US4486366A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of continuously producing heat shrinkable amorphous polystyrene foam layer
Assignee: Bank of America NA
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Filing: 1983-01-14
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Granted: 1984-12-04
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Expires: 2003-01-14
Abstract
Abstract There is provided a method of continuously producing a highly oriented heat shrinkable single layer of amorphous styrene foam or a composite of a thermoplastic film and an amorphous polystyrene foam to form a heat shrinkable two-layer sheet that is easily stored without substantial shrinkage at ambient temperature, the outstanding single-layer sheet or two-layer sheet being adapted for heat shrinking rapidly to form a label around a container or a cup. The outstanding method comprises extruding a single foam sheet or coextruding a thermoplastic film and an amorphous polystyrene foam layer to form the two-layer sheet, bringing the sheet to its orientation temperature, stretching the two-layer sheet at its orientation temperature in at least a longitudinal direction to provide a dimensionally stable, storable, oriented polystyrene foam sheet or a thermoplastic film/amorphous polystyrene foam layer sheet, printing on the oriented sheet to decorate the same, and heat shrinking the sheet to form a final attractive, decorated structure.
Inventors
- 👤 Subba K. Reddy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:59
CPC Classifications
B; B29; B29C; B29C61/00; B29C61/06; B29C61/08; B29C44/00; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/507; B29C61/0608; B29C61/0616; B65; B65C; B65C3/00; B65C3/06; B65C3/065; B29C63/00; B29K; B29K2025/00; B29K2105/00; B29K2105/04; B29K2995/00; B29K2995/0037; B29K2995/0039
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
149 words
A method of continuously producing a highly oriented polystyrene foam sheet which shrinks at substantially lower temperatures to form a label or a cup, the foam sheet being dimensionally stable during shipping and handling and have excellent surface appearance for printing and decoration, the method comprising the steps of: A. extruding an amorphous polystyrene foam sheet as a single layer with little or no orientation during the extrusion; B. heating the foam sheet by contacting hot rolls or by exposing to infrared heaters to the orientation temperature; C. stretching the sheet in a longitudinal direction between a pair of spaced rolls running at different speeds to reduce its thickness, and provide a dimensionally stable, highly oriented structure; D. printing on the oriented sheet to decorate the same to thereby provide a dimensionally stable, decorated sheet; and E. heat shrinking the decorated, oriented sheet to form a final attractive structure.
Claim 2
Independent Claim
149 words
A method of continuously producing a highly oriented polystyrene foam sheet which shrinks at substantially lower temperatures to form a label or a cup, the foam sheet being dimensionally stable during shipping and handling and have excellent surface appearance for printing and decoration, the method comprising the steps of: A. extruding an amorphous polystyrene foam sheet as a single layer with little or no orientation during the extrusion; B. heating the foam sheet by contacting hot rolls or by exposing to infrared heaters to the orientation temperature; C. stretching the sheet in a longitudinal direction between a pair of spaced rolls running at different speeds to reduce its thickness, and provide a dimensionally stable, highly oriented structure; D. printing on the oriented sheet to decorate the same to thereby provide a dimensionally stable, decorated sheet; and E. heat shrinking the decorated, oriented sheet to form a final attractive structure.
Claim 3
Dependent Claim
22 words
A method as defined in claim 1 in which the final structure is a label that is heat shrunk around a container.
Claim 4
Dependent Claim
15 words
A method as defined in claim 1 in which the final structure is a cup.
Claim 5
Dependent Claim
32 words
A method as defined in claim 1 in which the stretching in Step C is also done in the cross-machine direction that is substantially perpendicular to the longitudinal axis of the sheet.
Claim 6
Dependent Claim
18 words
A method as defined in claim 1 in which infrared heating is used in Steps B and E.
Claim 7
Independent Claim
173 words
A method of continuously producing a heat shrinkable thermoplastic film and an amorphous polystyrene foam to form a heat shrinkable two-layer sheet that is easily storable without substantial shrinkage at ambient temperature and a sheet that will heat shrink rapidly at substantially lower temperatures to form a label or a cup, the method comprising the steps of: A. coextruding a thermoplastic film and an amorphous polystyrene foam layer to form a two-layer sheet having a continuously formed length as it is conducted away from the coextruder, the length being greater than the width of the sheet; B. bringing the two-layer sheet to its orientation temperature after the foam layer is formed; C. stretching the two-layer sheet at its orientation temperature in a longitudinal direction to reduce its thickness and provide a dimensionally stable, storable, oriented thermoplastic film/amorphous polystyrene foam sheet; D. printing on the oriented sheet to decorate the same to thereby provide an oriented, decorated, storable sheet; and E. heat shrinking the storable, oriented sheet to form a final attractive, decorated structure.
Claim 8
Independent Claim
173 words
A method of continuously producing a heat shrinkable thermoplastic film and an amorphous polystyrene foam to form a heat shrinkable two-layer sheet that is easily storable without substantial shrinkage at ambient temperature and a sheet that will heat shrink rapidly at substantially lower temperatures to form a label or a cup, the method comprising the steps of: A. coextruding a thermoplastic film and an amorphous polystyrene foam layer to form a two-layer sheet having a continuously formed length as it is conducted away from the coextruder, the length being greater than the width of the sheet; B. bringing the two-layer sheet to its orientation temperature after the foam layer is formed; C. stretching the two-layer sheet at its orientation temperature in a longitudinal direction to reduce its thickness and provide a dimensionally stable, storable, oriented thermoplastic film/amorphous polystyrene foam sheet; D. printing on the oriented sheet to decorate the same to thereby provide an oriented, decorated, storable sheet; and E. heat shrinking the storable, oriented sheet to form a final attractive, decorated structure.
Claim 9
Dependent Claim
22 words
A method as defined in claim 6 in which the final structure is a label that is heat shrunk around a container.
Claim 10
Dependent Claim
15 words
A method as defined in claim 6 in which the final structure is a cup.
Claim 11
Dependent Claim
32 words
A method as defined in claim 6 in which the stretching in Step C is also done in the cross-machine direction that is substantially perpendicular to the longitudinal axis of the sheet.
Claim 12
Dependent Claim
16 words
A method as defined in claim 6 in which infrared heating is used in Step E.
Claim 13
Dependent Claim
27 words
A method as defined in claim 1 in which a thermoplastic film is extruded with the foamed amorphous polystyrene sheet to provide a polystyrene form/thermoplastic film composite.
Claim 14
Dependent Claim
63 words
A method as defined in claim 1 in which the heating in step B and the stretching in step C of the heated sheet at its orientation temperature provides a dimensionally stable structure that is highly oriented compared to the orientation, if any after step A, the structure after step C having a lower onset shrinkage temperature than the structure after step A.
Claim 15
Dependent Claim
52 words
A method as defined in claim 6 in which the stretching in step C of the two-layer sheet at its orientation temperature provides a highly oriented film/foam sheet that has an onset of shrinkage temperature as low as about 75° C., there being a shrinkage of about 40% at about 110° C.
References Cited (Backward Citations)
US3640915A
Cited
US3733381A
Cited
US3767496A
Cited
US3901835A
Cited
US3953558A
Cited
US4038446A
Cited
US4312960A
Cited
US4244900A
Cited
US4339551A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |