CA2046131A1 - Thermoformable laminate material and method of making the same - Google Patents
Thermoformable laminate material and method of making the sameInfo
- Publication number
- CA2046131A1 CA2046131A1 CA 2046131 CA2046131A CA2046131A1 CA 2046131 A1 CA2046131 A1 CA 2046131A1 CA 2046131 CA2046131 CA 2046131 CA 2046131 A CA2046131 A CA 2046131A CA 2046131 A1 CA2046131 A1 CA 2046131A1
- Authority
- CA
- Canada
- Prior art keywords
- flexible sheet
- rigid polymeric
- sheet material
- polymeric core
- core material
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000002648 laminated material Substances 0.000 title claims abstract description 30
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 6
- 239000000463 material Substances 0.000 claims abstract description 98
- 239000011162 core material Substances 0.000 claims abstract description 66
- 238000003475 lamination Methods 0.000 claims abstract description 9
- -1 polypropylene Polymers 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 12
- 229920000728 polyester Polymers 0.000 claims description 10
- 239000004743 Polypropylene Substances 0.000 claims description 8
- 229920001155 polypropylene Polymers 0.000 claims description 8
- 238000003856 thermoforming Methods 0.000 claims description 7
- 239000004698 Polyethylene Substances 0.000 claims description 6
- 238000010030 laminating Methods 0.000 claims description 6
- 229920000573 polyethylene Polymers 0.000 claims description 6
- 229920001634 Copolyester Polymers 0.000 claims description 5
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 claims description 4
- 239000004677 Nylon Substances 0.000 claims description 3
- 229920001893 acrylonitrile styrene Polymers 0.000 claims description 3
- 229920005669 high impact polystyrene Polymers 0.000 claims description 3
- 239000004797 high-impact polystyrene Substances 0.000 claims description 3
- 229920001778 nylon Polymers 0.000 claims description 3
- 239000010410 layer Substances 0.000 description 15
- 235000013305 food Nutrition 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 6
- 239000000853 adhesive Substances 0.000 description 5
- 230000001070 adhesive effect Effects 0.000 description 5
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 4
- 230000004888 barrier function Effects 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 229920003023 plastic Polymers 0.000 description 4
- 229920001328 Polyvinylidene chloride Polymers 0.000 description 3
- 239000012792 core layer Substances 0.000 description 3
- 239000004033 plastic Substances 0.000 description 3
- 229920001169 thermoplastic Polymers 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229920001971 elastomer Polymers 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229920000098 polyolefin Polymers 0.000 description 2
- 229920000915 polyvinyl chloride Polymers 0.000 description 2
- 239000004800 polyvinyl chloride Substances 0.000 description 2
- 239000005033 polyvinylidene chloride Substances 0.000 description 2
- 230000001681 protective effect Effects 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- NIXOWILDQLNWCW-UHFFFAOYSA-M Acrylate Chemical compound [O-]C(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-M 0.000 description 1
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- 235000006696 Catha edulis Nutrition 0.000 description 1
- 240000007681 Catha edulis Species 0.000 description 1
- 239000004801 Chlorinated PVC Substances 0.000 description 1
- 239000004709 Chlorinated polyethylene Substances 0.000 description 1
- 241001317374 Evides Species 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- 229920000459 Nitrile rubber Polymers 0.000 description 1
- 229920012485 Plasticized Polyvinyl chloride Polymers 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 229920006328 Styrofoam Polymers 0.000 description 1
- NTXGQCSETZTARF-UHFFFAOYSA-N buta-1,3-diene;prop-2-enenitrile Chemical compound C=CC=C.C=CC#N NTXGQCSETZTARF-UHFFFAOYSA-N 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 229920000457 chlorinated polyvinyl chloride Polymers 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 239000011247 coating layer Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229920000554 ionomer Polymers 0.000 description 1
- 239000002650 laminated plastic Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000002861 polymer material Substances 0.000 description 1
- 229920006324 polyoxymethylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229920001291 polyvinyl halide Polymers 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000008261 styrofoam Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 239000012780 transparent material Substances 0.000 description 1
- 229920006305 unsaturated polyester Polymers 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D25/00—Details of other kinds or types of rigid or semi-rigid containers
- B65D25/20—External fittings
- B65D25/205—Means for the attachment of labels, cards, coupons or the like
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B27/00—Layered products comprising a layer of synthetic resin
- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D1/00—Containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material, by deep-drawing operations performed on sheet material
- B65D1/34—Trays or like shallow containers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D2577/00—Packages formed by enclosing articles or materials in preformed containers, e.g. boxes, cartons, sacks, bags
- B65D2577/10—Container closures formed after filling
- B65D2577/20—Container closures formed after filling by applying separate lids or covers
- B65D2577/2025—Multi-layered container, e.g. laminated, coated
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Ceramic Engineering (AREA)
- Laminated Bodies (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Abstract
THERMOFORMABLE LAMINATE MATERIAL
AND METHOD OF MAKING THE SAME
Abstract of the Disclosure A thermoformable laminate material is disclosed which comprises a rigid polymeric core material having interior and exterior faces and a first flexible sheet material having two opposing sides laminated to one face of the rigid polymeric core material, wherein one side of the first flexible sheet material is printed prior to lamination.
AND METHOD OF MAKING THE SAME
Abstract of the Disclosure A thermoformable laminate material is disclosed which comprises a rigid polymeric core material having interior and exterior faces and a first flexible sheet material having two opposing sides laminated to one face of the rigid polymeric core material, wherein one side of the first flexible sheet material is printed prior to lamination.
Description
PATENT
;
~RER~IOFORMA13L~ S~MINAq~E ~TE}~IAL
AND MET~OD OF ~gING ~IE 8A~SE
Field of th~ ~n~ention This invention relates to a polymeric laminate material containing printed ma~ter which may be thermoformed into various shapes.
Back~roun~ of the Invention In general, laminated materials for ultimate use as containers, trays, etc. are knswn in ~he art.
For example, U.S. Patent No. 2,974,057 discloses plaskicized ~ilms comprising a rigid polymeric self-supporting sheet of plasticized polyvinyl chloride polymer and a coating o~ a cellulssic polymer ~nd ~n acrylate. The rigid self-suppor'ing sheet ~aterial ~ay optionally contain printed matter.
3~
;
~RER~IOFORMA13L~ S~MINAq~E ~TE}~IAL
AND MET~OD OF ~gING ~IE 8A~SE
Field of th~ ~n~ention This invention relates to a polymeric laminate material containing printed ma~ter which may be thermoformed into various shapes.
Back~roun~ of the Invention In general, laminated materials for ultimate use as containers, trays, etc. are knswn in ~he art.
For example, U.S. Patent No. 2,974,057 discloses plaskicized ~ilms comprising a rigid polymeric self-supporting sheet of plasticized polyvinyl chloride polymer and a coating o~ a cellulssic polymer ~nd ~n acrylate. The rigid self-suppor'ing sheet ~aterial ~ay optionally contain printed matter.
3~
- 2 ~
U.S. Patent No. 3,356,560 discloses a heat-formable sheet material comprising a core layer, a protective skin layer sn one side of the core and an outer coating layer on the opposing side of the core. ~he core layer of this patent comprises a gum-plastic, such as a rubber or a resin based on acrylonitrile, butadiene, and styrene. The protective skin layer is a mixture of a butadiene-acrylonitrile rubber and a polyvinyl chloride resin and the outer coa~ing layer is disclosed as being a blend of a polyvinyl halide polymer, styrene and methyl methacrylate.
U.S. Patent No. 3,562,095 discloses a synthetic resin laminate comprising a center core layer of an unsaturated polyester with one or more multifunctional monomers and a second layer comprising a synthetic resinous thermoplastic polymer bonded to at least one ~ace of the core.
The resinous thermoplastic polymer used in the laminate o~ this patent ~ay comprise polyvinyl chloride, chlorinated polyvinyl chloride, chlorinated polyethylene and related materials.
U.S~ Patent No. 4,~9,817 discloses lined, hollow plastic articles and a method of making the same. The articles of this patent comprise an outer pressure molded first portion of a transparent plastic material and a drawn inner second portion of a plastic material. The inner material may be any one of acetal polymers, polyolefins, e~c., while the outer thermoplastic layer must be $ransparent or translucent and may comprise polyolefins, polystyrene, e~c~ This patent is related to U.S. Patent Nos. 3,717,544;
U.S. Patent No. 3,356,560 discloses a heat-formable sheet material comprising a core layer, a protective skin layer sn one side of the core and an outer coating layer on the opposing side of the core. ~he core layer of this patent comprises a gum-plastic, such as a rubber or a resin based on acrylonitrile, butadiene, and styrene. The protective skin layer is a mixture of a butadiene-acrylonitrile rubber and a polyvinyl chloride resin and the outer coa~ing layer is disclosed as being a blend of a polyvinyl halide polymer, styrene and methyl methacrylate.
U.S. Patent No. 3,562,095 discloses a synthetic resin laminate comprising a center core layer of an unsaturated polyester with one or more multifunctional monomers and a second layer comprising a synthetic resinous thermoplastic polymer bonded to at least one ~ace of the core.
The resinous thermoplastic polymer used in the laminate o~ this patent ~ay comprise polyvinyl chloride, chlorinated polyvinyl chloride, chlorinated polyethylene and related materials.
U.S~ Patent No. 4,~9,817 discloses lined, hollow plastic articles and a method of making the same. The articles of this patent comprise an outer pressure molded first portion of a transparent plastic material and a drawn inner second portion of a plastic material. The inner material may be any one of acetal polymers, polyolefins, e~c., while the outer thermoplastic layer must be $ransparent or translucent and may comprise polyolefins, polystyrene, e~c~ This patent is related to U.S. Patent Nos. 3,717,544;
3,719,735; 3,787,157 and 3,939,239.
U.S. Patent No. 4,442,158 discloses a plastic laminate adapted for use as a food package comprising an exterior polypropylene layer, a middle polyvinylidene chloride layer and an inner ionomer resi~ layer. U.S. Patent Nos. 4,443,507 and 4,873,137 disclose examples of laminated polymeric materials which comprise layers reinforced with fibers and glass flakes, respectively.
Although laminated polymeric materials are known in the art, the known materials have demonstrated drawbacks, ~uch as difficulties with or a complete inability to print the material, delamination of the layers, etc. Therefore, there is a need for a thermoformable laminate material which is satisfActory in all respects.
;~ L3~
Bummary o f the Invention The present invention is directed to a thermoformable laminate material comprising a rigid polymeric core material having interior and exterior faces and a first flexible sheet material having two opposing sides laminated ko one face of the rigid polymeric core material, wherein one side of the flexible sheet is printed prior to lamination. Preferably, the first flexible sheet material is laminated to the exterior face of the core. The invention may further include a thermoformable material comprising a second flexible sheet material having two opposing sides which is laminated to the interior face of the rigid polymeric core material. The second flexible sheet material may also be printed on one side prior to lamination. The present laminate may also comprise a lid component attached to the rigid core material. A method for the production of the thermoformahle polymeric materials of this invention is also disclosed.
G~3~.
Brief Description of th~ Dr wi~g~
The foregoing summary as well as the following detailed description will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, there is shown in the drawings an embodiment which is presently preferred, it being understood, however, that the present invention is not limited to the precise embodiment~ shown. In the drawings:
Figure 1 is a sectional view of a two layer laminate according to the present invention;
Figure 2 is a sectional view of a three layer laminate according to the present invention;
and Figure 3 is a ~ectional view of an embodiment of the present laminats which i8 thermoformed into the shape of a tray, further comprising a lid co~ponent.
Detaile~ De~cri~tl~ of the ~n~ntion Referring to the drawîngs wherein like reference numerals are used to indicate like elements throughout the fisures, there is shown in Figure 1, a thermoformable laminate material 10 Vv '~ J ~ h3~
which comprises a rigid polymeric core material 11 haviny interior and exterior faces 21 and 22, respectively, and a first flexible sheet mat~rial 12 laminated thereto. The first flexible sheet material has two opposing sides 23 and 24 and is printed on one side with printed matter 13 prior to lamination to one face of the rigid polymeric core material. Such printed matter may include, without limitation, printing, designs, etc. Preferably, the printed side 23 of the first flexible sheet material is laminated to the exterior face 22 of the rigid polymeric core material 11. When laminated in this manner, the printed matter 13 will be protected from the environment by the first flexible sheet material 12 while remaining visible therethrough.
The present laminate provides an oxygen and moisture barrier for materials contained therein. This is particularly important when the present material i5 used to contain food materials, as the barrier prevents the food from rapidly degrading due to oxygen and moisture exposure.
It is preferred that the present laminate material be microwaveable. The microwaveability of the laminate material i5 desirable from the viewpoint of convenience, particularly whe~ ~he laminate is thermoformed into the shape of a tray or other container to hold microwaveable foods. In this instance, ~he consumer may purchase pre-cooked foods contained in the present thermoformed laminate, and place them dir~ctly from the freezer or refrigerator into a microwave oven without the necessity of using a separate container.
The rigid polymeric core material 11 employed in the present invention may be any of conventionally used polymeric materials. For example, any of polyester, polypropylene, copolyester, acrylonitrile or high impact polystyrene, such as Styrofoam~ may be used as the rigid polymeric core. Preferably, polyester is used as the rigid core material 11. Moreover, the rigid core 11 may be a 3 to 5 ply coextrusion of the chosen polymeric material. The rigid polymeric core material 11 should have a thickness of about 10 to about 50 mils., and pre~erably about 15 to about 25 mils. The rigid polymeric core material 11 may be either a si~gle layer of polymeric material or may itself be a laminate of two or more of such layers. The use of a single layer or - ~ ~
laminate c~re for a particular appl~cation will be evident to one of ordinary skill in the art based upon the present disclosure.
Preferably, the rigid polymeric core material ~1 is transparent. The use of a transparent material for the cnre facilitates viewing of matter printed ~n the flexible sheet materials in certain c~nstructions. Preferably, when the rigid polymeric core material 11 is transparent, the flexible sheet material 12 is surface-printed and the printed side of the flexible sheet is laminated directly to the interior face of the core material 11. Such a construction will facilitate viewing of the printed matter through the interior face of the core 11, while protecting the printed matter 13 from being scratched off. Moreover, this construction will protect any foodstuffs which are placed on the interior of the laminate from ~eing contaminated by the prin~ing.
As the first flexible sheet material 12 of the present invention, a nu~ber of conventionally used polymers may he employed. For example, polypropylene, polyethylene, ::opolye~ter nylon, polyester and co-extruded materials as re 3~
known and will be appreciated by those skilled in the art, may be used as the flexible sheet material 12 of the invention. Pr ferably, polyethylene is used as the first flexible sheet material 12. The first flexible sheet material 12 may have a thicXness of about .048 to about 5.0 mils., depending upon the particular shape the present laminate will be thermoformed into and the use to which it will be put. Preferably the first flexible sheet material will have a thickness of about .048 to about .075 mils. However, appropriate thicknesses for particular applications will be e~ident to one skilled in the art based upon the present disclosure.
When laminated ts one face of the rigid polymeric core 11, the first flexible sheet material 12 serves a number of functions. For example, th~ laminated flexiblP sheet material 12 provides both decorative functions (i.e., provides for the use of printed matter 13 on the laminate material, such as recipes, instructions, UPC codes, etc.) and barrier characteristics on the rigid polymeric core. WhPn laminated to the core material 11, the first flexible sheet material 12 2 ~ 2~
eliminates the necessity of using additional layers, ~uch as shrink wrap, box~s, labels, etc., to provide these functions.
The lamination of the first flexible ~heet material 12 to the rigid core material 11 allows for the provision of printed matter 13 on one face of the core ma~erial 11 without the necessity of using specialized equipment which is needed for printing on high-gauge materials.
Therefore, when the laminate of the present invention is used, conventional high-speed prlnters may be employed to preprint the first flexible sheet material 12 and the thus printed flexible sheet material 1~ may then be laminated directly to one face of the rigid pol~neric core material 11.
Conventional laminate materials xequire specialized equipment, such as sheet-fed offset presses, etc., ~or printing the sides or faces of rigid polymeric matexials. The u~e of such specialized equipment necessarily involves the expenditure of a high degree of expense and lab~r, making it ~ifficult to produce, thereby increasing the final cost of the materialO In contrast, in preparing the thennofo~nahle laminate material of the present invention, conventional high-speed printers, such as ro~o-gravure or flexographic printers, may be used to efficiently print the flexible sheet material 12 and conven~ional laminating techniques may be used to adhere the flexible sheet 12 to the rigid core material 11. Accordingly, the laminate of the present invention may be produced more efficiently and cost effectively in compariso~ to conventional packaqing constructions.
If desired, the present laminate may further comprise a second flexible sheet material.
As can best be seen in Figure 2, the second flexible sheet material 14 also has two opposing sides 25 and 26, and may be laminated to the opposing or interior face 21 of the rigid polymeric core material 11. This second flexible sheet material 14 may also be printed on one side prior to lamination in the same manner as the first flexible sheet material 1~. It is preferred that the printed side of the second flexible sheet material 14 be laminated to the opposing or interior ~ace 21 of the rigid polymeric core material 11.
The second flexible sheet material 14 may be composed of the same materials which may be used for the first flexible sheet material 12, disoussed above. Preferably, the second flexible sheet material 14 comprises polyester. The second flexible sheet material 14 ~ay also have a thickness of about n 048 to about S.0 mils., depending upon the particular shape ~he laminate will be thermoformed into and the p~rticular use to which it will be put. Preferably the second flexible sheet material 14 will have a thickness of about .048 to about .075 mils. However, appropriate thicknesse~ for particular applications will be evident to one skilled in the art based upon the present disclosure.
Both the first and second flexible sheet materials 12 and 14, respectively, may be printed in any conventional manner generally known in the art. The first and second flexible shee~ materials 12 and 14, may be either sur~ace printed or reverse-printed 60 khat the printed matter may best be seen from the chosen viewpoint. That is, depending upon which sheet is being printed, from which side the printed matter will be viewed and whether the printed side of the sheet material is laminated to the core or away from the core, the sheet may be either surface or reverse-printedO
For example, in the instance wherein the first flexible ~heet material 12 is laminated to the exterior fa~e 22 of the rigid polymeric core material 11 and the printed m~tter is to be viewed from the exterior of the laminate, the first flexible sheet material may be reverse-printed (if the printed side is to be laminated directly to the core) or surface printed (if the printed side is to face the exterior of the laminate). On the other hand, if the printed matter is to be viewed from the interior of the laminate (i.e., if the core is transparent), the first flexible sheet material should be surface printed if the print~d side is to be laminated directly to the core. This is also true for the second flexible sheet material 14, although the situations would be altered accordingly to faciliate viewing of the printed matter.
The flexible sheet materials 12 and 14 may be laminated to the rigid polymeric core material 11 with any of a number of adhesives conventionally used in the art. However, pxeferably, a polyvinyl dichloride ~PVDC~ adhesive is used to laminate the flexible ~heet material ~12 or 14) to the rigid polymeric core 11. More 3 ~
preferably, Saran~ adhesive manufactured ~y Dow Chemical Co., Midland, Michigan may be used to laminate the flexible ~heet materials 12 and 14 to the rigid polymeric core material ll. The Saran~
adhesive provides both lamination capabilities and barrier characteristics to the final product. To provide effective lamination, the a~hesives may be used in an amount of about 2 lbs. to about 3 lbs.
per ream and preferably about 2.5 lbs. to about 3 lbs. per ream, although other appropriate quantities of adhesive may be used as will be apparent to one skilled in the art based upon the present disclosure.
When thermoformed into the shape of a tray, container, or other object f~r carrying foodstuff or other materials, it is preferred that the laminate material of the present invention also comprise a lid component. This embodiment can best be seen in Figure 3. The lid component 15 should be of sufficient size to cover the entire interior face 21 of the rigid core 11. The lid 15 is preferably attached to the edges 16 of the rigid polymeric core material ll in such a manner so that it covers or encases the interior face 21 of the riyid core ll and forms a tight seal with the core material ll. Appropria~e me~hods of attachmPnt of the lid 15 to the core material 11 will be evident to one skilled in the art based upon the present disclosure. When the lid 15 is attached to the edges 16 of the cor~ material ~1 in this manner, a cavity 17 is closed between the rigid core material ll ~nd the lid 15. The cavi~y 17 facilitates holding of foodstuffs or other materials within the tray, container, etc.
The lid component 15 may comprise any suitable polymer material known and used in the art. However, it is preferred that a polymeric material be chosen ~o that the lid 15 is both chemically and physically compatible with both the rigid polymeric core 11 and the flexible sheet materials 12 and 14. Such chemical and physical compatibility facilitates recycling of the ~inal product. Accordinyly, the lid componant 15 may compr.ise a nu~ber of conventionally used polymers, including polyester, polypropylene, polyethylene, co-extruded materials, etc. The use of a specific polymer for the lid 15, as needed for a particular application, will be evident to one of ordinary skill in the art based upon the present disclosure.
" ~ 3~
The present invention also encompasses a method of making a thermoformable laminate material which comprises printing one side of a first ~lexible sheet material having opposing sides, laminating the first flexible sheet ma~erial to one face of a rigid polymeric core material having interior and exterior faces and thermoforming the resultant laminated ma~erial to provide a shaped object. Preferably, the printed ~ide of the first flexible sheet material is laminated directly to one face of the rigid polymeric core material.
More preferably, the printed side o~ the first flexible sheet material is laminated directly to the exterior face of the rigid polymeric core material.
Conventional laminating techniques employing laminating equipment known to those skilled in the art, may be used in the present process. The flexible sheet materials may be printed using conventional high-speed printers, such as roto gravure or flexographic printers.
The present process further comprises thermoforming the present laminate into a desired shape and size as needed ~or a parti ular purpose.
Any conventional thermoforming process using conventional thermoforming equipment may be used for this purpose. The use of a particular thermoforming process for a speclfic application will evide~t to one skilled in the art based upon the present disclosure.
The thermoformable laminate material of the present invention may be thermoformed into various shapes as needed for a particular use. For example, the laminate may be thermoformed into packages, trays, signs, etc. In a preferred embodiment of the invention, the laminate material is thermoformed into the shap~ of a tray for packaging food materials for ultimate consumer use.
The process for making the thermoformable laminate material of the present invention may further comprise printing one side of a second flexible sheet material having opposing sides and laminating the second flexible sh2et material to the interior face of the rigid polymeric core material. The second flexible sheet material may also be printed and laminated using conventional techniques, as discussed above with regerence to the first flexible sheet material.
3~
In constructions where a second flexible sheet material is laminated ~o the interior face of the rigid polymeric corP in this manner, both flexible sheet materials should be laminated to the core material prior to thermoforming.
~ rom the standpoint of practicality, the present material may be printed, laminated and then formed into rolls of desired lengths. Once the laminate is fQrmed, the material may then be unrolled, thermoformed and cut into the desired shape and size. Alternatively, the rigid core and printed flexible sheets may be laminated in-line, thermoformed and cut.
The present invention may be embodied in other specific forms without departing from the spirlt or essential attributes thereof and accordingly, reference should be made to the appended claims, rather than to the foregoing specification and drawings, as indicating the scope of the invention.
U.S. Patent No. 4,442,158 discloses a plastic laminate adapted for use as a food package comprising an exterior polypropylene layer, a middle polyvinylidene chloride layer and an inner ionomer resi~ layer. U.S. Patent Nos. 4,443,507 and 4,873,137 disclose examples of laminated polymeric materials which comprise layers reinforced with fibers and glass flakes, respectively.
Although laminated polymeric materials are known in the art, the known materials have demonstrated drawbacks, ~uch as difficulties with or a complete inability to print the material, delamination of the layers, etc. Therefore, there is a need for a thermoformable laminate material which is satisfActory in all respects.
;~ L3~
Bummary o f the Invention The present invention is directed to a thermoformable laminate material comprising a rigid polymeric core material having interior and exterior faces and a first flexible sheet material having two opposing sides laminated ko one face of the rigid polymeric core material, wherein one side of the flexible sheet is printed prior to lamination. Preferably, the first flexible sheet material is laminated to the exterior face of the core. The invention may further include a thermoformable material comprising a second flexible sheet material having two opposing sides which is laminated to the interior face of the rigid polymeric core material. The second flexible sheet material may also be printed on one side prior to lamination. The present laminate may also comprise a lid component attached to the rigid core material. A method for the production of the thermoformahle polymeric materials of this invention is also disclosed.
G~3~.
Brief Description of th~ Dr wi~g~
The foregoing summary as well as the following detailed description will be better understood when read in conjunction with the appended drawings. For the purposes of illustrating the invention, there is shown in the drawings an embodiment which is presently preferred, it being understood, however, that the present invention is not limited to the precise embodiment~ shown. In the drawings:
Figure 1 is a sectional view of a two layer laminate according to the present invention;
Figure 2 is a sectional view of a three layer laminate according to the present invention;
and Figure 3 is a ~ectional view of an embodiment of the present laminats which i8 thermoformed into the shape of a tray, further comprising a lid co~ponent.
Detaile~ De~cri~tl~ of the ~n~ntion Referring to the drawîngs wherein like reference numerals are used to indicate like elements throughout the fisures, there is shown in Figure 1, a thermoformable laminate material 10 Vv '~ J ~ h3~
which comprises a rigid polymeric core material 11 haviny interior and exterior faces 21 and 22, respectively, and a first flexible sheet mat~rial 12 laminated thereto. The first flexible sheet material has two opposing sides 23 and 24 and is printed on one side with printed matter 13 prior to lamination to one face of the rigid polymeric core material. Such printed matter may include, without limitation, printing, designs, etc. Preferably, the printed side 23 of the first flexible sheet material is laminated to the exterior face 22 of the rigid polymeric core material 11. When laminated in this manner, the printed matter 13 will be protected from the environment by the first flexible sheet material 12 while remaining visible therethrough.
The present laminate provides an oxygen and moisture barrier for materials contained therein. This is particularly important when the present material i5 used to contain food materials, as the barrier prevents the food from rapidly degrading due to oxygen and moisture exposure.
It is preferred that the present laminate material be microwaveable. The microwaveability of the laminate material i5 desirable from the viewpoint of convenience, particularly whe~ ~he laminate is thermoformed into the shape of a tray or other container to hold microwaveable foods. In this instance, ~he consumer may purchase pre-cooked foods contained in the present thermoformed laminate, and place them dir~ctly from the freezer or refrigerator into a microwave oven without the necessity of using a separate container.
The rigid polymeric core material 11 employed in the present invention may be any of conventionally used polymeric materials. For example, any of polyester, polypropylene, copolyester, acrylonitrile or high impact polystyrene, such as Styrofoam~ may be used as the rigid polymeric core. Preferably, polyester is used as the rigid core material 11. Moreover, the rigid core 11 may be a 3 to 5 ply coextrusion of the chosen polymeric material. The rigid polymeric core material 11 should have a thickness of about 10 to about 50 mils., and pre~erably about 15 to about 25 mils. The rigid polymeric core material 11 may be either a si~gle layer of polymeric material or may itself be a laminate of two or more of such layers. The use of a single layer or - ~ ~
laminate c~re for a particular appl~cation will be evident to one of ordinary skill in the art based upon the present disclosure.
Preferably, the rigid polymeric core material ~1 is transparent. The use of a transparent material for the cnre facilitates viewing of matter printed ~n the flexible sheet materials in certain c~nstructions. Preferably, when the rigid polymeric core material 11 is transparent, the flexible sheet material 12 is surface-printed and the printed side of the flexible sheet is laminated directly to the interior face of the core material 11. Such a construction will facilitate viewing of the printed matter through the interior face of the core 11, while protecting the printed matter 13 from being scratched off. Moreover, this construction will protect any foodstuffs which are placed on the interior of the laminate from ~eing contaminated by the prin~ing.
As the first flexible sheet material 12 of the present invention, a nu~ber of conventionally used polymers may he employed. For example, polypropylene, polyethylene, ::opolye~ter nylon, polyester and co-extruded materials as re 3~
known and will be appreciated by those skilled in the art, may be used as the flexible sheet material 12 of the invention. Pr ferably, polyethylene is used as the first flexible sheet material 12. The first flexible sheet material 12 may have a thicXness of about .048 to about 5.0 mils., depending upon the particular shape the present laminate will be thermoformed into and the use to which it will be put. Preferably the first flexible sheet material will have a thickness of about .048 to about .075 mils. However, appropriate thicknesses for particular applications will be e~ident to one skilled in the art based upon the present disclosure.
When laminated ts one face of the rigid polymeric core 11, the first flexible sheet material 12 serves a number of functions. For example, th~ laminated flexiblP sheet material 12 provides both decorative functions (i.e., provides for the use of printed matter 13 on the laminate material, such as recipes, instructions, UPC codes, etc.) and barrier characteristics on the rigid polymeric core. WhPn laminated to the core material 11, the first flexible sheet material 12 2 ~ 2~
eliminates the necessity of using additional layers, ~uch as shrink wrap, box~s, labels, etc., to provide these functions.
The lamination of the first flexible ~heet material 12 to the rigid core material 11 allows for the provision of printed matter 13 on one face of the core ma~erial 11 without the necessity of using specialized equipment which is needed for printing on high-gauge materials.
Therefore, when the laminate of the present invention is used, conventional high-speed prlnters may be employed to preprint the first flexible sheet material 12 and the thus printed flexible sheet material 1~ may then be laminated directly to one face of the rigid pol~neric core material 11.
Conventional laminate materials xequire specialized equipment, such as sheet-fed offset presses, etc., ~or printing the sides or faces of rigid polymeric matexials. The u~e of such specialized equipment necessarily involves the expenditure of a high degree of expense and lab~r, making it ~ifficult to produce, thereby increasing the final cost of the materialO In contrast, in preparing the thennofo~nahle laminate material of the present invention, conventional high-speed printers, such as ro~o-gravure or flexographic printers, may be used to efficiently print the flexible sheet material 12 and conven~ional laminating techniques may be used to adhere the flexible sheet 12 to the rigid core material 11. Accordingly, the laminate of the present invention may be produced more efficiently and cost effectively in compariso~ to conventional packaqing constructions.
If desired, the present laminate may further comprise a second flexible sheet material.
As can best be seen in Figure 2, the second flexible sheet material 14 also has two opposing sides 25 and 26, and may be laminated to the opposing or interior face 21 of the rigid polymeric core material 11. This second flexible sheet material 14 may also be printed on one side prior to lamination in the same manner as the first flexible sheet material 1~. It is preferred that the printed side of the second flexible sheet material 14 be laminated to the opposing or interior ~ace 21 of the rigid polymeric core material 11.
The second flexible sheet material 14 may be composed of the same materials which may be used for the first flexible sheet material 12, disoussed above. Preferably, the second flexible sheet material 14 comprises polyester. The second flexible sheet material 14 ~ay also have a thickness of about n 048 to about S.0 mils., depending upon the particular shape ~he laminate will be thermoformed into and the p~rticular use to which it will be put. Preferably the second flexible sheet material 14 will have a thickness of about .048 to about .075 mils. However, appropriate thicknesse~ for particular applications will be evident to one skilled in the art based upon the present disclosure.
Both the first and second flexible sheet materials 12 and 14, respectively, may be printed in any conventional manner generally known in the art. The first and second flexible shee~ materials 12 and 14, may be either sur~ace printed or reverse-printed 60 khat the printed matter may best be seen from the chosen viewpoint. That is, depending upon which sheet is being printed, from which side the printed matter will be viewed and whether the printed side of the sheet material is laminated to the core or away from the core, the sheet may be either surface or reverse-printedO
For example, in the instance wherein the first flexible ~heet material 12 is laminated to the exterior fa~e 22 of the rigid polymeric core material 11 and the printed m~tter is to be viewed from the exterior of the laminate, the first flexible sheet material may be reverse-printed (if the printed side is to be laminated directly to the core) or surface printed (if the printed side is to face the exterior of the laminate). On the other hand, if the printed matter is to be viewed from the interior of the laminate (i.e., if the core is transparent), the first flexible sheet material should be surface printed if the print~d side is to be laminated directly to the core. This is also true for the second flexible sheet material 14, although the situations would be altered accordingly to faciliate viewing of the printed matter.
The flexible sheet materials 12 and 14 may be laminated to the rigid polymeric core material 11 with any of a number of adhesives conventionally used in the art. However, pxeferably, a polyvinyl dichloride ~PVDC~ adhesive is used to laminate the flexible ~heet material ~12 or 14) to the rigid polymeric core 11. More 3 ~
preferably, Saran~ adhesive manufactured ~y Dow Chemical Co., Midland, Michigan may be used to laminate the flexible ~heet materials 12 and 14 to the rigid polymeric core material ll. The Saran~
adhesive provides both lamination capabilities and barrier characteristics to the final product. To provide effective lamination, the a~hesives may be used in an amount of about 2 lbs. to about 3 lbs.
per ream and preferably about 2.5 lbs. to about 3 lbs. per ream, although other appropriate quantities of adhesive may be used as will be apparent to one skilled in the art based upon the present disclosure.
When thermoformed into the shape of a tray, container, or other object f~r carrying foodstuff or other materials, it is preferred that the laminate material of the present invention also comprise a lid component. This embodiment can best be seen in Figure 3. The lid component 15 should be of sufficient size to cover the entire interior face 21 of the rigid core 11. The lid 15 is preferably attached to the edges 16 of the rigid polymeric core material ll in such a manner so that it covers or encases the interior face 21 of the riyid core ll and forms a tight seal with the core material ll. Appropria~e me~hods of attachmPnt of the lid 15 to the core material 11 will be evident to one skilled in the art based upon the present disclosure. When the lid 15 is attached to the edges 16 of the cor~ material ~1 in this manner, a cavity 17 is closed between the rigid core material ll ~nd the lid 15. The cavi~y 17 facilitates holding of foodstuffs or other materials within the tray, container, etc.
The lid component 15 may comprise any suitable polymer material known and used in the art. However, it is preferred that a polymeric material be chosen ~o that the lid 15 is both chemically and physically compatible with both the rigid polymeric core 11 and the flexible sheet materials 12 and 14. Such chemical and physical compatibility facilitates recycling of the ~inal product. Accordinyly, the lid componant 15 may compr.ise a nu~ber of conventionally used polymers, including polyester, polypropylene, polyethylene, co-extruded materials, etc. The use of a specific polymer for the lid 15, as needed for a particular application, will be evident to one of ordinary skill in the art based upon the present disclosure.
" ~ 3~
The present invention also encompasses a method of making a thermoformable laminate material which comprises printing one side of a first ~lexible sheet material having opposing sides, laminating the first flexible sheet ma~erial to one face of a rigid polymeric core material having interior and exterior faces and thermoforming the resultant laminated ma~erial to provide a shaped object. Preferably, the printed ~ide of the first flexible sheet material is laminated directly to one face of the rigid polymeric core material.
More preferably, the printed side o~ the first flexible sheet material is laminated directly to the exterior face of the rigid polymeric core material.
Conventional laminating techniques employing laminating equipment known to those skilled in the art, may be used in the present process. The flexible sheet materials may be printed using conventional high-speed printers, such as roto gravure or flexographic printers.
The present process further comprises thermoforming the present laminate into a desired shape and size as needed ~or a parti ular purpose.
Any conventional thermoforming process using conventional thermoforming equipment may be used for this purpose. The use of a particular thermoforming process for a speclfic application will evide~t to one skilled in the art based upon the present disclosure.
The thermoformable laminate material of the present invention may be thermoformed into various shapes as needed for a particular use. For example, the laminate may be thermoformed into packages, trays, signs, etc. In a preferred embodiment of the invention, the laminate material is thermoformed into the shap~ of a tray for packaging food materials for ultimate consumer use.
The process for making the thermoformable laminate material of the present invention may further comprise printing one side of a second flexible sheet material having opposing sides and laminating the second flexible sh2et material to the interior face of the rigid polymeric core material. The second flexible sheet material may also be printed and laminated using conventional techniques, as discussed above with regerence to the first flexible sheet material.
3~
In constructions where a second flexible sheet material is laminated ~o the interior face of the rigid polymeric corP in this manner, both flexible sheet materials should be laminated to the core material prior to thermoforming.
~ rom the standpoint of practicality, the present material may be printed, laminated and then formed into rolls of desired lengths. Once the laminate is fQrmed, the material may then be unrolled, thermoformed and cut into the desired shape and size. Alternatively, the rigid core and printed flexible sheets may be laminated in-line, thermoformed and cut.
The present invention may be embodied in other specific forms without departing from the spirlt or essential attributes thereof and accordingly, reference should be made to the appended claims, rather than to the foregoing specification and drawings, as indicating the scope of the invention.
Claims (16)
1. A thermoformabe laminate material comprising a rigid polymeric core material having interior and exterior faces and a first flexible sheet material having two opposing sides, one side of said sheet material being laminated to one face of said rigid polymeric core material, wherein one side of said flexible sheet material is printed prior to said lamination.
2. A thermoformable laminate material as in claim 1, wherein said rigid polymeric core material is selected from the group consisting of polyester, polypropylene, copolyester, acrylonitrile and high impact polystyrene.
3. A thermoformable laminate material as in claim 1, wherein said rigid polymeric core material is transparent.
4. A thermoformable laminate material as in claim 1, wherein said first flexible sheet material is selected from the group consisting of polypropylene, polyethylene, polyester, copolyester, nylon and co-extruded materials.
5. A thermoformable laminate material as in claim 1, wherein the preprinted side of said first flexible sheet material is laminated to the exterior face of said rigid polymeric core material.
6. A thermoformable laminate material as in claim 1, wherein said laminate material is thermoformed into the shape of a tray.
7. A thermoformable laminate material as in claim 1, further comprising a second flexible sheet material having two opposing sides, wherein one side of said flexible sheet material is laminated to the interior face of said rigid polymeric core material.
8. A thermoformable laminate material as in claim 1, further comprising a lid attached to said rigid polymeric core material, where said lid encases the interior face of said rigid polymeric core material.
9. A thermoformable laminate material as in claim 8, where said lid is printed.
10. A method of making a thermoformable laminate material comprising printing the side of a first flexible sheet material having two opposing sides and laminating one side of said flexible sheet material to the exterior face of a rigid polymeric core material having interior and exterior faces.
11. A method as in claim 10, further comprising thermoforming said laminate material into a desired product.
12. A method as in claim 10, wherein the printed side of said flexible sheet material is laminated to the exterior face of said rigid polymeric core material.
13. A method as in claim 12, further comprising attaching a lid material to said rigid polymeric core material.
14. A method as in claim 10, wherein said rigid polymeric core material is selected from the group consisting of polyester, polypropylene, copolyester, acrylonitrile and high-impact polystyrene.
15. A method as in claim 10, wherein said first flexible sheet material is selected from the group consisting of polypropylene, polyethylene, polyester, copolyester, nylon and co-extruded materials.
16. A method as in claim 10, wherein said second flexible sheet material is selected from the group consisting of polyproplylene, polyethylene, polyester and co-extruded materials.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US54878190A | 1990-07-06 | 1990-07-06 | |
| US548,781 | 1990-07-06 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2046131A1 true CA2046131A1 (en) | 1992-01-07 |
Family
ID=24190373
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2046131 Abandoned CA2046131A1 (en) | 1990-07-06 | 1991-07-03 | Thermoformable laminate material and method of making the same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2046131A1 (en) |
-
1991
- 1991-07-03 CA CA 2046131 patent/CA2046131A1/en not_active Abandoned
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