CA1198562A - Thermoforming coextruded plastic sheets - Google Patents
Thermoforming coextruded plastic sheetsInfo
- Publication number
- CA1198562A CA1198562A CA000420898A CA420898A CA1198562A CA 1198562 A CA1198562 A CA 1198562A CA 000420898 A CA000420898 A CA 000420898A CA 420898 A CA420898 A CA 420898A CA 1198562 A CA1198562 A CA 1198562A
- Authority
- CA
- Canada
- Prior art keywords
- thermoforming
- objects
- thermoformed
- plastic
- sheet
- 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.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C51/00—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor
- B29C51/14—Shaping by thermoforming, i.e. shaping sheets or sheet like preforms after heating, e.g. shaping sheets in matched moulds or by deep-drawing; Apparatus therefor using multilayered preforms or sheets
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/07—Flat, e.g. panels
- B29C48/08—Flat, e.g. panels flexible, e.g. films
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
- B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
- B29C48/21—Articles comprising two or more components, e.g. co-extruded layers the components being layers the layers being joined at their surfaces
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/30—Extrusion nozzles or dies
- B29C48/305—Extrusion nozzles or dies having a wide opening, e.g. for forming sheets
- B29C48/307—Extrusion nozzles or dies having a wide opening, e.g. for forming sheets specially adapted for bringing together components, e.g. melts within the die
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/07—Flat, e.g. panels
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Laminated Bodies (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Abstract
THERMOFORMING COEXTRUDED PLASTIC SHEETS
Abstract A process of making thermoformed plastic ob-jects comprising coextruding a multilayered sheet having adjacent layers of plastics that do not bond together during coextrusion, thermoforming the multilayered sheet, and separating individual thermoformed objects of different layers.
Abstract A process of making thermoformed plastic ob-jects comprising coextruding a multilayered sheet having adjacent layers of plastics that do not bond together during coextrusion, thermoforming the multilayered sheet, and separating individual thermoformed objects of different layers.
Description
THERMOFORMING COEXI'RUDED PLASTIC S~IEETS
~ield of the Invention The invention relates to preparing objects thermoformed from plastic sheets.
Background of the Invent:ion Plastic sheets are often produced by apparatus in which plastic material is heated and supplied under pressure to an extrusion die. The sheets can then be thermoformed to a desired shape, and individual objects can be trimmed from the thermoformed sheet.
Summary of the Invention In general the invention features coextruding a mu]tilayered sheet having adjacent layers of plastics that do not bond to each other during coextrusion, thermoforming said multilayered sheet into at least one object, and separating the thermoformed object into objects each comprising a different layer. With such a method, the productivity of the extrusion, thermoforming, and trimming apparatus is multiplied by the number of layers in the sheet.
In preferred embodiments one of the plastics in the multilayered sheet is polystyrene and another plastic is polypropylene; in some preferred embodiments one plastic is for a separator layer between plastic layers for 2n the thermoformed objects, and in other preferred embodiments the thermoformed objects are made from more than one of the plastics of the layers of the multilayered sheet. The thermoforming of the multilayered sheet with poly-propylene and polystyrene layers is faster than the slow~ and therefore expensive, thermoforming of polypropylene alone.
.
5~
Description of the Preferred Embodiment -The preferred embodiment of the invention will now be described after first describing the draw-ing, which is a diagrammatic view of a process of manufacturing plastic objects according to the in-vention.
Referring to the drawing, there is shown ap-paratus lO for manufacturing polypropylene bowls 12 and polystyrene bowls 14.
Two heated containers 16, 18 serve as sources of the polystyrene (70% crystal styrene and 30% rub-ber modifying plastomer sold by Phillips Chemical Company under the trade designation Solprene 416P, a block polymer having a butadiene/styrene ratio of 70/30, a molecular weight of 140 M, a density of 0.94, and a melt flow index of 2 decigrams/min~, and polypropylene (available from Rexene Company, Paramus, New Jersey, and having a melt flow index o~ 4 decigrams/min), respectively.
Conduits 20, 22l 24, 26, 28 supply the heated materials to coextrusion block`30. There the ma-terials merge together to form under pressure a unitary, five-layer thick stream 32 of generally circular cross section. Stream`32 passes into extrusion die 34 ~e.g., Welex standard 54" flex-lip die~ for extrusion into continuous sheet 36.
Sheet 36 then passes through a series of chill rolls 38.
The sheet, after coextrusion, may then be thermoformed into bowls or wound into spools (not shown) for storage and later themoforming.
To process sheet 36 into bowls, the shee-t is passed through conventional thermoforming apparatus 40 (the vacuum forming type well known in the art~;
which impresses the bowl shape.
After thermoforming, the shaped sheet 42 passes through trim press 44, in which the indivi-dual bowls 12 and 14 are trimmed. Because the polypropylene and polystyrene of bowls 12, 14, respectively, do no~ bond to each other during coextrusion or thermoformingl bowls 12, 14 can be easily separa~ed from each other. The simultaneous coextruding of five sheets and thermoforming and trimming of five bowls act to increase the produc-tivity of the coextrusion, thermoforming, and trimming apparatus by a factor of five. Also, the thermoforming of the five-layer sheet is faster than the siow, and therefore expensive, thermoform-ing of polypropylene alone.
Other Embodiments Other embodiments of the invention axe wlthin the scope of the appended claims. For example, other plastics that do not bond to each other can be used in place of the polystyrene and polypropy-lene. Also t one of the plastic layers could be a thin separator layer which would be used for scrap after separating the thermoformed objects from each other.
~ield of the Invention The invention relates to preparing objects thermoformed from plastic sheets.
Background of the Invent:ion Plastic sheets are often produced by apparatus in which plastic material is heated and supplied under pressure to an extrusion die. The sheets can then be thermoformed to a desired shape, and individual objects can be trimmed from the thermoformed sheet.
Summary of the Invention In general the invention features coextruding a mu]tilayered sheet having adjacent layers of plastics that do not bond to each other during coextrusion, thermoforming said multilayered sheet into at least one object, and separating the thermoformed object into objects each comprising a different layer. With such a method, the productivity of the extrusion, thermoforming, and trimming apparatus is multiplied by the number of layers in the sheet.
In preferred embodiments one of the plastics in the multilayered sheet is polystyrene and another plastic is polypropylene; in some preferred embodiments one plastic is for a separator layer between plastic layers for 2n the thermoformed objects, and in other preferred embodiments the thermoformed objects are made from more than one of the plastics of the layers of the multilayered sheet. The thermoforming of the multilayered sheet with poly-propylene and polystyrene layers is faster than the slow~ and therefore expensive, thermoforming of polypropylene alone.
.
5~
Description of the Preferred Embodiment -The preferred embodiment of the invention will now be described after first describing the draw-ing, which is a diagrammatic view of a process of manufacturing plastic objects according to the in-vention.
Referring to the drawing, there is shown ap-paratus lO for manufacturing polypropylene bowls 12 and polystyrene bowls 14.
Two heated containers 16, 18 serve as sources of the polystyrene (70% crystal styrene and 30% rub-ber modifying plastomer sold by Phillips Chemical Company under the trade designation Solprene 416P, a block polymer having a butadiene/styrene ratio of 70/30, a molecular weight of 140 M, a density of 0.94, and a melt flow index of 2 decigrams/min~, and polypropylene (available from Rexene Company, Paramus, New Jersey, and having a melt flow index o~ 4 decigrams/min), respectively.
Conduits 20, 22l 24, 26, 28 supply the heated materials to coextrusion block`30. There the ma-terials merge together to form under pressure a unitary, five-layer thick stream 32 of generally circular cross section. Stream`32 passes into extrusion die 34 ~e.g., Welex standard 54" flex-lip die~ for extrusion into continuous sheet 36.
Sheet 36 then passes through a series of chill rolls 38.
The sheet, after coextrusion, may then be thermoformed into bowls or wound into spools (not shown) for storage and later themoforming.
To process sheet 36 into bowls, the shee-t is passed through conventional thermoforming apparatus 40 (the vacuum forming type well known in the art~;
which impresses the bowl shape.
After thermoforming, the shaped sheet 42 passes through trim press 44, in which the indivi-dual bowls 12 and 14 are trimmed. Because the polypropylene and polystyrene of bowls 12, 14, respectively, do no~ bond to each other during coextrusion or thermoformingl bowls 12, 14 can be easily separa~ed from each other. The simultaneous coextruding of five sheets and thermoforming and trimming of five bowls act to increase the produc-tivity of the coextrusion, thermoforming, and trimming apparatus by a factor of five. Also, the thermoforming of the five-layer sheet is faster than the siow, and therefore expensive, thermoform-ing of polypropylene alone.
Other Embodiments Other embodiments of the invention axe wlthin the scope of the appended claims. For example, other plastics that do not bond to each other can be used in place of the polystyrene and polypropy-lene. Also t one of the plastic layers could be a thin separator layer which would be used for scrap after separating the thermoformed objects from each other.
Claims (3)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS
1. A process of making thermoformed plastic objects comprising coextruding a multilayered sheet having adjacent layers of plastics that do not bond to-gether during coextrusion, thermoforming said multilayered sheet into at least one object, and separating the thermoformed object into objects each comprising a different layer.
2. The process of claim 1 wherein said multilayered sheet is made of layers of polystyrene and polypropylene.
3. The process of claim 1 wherein one said plastic is for a separator layer between layers for said objects.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US34593882A | 1982-02-04 | 1982-02-04 | |
US345,938 | 1989-05-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA1198562A true CA1198562A (en) | 1985-12-31 |
Family
ID=23357183
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA000420898A Expired CA1198562A (en) | 1982-02-04 | 1983-02-04 | Thermoforming coextruded plastic sheets |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0101500A1 (en) |
CA (1) | CA1198562A (en) |
WO (1) | WO1983002747A1 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2541628B1 (en) * | 1983-02-25 | 1988-07-08 | Roquette Freres | IMPROVED PROCESS AND INSTALLATION FOR THE MANUFACTURE OF CORRUGATED PAPERBOARD |
US4657151A (en) * | 1984-04-12 | 1987-04-14 | Baxter Travenol Laboratories, Inc. | Container such as a nursing container, with flexible liner |
DE4101106A1 (en) * | 1991-01-16 | 1992-07-23 | Krauss Maffei Ag | METHOD AND DEVICE FOR PRODUCING LAMINATED MOLDED PARTS |
ES2049576B1 (en) * | 1991-06-28 | 1996-02-16 | Suprametal S A | MANUFACTURING PROCEDURE FOR IDENTIFICATION SIGNS AND RESULTING PRODUCT |
GB2284569A (en) * | 1993-12-08 | 1995-06-14 | Rolls Royce Plc | Manufacture of similarly shaped components |
US10618610B2 (en) | 2017-05-11 | 2020-04-14 | Vista Outdoor Operations Llc | Watersport boards and methods for forming the same |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2270185A (en) * | 1940-08-15 | 1942-01-13 | Dow Chemical Co | Simultaneous manufacture of containers and closures |
US4048428A (en) * | 1961-12-05 | 1977-09-13 | W. R. Grace & Co. | Method for preparing a film of vinylidene chloride polymer |
US3322870A (en) * | 1965-04-06 | 1967-05-30 | Union Carbide Corp | Method of producing clear, crystalline, high-gloss thermoplastic film |
US3494993A (en) * | 1968-01-29 | 1970-02-10 | Dow Chemical Co | Extrusion of wide thermoplastic film and sheet |
US3977153A (en) * | 1970-11-06 | 1976-08-31 | The Dow Chemical Company | Container for food products and method for making same |
DE2114065C2 (en) * | 1971-03-23 | 1982-08-19 | Heinrich Pannenbecker | Process for the production of foils from thermoplastics with adhesive properties |
US3971866A (en) * | 1974-06-07 | 1976-07-27 | Minnesota Mining And Manufacturing Company | Thermoformable release liner |
-
1983
- 1983-02-04 EP EP83901009A patent/EP0101500A1/en not_active Withdrawn
- 1983-02-04 WO PCT/US1983/000158 patent/WO1983002747A1/en unknown
- 1983-02-04 CA CA000420898A patent/CA1198562A/en not_active Expired
Also Published As
Publication number | Publication date |
---|---|
WO1983002747A1 (en) | 1983-08-18 |
EP0101500A1 (en) | 1984-02-29 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
MKEX | Expiry |