Patent US3992501A successfully refreshed from Google Patents.
US3992501A
Expired / Lapsed
US
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Process for the manufacture of void-free polyolefin foam moldings
Assignee: BASF SE
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Filing: 1974-06-18
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Granted: 1976-11-16
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Expires: 1994-06-18
Abstract
Abstract Foam moldings of olefin polymers are prepared by heating, and pressing together, foamed particles of an olefin polymer, containing crosslinked constituents, in molds, a temperature gradient of from 0.5° to 25° C per cm of loose mass of particles being established in the mold, which has a gas-permeable wall on the lower-temperature side.
Inventors
- 👤 Hermann Tatzel
- 👤 Wolfram Koegel
- 👤 Gilbert Beck
- 👤 Ludwig Zuern
- 👤 Arndt Christian Caesar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:35
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/22; C08J9/228; C08J9/232; B; B29; B29C; B29C44/00; B29C44/02; B29C44/10; B29C44/34; B29C44/36; B29C44/38; B29C44/44; B29C44/445; B29K; B29K2023/00; B29K2105/00; B29K2105/24; C08J2323/00; C08J2323/02; Y; Y10; Y10S; Y10S264/00; Y10S264/18; Y10S425/00; Y10S425/812; Y10S521/00; Y10S521/918; Y10S521/919
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
115 words
A process for the manufacture of void-free foam moldings from olefin polymers which comprises: differentially heating foamed cross-linked particles of an olefin polymer to the temperature at which they sinter or coalesce together in a mold which is not gas-tight when closed, said particles being heated in said mold so that a temperature gradient of 0.5° to 25° C per cm of the loose mass of particles is established in the mold which has a gas-permeable wall on the lower-temperature side; compressing said heated particles having said temperature gradient in said mold to bond the particles together and form a void-free foam article; cooling said compressed article and removing the foamed article from said mold.
Claim 2
Dependent Claim
115 words
A process for the manufacture of void-free foam moldings from olefin polymers which comprises: differentially heating foamed cross-linked particles of an olefin polymer to the temperature at which they sinter or coalesce together in a mold which is not gas-tight when closed, said particles being heated in said mold so that a temperature gradient of 0.5° to 25° C per cm of the loose mass of particles is established in the mold which has a gas-permeable wall on the lower-temperature side; compressing said heated particles having said temperature gradient in said mold to bond the particles together and form a void-free foam article; cooling said compressed article and removing the foamed article from said mold.
Claim 3
Dependent Claim
33 words
A process as set forth in claim 1 wherein the air trapped in the loose mass of material is allowed to escape through elongated hollow members inserted into the loose mass during compression.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-11-16 | 1980-05-17 | 1980-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-16 | 1984-05-17 | 1984-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-16 | 1988-05-17 | 1988-11-16 | $7700.00 | Window Closed / Lapsed |