Foil-free tongue seal

Abstract

The invention relates to a foil-free tongue seal. Various forms of tongue sealing members and laminates forming the sealing members are described. In some forms, the tongue sealing member may generally be formed from a material that may be handled with a single recovery stream. In one form, the tongue seal does not include any metal foil as traditionally included in an induction heating seal. Instead, the seals may be applied in other ways, such as using ultrasonic sealing, conductive heating, high frequency sealing / welding, pressure sensitive adhesives, and the like.

Description

[0001] This application is a divisional application of the invention patent application filed on November 25, 2020, with application number 202080094908.7 and invention title "Foil-free sealing device with tongue".

[0002] Cross-reference to related applications This application claims the benefit of U.S. Provisional Application No. 62 / 941,915, filed November 29, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a pull tab sealing member for sealing the opening of a container, and more particularly to a pull tab sealing member that does not contain foil or other metallic materials. Background Technology

[0004] It is generally desirable to use removable or peelable seals, sealing members, or inner seals to seal the opening of a container. Typically, a cap or other closure is then screwed onto or placed over the container opening, capturing the sealing member therein. In use, consumers typically remove the cap or other closure to access the sealing member and then remove or otherwise peel the seal from the container to dispense or access its contents.

[0005] Early attempts to seal container openings utilized inductive or conductive inner seals covering the container opening, where the seal was generally conformable to the shape of the opening, thus sealing a circular container opening using a disc of approximately the same size as the opening. These existing seals typically have a lower heat-activated sealing layer to anchor the periphery of the seal to the edge or other upper surface surrounding the container opening. When the seal is exposed to heat, the lower layer bonds to the edge of the container. In many cases, these seals include a foil layer capable of generating inductive heat to activate the lower heat-activated sealing layer. These existing seals tend to provide a good seal but are often difficult for consumers to remove because there is little for them to grip and remove the seal. Typically, consumers need to pry open the edge of the seal with their fingernails because there is little or no sealing material to hold.

[0006] Other types of seals used for containers include side flaps or other flanges extending outward from the peripheral edge of the seal. These side flaps are typically not fixed to the container rim and provide a gripping surface for the consumer to hold and remove the seal. However, these side flaps extend along the side of the container rim and often protrude into the threaded portion of the closure. If the side flaps are too large, this configuration can negatively affect the seal's ability to form a good heat seal. When the closure or other cap is placed on the container, the side flaps (and often the seal itself) may deform or wrinkle due to contact between the closure (and its threads) and the flapped portion of the seal. To minimize these problems, side flaps are typically very small; thus providing the consumer with very little surface area or material to grip for removal of the seal.

[0007] Other types of seals include sealing members with a tongue defined on the top of the seal. One method of these existing seals involves applying a pressure-sensitive adhesive to a portion of the tongue to secure it to a layer of foil. The tongue is formed from a complete layer extending across the entire surface of the sealing member, but this complete layer is only bonded to half of the seal to form the tongue. This type of top-tongue seal offers the advantage of a larger tongue, providing consumers with a larger gripping area to hold and peel off the seal, but requires a complete additional layer of material to form the tongue. In other methods, the seal may include a tongue formed from an additional complete film layer bonded to an additional complete adhesive layer, which utilizes a portion of paper or a portion of polymer layer (referred to as tongue material) to form the tongue. This portion of layer is inserted between the additional complete adhesive layer and the lower sealing portion to prevent the tongue from adhering to the underlying layer, thereby forming the tongue.

[0008] However, such tongues are typically induction-sealed to the container, thus requiring an induction heating layer such as metal foil. This metal foil complicates recycling because it needs to be separated from the sealing element. Furthermore, in some cases, a portion of the metal foil may remain on the container, complicating the recycling of the container itself.

[0009] In this respect, such tongue-and-groove sealing components and containers may be problematic, as is the case in Germany under the "Duales system." The component would be considered a composite material containing both plastic and metal foil. Such material cannot be processed into "hybrid plastic films," as is done through wind sieving according to the Duales system. Other countries are considering similar recycling systems and requirements, therefore the integral components used in sealing components must be taken into account.

[0010] Therefore, it may be desirable to provide a tongue-shaped sealing component that is more suitable for recycling according to different recycling systems and procedures. Summary of the Invention

[0011] Various forms of flap seals and the laminates forming the seals are described. In some forms, flap seals can typically be formed from materials that can be processed using a single recycling stream. In one form, the flap seal does not include any metal foil as conventionally included in induction-heated seals. Instead, the seal can be applied in other ways, such as using ultrasonic sealing, high-frequency sealing, conductive heating, pressure-sensitive adhesives, etc.

[0012] According to one embodiment, a tongue-and-groove sealing member is provided for sealing to an edge surrounding a container opening. The sealing member comprises a multilayer laminate including an upper laminate portion partially bonded to a lower laminate portion to form a clamping tongue completely defined within the periphery of the sealing member. The clamping tongue is configured for removing the sealing member from the container opening. The lower laminate portion is positioned below the clamping tongue and includes at least a sealant layer for bonding to the container edge. The upper laminate portion includes a support layer. The tongue-and-groove sealing member does not have a foil layer.

[0013] According to one embodiment, a tongue-and-groove sealing member is provided for sealing to an edge surrounding a container opening. The sealing member comprises a multilayer laminate including an upper laminate portion partially bonded to a lower laminate portion to form a clamping tongue completely defined within the periphery of the sealing member. The clamping tongue is configured for removing the sealing member from the container opening. The lower laminate portion is positioned below the clamping tongue and includes at least a sealant layer for bonding to the container edge. The sealant layer comprises a polyolefin. The sealant layer may also comprise a polyester, such as polyethylene terephthalate. In some embodiments, other materials such as EVA, acrylic, and EMA materials may also be included in the sealant layer. The upper laminate portion includes a polyolefin support layer. The tongue-and-groove sealing member does not have a metal foil layer.

[0014] In one embodiment, a laminate is provided for forming a tongue-and-groove sealing member. The laminate includes an upper laminate portion and a lower laminate portion. The upper laminate portion includes a support layer. The lower laminate portion includes at least a sealant layer for bonding to a container edge. The upper laminate portion is partially bonded to the lower laminate portion and configured to form a clamping tongue when the laminate is formed as a sealing member. The laminate does not have a foil layer.

[0015] In one configuration, both the support layer and the sealant layer comprise polyolefins.

[0016] In one form, the sealant layer is a pressure-sensitive adhesive.

[0017] In one form, the upper laminate portion includes a tongue layer.

[0018] In one form, the tongue layer is the printed layer.

[0019] In one configuration, the upper laminate portion includes a release layer.

[0020] In one form, the release layer is a paint layer.

[0021] In one form, the sealant layer is a relatively low-density and low-melting-point material compared to the support layer.

[0022] In one configuration, the support layer and the sealant layer each comprise polypropylene, polyethylene, or a combination thereof.

[0023] In one form, at least one of the support layer and the sealant layer comprises polyester.

[0024] In one configuration, both the support layer and the sealant layer comprise polyester.

[0025] These and other aspects can be more easily understood from the following description and accompanying figures. Attached Figure Description

[0026] Figure 1 It is a cross-sectional view of a tongue-type sealing component that does not include a metal foil layer; Figure 2 This is a cross-sectional view of another form of the tongue-and-groove sealing member that does not include the metal foil layer; Figure 3 This is a cross-sectional view of another form of the tongue-and-groove sealing member that does not include the metal foil layer; Figure 4 It is a cross-sectional view of one type of tongue-type sealing component with a two-piece construction; Figure 5 This is a cross-sectional view of one type of sealing component with a tongue; Figure 6 This is a bottom view of one form of tongue-and-groove sealing member, showing the heat seal that has been applied in accordance with the sealing member; Figure 7 It is a side view of one form of tongue-and-seal member installed on a container; and Figure 8 It is a perspective view of a form of laminate used to assemble a tongue-and-blade sealing member. Detailed Implementation

[0027] To facilitate understanding of the subject matter sought, embodiments of the subject matter are illustrated in the accompanying drawings. When considered in conjunction with the following description, the subject matter sought, its construction and operation, and its many advantages should be readily understood and appreciated by examining these embodiments.

[0028] This document describes a pull tab sealing member for containers, comprising an upper laminate with a pull tab that is coupled to a lower laminate capable of sealing to the mouth or opening of the container. Typically, the sealing member does not use metal foil, such as aluminum foil, which is typically used for inductive sealing of containers. Instead, many of the forms described herein can utilize alternative sealing technologies, such as conductive heating, ultrasonic sealing, high-frequency sealing, pressure-sensitive adhesives, etc.

[0029] For simplicity, this disclosure may generally refer to containers or bottles, but the sealing member described herein can be applied to any type of container, bottle, package, or other device having an rim or opening surrounding an access opening to an internal cavity. In this disclosure, references to the upper and lower surfaces of the components of the sealing member, as well as to the layers, refer to the orientation of the components as generally depicted in the figures and when used with a container in an upright position and having an opening at the top of the container. Different methods of sealing members will first be generally described, followed by explanations of various constructions and materials in greater detail. It should be appreciated that in some cases, the sealing members described herein function as either a one-piece or a two-piece sealing member configuration. A one-piece sealing member typically comprises only a sealing member attached to the rim of the container. A cap or closure may also be used with it. A two-piece sealing member comprises a sealing member temporarily attached to a liner. In this configuration, the sealing member is attached to the rim of the container, and the liner is configured to separate from the sealing member during heating to hold in place within a cap or other closure used on the container. Alternatively, the bond between the liner and the sealing element may be fragile, causing it to separate when the cap is removed from the container by the user. In a two-piece construction, for example, a wax layer can be used to temporarily bond the sealing element to the liner. Other types of releasable layers can also be used to provide a temporary bond between the seal and the liner.

[0030] As discussed above, flap seals can present problems associated with the use of metal foil in flap seal components. Once the seal is removed, this can result in a combination of metals and polymers from the removed seal and residual metals and polymers on the container. This combination of materials can make recycling difficult.

[0031] Figure 1 One form of foil-free tongue-type sealing member is shown. More specifically, Figure 1This is a cross-section of the tongue-and-switch sealing member 20, which is a multilayer laminate. As indicated by the arrow, the tongue-and-switch sealing member 20 includes a lower laminate portion 22 that is partially bonded to the upper laminate portion 24. This forms a tongue 27 for the user to grip. The lower laminate portion 22 includes a sealant layer 26 for bonding to the edge of the container and, in some forms, may include one or more polymer layers. The upper laminate portion 24 includes at least one polymer layer, such as polymer layer 28 and polymer layer 30. The upper laminate portion 24 also includes an optional tongue layer 32 and a release layer 34.

[0032] The sealant layer 26 can take many forms. For example, the sealant layer 26 can be a polyolefin film, including but not limited to polypropylene, polyethylene, high-density polyethylene, low-density polyethylene, metallocene, polybutene, etc. In some forms, the sealant layer can include a polyester material. For example, the sealant layer can include polyethylene terephthalate (PET) material, such as PET heat-sealing varnish. This material can be a copolyester resin.

[0033] In some forms, the sealant layer may be applied to another layer, such as a support layer in the lower laminate portion. In some forms, the sealant layer may be modified to suit its use with certain types of materials. For example, when used with polyester containers such as PET, the sealant may include polyesters such as PET. In other forms, the sealant layer may be used with polyolefin containers such as polypropylene and / or polyethylene. In these forms, it may be more suitable for the sealant layer to contain polypropylene and / or polyethylene to form the desired bond.

[0034] In one form, the sealant layer 26 may have a relatively low melting point, such as below about 110°C, below about 90°C, or below about 80°C. The sealant layer 26 may also have a melting point such as about 0.9 g / cm³. 3 Approximately 1.4 g / cm³ 3 The sealant layer has a relatively low density. In some forms, the sealant layer can have a thickness of about 1 μm to about 100 μm. In some forms, the sealant layer can be peelable (soft and / or hard). The sealant layer can also be maneuverable and suitable for use with top sealing devices.

[0035] Furthermore, the sealant layer 26 is particularly suitable for other forms of sealing besides inductive sealing, because the tongue-and-groove sealing member does not include a foil layer. For example, the sealant layer 26 can be configured for ultrasonic sealing, conductive sealing, high-frequency sealing, etc.

[0036] In some forms, the sealant layer can be configured as a pressure-sensitive adhesive. Such a pressure-sensitive adhesive may include about 0.2 to about 0.5 mils (or less) of adhesives, such as coated ethylene-vinyl acetate (EVA), polyolefins, two-component polyurethanes, ethylene-acrylic acid copolymers, curable two-component urethane adhesives, epoxy adhesives, ethylene methacrylate copolymers, and similar bonding materials.

[0037] Polymer layers such as polymer layers 28 and 30 can take many forms and perform a variety of different functions. For example, in some forms, at least one of polymer layers 28 and 30 can serve as a support layer to provide structural stability. In some forms, at least one of polymer layers 28 and 30 can serve as an adhesive layer between the upper laminate portion 24 and the lower laminate portion 22, such as in... Figure 1 The arrow in the image indicates the location.

[0038] A variety of different materials can be used in polymer layers 28 and 30. For example, polymer layer 28 may include a polyolefin film, such as polypropylene, polyethylene, or combinations thereof. In some forms, the material may be in the form of a single-layer film or a co-extruded film.

[0039] The polymer layer 30 may also comprise a variety of different materials. For example, the polymer layer 30 may comprise a polyolefin film, such as polypropylene, polyethylene, HDPE, LLDPE, MDPE, LDPE, metallocene, polybutene, combinations thereof, etc. Furthermore, the material may be a single-layer film or a co-extruded film.

[0040] Polymer layers 28 and 30 may also take other forms, such as including polyester. For example, at least one of polymer layers 28 and 30 may include polyester terephthalate (PET). These materials may include ordinary PET film, PET co-extruded film, heat-sealable PET film, amorphous PET film, PET film with different crystallinity, etc. For example, PET film with a crystallinity of up to about 50% may be used in some forms. In some forms, when disposed in the lower laminate portion, the upper portion of the polymer layer may provide support and / or insulation, while the lower polymer layer may provide compressibility and flexibility as well as a substrate for the sealant coating.

[0041] In one embodiment, the polymer layers 28 and 30 in the upper laminate portion 24 have a relatively higher melting point and / or higher density than the polymer used in the lower laminate portion 22. For example, the polymer layers 28 and 30 may have a melting point of about 115°C to about 270°C. The polymer layers 28 and 30 may also have a density of about 0.90 g / cm³. 3 Approximately 1.4 g / cm³ 3The density. In some forms, polypropylene can be used, such as those having a melting point of about 145°C to about 170°C and a density of about 0.90 g / cm³. 3 Approximately 0.93 g / cm³ 3 Polypropylene with a density of [missing information].

[0042] The polymer layer can also be transparent, such as when forming one or more of the upper laminate. In this form, the transparent polymer layer in the upper laminate can allow other parts of the sealing member to be seen, such as when printing or other features are included.

[0043] Depending on the requirements, the tongue layer 32 can also take many different forms and provide different properties. In one form, the tongue layer can be a printed layer. Generally, a printed layer can be applied to another layer, such as in a printed form. Printing inks can be used, including but not limited to nitrocellulose, PVD (physical vapor deposition) pigments, acrylics, polyurethanes, polyvinyl butyral (PVB), etc. In some forms, the printed layer is applied to one of the polymer layers 28, 30. In other forms, the printed layer 32 can be applied to different layers, such as polymer layers, and then the polymer layer is combined with one or more of the polymer layers 28, 30.

[0044] Typically, a release layer 34 may be included to allow separation of the lower laminate portion 22 and a portion of the upper laminate portion 24, or separation from each other by the user in other ways. The release layer 34 may take various forms, such as a film, a coating, etc. In one form, the release layer may be a silicone coating. According to another form, the release layer 34 may be a varnish layer. The release layer 34 may also include a polyamide coating, a nitrocellulose / polyamide blend, a polyurethane resin coating, an acrylic resin, etc. In some forms, the release layer is a physical release rather than an anti-stick layer (such as having silicone). In this respect, a physically non-melting layer may be suitable as a release layer.

[0045] Figure 2 Another form of the tongue-and-switch seal member is shown. The tongue-and-switch seal member 120 typically includes similar features as described above. However, in this form, the tongue-and-switch seal member 120 does not include the printed layer 32. In some forms, the release layer 34 can be manufactured to be thicker or thinner as needed, and to provide a suitable gripping surface for the user.

[0046] Figure 3 An illustration of a tongue-and-blade sealing member 220 is provided. This form is similar to... Figure 1 The form seen in the diagram. However, the tongue-and-switch seal 220 includes a single polymer layer 30. In this form, the polymer layer 30 can at least serve as a support layer, providing the user with sufficient strength to grip the tongue 27 and remove at least a portion of the tongue-and-switch seal 220.

[0047] Figure 4 The diagram illustrates a two-piece configuration. Typically, this configuration can include any different combination of the features described herein, as well as the liner portion 40. More specifically, the flap seal member 320 includes the liner portion 40, which comprises a backing layer 42 and a temporary bonding layer 44. The temporary bonding layer 44 can take various forms and provide a temporary bond to the upper laminate portion 24 in various ways. In one form, the temporary bonding layer 44 can take the form of wax, which can be absorbed into one of the backing layer 42 and the upper laminate portion 24. For example, the backing layer 42 can be a paper or pulp layer, such that the wax can melt and be absorbed when the flap seal member 320 is heated and mounted onto the container. In another form, the temporary bonding layer can simply provide a weak bond that can easily break, such as when the closure is removed from the container.

[0048] Figure 5 Another form of the sealing member 420 is illustrated. This form is similar to many of the embodiments described above. Figure 5 The difference lies in that the lower laminate portion 22 includes various polymer layers. More specifically, the lower laminate includes a sealant layer 26, as well as polymer layers 50 and 52. A partial adhesive layer 54 is positioned to form a partial bond, providing a tongue portion 27. The upper laminate includes a polymer layer 28.

[0049] Now will describe Figure 5 One exemplary form of the features. In some forms, each of the layers in the sealing member may include a common type of material. For example, each of the layers may include a form of polyester, such as PET. In some forms, sealant layer 26 may be a PET heat-sealing varnish. PET heat-sealing varnish may be applied to various PET-containing materials in polymer layer 50. For example, polymer layer 50 may be a chemically treated (such as acrylic treatment) PET film. Other treatments may include, but are not limited to, corona treatment, copolyester treatment, etc. Furthermore, polymer layer 52 may include polyester materials, such as amorphous PET materials.

[0050] Amorphous PET can be particularly useful in certain sealing components because it can provide compressibility, replacing some of the functions of foam traditionally used in sealing members. Furthermore, PET materials can contain pigments to protect the contents of the container from light. While PET materials are generally quite rigid, amorphous PET can be used to provide a degree of compressibility and flexibility in sealing members.

[0051] Although not in Figure 5As shown, however, an adhesive such as a two-component polyurethane adhesive can be used between polymer layers 50 and 52. Similarly, a portion of adhesive layer 54 can be a two-component polyurethane adhesive. Finally, polymer layer 28 can be a transparent PET film.

[0052] Figure 6 Another form of the sealing member 520 is illustrated. (As shown) Figure 6 As shown, the sealant layer 526 is applied in accordance with the size and shape of the sealing member 520. In this configuration, the sealant layer 526 is applied to the area of ​​the sealing member that will contact and seal the edge of the container upon installation. Therefore, when viewed from the bottom, the sealant layer 526 is shown facing the edge of the sealing member 520, while the layer above the sealant layer is shown in an area not typically positioned above the edge of the container. For example, in a similar... Figure 5 In this configuration, the polymer layer 50 is visible from the bottom of the sealing member. When preparing such a sealing member, the sealant layer 526 can be applied only to specific areas of the polymer layer 50, when it is in the form of a laminate or sheet. Then, when the laminate or sheet is cut, the cut is aligned with the position of the sealant layer 526. This helps to position the sealant layer 526 generally just towards the outer edge of the sealing member 520 in the location where the sealing member will contact and seal the container. It should be understood that this application of a sealant layer aligned with the sealing member can be used and applied to any of the above embodiments.

[0053] In some forms, it should be understood that many and / or all layers in the sealing member comprise materials of common forms. For example, layers may typically comprise polyolefins. In some forms, layers may typically comprise polyesters such as PET. In some forms, layers may comprise materials of common forms, in addition to the sealant layer. For example, the polymer layer of the sealing member may comprise polyesters such as PET, while the sealing member may comprise polyolefins such as polypropylene and / or polyethylene. In this form, most of the sealing member, except for the sealant layer, can be considered a single material from the same type of material.

[0054] Single-material sealing components may be particularly suitable for recycling purposes. Furthermore, single-material systems can be used with common polymer layers for different types of seals where only the sealant layer is modified. One such example could include a polyester single-material sealing component, where each of the polymer layers comprises a form of PET. In the case of a single-material system used on a PET container, the sealant layer may also comprise PET. In the case of a single-material system used with polypropylene, the polymer layers will still comprise the same PET material, but the sealant layer will comprise polypropylene instead of PET. This system can be useful when the same polymer layer is used for different types of seals, requiring only modification of the sealant layer as needed. Other types of single-material systems can be constructed in a similar manner, such as polyolefin single-material systems with different sealant layers.

[0055] When used in a single-material sealing system, the sealant layer can be applied in registration with the sealing member, as described above, to minimize the amount of any foreign material. For example, in a PET single-material sealing system, a polypropylene sealant layer can be applied in registration, as described above, to minimize the amount of any non-PET material. This can increase its usability as a recyclable stream.

[0056] It should be recognized that various adhesives may be included in the layers described above for the various embodiments. For example, adhesives and / or adhesive layers may be provided between various polymer layers as needed.

[0057] The tongue-and-blade sealing member 100 is shown mounted on container 101. The tongue-and-blade sealing member 100 may include any of the above embodiments and combinations of features from these embodiments. Figure 7 As shown, the tongue 102 is being lifted from the lower laminate portion 104 sealed on the container 101. The user can grasp the tongue 102 to remove at least a portion of the tongue-sealed member 100 from the container 101.

[0058] Figure 6 The diagram illustrates one form of assembling a tongue-and-groove sealing member. In this form, an upper laminate portion 24 is joined to a lower laminate portion 22, with a printed layer 32 between them. It should be appreciated that a release layer 34 may also, or alternatively, be positioned between them. In some forms, the upper laminate portion may be pre-formed, for example, using a higher density, higher melting point material that adheres to each other in a separate bonding process. This pre-formed material can then be adhered to the lower laminate portion using a hot lamination process, using heated rollers, and / or using a separate adhesive.

[0059] These layers can also be assembled in other ways. For example, in addition to heat lamination, other adhesives or laminating materials can be used. Polyurethane adhesive lamination can be used between one or more layers and can also include strips of this material, such as those applied to or near a release lacquer. Similarly, partial application of polyurethane adhesive can be used between one or more layers. Other partial applications can also be used with other materials such as hot melt adhesives, low-melt copolyesters, etc.

[0060] In some forms, the tab-type sealing members described herein may be more suitable for recycling. For example, tab-type sealing members do not have metal foil, which could otherwise contaminate or complicate the recycling process of the tab-type sealing member and / or the container. In some conventional sealing members, at least a portion of the foil layer can remain on the container and / or with the sealing member when the seal is removed. Metal foil typically cannot be recycled with the polymer layer, necessitating its removal, or the entire material cannot be recycled. Furthermore, in some forms, tab-type sealing members may be made substantially of the same type of polymer material, allowing the seal to be recycled in a single process or otherwise easily separated into component layers. For example, the layers may include polyolefins and similar recyclable materials.

[0061] In one form, the sealant layer is a low-density, low-melting-point material that does not require significant heat to adhere to the container. Such materials can include, but are not limited to, co-extruded polypropylene and random copolymers. Other layers in the tongue-and-groove seal can be of relatively high density and high melting point, such that they do not melt during the heating process used to apply the seal to the container.

[0062] In some forms, the tongue-and-switch seals described herein can be fabricated in a way that eliminates the need for a specific tongue layer, such as a PET layer, as used in many conventional tongue-and-switch seals. This can reduce costs and / or provide a thinner laminate.

[0063] Similarly, in some forms, the PET layer can be eliminated from the upper laminate portion as needed. Instead, the PET layer in the upper laminate portion can be replaced with other materials such as co-extruded polypropylene. This can also help improve the recyclability of the tongue-and-groove seal. As noted above, essentially the entire tongue-and-groove seal can include polyolefin layers such as polypropylene and / or polyethylene.

[0064] It should be recognized that the layers described herein may be a combination of two or more materials, such as a co-extrusion of multiple materials, wherein the first material is an adhesive and the second material can provide additional support and / or strength.

[0065] By eliminating the metal foil layer from the tongue-type sealing member, it is possible to provide a seal in which the internal contents of the container are visible when the tongue is raised.

[0066] In some forms, since the lower laminate portion 22 does not include an induction heating layer, the lower laminate may or may not provide sufficient barrier properties. Such barrier properties include, but are not limited to, oxygen barriers, moisture barriers, etc. However, in some forms, it may be desirable to improve these properties without adding a metal foil layer. In such forms, barrier films and / or coatings can be used. Such materials include, but are not limited to, SiOx, AlOx, EVOH, and combinations thereof.

[0067] As described above, the upper and lower laminate portions can include multiple layers. These layers can include different polymer materials, such as films, foams, paper, combinations thereof, etc. These layers can be constructed using various backings and a variety of HDPE foams of different densities. Other paper or fiber materials can also be used for insulation in the upper laminate, since tensile strength is no longer an issue compared to the lower laminate.

[0068] Further general details regarding the tongue seal and layer are provided below.

[0069] Additional layers may be included in upper and / or lower laminates such as polyethylene terephthalate (PET), nylon, or other structural polymer layers, and in some methods may be about 0.5 to about 1 mil thick. In some methods, additional layers may be included in the lower laminate. It should be understood that the lower sealing laminate may include any number of other layers, such as polymer layers, adhesives, polymer films, polymer foams, etc.

[0070] The undersealing or heat-sealing layer can be composed of any material suitable for bonding to the edge of the container, such as, but not limited to, inductive, conductive, or direct bonding methods. Suitable adhesives, hot-melt adhesives, or sealants for the heat-sealing layer include, but are not limited to, polyesters, polyolefins, ethylene-vinyl acetate, ethylene-acrylic acid copolymers, sarin, and other suitable materials. By one method, the heat-sealing layer can be a single-layer or multi-layer structure of such material with a thickness of about 0.2 to about 3 mils. By some methods, the heat-sealing layer is selected to have a composition similar to and / or including the same polymer type as the composition of the container. For example, if the container includes polyethylene, then the heat-sealing layer will also contain polyethylene. If the container includes polypropylene, then the heat-sealing layer will also contain polypropylene. Other similar materials and combinations are also possible.

[0071] The polymer layers used in the upper and / or lower laminates can take various forms, such as coatings, films, foams, etc. Suitable polymers include, but are not limited to, polyethylene, polypropylene, polyester, ethylene-propylene copolymers, blends thereof, and copolymers or blends with high-α-olefins. By one method, one or more of the polymer layers can be blends of polyolefin materials, such as blends of one or more high-density polyolefin components with one or more low-density polyolefin components. In one form, one polymer layer can be a polyethylene film, and the other polymer layer can be a PET film. According to one form, the polyethylene film can have a thickness of about 5 to about 20 micrometers, and the PET film can have a thickness of about 5 to about 20 micrometers.

[0072] A support layer may be optional in the laminate. If included, it may be a layer of polyethylene terephthalate (PET), nylon, or other structural polymers, and in some methods may be about 0.5 to about 1 mil thick.

[0073] In some forms, the seal may include an insulating layer or a heat redistribution layer. In one form, the insulating layer may be a foamed polymer layer. Suitable foamed polymers include foamed polyolefins, foamed polypropylene, foamed polyethylene, polyester foam, amorphous polyester, etc. In some forms, these foams typically have an internal burst strength of about 2000 to about 3500 g / in. In some methods, the foamed polymer layer 106 may also have a density of less than 0.6 g / cc (and in some cases, about 0.4 to less than about 0.6 g / cc). In other methods, the density can range from about 0.4 g / cc to about 0.9 g / cc. The foamed polymer layer may be about 1 to about 5 mils thick.

[0074] In other methods, a non-foamed heat-distributing or heat-redistributing layer may be included. In such methods, the non-foamed heat-distributing film is a blend of polyolefin materials, such as a blend of one or more high-density polyolefin components with one or more lower-density polyolefin components. Suitable polymers include, but are not limited to, polyethylene, polypropylene, ethylene-propylene copolymers, blends thereof, and copolymers or blends with high-α-olefins. In one method, the non-foamed heat-distributing polyolefin film is a blend of about 50% to about 70% of one or more high-density polyolefin materials with the remainder of one or more lower-density polyolefin materials. This blend is selected to achieve an effective density to provide an intact heat seal for the container and separation of the liner from the seal.

[0075] Thermally activated bonding layers can comprise any polymeric material that is thermally activated or heated to achieve its bonding properties or applied to a seal. By one method, a thermally activated bonding layer can have a density of about 0.9 to about 1.0 g / cc and a peak melting point of about 145°F to about 155°F. The melt index of bonding layer 120 can be about 20 to about 30 g / 10 min (ASTM D1238). Suitable examples include ethylene-vinyl acetate (EVA), polyolefins, two-component polyurethanes, ethylene-acrylic acid copolymers, curable two-component urethane adhesives, epoxy adhesives, ethylene methacrylate copolymers, polybutene, combinations thereof, and similar bonding materials.

[0076] Adhesives that can be used in any of the adhesive layers or bonding layers described herein include, for example, ethylene-vinyl acetate (EVA), polyolefins, two-component polyurethanes, ethylene-acrylic acid copolymers, curable two-component urethane adhesives, epoxy adhesives, ethylene methacrylate copolymers, polybutene, copolyesters, combinations thereof, and similar bonding materials. Other suitable materials may include low-density polyethylene, ethylene-acrylic acid copolymers, and ethylene methacrylate copolymers. By one method, any optional adhesive layer may be a coated polyolefin adhesive layer. If desired, such an adhesive layer may be a coating of about 0.2 to about 0.5 mils (or less) of adhesive, such as coated ethylene-vinyl acetate (EVA), polyolefins, two-component polyurethanes, ethylene-acrylic acid copolymers, curable two-component urethane adhesives, epoxy adhesives, ethylene methacrylate copolymers, copolyesters, and similar bonding materials.

[0077] In one aspect, the tongue can be formed from a complete layer or a partial layer of material combined with a partially width composite adhesive structure comprising a polyester core having an upper adhesive and a lower adhesive on opposite sides thereon. This partially composite adhesive structure bonds the upper laminate to the lower laminate to form a clamping tongue.

[0078] In other aspects of this disclosure, the upper laminate of the seal does not extend the full width of the sealing member to define the clamping tongue. Therefore, the tab seal member described herein can also combine the advantages of a tongue-type seal member with a large clamping tongue fully defined within the periphery of the seal, but achieves this functionality with less material (considering the partial layers of the upper laminate) and allows such a tongue structure to be formed on many different types of preformed lower laminates. In some methods, the partial upper laminate structure is advantageous for use with seals configured for large or wide-mouth containers, such as containers having openings from about 30 to about 100 mm (in other methods, about 60 to about 100 mm). These seals can also be used with 38 mm or 83 mm container openings, or can be used with containers of any size.

[0079] In another aspect of this disclosure, the sealing member herein may include a pull tab or clamping tongue defined entirely within the periphery or circumference of the sealing member in an upper laminate portion, wherein the upper surface of the sealing member is partially defined by the upper laminate portion and partially by a lower laminate portion. In one method of this aspect, the top surface of the sealing member is provided by a small portion of the upper laminate and a large portion of the lower laminate. In other methods of this aspect, the lower laminate is partially exposed at the top surface of the seal, wherein about 50% to about 75% (or more) of the lower laminate is exposed over the entire top surface of the seal. The seal of this aspect allows a consumer to remove the sealing member using a tongue (as in conventional pull tab seals) and / or puncture the sealing member by piercing the exposed lower laminate portion to provide push / pull functionality according to consumer preference.

[0080] In various embodiments, the seals of this disclosure, which define a tongue (formed by a full layer or partial layer) entirely within the periphery or circumference of the seal, also provide an improved capability for tongue-mounted seal members to function as a two-piece seal and liner assembly. In the two-piece seal and liner assembly, the tongue-mounted seal member is temporarily adhered to the liner on its top surface. After the container is opened and the cap or closure is removed, the seal member remains adhered to the container opening, and the liner detaches and remains within the cap of the container.

[0081] In some existing forms of two-piece seal and liner assemblies, the bottom layer of the seal is a heat-sealed layer that is activated by heating (such as by induction or conduction) to adhere or bond the outer periphery of the seal to the edge surrounding the opening of the container. In the two-piece seal and liner assembly, the upper surface of the seal is temporarily adhered to the lower surface of the liner by a release layer, typically a heat-activated release layer, such as an intervening wax layer. During heating to bond the seal to the container, heat not only activates the lower heat-sealed layer but also propagates upwards through the seal to melt the intervening wax across the entire surface of the seal, thereby separating the liner from the seal. Typically, the molten wax is absorbed by the liner to allow for easy separation of the liner from the seal. It can be recognized that for the seal and liner assembly to function correctly, the intervening wax layer needs to melt across the entire surface of the seal. If the wax does not melt uniformly across the upper surface of the seal, the liner may not be able to separate properly from the lower seal portion.

[0082] The individual layers of the sealing member are assembled through a thermal lamination process involving the application of an adhesive, the application of a film, and / or the formation of the layers from a sheet. Extrusion lamination can also be used. The resulting laminated sheet of the sealing member can be cut into appropriately sized discs or other shapes as needed to form a container closure assembly or a tongue-and-groove sealing member. The cut sealing member is inserted into a cap or other closure, which is then applied to the neck of the container to be sealed. A nut can be screwed onto the open neck of the container, thereby clamping the sealing member between the open neck of the container and the top of the cap. The sealing layer can be a pressure-sensitive adhesive, which can be activated by the force applied to the closure to the container.

[0083] Example One form of the single-material sealing component system can be formed from a polyester material such as PET. In the lower laminate portion, a 12-micron PET film that has been acrylamide-treated has a 3 gsm PET heat-sealing varnish applied to the treated side of the film. On the opposite side of the PET film is a two-component polyurethane adhesive that bonds a 250-micron amorphous PET layer. A portion of the adhesive layer, including the two-component polyurethane, is used to bond a 36-micron transparent PET film to the amorphous PET layer, thereby forming a tongue portion between the two.

[0084] Another form of single-material sealing member can typically be formed from polypropylene. The upper laminate comprises 50-micron co-extruded three-layer oriented polypropylene (OPP), which is partially adhered to the lower laminate portion by a two-component polyurethane partially applied to form a tongue layer. The lower laminate portion comprises 75-micron cast polypropylene (CPP), which can be a single layer and can also have a color such as white. This layer can be used to provide compressibility. Below this layer, a 40-micron two-component polyurethane adhesive can be used to adhere to the co-extruded three-layer cast polypropylene (CPP) along with the copolymer blend in the heat seal. Additional polypropylene layers, such as 16-micron polypropylene coated with alumina, can also be included. This layer can be included in the lower laminate portion and can provide oxygen and water barrier properties. The alumina layer is typically very thin, such as in the angstrom range, and is invisible.

[0085] The matters set forth in the above description and accompanying drawings are provided by way of illustration only and not as limitations. While specific embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications can be made without departing from the broader aspects of the applicant's contributions. The actual scope of protection sought is defined in the appended claims when viewed from the proper perspective of the prior art.

Claims

1. A tongue-and-groove sealing member for sealing to an edge surrounding a container opening, the sealing member comprising: A multilayer laminate includes an upper laminate portion that is partially bonded to a lower laminate portion to form a clamping tongue, the clamping tongue being configured to remove the sealing member from the container opening. The lower laminate portion is positioned below the clamping tongue and includes at least a sealant layer for bonding to the edge of the container. The upper laminate portion includes a support layer, and The tongue-type sealing component does not have a metal foil layer.

2. The sealing member with a tongue according to claim 1, wherein, The support layer and the sealant layer each comprise a polyolefin.

3. The sealing member with a tongue according to claim 1, wherein, The support layer and the sealant layer each comprise polyester.

4. The sealing member with a tongue according to claim 1, wherein, The upper laminate portion includes a printed layer.

5. The sealing member with a tongue according to claim 4, wherein, The printed layer is a tongue layer.

6. The sealing member with a tongue according to claim 1, wherein, The lower laminate portion includes a polymer layer.

7. The sealing member with a tongue according to claim 6, wherein, The polymer layer comprises amorphous polyethylene terephthalate.

8. The sealing member with a tongue according to claim 6, wherein, The polymer layer comprises chemically treated polyethylene terephthalate.

9. The sealing member with a tongue according to claim 1, wherein, The support layer and the sealant layer each comprise polypropylene, polyethylene, or a combination thereof.

10. The sealing member with a tongue according to claim 1, wherein, The sealant layer is positioned at the outer periphery of the sealing member such that, during installation, the sealant layer aligns with the edge of the container.

11. A tongue-and-groove sealing member for sealing to an edge surrounding a container opening, the sealing member comprising: A multilayer laminate includes an upper laminate portion partially bonded to a lower laminate portion forming a clamping tongue configured for removing the sealing member from the container opening. The lower laminate portion is positioned below the clamping tongue and includes at least a sealant layer for bonding to the edge of the container and at least one polymer layer comprising polyester. The upper laminate includes a support layer comprising polyester, and The tongue-type sealing component does not have a metal foil layer.

12. The sealing member with a tongue according to claim 11, wherein, The sealant layer comprises polyester.

13. The sealing member with a tongue according to claim 11, wherein, The sealant layer comprises polyolefin.

14. The sealing member with a tongue according to claim 11, wherein, The upper laminate portion includes a printed layer.

15. The tongue-type sealing member according to claim 14, wherein, The printed layer is a tongue layer.

16. The sealing member with a tongue according to claim 11, wherein, The polymer layer comprises amorphous polyethylene terephthalate.

17. The sealing member with a tongue according to claim 11, wherein, The lower laminate portion further includes a second polymer layer, which comprises chemically treated polyethylene terephthalate.

18. The sealing member with a tongue according to claim 11, wherein, The support layer in the upper laminate portion is a transparent polyester terephthalate film.

19. The sealing member with a tongue according to claim 11, wherein, The sealant layer is positioned at the outer periphery of the sealing member such that, during installation, the sealant layer aligns with the edge of the container.

20. A laminate for forming a tongue-and-groove sealing member, the laminate comprising: The upper laminate portion includes a support layer comprising polyester; and The lower laminate portion includes a sealant layer for bonding to the edge of the container and at least one polymer layer comprising polyester. The upper laminate portion is partially bonded to the lower laminate portion and is configured to form a clamping tongue when the laminate is formed as the sealing member, the laminate having no metal foil layer.

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