US3790436A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extruded cellular slab of varying densities
Assignee: Armstrong World Industries Inc
•
Filing: 1972-08-10
•
Granted: 1974-02-05
•
Expires: 1992-08-10
Abstract
Abstract A thick, foamed plastic slab having a smooth surface, a densified core, and rounded edges is produced by extruding foamable, substantially unplasticized poly(vinyl chloride) in the form of a tube into a region of lower pressure, immediately cooling the outer surface of the tube while allowing entrapped gases to cause formation of a rough-textured inner surface thereon and then compressing the tube at right angles to the direction of extrusion.
Inventors
- 👤 A Graham
- 👤 R Sitler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:07
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/34; B; B29; B29C; B29C44/00; B29C44/20; B29C44/22; B29C44/34; B29C44/36; B29C44/46; B29C44/50; B29C44/505; B29C44/56; B29K; B29K2027/00; B29K2027/06; B29K2105/00; B29K2105/04; B29K2105/043; Y; Y10; Y10S; Y10S273/00; Y10S273/05; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/24992; Y10T428/249921; Y10T428/249953; Y10T428/249987; Y10T428/249988; Y10T428/249989
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
43 words
A cellular plastic slab according to claim 1 wherein the main body portion consists of foamed, substantially unplasticized poly(vinyl chloride) and the core extends the entire length of the slab and extends transversely over at least a major portion of the width thereof.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |