US4747983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for manufacturing foamed structures with integral skin
Assignee: Mobil Oil AS
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Filing: 1985-12-30
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Granted: 1988-05-31
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Expires: 2005-12-30
Abstract
Abstract A foamed thermoplastic article having an integral outer unfoamed skin layer is formed from a mixture of thermoplastic resin containing a blowing agent by removing at least a portion of the blowing agent in the die of the extruder. The blowing agent is removed, e.g., by modifying the die so that it incorporates a porous section whcih allows the blowing agent to be removed from the mixture.
Inventors
- 👤 Edward A. Colombo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:22
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/20; B29C44/22; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/507; B29C44/56; B29C44/5609; B29C33/00; B29C33/38; B29C33/3814; B29K; B29K2105/00; B29K2105/04; B29K2105/043; Y; Y10; Y10S; Y10S264/00; Y10S264/05
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
102 words
In a method of producing a thermoplastic article from a mixture of a plastified thermoplastic resin containing a blowing agent, the method comprising passing the mixture through an extruder means equipped with a die means, the improvement comprising removing in the die means at least a portion of the blowing agent, thereby forming a skin layer on the surface of the article, the die means containing no dividing means within the cross-section of its flow channel, thereby producing the article with the skin layer integrated into the surface of the article substantially upon the commencement of the formation of the skin layer.
Claim 2
Dependent Claim
102 words
In a method of producing a thermoplastic article from a mixture of a plastified thermoplastic resin containing a blowing agent, the method comprising passing the mixture through an extruder means equipped with a die means, the improvement comprising removing in the die means at least a portion of the blowing agent, thereby forming a skin layer on the surface of the article, the die means containing no dividing means within the cross-section of its flow channel, thereby producing the article with the skin layer integrated into the surface of the article substantially upon the commencement of the formation of the skin layer.
Claim 3
Dependent Claim
18 words
A method of claim 1 wherein the skin layer has a density substantially greater than the thermoplastic article.
Claim 4
Dependent Claim
19 words
A method of claim 2 wherein the blowing agent is removed through a porous section of the die means.
Claim 5
Dependent Claim
44 words
A method of claim 3 wherein the porous section has such a permeability that it allows molecules of the blowing agent to be removed through the porous section but does not allow molecules of the thermoplastic resin to be removed through the porous section.
Claim 6
Dependent Claim
38 words
A method of claim 4 wherein the porous section has a permeability defined by the flow curves for water, in FIG. 1, of a porous media having standard micron sizes of between about 0.25 to about 3 microns.
Claim 7
Dependent Claim
38 words
A method of claim 5 wherein the porous section has a permeability defined by the flow curves for water, in FIG. 1, of a porous media having standard micron sizes of between about 0.5 to about 2 microns.
Claim 8
Dependent Claim
14 words
A method of claim 6 wherein the die means is an annular die means.
Claim 9
Dependent Claim
25 words
A method of claim 7 wherein the die means has one porous section on the inner and one porous section on the outer surfaces thereof.
Claim 10
Dependent Claim
20 words
A method of claim 8 wherein the thermoplastic article has skin layers on the inner and the outer surfaces thereof.
Claim 11
Dependent Claim
20 words
A method of claim 9 wherein the surface skin layer has the thickness of about 0.1 to about 1.25 mils.
Claim 12
Dependent Claim
20 words
A method of claim 10 wherein the surface skin layer has the thickness of about 0.5 to about 1.0 mils.
Claim 13
Dependent Claim
34 words
A method of claim 11 wherein the porous section has a permeability defined by the flow curves for water, in FIG. 1, of a porous media having standard micron sizes of about 0.5 microns.
Claim 14
Dependent Claim
46 words
A method of claim 12 wherein the thermoplastic article is made from a styrenic polymer, it has the density of about 3 to about 6 lbs/ft 3 , and the surface film layer thereof has the density of about 15 to about 65 lbs/ft 3 .
Claim 15
Dependent Claim
65 words
In an extruder means having a die means, containing no dividing means within the cross-section of its flow channel, the improvement comprising providing in the die means a porous section having such a permeability that it allows molecules of a blowing agent to be removed through the porous section but does not allow molecules of a thermoplastic resin to be removed through the porous section.
Claim 16
Dependent Claim
65 words
In an extruder means having a die means, containing no dividing means within the cross-section of its flow channel, the improvement comprising providing in the die means a porous section having such a permeability that it allows molecules of a blowing agent to be removed through the porous section but does not allow molecules of a thermoplastic resin to be removed through the porous section.
Claim 17
Dependent Claim
39 words
An extruder means of claim 12 wherein the porous section has a permeability defined by the flow curves for water, in FIG. 1, of a porous media having standard micron sizes of between about 0.25 to about 3 microns.
Claim 18
Dependent Claim
39 words
An extruder means of claim 14 wherein the porous section has a permeability defined by the flow curves for water, in FIG. 1, of a porous media having standard micron sizes of between about 0.5 to about 2 microns.
Claim 19
Dependent Claim
35 words
An extruder means of claim 16 wherein the porous section has a permeability defined by the flow curves for water, in FIG. 1, of a porous media having standard micron sizes of about 0.5 microns.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-05-31 | 1991-11-30 | 1992-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-31 | 1995-11-30 | 1996-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-31 | 1999-11-30 | 2000-05-31 | $7700.00 | Window Closed / Lapsed |