US4161502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for forming plastic articles
Assignee: Dow Chemical Co
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Filing: 1977-04-02
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Granted: 1979-07-17
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Expires: 1997-04-02
Abstract
Abstract An improvement in the process of forming plastic articles wherein such articles are forged from a compression formed briquette of resinous powder, such improvement comprising (1) compressing a resinous powder having lamellar crystalline nonspherulitic morphology into a substantially unoriented briquette having green strength, (2) removing the briquette from the compressing device and placing the briquette in a forging press wherein lubrication is provided between the contacting surfaces of the briquette and the forging press to permit plug flow, and (3) forging the briquette into a shaped article while maintaining the briquette at a temperature between the alpha-transition temperature and the melt temperature of the resinous powder.
Inventors
- 👤 Ritchie A. Wessling
- 👤 Edward F. Gurnee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:20
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/02; B29C43/16; B29C43/14; B29C2791/00; B29C2791/001; B29K; B29K2105/00; B29K2105/25; B29K2105/251; B29K2105/253; B29K2105/255
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
102 words
A process of forming decomposition-free, substantially fused, clear, flexible plastic shaped articles comprising the sequential steps of (1) compressing in a compressing device a resinous powder having lamellar crystalline nonspherulitic morphology into a substantially unoriented briquette having green strength, (2) removing said briquette from the compressing device and placing said briquette in a forging press wherein lubrication is provided between the contacting surfaces of the briquette and said forging press to effect plug flow, and (3) forging said briquette into a shaped article while maintaining said briquette at a temperature between the alpha-transition temperature and the melting point of said resinous powder.
Claim 2
Dependent Claim
102 words
A process of forming decomposition-free, substantially fused, clear, flexible plastic shaped articles comprising the sequential steps of (1) compressing in a compressing device a resinous powder having lamellar crystalline nonspherulitic morphology into a substantially unoriented briquette having green strength, (2) removing said briquette from the compressing device and placing said briquette in a forging press wherein lubrication is provided between the contacting surfaces of the briquette and said forging press to effect plug flow, and (3) forging said briquette into a shaped article while maintaining said briquette at a temperature between the alpha-transition temperature and the melting point of said resinous powder.
Claim 3
Dependent Claim
45 words
The process of claim 1 wherein the briquette is heated to a temperature of from about the alpha-transition temperature to less than the melt temperature of said resinous powder, after being removed from said compressing device and prior to being placed in said forging press.
Claim 4
Dependent Claim
15 words
The process of claim 2 wherein said resinous powder is a crystalline vinylidene chloride polymer.
Claim 5
Dependent Claim
11 words
The process of claim 2 wherein said resinous powder is polyethylene.
Claim 6
Dependent Claim
11 words
The process of claim 2 wherein said resinous powder is polypropylene.
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) | 1982-07-16 | 1983-01-15 | 1983-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-07-16 | 1987-01-15 | 1987-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-07-16 | 1991-01-15 | 1991-07-17 | $7700.00 | Window Closed / Lapsed |