PACKAGE AND PACKAGING METHOD

Abstract

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.

Claims

1 A packaging construction comprising the combination of: a first backing; and a second backing with a first major surface comprising an adhesive layer, wherein the adhesive layer is overlain by a passivation layer, the passivation layer comprising a patterned seal area that is substantially free of the passivation layer such that the adhesive layer is exposed in the patterned seal area.

2. The packaging construction of claim 1, wherein the patterned seal area comprises a product-specific pattern.

3. The packaging construction of claim 1, wherein the adhesive layer bonds to the first backing when an adhesive in the adhesive layer is activated.

4. The packaging construction of claim 3, wherein the adhesive bonds to the first backing when heat is applied to the packaging construction.

5. The packaging construction of claim 1, wherein the first backing is chosen from nonwoven materials, polymeric films, paper, and mixtures and combinations thereof.

6. The packaging construction of claim 1, wherein the first backing is a gas-permeable nonwoven material.

7. The packaging construction of claim 1, wherein the first backing comprises a first adhesive layer on a major surface thereof.

8. The packaging construction of claim 7, wherein the first adhesive layer is bondable with the adhesive layer on the second backing.

9. The packaging construction of claim 7, wherein the first adhesive layer bonds to the adhesive layer on the second backing when heat is applied to the packaging construction to form a reaction product of an adhesive in the first adhesive layer and an adhesive from the adhesive layer on the second backing.

10. The packaging construction of claim 7, wherein the first adhesive layer comprises a thermoplastic heat-softenable adhesive chosen from ethylene vinyl acetate (EVA), low- or linear low-density polyethylene (LDPE, LLDPE), epoxies, urethanes, acrylates, and mixtures and combinations thereof.

11. The packaging construction of claim 1, wherein the second backing comprises a polymeric film.

12. The packaging construction of claim 1, wherein the adhesive in the adhesive layer on the first major surface of the second backing is chosen from ethylene vinyl acetate (EVA), low- or linear low-density polyethylene (LDPE, LLDPE), epoxies, urethanes, acrylates, and mixtures and combinations thereof.

13. The packaging construction of claim 1, wherein the passivation layer comprises a low adhesive backside material chosen from urethanes, acrylates, silicone polyureas, silicone acrylates, or silicones functionalized with acrylates or epoxies.

14. The packaging construction of claim 1, wherein the patterned seal area comprises an arrangement of channels formed in the passivation layer.

15. The packaging construction of claim 14, wherein the channels form a continuous closed perimeter.

16. A package comprising: a first backing, wherein a major surface of the first backing comprises a first adhesive layer; a second backing with a first major surface comprising a second adhesive layer, and a passivation layer over the second adhesive layer, wherein the passivation layer comprises 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.

17. The package of claim 16, wherein the first backing comprises a vapor permeable nonwoven material, and the article is sterilizable by application of an antimicrobial gas to the package.

18. The package of claim 16, wherein the article is releasable from the passivation layer and the first adhesive layer.

19-32. (canceled).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0010] FIG. 1 is a schematic cross-sectional view of an embodiment of a product packaging construction.

[0011] FIG. 2 is a schematic overhead perspective view of a portion of the product packaging construction of FIG. 1.

[0012] FIG. 3 is a schematic cross-sectional view of an embodiment of a package formed from the product packaging construction of FIG. 1.

[0013] FIG. 4 is a schematic cross-sectional view of an embodiment of a roll-to-roll process line that can be used to make the package of FIG. 3.

[0014] Like symbols in the drawings indicate like elements.

DETAILED DESCRIPTION

[0015] FIG. 1 is a schematic cross-sectional view of a product packaging construction 10 including a first packaging layer 2 with a first backing 12, and a second packaging layer 4 with a second backing 22. The first and the second packaging layers 2,4 can be laminated and bonded together to form a package for an article.

[0016] 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

[0017] 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.

[0018] In the embodiment of FIG. 1, the first backing 12 includes a first major surface 13 having thereon an optional layer 14 of an adhesive. The adhesive in the adhesive layer 14 may vary widely and may be selected from any thermoplastic heat softenable adhesive suitable for forming seal coatings. The adhesive layer 14 may include adhesives activated by any suitable technique, including heat, steam, ionizing radiation, pressure, ultrasonic, and combinations thereof. Non-limiting examples of suitable adhesives for the adhesive layer 14 include ethylene vinyl acetate (EVA), low- or linear low-density polyethylene (LDPE, LLDPE), epoxies, urethanes, acrylates, and mixtures and combinations thereof.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] The adhesive layer 24 may include adhesives activated by any suitable technique, including heat, steam, ionizing radiation, pressure, ultrasonic, and combinations thereof

[0024] 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.

[0025] 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 FIG. 2, the patterned seal area 30 in the second packaging construction 4 is substantially free of the passivation layer 26, and exposes a limited region of the underlying adhesive layer 24 for subsequent bonding to the first backing 12 or the adhesive layer 14 when the first packing construction 2 and the second packing construction 4 are laminated or otherwise joined.

[0026] 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 (FIG. 1). In the embodiment of FIG. 2, the second packaging construction 4 includes a patterned seal area 30 including an arrangement of linear channels 35 forming elements of a rectangle 32 and a chevron 34 but may include any regular or irregular geometric shape including squares, circles, trapezoids, tortuous paths, meandering paths, and mixtures and combinations thereof The channels 35 may have any suitable cross-sectional shape, including rectangular, square, trapezoidal, rounded, and the like, as appropriate for enclosing a particular article 40. The channels 35 need not be linear and can be configured to have any suitable shape that at least partially surrounds the article 40 to be packaged. In some embodiments, the patterned seal area 30 forms a continuous and uninterrupted closed perimeter about the article 40.

[0027] 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 FIGS. 1-2, the article 40 is placed in the article placement region 42 within the bounds of the patterned seal area 30 such that the channels 35 form a continuous and uninterrupted enclosure about the article 40. However, the area of article placement region 42 within the patterned seal area 30 should be shaped and made sufficiently large that the article 40 does not contact the exposed adhesive 24 in the channels 35.

[0028] 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.

[0029] Referring again to FIG. 1, the first packaging construction 2 and the second packaging construction 4 may be moved along the direction of the arrow 50 and joined or laminated to form a package 100 (FIG. 3). When so laminated, the first major surface 13 of the backing 12, or the exposed major surface 15 of the adhesive layer 14, if present, contacts an exposed major surface 27 of the passivation layer 26. The exposed major surfaces 13 or 15 also overlie the article 40, which is retained on the article placement region 42 within the bounds of the patterned seal area 30, and between the packaging constructions 2 and 4.

[0030] Referring now to FIG. 3, the package 100 includes laminated packaging constructions 102 and 104, which are joined along an interface 160 formed between the major surface 127 of the patterned passivation layer 126 and either the major surface 115 of the adhesive layer 114 on the first backing 112, or the major surface 113 of the first backing 112 (embodiment not shown in FIG. 3). The exposed major surfaces 113 or 115 also overlie the article 140, which is retained on the article placement region 142 within the bounds of the patterned seal area 130. Prior to, during or after the lamination of the first packaging construction 102 and the second packaging construction 104, the adhesive in the adhesive layer 124 is activated by at least one of heat, steam, pressure, ultrasonic, ionizing radiation, and combinations thereof applied along the direction of the arrows 170. The adhesive in the adhesive layer 114, if present, may also be activated by at least one of heat, steam, pressure, ultrasonic or ionizing radiation applied along the direction of the arrows 170.

[0031] In the embodiment of FIG. 3, the adhesives in the adhesive layers 114 and 124 are activated, soften, and bond in the channels 135 of the patterned seal area 130. The bond thus formed forms an uninterrupted perimeter around the article 140 and seals the article 140 within the enclosed patterned seal area 130. Following the bonding step, the channels 135 of the patterned seal area contain the reaction product of the adhesives in the adhesive layers 114 and 124. For example, in one embodiment, the channels 135 include a reaction product of the thermoplastic adhesive in the adhesive layer 114 and an EVA adhesive from the adhesive layer 124.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] FIG. 4 schematically illustrates an embodiment of a roll-to-roll process line 300 and packaging system 210 that can be used to seal an article 240 between a first packaging construction 202 and a second packaging construction 204 to form a package 200. In the process line 300, a packaging film construction 202 unwinds from a first roller 272. In the embodiment of FIG. 4, the first packaging construction 202 includes a backing 212 that may be chosen from nonwoven materials, polymeric films, paper, and mixtures and combinations thereof. The packaging construction 202 may be any suitable width, and in some non-limiting examples may be up to about 60 inches (about 150 cm) wide. In some embodiments, the backing 212 may have a thickness of less than about 1 mm, or less than about 0.1 mm.

[0036] In the embodiment of FIG. 4, the backing 212 includes an adhesive layer 214, which in various embodiments may be applied on a major surface of the film 212 by any suitable technique including, for example, coating, extrusion, and the like. In some embodiments, the adhesive layer 214 includes a heat softenable thermoplastic adhesive.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 FIG. 4).

[0045] 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.