Packaging materials can be closed about an article using a direct contact heat sealing process in which the article is placed between a first layer a second layer, at least one of which includes a layer of a thermally softenable material. Heat and pressure are then applied to activate the thermally softenable material and seal the first and second layers together to form a sealed chamber area about the article. In the direct contact method of heat sealing, a constantly heated die or sealing bar is used to apply heat to a specific contact area, path, or shape, which activates the thermally softenable material and seals the first and second layers together in the designed contact area surrounding the article. To package a wide variety of articles with different shapes and sizes, in many cases a uniquely shaped die or sealing bar is required to effectively form a seal around each type of article matched to its intrinsic shape and sizes. When a wide range of products need to be packaged on a single production line, utilizing shape and size-dependent heat-sealing dies and bars in a direct contact heat sealing process can be expensive, inefficient, and slow.
In general, the present disclosure is directed to a package in which a heat seal pattern is incorporated into the packaging material itself, which eliminates the need for article-dependent sealing equipment such as shaped dies and sealing bars. The package of the present disclosure includes a first packaging layer and a second packaging layer that may be laminated together to form a package enclosing an article therebetween. At least one packaging layer includes a major surface having thereon a layer of a thermally softenable material and a patterned blocking passivation layer on the thermally softenable layer. The patterned passivation layer includes a patterned seal area that is substantially free of the passivation material such that the underlying thermally softenable material is exposed in the patterned seal area. An article to be packaged can be placed within the patterned seal area and the first packaging construction is contacted with the second packaging construction. When the thermally softenable material is activated, the first packaging layer and the second packaging layer releasably or permanently bond to one another only along the patterned seal area to form a package, and the article is enclosed and sealed within the patterned seal area. The passivation layer thus limits bonding between the first packaging layer and the second packaging layer to the patterned seal area and blocks unwanted bonding between other portions of the first and second packaging layers, while also preventing adhesion between the article and the packaging layers.
In some embodiments, the patterned seal area can include an article-specific pattern configured to seal an article with a selected size, shape, and the like. A packaging system utilizing the first and the second packaging layers can reduce both the time and materials required to package a wide variety of articles, compared to conventional direct contact heat sealing methods in which a different uniquely designed heating die or bar is required to package each different type of article. In some embodiments, the packaging system can be used in a roll-to-roll process line and can be adapted to both package and sterilize articles intended for use in the healthcare industry. The packaging system of the present disclosure can reduce the requirement of uniquely designed tooling dedicated to specifically shaped and sized articles, eliminate the need for dedicated machine set-up, minimize costs, and allow much faster run speed and higher throughput in a roll-to-roll process.
In one aspect, the present disclosure is directed to a packaging construction including the combination of: a first backing; and a second backing with a first major surface including an adhesive layer, wherein the adhesive layer is overlain by a passivation layer, the passivation layer including a patterned seal area that is substantially free of the passivation layer such that the adhesive layer is exposed in the patterned seal area.
In another aspect, the present disclosure is directed to a package, including: a first web; and a second web with a first major surface having an adhesive layer, wherein the adhesive layer is overlain by a passivation layer, the passivation layer including a product-specific patterned seal area that is substantially free of the passivation layer such that the adhesive layer is exposed in the patterned seal area; wherein the first web contacts the adhesive layer exposed in the patterned seal area.
In another aspect, the present disclosure is directed to a method of packaging an article, the method including: in a packaging construction including a first web and a second web, the second web having a first major surface including an adhesive layer, and a passivation layer on the adhesive layer, the passivation layer including a product-specific patterned seal area that is substantially free of the passivation layer such that the adhesive layer is exposed in the patterned seal area; placing the article between the first web and the second web of the packaging construction such that the article resides on the passivation layer and is enclosed within the patterned seal area; and laminating the first web and the second web such that the adhesive layer in the patterned seal area bonds to the first web and forms a package for the article.
In another aspect, the present disclosure is directed a roll-to-roll packaging method, the method including: coating a first adhesive layer on a first web; coating a second adhesive layer on a first major surface of a second web; coating a passivation layer on the second adhesive layer, wherein the passivation layer includes a product-specific patterned seal area that is substantially free of the passivation layer such that the second adhesive layer is exposed in the patterned seal area; placing an article between the first web and the second web, wherein the article is placed within the patterned seal area; and laminating the first web and the second web such that the second adhesive layer in the patterned seal area bonds to the first adhesive layer on the first web to form a package for the article.
In another aspect, the present disclosure is directed a package, including: a first backing, wherein a major surface of the first backing includes a first adhesive layer; and a second backing with a first major surface including a second adhesive layer, and a passivation layer over the second adhesive layer, wherein the passivation layer includes a patterned seal area that is substantially free of the passivation coating such that the second adhesive layer is exposed in the patterned seal area; and an article enclosed within the patterned seal area; wherein the first adhesive layer and the second adhesive layer bond in the patterned seal area to form a reaction product of an adhesive in the first adhesive layer and an adhesive in the second adhesive layer.
These and other embodiments are described below and in the following claims.
Like symbols in the drawings indicate like elements.
In various embodiments, the first backing 12 and the second backing 22 may be independently selected from any suitable packaging materials including, but not limited to, polymeric films, nonwovens, paper, metal foils, and laminates and combinations thereof
For example, in one embodiment, the first backing 12 is a vapor-permeable material such as paper or a nonwoven. Suitable vapor-permeable nonwoven materials include, but are not limited to, nonwoven webs made from high density polyethylene (PE) available under the trade designation TYVEK from DowDupont, Wilmington, Del., such as TYVEK 2FS. In some embodiments, nonwoven material webs can have better dimensional stability than papers when the package is heated or undergoes sterilization procedures.
In the embodiment of
The second backing 22 may be selected from polymeric films, nonwovens, paper, metal foils, and laminates and combinations thereof. In some embodiments, the second backing 22 is a thermoplastic polymeric film, and suitable films that have good dimensional stability in each direction when exposed to the elevated temperatures and pressures required in some sealing processes. In some embodiments, the second backing 22 should have a dimensional change of less than 5%, or less than 3%, or less than 2%, in each direction when sealing temperatures and pressures are applied to the backing. In some embodiments, which are not intended to be limiting, the second backing 22 is a polyester film such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), PET glycol modified (PETG), polyamide, and combinations thereof.
In various embodiments, the thickness of the second backing 22 can be selected to provide a balance between processability and heat transfer during sealing processes, and in various embodiments the second backing 22 has a thickness of less than about 1 mm, or less than about 0.1 mm, or less than about 0.05 mm, or less than about 0.03 mm, or less than about 0.02 mm.
The second backing 22 includes a first major surface 23 having thereon a layer 24 of an adhesive. The adhesive in the adhesive layer 24 may vary widely and may be selected from any thermoplastic adhesive that is releasably or permanently bondable with the first backing 12, or with the adhesive layer 14 on the first backing 12, using any combination of heat, pressure, ultrasonic, or ionizing radiation. The adhesive in the adhesive layer 24 can be coated or extruded on the second backing 22 and should have good melt flow at the temperatures used during extrusion, coating, and sealing, as well as good stability for extended periods of time at ambient temperatures after the packaging construction 10 has been sealed.
Non-limiting examples of the adhesives in the adhesive layer 24 include ethylene vinyl acetate (EVA), low- or linear low-density polyethylene (LDPE, LLDPE), epoxies, urethanes, or acrylates. In some embodiments, which are not intended to be limiting, the adhesives in the adhesive layer 24 include EVA resins include those having a Vicat softening point of about 40° C. to about 70° C. such as those available under the trade designation ELVAX from DowDuPont, Wilmington, Del., particularly ELVAX 3155, 3165, 3170, 3174, 3176, or 3200-2.
The adhesive layer 24 may include adhesives activated by any suitable technique, including heat, steam, ionizing radiation, pressure, ultrasonic, and combinations thereof
The thickness of the adhesive layer 24 is selected to prevent voids and provide good heat transfer for heat sealing processes, and in some embodiments, which are provided as examples and not intended to be limiting, the adhesive layer 24 has a thickness of about 0.1 mm to about 0.05 mm, or about 0.025 mm to about 0.05 mm.
A first major surface 25 of the adhesive layer 24 includes an overlying patterned passivation layer 26 configured to prevent bonding of the adhesive layer 24 to any layer of the first packaging construction 2. The passivation layer 26 includes an open region of a predetermined shape, referred to herein as the patterned seal area 30, in which the adhesive layer 24 is exposed. Referring also to the non-limiting example shown in
The shape of the patterned seal area 30 may vary widely depending on the shape and size of an article 40 to be placed within the packaging construction 10 (
The patterned seal area 30 is configured to bound an article placement region 42 of the passivation coating 26 wherein the article 40 is intended to reside within the package. The patterned seal area 30 can have any suitable continuous or discontinuous shape that can provide placement for the article 40. As shown in
The materials chosen for the passivation layer 26 may vary widely, and in various embodiments are chosen from surface energy low adhesive backside (LAB) materials that release from the first backing 12 or the adhesive layer 14. In some embodiments, which are not intended to be limiting, the LAB materials in the passivation coating layer 26 include any material that can prevent bonding of the adhesive layer 24 to the first packaging construction 2 can be used for passivation coating 26 such as, for example, LAB materials based on urethanes, acrylates, silicone polyureas, silicone acrylates, or silicones functionalized with acrylates or epoxies.
Referring again to
Referring now to
In the embodiment of
In another embodiment, if the adhesive layer 114 is not present, a bond forms between the adhesive in the adhesive layer 124 and the major surface 113 of the first backing 112. Following the bonding step, the channels 135 of the patterned seal area contain the reaction product of the backing 112 and the adhesive in the adhesive layer 124. For example, in one embodiment, the channels 135 include a reaction product of a PE nonwoven material from the backing 112 an EVA adhesive from the adhesive layer 124.
The passivation layer 126 does not bond to the adhesive layer 114 or the first backing 112 along the interface 160 during or after the lamination process. In addition, neither the passivation layer 126, the adhesive layer 114, nor the first backing 112 bond to the article 140 residing in the article placement region 142 and within the bounds of the patterned seal area 130. The patterned seal area 130 and the passivation layer 126 thus operate together to control the points of adhesion along the interface 160 between the first packaging construction 102 and the second packaging construction 104, and a bond between the packaging constructions 102, 104 occurs only along the channels 135 of the patterned seal area 130.
To open the package 100 and remove the article 140 packaged within, the first packaging construction 102 is stripped from the second packaging construction 104 along the interface 160. Since the low surface energy passivation layer 126 releases from the backing 112 or the adhesive layer 114 (if present), the first packaging construction 102 and the second packaging construction 104 may be easily peeled apart. In some embodiments, depending on the strength of the bond between the first packaging construction 102 and the second packaging construction 104 within the channels 135 of the patterned seal area 130, the packaging constructions 102, 104 may peel away from one another approximately along the interface 160 and the bond along the channels 135 is smoothly released. In some embodiments, if the bond along the channels 135 is stronger, separation of the first and second packaging constructions 102, 104 may delaminate or strip away portions of the bonded adhesives in the patterned seal area 130, and residue of the bonded adhesives may remain on the first packaging construction 102, the second packaging construction 104, or both, to form a tamper-evident release construction. In some embodiments, if the first packaging construction 102 includes a nonwoven material as the first backing 112, substantially all the residue of the bonded adhesives will remain on the first major surface 113 of the first backing 112 when the first and second packaging constructions 102, 104 are stripped apart.
In the embodiment of
A second packaging construction 204 unwinds from a second roller 274 in the process line 300. Like the first packaging construction 202, in some embodiments the second packaging construction 204 can be up to about 60 inches (about 150 cm) wide. The second packaging construction 204 includes a backing 222 that may be chosen from nonwoven materials, polymeric films, paper, and mixtures and combinations thereof. The thickness of the backing 222 is less than 1 mm, or less than 0.1 mm, and some embodiments the backing 222 is a polyester film such as, for example, PET.
A layer of an adhesive 224 is applied onto the polymeric backing 222, which in various example embodiments has a thickness of less than about 0.1 mm, or less than about 0.5 mm. The adhesive layer 224 includes any adhesive that can be bonded with the backing 212 or the adhesive layer 214 on the first packaging construction 202. In some non-limiting example embodiments, the adhesive layer 224 includes an EVA adhesive, and may be applied on a major surface of the backing 222 by any suitable technique including, for example, coating, extrusion, and the like.
A patterned low adhesion backside (LAB) passivation layer 226 is on the adhesive layer 224. The passivation layer 226 may be applied over the adhesive layer 224 by any suitable technique including, for example, coating, extrusion, and the like. The passivation layer 226 may be selected from any LAB or release coating material that blocks or prevents bonding of the adhesive layer 224 to either of the layers 212, 214 of the packaging construction 202. In some embodiments, which are not intended to be limiting, the materials in the passivation layer 226 include silicones, and silicone polyureas (SPU) have been found to be particularly suitable.
The passivation layer 226 substantially prevents bonding of the adhesive layer 224 to adjacent surfaces from the first packaging construction 202, except in an open patterned seal area 230 of a predetermined shape in which the adhesive layer 224 is exposed and available for bonding. The patterned seal area 230 is substantially free of the release materials in the passivation layer 226 and exposes a limited region of the underlying adhesive layer 224 for subsequent bonding to the first backing 212 or the adhesive layer 214 when the first packaging construction 202 and the second packaging construction 204 are laminated together.
The shape of the patterned seal area 230 may vary widely depending on the shape and size of an article 240 to be placed within the package 200, and in some embodiments includes an arrangement of channels 235 sized and arranged to provide an article placement region 242 fully and continuously enclosed within the channels 235. The article 240 to be packaged is placed in the article placement region 242 such that the article 240 is within the perimeter formed by the channels 235 and does not contact the exposed adhesive 224 in the patterned seal area 230.
The packaging constructions 202 and 204 forming the packaging system 210 are then laminated and bonded along an interface 260 by running the packaging constructions 202, 204 through an arrangement of nip rollers 280, 282 to form the package 200 with the article 240 contained therein. Contact between the adhesive layer 214 and the adhesive layer 224 in the nip between the rollers 280, 282 forms a bond along an interface 260 between the adhesive layers 214 and 224 along the channels 235, which encloses and fully seals the article 240 within the perimeter of patterned seal area 230. In some embodiments, one or more of the rollers 280, 282 may be heated, which can enhance or activate the bond between the adhesive layers 214 and 224. In some embodiments, bonding between the adhesive layers 214 and 224 forms a reaction product of a first adhesive in the adhesive layer 214 and a second adhesive in the adhesive layer 224 in the channels 235 of the patterned seal area 230.
After the package 200 is formed, in some embodiments the article 240 may be sterilized. For example, if either of the packaging constructions 202, 204 are gas-permeable, the package 200 may be treated with an antimicrobial gas such as, for example, ethylene oxide, to sterilize the article 240 while the article 240 is sealed with the package 200. In another embodiment, the package 200 may be heated, alone or in combination with the antimicrobial gas treatment, to sterilize the article 240.
The web forming the package 200 may be further processed by, for example, slitting, die-cutting, or rolling all or a portion of the web onto another roller (not shown in
To open the package 200 and remove the article 240 packaged within, as discussed above the first packaging construction 202 is delaminated from the second packaging construction 204 along the interface 160. Since the passivation layer 226 releases from the adhesive layer 214, the first packaging construction 202 and the second packaging construction 204 may be easily peeled apart. The bond between the first packaging construction 202 and the second packaging construction 204 within the channels 235 of the patterned seal area 230 releases with low peel force, the packaging constructions 202, 204 separate smoothly along the interface 260, and in some embodiments substantially no residue of the bonded adhesive remains on the first packaging construction 202 or the second packaging construction 204 after the separation step. In some embodiments, separation of the first and second packaging constructions 202, 204 may delaminate or strip away portions of the bonded adhesives in the patterned seal area 230, and residue of the bonded adhesives may remain on the first packaging construction 202, the second packaging construction 204, or both, to form a tamper-evident release construction. In some embodiments, if the first packaging construction 202 includes a backing of a nonwoven material 212, substantially all the residue of the bonded adhesives will remain on the first major surface 213 of the nonwoven backing 212 when the first and second packaging constructions 202, 204 are stripped apart.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2020/051636 | 2/26/2020 | WO | 00 |
Number | Date | Country | |
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62812134 | Feb 2019 | US |