/271,928 (filed 26 Oct. 2021) and U.S. Provisional Application No. 63/330,268 (filed 12 Apr. 2022), the entire contents of which are incorporated herein by reference.

The subject matter described herein relates to reclosable bags, and more particularly to zippers of reclosable bags.

It is well known that there is an increasing amount of plastic waste in the world. It is further well known that plastic waste in landfills or similar environments is very slow to biodegrade.

Plastic bags are used to contain various products, and typically include one or more films used to form an enclosure. While the film of a plastic bag has a thickness of only a few thousandths of an inch, the typical plastic polyethylene bag degrades very slowly, with essentially no degradation in thicker laminates.

Additionally, many known plastic bags include a zipper having flanges. However, the addition of a zipper with flanges poses additional problems in relation to degradation. For example, a zipper is typically much thicker than a film, and therefore degrades much slower than the film. Bioresins (that is, resins using biomass organic materials instead of traditional petroleum feedstock) can be used to facilitate degradation. However, further improvements in relation to degradation are sought, particularly such that maintain certain desired qualities.

A need exists for a reclosable bag having a zipper exhibiting increased repulpability, biodegradability, recyclability, and the like.

With that need in mind, certain embodiments of the present disclosure provide a zipper for a reclosable bag. The zipper includes a first interlocking element, and a second interlocking element. The first interlocking element and the second interlocking element are configured to cooperate to selectively open and close the zipper. One or both of the first interlocking element and the second interlocking element are formed of a material including air cavities.

In at least one embodiment, both the first interlocking element and the second interlocking element are formed of the material.

In at least one embodiment, the air cavities are formed through foaming.

In at least one embodiment, the material further includes filler. As an example, the filler includes cellulose.

In at least one embodiment, the zipper also includes a first flange extending from the first interlocking element, and a second flange extending from the second interlocking element. One or both of the first flange or the second flange can also be formed of the material. As a further example, the first flange and the second flange are both formed of the material.

As an example, a slider is operatively coupled to the zipper. The slider can also be formed of the material.

Certain embodiments of the present disclosure provide a method of forming a zipper for a reclosable bag. The method includes forming one or more air cavities within a material; and using the material to form one or both of a first interlocking element or a second interlocking element of the zipper, wherein the first interlocking element and the second interlocking element are configured to cooperate to selectively open and close the zipper.

In at least one embodiment, said forming includes foaming the air cavities within the material.

In at least one embodiment, said forming includes providing filler within the material.

In accordance with one example or aspect, a reclosable package is provided that includes a flexible sheet material having side walls. The side walls may be positioned to close an interior portion of the reclosable package. First and second mounting webs are coupled to upper areas of the side walls. A zipper assembly includes a first interlocking portion coupled to the first mounting web and a second interlocking portion coupled to the second mounting web. The first interlocking portion and the second interlocking portion mate with each other to close the zipper assembly and may separate from each other to open the zipper assembly. The first mounting web and the second mounting web are formed at least in part from a repulpable material.

In accordance with one example or aspect, a zipper assembly is provided that includes flanges having opposite interior and exterior surfaces. The exterior surfaces of the flanges are positioned to be coupled with one or more side walls of the enclosure. The flanges include interlocking members protruding from the flanges. The interlocking members are positioned to mate with each other and to close the enclosure and to separate from each other to open the enclosure. The flanges are formed at least in part from a repulpable material.

In accordance with one example or aspect, a method is provided that includes coupling a first mounting portion with one or more panels. The first mounting portion and the one or more panels are formed at least in part from a repulpable material. The method includes coupling a second mounting portion with one or more panels. The second mounting portion is formed at least in part of a repulpable material. A first interlocking portion of a zipper assembly is coupled to the first mounting portion. A second interlocking portion of the zipper assembly is coupled to the second mounting portion.

In accordance with one example or aspect, a method is provided that includes coupling a zipper assembly onto a mounting portion. The mounting portion is formed at least in part from a repulpable material. The zipper assembly and mounting portion are coupled to a panel of an enclosure. The zipper assembly is openable to open and close the enclosure.

Certain embodiments of the present disclosure provide a zipper for a reclosable container, such as a bag. The zipper is formed of a dissolvable material. In at least one embodiment, the zipper is formed of a dissolvable material containing air cavities, which increase solubility. In at least one embodiment, the dissolvable material also contains a filler, such as wood fiber, to limit or otherwise control the formation of the air cavities. Filler, like air cavities, also reduces an amount of polymeric binder used to form the zipper and/or the container. As an example, the filler can be formed, at least in part, of cellulose.

Foaming can be used to form the air cavities. For example, foaming has been used in extruded polyethylene zippers, as disclosed in U.S. Pat. No. 5,520,463, entitled “Foamed Zipper” issued May 28, 1996, which is hereby incorporated by reference in its entirety. United States Patent Application Publication No. 2013/0174386, entitled “More Sustainable Biodegradable Foamed Zipper,” published Jul. 11, 2013, which is hereby incorporated by reference in its entirety, also discloses forming a zipper through foaming. In at least one example, the air cavities can be formed using a foaming process, such as described in U.S. Pat. No. 5,520,463, or United States Patent Application Publication No. 2013/0174386.

It has been found that a zipper having air cavities formed through foaming, and also including a cellulose-based filler may aid in meeting standards and requirements as promulgated by the Flexible Box Associations.

If filler is used in the zipper, a ratio of air cavities and filler content can be adjusted, as desired, to affect certain mechanical properties of the zipper. For example, increased air cavities increases flexibility, while the filler can increase stiffness.

The zipper may or may not include flanges. The presence of air cavities and filler can be present in an entirety of the zipper, or in less than an entirety of the zipper. Further, a slider and/or a clip used in relation to the zipper can also be formed of the same material as the zipper.

illustrates a front view of reclosable bag, according to an embodiment of the present disclosure. The bagincludes a containerincluding a front wallthat is coextensive with a rear wall. The front walland the rear wallcan be joined to each other by side seals,, and a bottom seal(or optionally a fold). Upper edgesdefine a mouth, which is reclosable by a zipper.

In at least one embodiment, the containeris formed of a biodegradable material. For example, the containercan be formed of paper, which may or may not be coated. Alternatively, the containercan be formed of a polymeric material.

illustrates a cross-sectional view of the zipperof the reclosable bagalong line-of. The zipperincludes a first profileand a second profileopposite from the first profile. The first profileand the second profileincluding cooperating interlocking elements. In particular, the first profileincludes a first or male interlocking elementand a first flange(such as extending from or otherwise coupled to the male interlocking element), and the second profileincludes a second or female interlocking elementand a second flange(such as extending from or otherwise coupled to the female interlocking element). It is to be understood that the terms “first,” “second,” and the like are merely used to denote a number of items. For example, the female interlocking elementcan be considered the first interlocking element, and the male interlocking elementcan be considered the second interlocking element.

Referring to, the first profileis sealed to the front wallwhile second profileis sealed to the rear wall. In the closed or interlocked position, the male interlocking elementis received and engaged with the female interlocking element. In the open position, the male interlocking elementand the female interlocking elementsare free of engagement with each other.

In at least one embodiment, the slidermay also be used in relation to the zipper. That is, the slidercan be operatively coupled to the zipper. The slidercan be moved in an opening direction to separate the male interlocking elementfrom the female interlocking elements. Conversely, the slider can be moved in a closing direction to interlock the male interlocking elementand the female interlocking element. Optionally, the bagmay not include the slider.

illustrates a cross-sectional view of the zipperaccording to an embodiment of the present disclosure. At least a portion of the zipperis formed of a materialhaving a plurality of air cavities. The materialcan be a water soluble resin, such as polyvinyl alcohol (PVOH). As another example, the materialcan be polyacrylic acid (PAA), polyethylene glycol (PEG), polyvinylpyrroliodone (PVP), poly(2-ethyl-2-oxazoline), polyacrylamide (PAM), or the like. PVOH may be used due to PVOH being more water soluble, having greater mechanical strength, increased film clarity, and/or better barrier performance than other water soluble resins. The materialcan also include fillerdispersed therethrough. The fillercan be cellulose, calcium carbonate (CaCO), clay, or talc as examples. Cellulose can be used as the fillerto maintain integrity of the film and improved dissolution when compared with other fillers. For example, cellulose is organic and hydrophilic, and swells and disperses in water along with the PVOH matrix to maintain uniform dissolution. In contrast, inorganic fillers (such as calcium carbonate, clay, talc, etc.) are insoluble and remain as particulates in the dissolution medium. This can slow the dissolution rate, leave visible residue or sediment, and cause cloudiness in the dissolved solution. Cellulose may have better compatibility with a PVOH matrix of the material, as the hydrophilic hydroxyl groups in the cellulose hydrogen bond with the PVOH and create better dispersion and film cohesion. In contrast, inorganic fillers can be harder to disperse uniformly and may require surface treatments to avoid agglomeration. Microcrystalline or finely dispersed cellulose can maintain or only slightly reduce film clarity, whereas inorganic fillers may scatter light more and reduce optical clarity. Additionally, cellulose fibers can improve tensile strength, tear resistance, and flexibility of the film when compared with inorganic or some other fillers.

Calcium carbonate may be used as the fillerinstead of cellulose, clay, or talc for other reasons. First, calcium carbonate may be less expensive than these other fillers. Second, calcium carbonate can increase stiffness and dimensional stability of the components formed with calcium carbonate as the filler. A remainder or substrateof the material(other than the air cavitiesand the filler) can be formed of a plastic, for example.

An entirety of the zippercan be formed of the material. For example, the male interlocking element, the female interlocking element, the first flange, and the second flangecan all be formed of the material. In at least one embodiment, the zipperdoes not include one or both of the first flangeor the second flange.

As another example, less than an entirety of the zippercan be formed of the material. For example, only the male interlocking elementand/or the female interlocking elementcan be formed of the material, while the remaining portions (such as the first flangeand the second flange) may be formed of a different material (for example, a plastic that does not include the air cavitiesand/or the filler). Forming less than entirety of the zipperfrom the materialmay be desired, such as if certain standards allow for a certain amount of the zipper (such as 15%) to not exceed biodegradability and/or repulpability requirements.

Referring to, the slidercan also be formed of the material. Optionally, the slidermay not be formed of the material. As noted, the bagmay or may not include the slider.

As shown, one or more sealing areascan be coupled to outer surfaces of the first flangeand/or the second flange. Referring to, the sealing areassealingly engage interior surfaces of the containerproximate to the mouth. The sealsmay or may not be formed, at least in part, of the material. In at least one example, instead of being formed of the material, the sealing areascan be formed of a sealant and/or adhesive.

The materialis dissolvable. The air cavitiesincrease the solubility of the material. In at least one example, the air cavitiesare formed through foaming. For example, foaming agents form the air cavities. The air cavitiesreduce the overall amount and weight of the zipper, while increasing surface area. The increased surface area provides increased area for compostability, for example, thereby reducing the time for such process.

In at least one embodiment, the filleris a cellulose-based material. For example, the filleris formed, at least in part, of cellulose. As an example, the fillercan be wood fiber. The fillerlimits or otherwise controls the formation of the air cavities. The filler, like the air cavities, also reduces an amount of polymeric binder used to form the zipperand/or the container.

The ratio of the air cavitiesto the fillerwithin the materialcan be 1:1. Optionally, the ratio of the air cavitiesto the fillercan be 2:1, 3:1, or the like. Notably, increasing the percentage of the air cavitieswithin the materialincreases the flexibility of the zipper. Conversely, the ratio of the air cavitiesto the fillercan be 1:2, 1:3, or the like. Increasing the percentage of the fillerwithin the materialincreases the stiffness and rigidity of the zipper. As such, the amount of the air cavitiesand the fillercan be adjusted depending on a desired amount of flexibility and stiffness. Alternatively, the materialmay not include the filler.

It has been found that the zipperhaving the air cavitiesformed through foaming, and also including the filler, which can be cellulose-based, may aid in meeting standards and requirements as promulgated by the Flexible Box Associations.

By forming at least a portion of the zipperfrom the material, the zipperis more biodegradable, repulpable, recyclable, and compostable in comparison to known zippers. The materialcan be dissolvable.

As described herein, the zipperfor a reclosable bagincludes a first interlocking elementor, and a second interlocking element (the other ofor). The first interlocking element and the second interlocking element are configured to cooperate to selectively open and close the zipper. One or both of the first interlocking element and the second interlocking element are formed of the materialincluding air cavities. The air cavitiescan be formed through foaming. In at least one example, both the first interlocking element and the second interlocking element are formed of the material. In at least one example, the materialalso includes the filler. As an example, the fillerincludes cellulose.

illustrates a flow chart of a method of forming a zipper, according to an embodiment of the present disclosure. Referring to, at, air cavitiesare formed within the material. At, the amount of air cavitieswithin the materialare controlled by a filler(that is, the addition of the fillerinto the material). Optionally, the amount of air cavitiescan be independent of the filler. At, the materialis then used to form at least part of the zipper.

In one example, a zipper for a reclosable bag is provided. The zipper may include a first interlocking element and a second interlocking element. The first interlocking element and the second interlocking element are configured to cooperate to selectively open and close the zipper. One or both of the first interlocking element and the second interlocking element may be formed of a material including air cavities.

Optionally, both the first interlocking element and the second interlocking element may be formed of the material that includes the air cavities. The air cavities may be formed through foaming. The material may also include filler, such as cellulose. The zipper also may include a first flange extending from the first interlocking element, and a second flange extending from the second interlocking element. One or both of the first flange or the second flange also may be formed of the material. A slider may be operatively coupled to the zipper. The slider also may be formed of the material.

In another example, a method of forming a zipper for a reclosable bag is provided. The method may include forming one or more air cavities within a material, and using the material to form one or both of a first interlocking element or a second interlocking element of the zipper. The first interlocking element and the second interlocking element may cooperate to selectively open and close the zipper.

The material may be used to form both the first interlocking element and the second interlocking element. Air cavities may be formed within the material. The forming operation may include providing filler within the material, such as cellulose.

The material may be used to form one or both of the first flange or a second flange of the zipper. The material also may be used to form a slider configured to operatively couple to the zipper.

In another example, a zipper for a reclosable bag is provided. The zipper may include a first interlocking element and a second interlocking element. The first interlocking element and the second interlocking element may cooperate to selectively open and close the zipper. The first interlocking element and the second interlocking element may be formed of a material including air cavities and filler, where the air cavities are formed through foaming.

The filler may include cellulose. The zipper also may include a first flange extending from the first interlocking element, and a second flange extending from the second interlocking element. The first flange and the second flange also may be formed of the material.

As described herein, embodiments of the present disclosure provide a zipper for a reclosable bag exhibiting increased repulpability, biodegradability, recyclability, and the like.