PFAS-free composite cap liner and venting port membrane

Abstract

A venting port membrane is provided for sealing a venting port in a closure cap liner, wherein the venting port membrane is made of a microporous material that is PFAS-free, such as a microporous expanded polyethylene (ePE), where the ePE is an ultrahigh molecular weight polyethylene for chemical compatibility and membrane strength. The ePE vent membrane is compatible for use with oxidizing agents such as cleaning products containing bleach (sodium hypochlorite) or hydrogen peroxide. In addition, the ePE venting port membrane provides a higher abrasion resistance than an expanded polytetrafluorethylene-based vent membrane (PFAS based).

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 756,467, filed on Feb. 10, 2025, which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The present invention relates to a composite cap liner and venting port membrane, secured to cover a dispensing aperture in a container, that is free of per- and polyfluoroalkyl substances (PFAS-free) while providing desired structural and functional performance and allowing gas-permeability and liquid-impermeability.BACKGROUND

[0003] Venting liners (also known as venting cap or closure liners) are utilized as a packaging component (e.g., a liner disc inserted inside the closure cap and applied over the dispensing aperture of a filled container or bottle) in order to equilibrate pressure inside the sealed container to that of the ambient pressure (pressure outside the sealed container).

[0004] The venting liner acts as a two-way valve to de-gas (vent) any gas built up inside the sealed container (e.g., because of product chemistry, altitude changes during transportation, etc.) and / or to let the outside air flow into the sealed container to prevent the paneling (collapsing) of the container side walls, e.g., because of package head space gas absorption by the product (such as antioxidant vitamins) or due to product filling conditions (such as a hot-filled product that cools down to generate a vacuum inside the package).

[0005] The venting liner is intended to allow gas transport into / out of the container, but not allow liquid transport (not allow a liquid product to leak out of the container through the liner).

[0006] The design of a venting liner is complicated by the need to address additional performance parameters required by the intended use, i.e., product and container composition, structure and function. For example, the venting liner preferably (1) shall not disintegrate with product interaction (i.e. be compatible with the product), and (2) shall not get excessively blocked by the product residue and / or dried product formed on the liner.

[0007] There are different types of venting closure liners known in the art and each type raises additional limitations on cost (of materials and manufacture), function or performance. One type of venting liner provides an overall microporous liner layer that is then bonded to a backing layer. The backing layer includes a broad array of multiple small apertures (holes) each extending through the backing layer to enable venting across the entire liner area. Another type of venting liner provides a single smaller venting port through the liner thickness, with a vent membrane secured to cover the port and allow the venting of gas through the limited port area. Where a smaller venting port is utilized, the vent membrane must maintain a weld bond to the periphery of the aperture (vent hole) formed in the closure liner.

[0008] Other limitations on the known venting liners relate to materials of use, and the ability of those materials to be recycled or to avoid use of certain chemicals that are disfavored for environmental reasons. For example, it would be desirable to avoid use of per- and polyfluoroalkyl (PFAS substances), which are known as “forever chemicals” in both the packaging and the product itself. Again the materials selected must satisfy multiple performance parameters as outlined above, in addition to being free from undesirable chemicals.SUMMARY OF THE INVENTION

[0009] According to one embodiment of the invention, a venting port membrane is provided for sealing a venting port in a closure cap liner, wherein the venting port membrane is made of a microporous material that is PFAS-free, such as a microporous expanded polyethylene (ePE), where the ePE is an ultrahigh molecular weight polyethylene for chemical compatibility and membrane strength. The ePE vent membrane is compatible for use with oxidizing agents such as cleaning products containing bleach (sodium hypochlorite) or hydrogen peroxide. In addition, the ePE venting port membrane provides a higher abrasion resistance than an expanded polytetrafluorethylene-based vent membrane (PFAS based).

[0010] In one embodiment, the ultrahigh molecular weight polyethylene has a weight-average molecular weight (Mw) in a range of 1 million of 10 million, more preferably in a range of 2 million to 8 million, and more preferably in a range of 3 million to 6 million.

[0011] The venting port membrane of the invention is made from a PFAS-free material, namely ePE as defined above, and can be used with a liner to form a bottle seal, such as a bottle seal that is induction heat sealed (including a metal foil layer for induction heating) or conduction heat sealed to the rim of the bottle opening.

[0012] In various embodiments of the invention, the bottle or container can be for example made of plastic, glass or metal.

[0013] The venting port membrane of the invention can preferably be used without a backing (support) layer, as is typically required in the prior art. This simplifies the structure and reduces the cost of materials and manufacture. When used without the backing layer, the venting port membrane includes multiple spaced-apart surface grooves (recessed areas extending partially through the thickness of the liner body) that provide structural strength and integrity during processing of the membrane (e.g., slitting, die cutting, placement and heat stake welding). The grooves also improve the abrasion resistance. Still further the use of ePE provides a higher abrasion resistance than an expanded polytetrafluorethylene-based (PFAS-based) vent membrane.

[0014] In various embodiments, the venting port membrane can be used with a woven or non-woven backing layer that is compatible with the surface of the closure liner for heat staking / welding the venting port membrane to the cap liner. For example, the ePE venting port membrane can be used with a scrim (woven backing layer). A backing layer assists with processing of the membrane (e.g., being slit, die cut, placed and welded to the periphery of the venting port in the liner body).

[0015] The venting port membrane of the invention further provides a desired leak performance (resistance to leakage of the liquid product through the venting port membrane and accompanying closure liner), as well as a desired gas venting performance.

[0016] The venting port membrane of the invention has various applications, with a variety of liquid products. It is particularly well suited for use with bleach (sodium hypochlorite) based cleaning products, a widely used household cleaning chemical, pool chemical, etc. Sodium hypochlorite naturally releases gas causing pressure to build-up inside the container and requiring the package to vent (degas) for safe use of the container / product and to prevent the container bulge (rocker bottom) that would interfere with stable transport / placement of the container.

[0017] The disadvantages of the prior art, and comparable advantages of the invention include, in various embodiments, one or more of the following:

[0018] 1) Prior art PFAS-based microporous ePTFE vent membrane has a higher cost compared to PFAS-free microporous ePE venting port membrane of the invention.

[0019] 2) Prior art PFAS-based ePTFE membrane contains forever chemicals harmful to the environment compared to PFAS-free microporous ePE venting port membrane of the invention.

[0020] 3) The venting port membrane of the present invention may be thermally laminated to the periphery surrounding the venting port in the liner (e.g., bonded to a peripheral area surrounding a single annular venting port having a diameter of 0.155 inch (3.9 mm)). This conserves material with the same overall functionality of prior container venting liners and prevents liquid leaks compared to the prior art overall microporous ePTFE venting liner with multiple venting apertures provided over the entire liner area. For products requiring faster venting, a larger single aperture greater in diameter than the 0.155 inch vent size can be used depending on the liner disc size. Also, two venting port membranes each heat stake / welded to the periphery of a matching vent hole in the liner can be used and would still be more cost effective than the overall microporous ePTFE venting liner with multiple venting apertures of the prior art.

[0021] In accordance with one embodiment of the invention, a composite non-PFAS gas-permeable and liquid-impermeable cap liner and venting port membrane (10) is provided configured to fit between a closure cap (2) and a rim (9) surrounding a dispensing aperture (31) of a container (8), the composite cap liner and venting port membrane (10) comprising:

[0022] a disc-shaped liner body (11) comprising a material that is substantially gas-impermeable and liquid-impermeable, the liner body having a bottom surface (13) facing the rim (9) surrounding the dispensing aperture (31) of the container and an opposing top surface (12) facing an inner top wall (4) of the closure cap (2), the liner body (11) having a venting port (16) that extends through the liner body from the top surface (12) to the bottom surface (13) and having a venting port periphery (17) that is less than a periphery (14) of the liner body;

[0023] a venting port membrane (20) made of a microporous expanded and ultrahigh molecular weight polyethylene (ePE) layer (21) that is gas permeable and compatible for use with oxidizing agents in cleaning products containing bleach or hydrogen peroxide, the venting port membrane being bonded at its periphery (24) to a peripheral area (17) surrounding the venting port (16) on either the bottom or top surfaces of the liner body (11) to provide a single gas-permeable venting port membrane (20) through the liner body that is also liquid-impermeable, and wherein the composite liner body and venting port membrane (10) are substantially free of per- and polyfluoroalkyl (PFAS) substances.

[0024] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane (20) comprises an ePE layer (21) of the microporous expanded ultrahigh molecular weight polyethylene (ePE) without a backing layer, and the ePE layer is disposed on either one of the top and bottom surfaces (12, 13) of the liner body.

[0025] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane includes a first layer (21) of the ePE and further includes a backing layer (30) for membrane strength.

[0026] In one embodiment of the composite cap liner and venting port membrane, either the first layer of the ePE (21) or the backing layer (30) is bonded to the peripheral area (17) surrounding the venting port (16) on either of the top and bottom surfaces (12, 13) of the liner body.

[0027] In one embodiment of the composite cap liner and venting port membrane, the ePE layer (21) has substantially equally spaced grooves (25) disposed along its top or bottom surfaces (22, 23) for membrane strength.

[0028] In one embodiment of the composite cap liner and venting port membrane, the thickness of the venting port membrane (20) is in a range of from 0.004 inch to 0.010 inch for membrane strength.

[0029] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane (20) has a series of substantially equally spaced grooves (25) extending into the top or bottom surface that are spaced apart in a range of 0.1 to 0.2 inches, and wherein the grooves are of a depth in a range of 0.001 to 0.003 inches.

[0030] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane (20) has a pore size in a range of from 0.2 to 0.9 microns.

[0031] In one embodiment of the composite cap liner and venting port membrane, the disc-shaped liner body (11) is annular and has a diameter in a range of 0.750 to 2.750 inches (19 to 70 mm), and the venting port (16) is substantially annular and having a diameter in a range of from 0.15 to 0.5 inches.

[0032] In one embodiment of the composite cap liner and venting port membrane, the liner body (11) consists wholly or partially of a foam material.

[0033] In one embodiment of the composite cap liner and venting port membrane, the liner body (11) includes solid and foamed layers between the top and bottom surfaces.

[0034] In accordance with another embodiment of the invention, a combination is provided comprising:

[0035] a container (8) having an annular neck (1) and rim (9) surrounding an opening (31) for dispensing a product from the container,

[0036] a removable closure cap (2) having an inner top wall (3) and a peripheral cap flange (5) extending downwardly from the inner top wall that is secured to the annular neck (1) for enclosing the opening (31),

[0037] the composite cap liner and venting port membrane (10) being disposed between the annular rim (9) and inner top wall (3) of the closure cap and providing a liquid impervious seal that is gas permeable.

[0038] In one embodiment of the combination, the closure cap (2) and container neck (1) have mating threads to removably secure the closure cap to the neck.

[0039] In one embodiment of the combination, the venting port membrane (20) has a series of substantially equally spaced grooves (25) extending into the top or bottom surface that are spaced apart in a range of 0.1 to 0.2 inches, and wherein the grooves are of a depth in a range of 0.001 to 0.003 inches.

[0040] In one embodiment of the combination, the closure cap (2) has a gas venting port (32) that provides gas permeability through the closure cap.

[0041] In one embodiment of the combination, a portion of the composite cap liner and venting port membrane (10) is bonded to the inner top wall (3) of the closure cap, wherein the bonded portion does not include the venting port membrane (20) such that the venting port membrane remains gas permeable.

[0042] In one embodiment of the combination, the composite cap liner and venting port membrane (10) is disposed within a retainer groove in the cap flange (5).

[0043] In one embodiment of the combination, a portion of the composite cap liner and venting port membrane (10) is bonded to the container rim (9).

[0044] In one embodiment of the combination, the composite cap liner and venting port membrane (10) is not bonded to the container rim (9) and is not bonded to the closure cap (2).

[0045] In one embodiment of the combination, the ultrahigh molecular weight polyethylene ePE has a weight average molecular weight in a range of 1 million of 10 million, preferably in a range of 2 million to 8 million, and more preferably in a range of 3 million to 6 million.BRIEF DESCRIPTION OF THE FIGURES

[0046] FIGS. 1A and 1B are top perspective views of a composite cap liner and venting port membrane according to one embodiment of the invention disposed between a closure cap and container, FIG. 1A showing the composite liner / membrane spaced from the rim, and in FIG. 1B sealed to the rim.

[0047] FIGS. 2A, 2B and 2C show a composite cap liner and venting port membrane according to one embodiment; FIG. 2A is plan view of the filtration side (facing the product) of the composite cap liner / membrane; FIG. 2B is a plan view of the opposite side (facing the inside top wall of the closure cap) of the composite cap liner / membrane; and FIG. 2C is a plan view of the composite cap liner and venting port membrane positioned inside a closure cap; FIGS. 2D and 2E show an alternative embodiment of a venting membrane with a grooved surface (top and cross sectional views respectively).

[0048] FIGS. 3A and 3B are planar views of opposing top (facing the interior top wall of the closure cap) and bottom (facing the product) sides respectively of the composite cap liner and venting port membrane, according to one embodiment; FIGS. 3C and 3D are cross-sectional and exploded views of alternative liner bodies with surface grooves (FIG. 3C) and three layers (FIG. 3D).

[0049] FIG. 4 is an exploded perspective view of three components: 1) a closure cap; 2) a composite cap liner, and venting port membrane including a backing layer and ePE layer; and 3) a container neck with a product dispensing aperture; the arrows (A) illustrate the gas flow between the three components (into and out of the container) according to one embodiment.

[0050] FIGS. 5A, 5B and 5C are perspective views of the three components (closure cap, composite cap liner and venting port membrane, and container neck, as in FIG. 4), according to various embodiments; FIG. 5A is a schematic view of a composite liner / membrane, container neck and attached closure cap, the closure cap having a venting hole in the top wall of the cap, showing gas flow (arrow A) out the cap venting hole; FIG. 5B is a schematic view of a closure cap (without a venting hole) attached to the neck of a container and a composite cap liner / membrane, the liner having surface grooves facing the top wall of the closure cap, showing gas flow (arrow A) between the grooves and out between the mating threads on the cap flange and container neck; and FIG. 5C is a schematic view of a composite liner / membrane, disposed between a closure cap (without a venting hole in the cap) and the rim of a container neck, showing gas flow (arrow A) out between the mating threads of the closure cap flange and container neck.

[0051] FIG. 6 shows perspective and plan views of ten liquid germicidal bleach filled test containers each with an attached closure cap and composite cap liner with venting port membrane, according to one embodiment for testing.

[0052] FIG. 7 is a perspective view of six liquid pool bleach filled test containers each with an attached closure cap and composite cap liner with venting port membrane, according to one embodiment for testing.DETAILED DESCRIPTION

[0053] The following detailed description and figures show various embodiments of the invention and are meant to illustrate without limiting the invention to these specific embodiments.

[0054] In the figures and text, the following reference numbers are used to illustrate various components of the invention and use thereof:

[0055] 1 neck of container (bottle), with product dispensing aperture, and exterior threads

[0056] 2 cap or closure

[0057] 3 top wall of cap

[0058] 4 interior surface of the top wall of cap (facing the liner)

[0059] 5 flange or shoulder of cap, depending down from the top wall

[0060] 6 interior surface of shoulder, threaded

[0061] 7 liquid product (held in the container)

[0062] 8 container, bottle or package

[0063] 9 rim surrounding the product dispensing aperture in neck of the container

[0064] 10 composite cap liner and venting port membrane

[0065] 11 liner body, e.g., low density polyethylene PE foam; or 3 layers comprising: solid PE top layer, foam PE middle layer, solid PE bottom layer

[0066] 12 top surface (back side) of liner 11 (faces interior surface 4 of cap)

[0067] 13 bottom surface (front side) of liner 11 (faces product 7 in container)

[0068] 14 periphery of liner

[0069] 15 transverse axial centerline (extending through closure cap, composite liner / membrane, container neck)

[0070] 16 venting port (aperture or through hole) in liner

[0071] 17 periphery around venting port 16

[0072] 18 surface grooves on liner body 11

[0073] 20 venting port membrane

[0074] 21 venting port membrane body

[0075] 22 top surface (back side) of vent membrane body (faces interior surface 4 of cap)

[0076] 23 bottom surface (front side) of venting port membrane body (faces product 7 in container)

[0077] 24 periphery of venting port membrane body heat seal bonded to liner body at periphery 17 around venting port 16

[0078] 25 surface grooves on venting port membrane body 21

[0079] 30 backing layer (woven or non-woven) of venting port membrane

[0080] 31 dispensing aperture of container 8

[0081] 32 gas venting port on cap top wall

[0082] 33 exterior threads on neck 1

[0083] 34 interior threads on cap flange 5

[0084] FIGS. 1-5 show various embodiments of a PFAS-free microporous ePE venting port membrane 20 attached to a liner body 11 that provides a gas-permeable liquid-impermeable seal between a closure cap 5 and container rim 9.

[0085] In one example (FIG. 3D), a 3-layer annular cap liner (11) having solid LDPE, foamed LDPE, and solid LDPE layers in serial order from top to bottom is utilized that is sized to fit within an annular closure cap (2). In one example (FIGS. 3A-3C), the liner body 11 has surface grooves 18 for enhanced strength.

[0086] FIGS. 2A-2C show the closure liner (11) of 1 mm thickness and approx. 36 mm in diameter with an aperture (vent hole) (16) in the liner body that is 3.9 mm in diameter. A microporous ePE venting port membrane (20) is then heat stake / welded to the periphery (17) of the venting port aperture (16) in the liner, to either one of the two sides (12, 13) of the foamed closure liner (11). This venting port membrane body (21) is die cut into an annular disc about 11 mm in diameter to provide an approx. 3.5 mm extension of the vent membrane body to contact the liner disc surface around the periphery (17) of the venting port aperture (16) for heat staking / welding.

[0087] FIGS. 2D-2E show one embodiment of a venting port membrane body 21 having surface grooves 25 in one surface for enhanced strength.

[0088] The composite cap liner and venting port membranes (10) of FIGS. 1-5 provide:

[0089] 1) a PFAS-free ePE microporous venting port membrane that is able to form seal comparable to the prior art microporous ePTFE membrane;

[0090] 2) a PFAS-free ePE microporous venting port membrane that is heat stable, maintains structural integrity, and exhibits no significant deformation during the heat staking / welding process for bonding to the periphery of the venting port aperture of the foamed closure liner;

[0091] 3) a PFAS-free ePE microporous venting port membrane that can be processed using the known manufacturing equipment and processes (slitting and die cutting of sheet material to form a venting port membrane, placing and heat stake / welding the venting port membrane to the periphery of the venting port aperture of the closure liner using the known Vent Assembly Machine).

[0092] FIGS. 2A-2C and 3A-3B show various embodiments of a composite cap liner and venting port membrane (10) according to the present invention with the periphery (24) of the vent membrane body (20) heat staked to one side (13) of the liner body (11) at the periphery (17) of the venting port aperture (16). The venting port membrane (20) is bonded to the product facing side (13) of the liner body (11). The opposing back side (12) of the foam liner body may be grooved (18), as shown in FIGS. 3A-3C, where the grooves act as channels for gas to slide through and then outside the package through the interface at the side of the exterior bottle neck (1) finish threads and the interior closure flange (6) threads. The threads may be segmented to further enhance venting.

[0093] FIGS. 5A, 5B and 5C illustrate various examples of gas flow (via arrows A) between the interior of the container (8), the composite cap liner and venting port membrane (10) and the closure cap (2), e.g., allowing gas to enter / exit via the mating threads on the interior surface of cap flange (5) and the exterior surface of the container neck (1) as shown in FIGS. 5B-5C.

[0094] In one embodiment (FIG. 5A), the closure cap (2) (e.g., a molded plastic closure shell) may further include a vent hole (32) for venting (de-gas out of package) in lieu of the aforementioned grooves 18 (in the foam liner body 11). In such case, the package vents (de-gas) through the composite PFAS-Free ePE microporous membrane and cap liner (10) and the gas then exits out of the package through the hole (32) in the closure cap. In another embodiment (FIG. 5C), there is no vent hole (VH) in the cap (2) and no grooves (18) in the back side (12) of the liner (11); this allows for slow venting of gas between the mating threads 33, 34 of the container neck and cap.

[0095] The mechanisms of various venting profiles include:

[0096] a) Microporous ePE venting port membrane (20) with an optional backing layer (30) compatible with the liner. Example, the optional backer (30) may be polyolefin material either non-woven or woven polyethylene or polypropylene in the case of heat stake to polyethylene foam liner at the periphery of its aperture (hole) (16).

[0097] b) The gas released by the product, as per the chemical nature of the product such as sodium hypochlorite and / or pressure difference during transportation (altitude differences), will pass through the venting port membrane i.e. through the ePE layer, the optional backer, the venting port, and then either through a hole in the closure shell (if non-grooved foam), or through grooves (grooves or ridges in the back side of the liner foam). In case of a slow venting product, neither a hole in the closure shell nor grooves in the venting closure liner foam may be required, as the gas slowly vents through the venting port membrane and optional backing layer and is slowly released from the closure / bottle thread (side) interface.

[0098] c) In the same regards as above, an induction heat seal bottle seal liner is provided with a venting port membrane. However, it is not necessary for this venting bottle seal liner to be grooved on the back side. Essentially, the venting bottle seal liner is placed inside the closure (facing the product) along with a grooved or non-grooved foam venting closure liner on the back side (placed onto the closure side). As aforementioned in b), the closure shell may or may not include of a hole (depending on the rate of venting). If the package is a single-use package, then a venting closure liner on the back side may not be required.

[0099] Alternatively, the liner may be a two-piece wax bonded or waxless bonded structure that is converted to make a composite cap liner and venting port membrane by adding an aperture to the liner that is covered by a vent membrane (w / woven or non-woven backing layer compatible to heat stake to the heat seal surface layer of this two-piece liner). In this case the backing layer (with an aperture) will remain in the closure. This is especially useful for a single-use package because the bottle seal portion has a vent membrane.

[0100] In addition, a two-piece wax bonded pulp backed induction heat seal foil seal can be used with the venting port membrane.

[0101] In various embodiments, the composite cap liner and venting port membrane can be applied via conduction heat sealing or ultrasonic welding, in which case the liner disc will not be placed / inserted inside the closure shell but rather be placed directly on to the bottle rim for sealing thereto.Example A: PFAS-Free Microporous ePE Venting Port Membrane for Cap Liner

[0102] In one embodiment (FIGS. 2D-2E), a microporous ePE venting port membrane body (21) is provided having parallel spaced-apart grooves (25) on one side of the membrane spaced 0.15 inch (3.8 mm apart). These grooves, extending partially through the thickness of the disc-shaped membrane (21), provide strength to the membrane and help process / convert the membrane without a need for a backing layer. In one embodiment, the membrane is about 5.5 mil (0.0055 inch) thick in the non-ridge area and about 6.7 mil (0.0067 inch) thick in the ridge area.

[0103] The microporous ePE venting port membrane (20) with equal spaced grooves for membrane strength enables the membrane to be processed without a backer (i.e., enables the single layer ePE membrane to be directly slit, die cut, placed and weld to the periphery of the aperture of the liner substrate).

[0104] In one embodiment, the pore size of this microporous ePE venting port membrane (20) is in a range of 0.2 to 0.9 micron.

[0105] Comparatively, a known microporous ePTFE based venting closure liner in use for oxidizing agents such as cleaning bleach products is 0.7-0.9 micron.Example B: PFAS-Free Composite Cap Liner with Microporous ePE Venting Port Membrane

[0106] In one embodiment, a composite cap liner made with the microporous ePE venting port membrane (20) as described in Example A above provides the required package performance (leak performance and gas venting performance) for packaging of bleach (hypochlorite) based product(s).

[0107] The testing is performed on a composite cap liner and venting port membrane i.e., taking the microporous ePE venting port membrane (20) described in Example A and a foamed PE cap liner body (11) and converting of these two materials to form a composite venting closure liner disc while ensuring the venting port membrane is bonded (heat stake / weld) adequately to the periphery of the aperture in the foam liner disc. A weld check to the venting port membrane to foamed PE closure liner weld is done by the means of a standard leak test to ensure that no water droplets penetrate the venting port membrane from the back side of the cap liner.

[0108] The composite venting cap liner membrane disc so formed is then inserted into a closure cap to conduct package / performance testing. The package / performance testing assesses for product compatibility, package / product leakage and venting. The results are deemed similar to the known PFAS-based microporous expanded Polytetrafluoroethylene (ePTFE) venting closure liner.Product Compatibility / Leak Test—Germicidal Bleach, FIG. 6:Closure Torque: 22 in-lbs.; 38 mm size Closure cap;

[0110] Test product: Germicidal Bleach, Disinfecting Bleach, and Outdoor Bleach;

[0111] Sample ID:Venting Cap Liner: 0.040 inch thick F-217*Flat PE foamed closure liner disc with 3.9 mm aperture; 11 mm diameter microporous ePE venting port membrane heat stake / welded to the periphery of the aperture on one side of the foamed closure liner (see FIGS. 2A-2C).Leaks within . . .2471430Observations / ProductshrDaysDaysDaysCommentGermicidal Bleach (7.5%0 / 100 / 100 / 100 / 10No leakNaClO)Disinfecting Bleach (7.5%0 / 100 / 100 / 100 / 10No leakNaClO)Outdoor Bleach0 / 100 / 100 / 100 / 10No leak*Tri-Seal Blauvelt, NY made .040 inch thick F-217 polyethylene (PE) foam structure (LDPE skin / LDPE foam / LDPE skin), .040 inch target thickness and 25 lbs. / ft. cube densityProduct Compatibility / Leak Test—Pool Bleach (FIG. 7):Closure Torque: 22 in-lbs.; 33 mm Closure cap;Test product: Pool cleaning solution (10% NaClO), Drain Cleaner;

[0114] Sample ID: Venting Cap Liner: 0.040 inch thick F-217*Flat PE foamed closure liner disc with 3.9 mm aperture; 0.43 inch diameter microporous ePE venting port membrane heat stake / welded to the periphery of the aperture on one side of the foamed closure liner (see FIGS. 2A-2C).Leaks within . . .2471430Observations / ProductshrDaysDaysDaysCommentPool Bleach (10% NaClO)0 / 100 / 100 / 100 / 10No leakDrain Cleaner0 / 100 / 100 / 100 / 10No leak*Tri-Seal Blauvelt, NY made .040 inch thick F-217 polyethylene (PE) foam structure (LDPE skin / LDPE foam / LDPE skin), .040 inch target thickness and 25 lbs. / ft. cube densityPackage Vent Test Results:Venting Cap Liner: 0.040″ thick F-217*Flat PE foamed closure liner disc w / 0.155 inch / 3.9 mm mm aperture; 0.43 inch 11 diameter microporous ePE venting port membrane heat stake / welded to the periphery of the aperture on one side of the foamed closure liner (see FIGS. 2A-2C);Oven temperature=50° C.;

[0117] Test product: Germicidal Bleach, Disinfecting Bleach, and Outdoor Bleach;

[0118] Package: HDPE container with handle composite approximately 75 oz., with 38 mm size closure with vent hole lined with the aforementioned cap liner made from Flat F-217 heat stake / welded 0.155 inch (3.9 mm) in diameter cap liner with of a microporous ePE vent membraneNo. of bottles withrocker bottom (RB)Observations / Products24 hr7 Days14 DaysCommentGermicidal Bleach (7.5%0 / 30 / 30 / 3PassedNaClO)Disinfecting Bleach (7.5%0 / 30 / 30 / 3PassedNaClO)Outdoor Bleach0 / 30 / 30 / 3Passed

[0119] An accelerated test was conducted to assess the venting capability of the venting cap liner structure of the present invention with PFAS-free microporous ePE venting port membrane welded to the periphery of the venting port aperture of the foamed closure liner body (the “Test”) compared to the known package consisting of a microporous ePTFE (PFAS based) venting cap liner as the “Control”.

[0120] The “Test” and “Control” packages were placed in the oven at 50° C. to degas / building pressure in the package. Test Criteria: If the package does not bulge to a rocker bottom form within the first 7 days then the package effectively vents, i.e., releases the built up pressure.

[0121] The packages with the PFAS-Free microporous ePE venting port membrane based cap liner structure of the invention (the “Test”) performed comparably to the packages with known ePTFE (PFAS based) venting liner vent membrane as the “Control”.

[0122] The foregoing description is intended to illustrate and not limit the scope of the invention; those skilled in the art will realize that equivalents thereof are contemplated by the description above and that changes and modifications may be made thereto without departing from the invention, all such equivalents, changes and modifications falling within the scope of the claims hereof.

Examples

example a

PFAS-Free Microporous ePE Venting Port Membrane for Cap Liner

[0102]In one embodiment (FIGS. 2D-2E), a microporous ePE venting port membrane body (21) is provided having parallel spaced-apart grooves (25) on one side of the membrane spaced 0.15 inch (3.8 mm apart). These grooves, extending partially through the thickness of the disc-shaped membrane (21), provide strength to the membrane and help process / convert the membrane without a need for a backing layer. In one embodiment, the membrane is about 5.5 mil (0.0055 inch) thick in the non-ridge area and about 6.7 mil (0.0067 inch) thick in the ridge area.

[0103]The microporous ePE venting port membrane (20) with equal spaced grooves for membrane strength enables the membrane to be processed without a backer (i.e., enables the single layer ePE membrane to be directly slit, die cut, placed and weld to the periphery of the aperture of the liner substrate).

[0104]In one embodiment, the pore size of this microporous ePE venting port membrane...

example b

PFAS-Free Composite Cap Liner with Microporous ePE Venting Port Membrane

[0106]In one embodiment, a composite cap liner made with the microporous ePE venting port membrane (20) as described in Example A above provides the required package performance (leak performance and gas venting performance) for packaging of bleach (hypochlorite) based product(s).

[0107]The testing is performed on a composite cap liner and venting port membrane i.e., taking the microporous ePE venting port membrane (20) described in Example A and a foamed PE cap liner body (11) and converting of these two materials to form a composite venting closure liner disc while ensuring the venting port membrane is bonded (heat stake / weld) adequately to the periphery of the aperture in the foam liner disc. A weld check to the venting port membrane to foamed PE closure liner weld is done by the means of a standard leak test to ensure that no water droplets penetrate the venting port membrane from the back side of the cap lin...

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 756,467, filed on Feb. 10, 2025, which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The present invention relates to a composite cap liner and venting port membrane, secured to cover a dispensing aperture in a container, that is free of per- and polyfluoroalkyl substances (PFAS-free) while providing desired structural and functional performance and allowing gas-permeability and liquid-impermeability.BACKGROUND

[0003] Venting liners (also known as venting cap or closure liners) are utilized as a packaging component (e.g., a liner disc inserted inside the closure cap and applied over the dispensing aperture of a filled container or bottle) in order to equilibrate pressure inside the sealed container to that of the ambient pressure (pressure outside the sealed container).

[0004] The venting liner acts as a two-way valve to de-gas (vent) any gas built up inside the sealed container (e.g., because of product chemistry, altitude changes during transportation, etc.) and / or to let the outside air flow into the sealed container to prevent the paneling (collapsing) of the container side walls, e.g., because of package head space gas absorption by the product (such as antioxidant vitamins) or due to product filling conditions (such as a hot-filled product that cools down to generate a vacuum inside the package).

[0005] The venting liner is intended to allow gas transport into / out of the container, but not allow liquid transport (not allow a liquid product to leak out of the container through the liner).

[0006] The design of a venting liner is complicated by the need to address additional performance parameters required by the intended use, i.e., product and container composition, structure and function. For example, the venting liner preferably (1) shall not disintegrate with product interaction (i.e. be compatible with the product), and (2) shall not get excessively blocked by the product residue and / or dried product formed on the liner.

[0007] There are different types of venting closure liners known in the art and each type raises additional limitations on cost (of materials and manufacture), function or performance. One type of venting liner provides an overall microporous liner layer that is then bonded to a backing layer. The backing layer includes a broad array of multiple small apertures (holes) each extending through the backing layer to enable venting across the entire liner area. Another type of venting liner provides a single smaller venting port through the liner thickness, with a vent membrane secured to cover the port and allow the venting of gas through the limited port area. Where a smaller venting port is utilized, the vent membrane must maintain a weld bond to the periphery of the aperture (vent hole) formed in the closure liner.

[0008] Other limitations on the known venting liners relate to materials of use, and the ability of those materials to be recycled or to avoid use of certain chemicals that are disfavored for environmental reasons. For example, it would be desirable to avoid use of per- and polyfluoroalkyl (PFAS substances), which are known as “forever chemicals” in both the packaging and the product itself. Again the materials selected must satisfy multiple performance parameters as outlined above, in addition to being free from undesirable chemicals.SUMMARY OF THE INVENTION

[0009] According to one embodiment of the invention, a venting port membrane is provided for sealing a venting port in a closure cap liner, wherein the venting port membrane is made of a microporous material that is PFAS-free, such as a microporous expanded polyethylene (ePE), where the ePE is an ultrahigh molecular weight polyethylene for chemical compatibility and membrane strength. The ePE vent membrane is compatible for use with oxidizing agents such as cleaning products containing bleach (sodium hypochlorite) or hydrogen peroxide. In addition, the ePE venting port membrane provides a higher abrasion resistance than an expanded polytetrafluorethylene-based vent membrane (PFAS based).

[0010] In one embodiment, the ultrahigh molecular weight polyethylene has a weight-average molecular weight (Mw) in a range of 1 million of 10 million, more preferably in a range of 2 million to 8 million, and more preferably in a range of 3 million to 6 million.

[0011] The venting port membrane of the invention is made from a PFAS-free material, namely ePE as defined above, and can be used with a liner to form a bottle seal, such as a bottle seal that is induction heat sealed (including a metal foil layer for induction heating) or conduction heat sealed to the rim of the bottle opening.

[0012] In various embodiments of the invention, the bottle or container can be for example made of plastic, glass or metal.

[0013] The venting port membrane of the invention can preferably be used without a backing (support) layer, as is typically required in the prior art. This simplifies the structure and reduces the cost of materials and manufacture. When used without the backing layer, the venting port membrane includes multiple spaced-apart surface grooves (recessed areas extending partially through the thickness of the liner body) that provide structural strength and integrity during processing of the membrane (e.g., slitting, die cutting, placement and heat stake welding). The grooves also improve the abrasion resistance. Still further the use of ePE provides a higher abrasion resistance than an expanded polytetrafluorethylene-based (PFAS-based) vent membrane.

[0014] In various embodiments, the venting port membrane can be used with a woven or non-woven backing layer that is compatible with the surface of the closure liner for heat staking / welding the venting port membrane to the cap liner. For example, the ePE venting port membrane can be used with a scrim (woven backing layer). A backing layer assists with processing of the membrane (e.g., being slit, die cut, placed and welded to the periphery of the venting port in the liner body).

[0015] The venting port membrane of the invention further provides a desired leak performance (resistance to leakage of the liquid product through the venting port membrane and accompanying closure liner), as well as a desired gas venting performance.

[0016] The venting port membrane of the invention has various applications, with a variety of liquid products. It is particularly well suited for use with bleach (sodium hypochlorite) based cleaning products, a widely used household cleaning chemical, pool chemical, etc. Sodium hypochlorite naturally releases gas causing pressure to build-up inside the container and requiring the package to vent (degas) for safe use of the container / product and to prevent the container bulge (rocker bottom) that would interfere with stable transport / placement of the container.

[0017] The disadvantages of the prior art, and comparable advantages of the invention include, in various embodiments, one or more of the following:

[0018] 1) Prior art PFAS-based microporous ePTFE vent membrane has a higher cost compared to PFAS-free microporous ePE venting port membrane of the invention.

[0019] 2) Prior art PFAS-based ePTFE membrane contains forever chemicals harmful to the environment compared to PFAS-free microporous ePE venting port membrane of the invention.

[0020] 3) The venting port membrane of the present invention may be thermally laminated to the periphery surrounding the venting port in the liner (e.g., bonded to a peripheral area surrounding a single annular venting port having a diameter of 0.155 inch (3.9 mm)). This conserves material with the same overall functionality of prior container venting liners and prevents liquid leaks compared to the prior art overall microporous ePTFE venting liner with multiple venting apertures provided over the entire liner area. For products requiring faster venting, a larger single aperture greater in diameter than the 0.155 inch vent size can be used depending on the liner disc size. Also, two venting port membranes each heat stake / welded to the periphery of a matching vent hole in the liner can be used and would still be more cost effective than the overall microporous ePTFE venting liner with multiple venting apertures of the prior art.

[0021] In accordance with one embodiment of the invention, a composite non-PFAS gas-permeable and liquid-impermeable cap liner and venting port membrane (10) is provided configured to fit between a closure cap (2) and a rim (9) surrounding a dispensing aperture (31) of a container (8), the composite cap liner and venting port membrane (10) comprising:

[0022] a disc-shaped liner body (11) comprising a material that is substantially gas-impermeable and liquid-impermeable, the liner body having a bottom surface (13) facing the rim (9) surrounding the dispensing aperture (31) of the container and an opposing top surface (12) facing an inner top wall (4) of the closure cap (2), the liner body (11) having a venting port (16) that extends through the liner body from the top surface (12) to the bottom surface (13) and having a venting port periphery (17) that is less than a periphery (14) of the liner body;

[0023] a venting port membrane (20) made of a microporous expanded and ultrahigh molecular weight polyethylene (ePE) layer (21) that is gas permeable and compatible for use with oxidizing agents in cleaning products containing bleach or hydrogen peroxide, the venting port membrane being bonded at its periphery (24) to a peripheral area (17) surrounding the venting port (16) on either the bottom or top surfaces of the liner body (11) to provide a single gas-permeable venting port membrane (20) through the liner body that is also liquid-impermeable, and wherein the composite liner body and venting port membrane (10) are substantially free of per- and polyfluoroalkyl (PFAS) substances.

[0024] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane (20) comprises an ePE layer (21) of the microporous expanded ultrahigh molecular weight polyethylene (ePE) without a backing layer, and the ePE layer is disposed on either one of the top and bottom surfaces (12, 13) of the liner body.

[0025] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane includes a first layer (21) of the ePE and further includes a backing layer (30) for membrane strength.

[0026] In one embodiment of the composite cap liner and venting port membrane, either the first layer of the ePE (21) or the backing layer (30) is bonded to the peripheral area (17) surrounding the venting port (16) on either of the top and bottom surfaces (12, 13) of the liner body.

[0027] In one embodiment of the composite cap liner and venting port membrane, the ePE layer (21) has substantially equally spaced grooves (25) disposed along its top or bottom surfaces (22, 23) for membrane strength.

[0028] In one embodiment of the composite cap liner and venting port membrane, the thickness of the venting port membrane (20) is in a range of from 0.004 inch to 0.010 inch for membrane strength.

[0029] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane (20) has a series of substantially equally spaced grooves (25) extending into the top or bottom surface that are spaced apart in a range of 0.1 to 0.2 inches, and wherein the grooves are of a depth in a range of 0.001 to 0.003 inches.

[0030] In one embodiment of the composite cap liner and venting port membrane, the venting port membrane (20) has a pore size in a range of from 0.2 to 0.9 microns.

[0031] In one embodiment of the composite cap liner and venting port membrane, the disc-shaped liner body (11) is annular and has a diameter in a range of 0.750 to 2.750 inches (19 to 70 mm), and the venting port (16) is substantially annular and having a diameter in a range of from 0.15 to 0.5 inches.

[0032] In one embodiment of the composite cap liner and venting port membrane, the liner body (11) consists wholly or partially of a foam material.

[0033] In one embodiment of the composite cap liner and venting port membrane, the liner body (11) includes solid and foamed layers between the top and bottom surfaces.

[0034] In accordance with another embodiment of the invention, a combination is provided comprising:

[0035] a container (8) having an annular neck (1) and rim (9) surrounding an opening (31) for dispensing a product from the container,

[0036] a removable closure cap (2) having an inner top wall (3) and a peripheral cap flange (5) extending downwardly from the inner top wall that is secured to the annular neck (1) for enclosing the opening (31),

[0037] the composite cap liner and venting port membrane (10) being disposed between the annular rim (9) and inner top wall (3) of the closure cap and providing a liquid impervious seal that is gas permeable.

[0038] In one embodiment of the combination, the closure cap (2) and container neck (1) have mating threads to removably secure the closure cap to the neck.

[0039] In one embodiment of the combination, the venting port membrane (20) has a series of substantially equally spaced grooves (25) extending into the top or bottom surface that are spaced apart in a range of 0.1 to 0.2 inches, and wherein the grooves are of a depth in a range of 0.001 to 0.003 inches.

[0040] In one embodiment of the combination, the closure cap (2) has a gas venting port (32) that provides gas permeability through the closure cap.

[0041] In one embodiment of the combination, a portion of the composite cap liner and venting port membrane (10) is bonded to the inner top wall (3) of the closure cap, wherein the bonded portion does not include the venting port membrane (20) such that the venting port membrane remains gas permeable.

[0042] In one embodiment of the combination, the composite cap liner and venting port membrane (10) is disposed within a retainer groove in the cap flange (5).

[0043] In one embodiment of the combination, a portion of the composite cap liner and venting port membrane (10) is bonded to the container rim (9).

[0044] In one embodiment of the combination, the composite cap liner and venting port membrane (10) is not bonded to the container rim (9) and is not bonded to the closure cap (2).

[0045] In one embodiment of the combination, the ultrahigh molecular weight polyethylene ePE has a weight average molecular weight in a range of 1 million of 10 million, preferably in a range of 2 million to 8 million, and more preferably in a range of 3 million to 6 million.BRIEF DESCRIPTION OF THE FIGURES

[0046] FIGS. 1A and 1B are top perspective views of a composite cap liner and venting port membrane according to one embodiment of the invention disposed between a closure cap and container, FIG. 1A showing the composite liner / membrane spaced from the rim, and in FIG. 1B sealed to the rim.

[0047] FIGS. 2A, 2B and 2C show a composite cap liner and venting port membrane according to one embodiment; FIG. 2A is plan view of the filtration side (facing the product) of the composite cap liner / membrane; FIG. 2B is a plan view of the opposite side (facing the inside top wall of the closure cap) of the composite cap liner / membrane; and FIG. 2C is a plan view of the composite cap liner and venting port membrane positioned inside a closure cap; FIGS. 2D and 2E show an alternative embodiment of a venting membrane with a grooved surface (top and cross sectional views respectively).

[0048] FIGS. 3A and 3B are planar views of opposing top (facing the interior top wall of the closure cap) and bottom (facing the product) sides respectively of the composite cap liner and venting port membrane, according to one embodiment; FIGS. 3C and 3D are cross-sectional and exploded views of alternative liner bodies with surface grooves (FIG. 3C) and three layers (FIG. 3D).

[0049] FIG. 4 is an exploded perspective view of three components: 1) a closure cap; 2) a composite cap liner, and venting port membrane including a backing layer and ePE layer; and 3) a container neck with a product dispensing aperture; the arrows (A) illustrate the gas flow between the three components (into and out of the container) according to one embodiment.

[0050] FIGS. 5A, 5B and 5C are perspective views of the three components (closure cap, composite cap liner and venting port membrane, and container neck, as in FIG. 4), according to various embodiments; FIG. 5A is a schematic view of a composite liner / membrane, container neck and attached closure cap, the closure cap having a venting hole in the top wall of the cap, showing gas flow (arrow A) out the cap venting hole; FIG. 5B is a schematic view of a closure cap (without a venting hole) attached to the neck of a container and a composite cap liner / membrane, the liner having surface grooves facing the top wall of the closure cap, showing gas flow (arrow A) between the grooves and out between the mating threads on the cap flange and container neck; and FIG. 5C is a schematic view of a composite liner / membrane, disposed between a closure cap (without a venting hole in the cap) and the rim of a container neck, showing gas flow (arrow A) out between the mating threads of the closure cap flange and container neck.

[0051] FIG. 6 shows perspective and plan views of ten liquid germicidal bleach filled test containers each with an attached closure cap and composite cap liner with venting port membrane, according to one embodiment for testing.

[0052] FIG. 7 is a perspective view of six liquid pool bleach filled test containers each with an attached closure cap and composite cap liner with venting port membrane, according to one embodiment for testing.DETAILED DESCRIPTION

[0053] The following detailed description and figures show various embodiments of the invention and are meant to illustrate without limiting the invention to these specific embodiments.

[0054] In the figures and text, the following reference numbers are used to illustrate various components of the invention and use thereof:

[0055] 1 neck of container (bottle), with product dispensing aperture, and exterior threads

[0056] 2 cap or closure

[0057] 3 top wall of cap

[0058] 4 interior surface of the top wall of cap (facing the liner)

[0059] 5 flange or shoulder of cap, depending down from the top wall

[0060] 6 interior surface of shoulder, threaded

[0061] 7 liquid product (held in the container)

[0062] 8 container, bottle or package

[0063] 9 rim surrounding the product dispensing aperture in neck of the container

[0064] 10 composite cap liner and venting port membrane

[0065] 11 liner body, e.g., low density polyethylene PE foam; or 3 layers comprising: solid PE top layer, foam PE middle layer, solid PE bottom layer

[0066] 12 top surface (back side) of liner 11 (faces interior surface 4 of cap)

[0067] 13 bottom surface (front side) of liner 11 (faces product 7 in container)

[0068] 14 periphery of liner

[0069] 15 transverse axial centerline (extending through closure cap, composite liner / membrane, container neck)

[0070] 16 venting port (aperture or through hole) in liner

[0071] 17 periphery around venting port 16

[0072] 18 surface grooves on liner body 11

[0073] 20 venting port membrane

[0074] 21 venting port membrane body

[0075] 22 top surface (back side) of vent membrane body (faces interior surface 4 of cap)

[0076] 23 bottom surface (front side) of venting port membrane body (faces product 7 in container)

[0077] 24 periphery of venting port membrane body heat seal bonded to liner body at periphery 17 around venting port 16

[0078] 25 surface grooves on venting port membrane body 21

[0079] 30 backing layer (woven or non-woven) of venting port membrane

[0080] 31 dispensing aperture of container 8

[0081] 32 gas venting port on cap top wall

[0082] 33 exterior threads on neck 1

[0083] 34 interior threads on cap flange 5

[0084] FIGS. 1-5 show various embodiments of a PFAS-free microporous ePE venting port membrane 20 attached to a liner body 11 that provides a gas-permeable liquid-impermeable seal between a closure cap 5 and container rim 9.

[0085] In one example (FIG. 3D), a 3-layer annular cap liner (11) having solid LDPE, foamed LDPE, and solid LDPE layers in serial order from top to bottom is utilized that is sized to fit within an annular closure cap (2). In one example (FIGS. 3A-3C), the liner body 11 has surface grooves 18 for enhanced strength.

[0086] FIGS. 2A-2C show the closure liner (11) of 1 mm thickness and approx. 36 mm in diameter with an aperture (vent hole) (16) in the liner body that is 3.9 mm in diameter. A microporous ePE venting port membrane (20) is then heat stake / welded to the periphery (17) of the venting port aperture (16) in the liner, to either one of the two sides (12, 13) of the foamed closure liner (11). This venting port membrane body (21) is die cut into an annular disc about 11 mm in diameter to provide an approx. 3.5 mm extension of the vent membrane body to contact the liner disc surface around the periphery (17) of the venting port aperture (16) for heat staking / welding.

[0087] FIGS. 2D-2E show one embodiment of a venting port membrane body 21 having surface grooves 25 in one surface for enhanced strength.

[0088] The composite cap liner and venting port membranes (10) of FIGS. 1-5 provide:

[0089] 1) a PFAS-free ePE microporous venting port membrane that is able to form seal comparable to the prior art microporous ePTFE membrane;

[0090] 2) a PFAS-free ePE microporous venting port membrane that is heat stable, maintains structural integrity, and exhibits no significant deformation during the heat staking / welding process for bonding to the periphery of the venting port aperture of the foamed closure liner;

[0091] 3) a PFAS-free ePE microporous venting port membrane that can be processed using the known manufacturing equipment and processes (slitting and die cutting of sheet material to form a venting port membrane, placing and heat stake / welding the venting port membrane to the periphery of the venting port aperture of the closure liner using the known Vent Assembly Machine).

[0092] FIGS. 2A-2C and 3A-3B show various embodiments of a composite cap liner and venting port membrane (10) according to the present invention with the periphery (24) of the vent membrane body (20) heat staked to one side (13) of the liner body (11) at the periphery (17) of the venting port aperture (16). The venting port membrane (20) is bonded to the product facing side (13) of the liner body (11). The opposing back side (12) of the foam liner body may be grooved (18), as shown in FIGS. 3A-3C, where the grooves act as channels for gas to slide through and then outside the package through the interface at the side of the exterior bottle neck (1) finish threads and the interior closure flange (6) threads. The threads may be segmented to further enhance venting.

[0093] FIGS. 5A, 5B and 5C illustrate various examples of gas flow (via arrows A) between the interior of the container (8), the composite cap liner and venting port membrane (10) and the closure cap (2), e.g., allowing gas to enter / exit via the mating threads on the interior surface of cap flange (5) and the exterior surface of the container neck (1) as shown in FIGS. 5B-5C.

[0094] In one embodiment (FIG. 5A), the closure cap (2) (e.g., a molded plastic closure shell) may further include a vent hole (32) for venting (de-gas out of package) in lieu of the aforementioned grooves 18 (in the foam liner body 11). In such case, the package vents (de-gas) through the composite PFAS-Free ePE microporous membrane and cap liner (10) and the gas then exits out of the package through the hole (32) in the closure cap. In another embodiment (FIG. 5C), there is no vent hole (VH) in the cap (2) and no grooves (18) in the back side (12) of the liner (11); this allows for slow venting of gas between the mating threads 33, 34 of the container neck and cap.

[0095] The mechanisms of various venting profiles include:

[0096] a) Microporous ePE venting port membrane (20) with an optional backing layer (30) compatible with the liner. Example, the optional backer (30) may be polyolefin material either non-woven or woven polyethylene or polypropylene in the case of heat stake to polyethylene foam liner at the periphery of its aperture (hole) (16).

[0097] b) The gas released by the product, as per the chemical nature of the product such as sodium hypochlorite and / or pressure difference during transportation (altitude differences), will pass through the venting port membrane i.e. through the ePE layer, the optional backer, the venting port, and then either through a hole in the closure shell (if non-grooved foam), or through grooves (grooves or ridges in the back side of the liner foam). In case of a slow venting product, neither a hole in the closure shell nor grooves in the venting closure liner foam may be required, as the gas slowly vents through the venting port membrane and optional backing layer and is slowly released from the closure / bottle thread (side) interface.

[0098] c) In the same regards as above, an induction heat seal bottle seal liner is provided with a venting port membrane. However, it is not necessary for this venting bottle seal liner to be grooved on the back side. Essentially, the venting bottle seal liner is placed inside the closure (facing the product) along with a grooved or non-grooved foam venting closure liner on the back side (placed onto the closure side). As aforementioned in b), the closure shell may or may not include of a hole (depending on the rate of venting). If the package is a single-use package, then a venting closure liner on the back side may not be required.

[0099] Alternatively, the liner may be a two-piece wax bonded or waxless bonded structure that is converted to make a composite cap liner and venting port membrane by adding an aperture to the liner that is covered by a vent membrane (w / woven or non-woven backing layer compatible to heat stake to the heat seal surface layer of this two-piece liner). In this case the backing layer (with an aperture) will remain in the closure. This is especially useful for a single-use package because the bottle seal portion has a vent membrane.

[0100] In addition, a two-piece wax bonded pulp backed induction heat seal foil seal can be used with the venting port membrane.

[0101] In various embodiments, the composite cap liner and venting port membrane can be applied via conduction heat sealing or ultrasonic welding, in which case the liner disc will not be placed / inserted inside the closure shell but rather be placed directly on to the bottle rim for sealing thereto.Example A: PFAS-Free Microporous ePE Venting Port Membrane for Cap Liner

[0102] In one embodiment (FIGS. 2D-2E), a microporous ePE venting port membrane body (21) is provided having parallel spaced-apart grooves (25) on one side of the membrane spaced 0.15 inch (3.8 mm apart). These grooves, extending partially through the thickness of the disc-shaped membrane (21), provide strength to the membrane and help process / convert the membrane without a need for a backing layer. In one embodiment, the membrane is about 5.5 mil (0.0055 inch) thick in the non-ridge area and about 6.7 mil (0.0067 inch) thick in the ridge area.

[0103] The microporous ePE venting port membrane (20) with equal spaced grooves for membrane strength enables the membrane to be processed without a backer (i.e., enables the single layer ePE membrane to be directly slit, die cut, placed and weld to the periphery of the aperture of the liner substrate).

[0104] In one embodiment, the pore size of this microporous ePE venting port membrane (20) is in a range of 0.2 to 0.9 micron.

[0105] Comparatively, a known microporous ePTFE based venting closure liner in use for oxidizing agents such as cleaning bleach products is 0.7-0.9 micron.Example B: PFAS-Free Composite Cap Liner with Microporous ePE Venting Port Membrane

[0106] In one embodiment, a composite cap liner made with the microporous ePE venting port membrane (20) as described in Example A above provides the required package performance (leak performance and gas venting performance) for packaging of bleach (hypochlorite) based product(s).

[0107] The testing is performed on a composite cap liner and venting port membrane i.e., taking the microporous ePE venting port membrane (20) described in Example A and a foamed PE cap liner body (11) and converting of these two materials to form a composite venting closure liner disc while ensuring the venting port membrane is bonded (heat stake / weld) adequately to the periphery of the aperture in the foam liner disc. A weld check to the venting port membrane to foamed PE closure liner weld is done by the means of a standard leak test to ensure that no water droplets penetrate the venting port membrane from the back side of the cap liner.

[0108] The composite venting cap liner membrane disc so formed is then inserted into a closure cap to conduct package / performance testing. The package / performance testing assesses for product compatibility, package / product leakage and venting. The results are deemed similar to the known PFAS-based microporous expanded Polytetrafluoroethylene (ePTFE) venting closure liner.Product Compatibility / Leak Test—Germicidal Bleach, FIG. 6:Closure Torque: 22 in-lbs.; 38 mm size Closure cap;

[0110] Test product: Germicidal Bleach, Disinfecting Bleach, and Outdoor Bleach;

[0111] Sample ID:Venting Cap Liner: 0.040 inch thick F-217*Flat PE foamed closure liner disc with 3.9 mm aperture; 11 mm diameter microporous ePE venting port membrane heat stake / welded to the periphery of the aperture on one side of the foamed closure liner (see FIGS. 2A-2C).Leaks within . . .2471430Observations / ProductshrDaysDaysDaysCommentGermicidal Bleach (7.5%0 / 100 / 100 / 100 / 10No leakNaClO)Disinfecting Bleach (7.5%0 / 100 / 100 / 100 / 10No leakNaClO)Outdoor Bleach0 / 100 / 100 / 100 / 10No leak*Tri-Seal Blauvelt, NY made .040 inch thick F-217 polyethylene (PE) foam structure (LDPE skin / LDPE foam / LDPE skin), .040 inch target thickness and 25 lbs. / ft. cube densityProduct Compatibility / Leak Test—Pool Bleach (FIG. 7):Closure Torque: 22 in-lbs.; 33 mm Closure cap;Test product: Pool cleaning solution (10% NaClO), Drain Cleaner;

[0114] Sample ID: Venting Cap Liner: 0.040 inch thick F-217*Flat PE foamed closure liner disc with 3.9 mm aperture; 0.43 inch diameter microporous ePE venting port membrane heat stake / welded to the periphery of the aperture on one side of the foamed closure liner (see FIGS. 2A-2C).Leaks within . . .2471430Observations / ProductshrDaysDaysDaysCommentPool Bleach (10% NaClO)0 / 100 / 100 / 100 / 10No leakDrain Cleaner0 / 100 / 100 / 100 / 10No leak*Tri-Seal Blauvelt, NY made .040 inch thick F-217 polyethylene (PE) foam structure (LDPE skin / LDPE foam / LDPE skin), .040 inch target thickness and 25 lbs. / ft. cube densityPackage Vent Test Results:Venting Cap Liner: 0.040″ thick F-217*Flat PE foamed closure liner disc w / 0.155 inch / 3.9 mm mm aperture; 0.43 inch 11 diameter microporous ePE venting port membrane heat stake / welded to the periphery of the aperture on one side of the foamed closure liner (see FIGS. 2A-2C);Oven temperature=50° C.;

[0117] Test product: Germicidal Bleach, Disinfecting Bleach, and Outdoor Bleach;

[0118] Package: HDPE container with handle composite approximately 75 oz., with 38 mm size closure with vent hole lined with the aforementioned cap liner made from Flat F-217 heat stake / welded 0.155 inch (3.9 mm) in diameter cap liner with of a microporous ePE vent membraneNo. of bottles withrocker bottom (RB)Observations / Products24 hr7 Days14 DaysCommentGermicidal Bleach (7.5%0 / 30 / 30 / 3PassedNaClO)Disinfecting Bleach (7.5%0 / 30 / 30 / 3PassedNaClO)Outdoor Bleach0 / 30 / 30 / 3Passed

[0119] An accelerated test was conducted to assess the venting capability of the venting cap liner structure of the present invention with PFAS-free microporous ePE venting port membrane welded to the periphery of the venting port aperture of the foamed closure liner body (the “Test”) compared to the known package consisting of a microporous ePTFE (PFAS based) venting cap liner as the “Control”.

[0120] The “Test” and “Control” packages were placed in the oven at 50° C. to degas / building pressure in the package. Test Criteria: If the package does not bulge to a rocker bottom form within the first 7 days then the package effectively vents, i.e., releases the built up pressure.

[0121] The packages with the PFAS-Free microporous ePE venting port membrane based cap liner structure of the invention (the “Test”) performed comparably to the packages with known ePTFE (PFAS based) venting liner vent membrane as the “Control”.

[0122] The foregoing description is intended to illustrate and not limit the scope of the invention; those skilled in the art will realize that equivalents thereof are contemplated by the description above and that changes and modifications may be made thereto without departing from the invention, all such equivalents, changes and modifications falling within the scope of the claims hereof.

Examples

example a

PFAS-Free Microporous ePE Venting Port Membrane for Cap Liner

[0102]In one embodiment (FIGS. 2D-2E), a microporous ePE venting port membrane body (21) is provided having parallel spaced-apart grooves (25) on one side of the membrane spaced 0.15 inch (3.8 mm apart). These grooves, extending partially through the thickness of the disc-shaped membrane (21), provide strength to the membrane and help process / convert the membrane without a need for a backing layer. In one embodiment, the membrane is about 5.5 mil (0.0055 inch) thick in the non-ridge area and about 6.7 mil (0.0067 inch) thick in the ridge area.

[0103]The microporous ePE venting port membrane (20) with equal spaced grooves for membrane strength enables the membrane to be processed without a backer (i.e., enables the single layer ePE membrane to be directly slit, die cut, placed and weld to the periphery of the aperture of the liner substrate).

[0104]In one embodiment, the pore size of this microporous ePE venting port membrane...

example b

PFAS-Free Composite Cap Liner with Microporous ePE Venting Port Membrane

[0106]In one embodiment, a composite cap liner made with the microporous ePE venting port membrane (20) as described in Example A above provides the required package performance (leak performance and gas venting performance) for packaging of bleach (hypochlorite) based product(s).

[0107]The testing is performed on a composite cap liner and venting port membrane i.e., taking the microporous ePE venting port membrane (20) described in Example A and a foamed PE cap liner body (11) and converting of these two materials to form a composite venting closure liner disc while ensuring the venting port membrane is bonded (heat stake / weld) adequately to the periphery of the aperture in the foam liner disc. A weld check to the venting port membrane to foamed PE closure liner weld is done by the means of a standard leak test to ensure that no water droplets penetrate the venting port membrane from the back side of the cap lin...

Claims

1. A composite non-PFAS gas-permeable and liquid-impermeable cap liner and venting port membrane (10) configured to fit between a closure cap (2) and a rim (9) surrounding a dispensing aperture (31) of a container (8), the composite cap liner and venting port membrane (10) comprising:a disc-shaped liner body (11) comprising a material that is substantially gas-impermeable and liquid-impermeable, the liner body having a bottom surface (13) facing the rim (9) surrounding the dispensing aperture (31) of the container and an opposing top surface (12) facing an inner top wall (4) of the closure cap (2), the liner body (11) having a venting port (16) that extends through the liner body from the top surface (12) to the bottom surface (13) and having a venting port periphery (17) that is less than a periphery (14) of the liner body;a venting port membrane (20) made of a microporous expanded and ultrahigh molecular weight polyethylene (ePE) layer (21) that is gas permeable and compatible for use with oxidizing agents in cleaning products containing bleach or hydrogen peroxide, the venting port membrane being bonded at its periphery (24) to a peripheral area (17) surrounding the venting port (16) on either the bottom or top surfaces of the liner body (11) to provide a single gas-permeable venting port membrane (20) through the liner body that is also liquid-impermeable, and wherein the composite liner body and venting port membrane (10) are substantially free of per- and polyfluoroalkyl (PFAS) substances.

2. The composite cap liner and venting port membrane of claim 1, wherein the venting port membrane (20) comprises an ePE layer (21) of the microporous expanded ultrahigh molecular weight polyethylene (ePE) without a backing layer, and the ePE layer is disposed on either one of the top and bottom surfaces (12, 13) of the liner body.

3. The composite cap liner and venting port membrane of claim 1, wherein the venting port membrane includes a first layer (21) of the ePE and further includes a backing layer (30) for membrane strength.

4. The composite cap liner and venting port membrane of claim 3, wherein either the first layer of the ePE (21) or the backing layer (30) is bonded to the peripheral area (17) surrounding the venting port (16) on either of the top and bottom surfaces (12, 13) of the liner body.

5. The composite cap liner and venting port membrane of claim 2, wherein the ePE layer (21) has substantially equally spaced grooves (25) disposed along its top or bottom surfaces (22, 23) for membrane strength.

6. The composite cap liner and venting port membrane of claim 1, wherein the thickness of the venting port membrane (20) is in a range of from 0.004 inch to 0.010 inch for membrane strength.

7. The composite cap liner and venting port membrane of claim 6, wherein the venting port membrane (20) has a series of substantially equally spaced grooves (25) extending into the top or bottom surface that are spaced apart in a range of 0.1 to 0.2 inches, and wherein the grooves are of a depth in a range of 0.001 to 0.003 inches.

8. The composite cap liner and venting port membrane of claim 1, wherein the venting port membrane (20) has a pore size in a range of from 0.2 to 0.9 microns.

9. The composite cap liner and venting port membrane of claim 1, wherein the disc-shaped liner body (11) is annular and has a diameter in a range of 0.750 to 2.750 inches (19 to 70 mm), and the venting port (16) is substantially annular and having a diameter in a range of from 0.15 to 0.5 inches.

10. The composite cap liner and venting port membrane of claim 1, wherein the liner body (11) consists wholly or partially of a foam material.

11. The composite cap liner and venting port membrane of claim 1, wherein the liner body (11) includes solid and foamed layers between the top and bottom surfaces.

12. In combination,a container (8) having an annular neck (1) and rim (9) surrounding an opening (31) for dispensing a product from the container,a removable closure cap (2) having an inner top wall (3) and a peripheral cap flange (5) extending downwardly from the inner top wall that is secured to the annular neck (1) for enclosing the opening (31),the composite cap liner and venting port membrane (10) of claim 1 being disposed between the annular rim (9) and inner top wall (3) of the closure cap and providing a liquid impervious seal that is gas permeable.

13. The combination of claim 12, wherein the closure cap (2) and container neck (1) have mating threads to removably secure the closure cap to the neck.

14. The combination of claim 13, wherein the venting port membrane (20) has a series of substantially equally spaced grooves (25) extending into the top or bottom surface that are spaced apart in a range of 0.1 to 0.2 inches, and wherein the grooves are of a depth in a range of 0.001 to 0.003 inches.

15. The combination of claim 12, wherein the closure cap (2) has a gas venting port (32) that provides gas permeability through the closure cap.

16. The combination of claim 12, wherein a portion of the composite cap liner and venting port membrane (10) is bonded to the inner top wall (3) of the closure cap, wherein the bonded portion does not include the venting port membrane (20) such that the venting port membrane remains gas permeable.

17. The combination of claim 12, wherein the composite cap liner and venting port membrane (10) is disposed within a retainer groove in the cap flange (5).

18. The combination of claim 12, wherein a portion of the composite cap liner and venting port membrane (10) is bonded to the container rim (9).

19. The combination of claim 12, wherein the composite cap liner and venting port membrane (10) is not bonded to the container rim (9) and is not bonded to the closure cap (2).

20. The combination of claim 12, wherein the ultrahigh molecular weight polyethylene ePE has a weight average molecular weight in a range of 1 million of 10 million, preferably in a range of 2 million to 8 million, and more preferably in a range of 3 million to 6 million.

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