US3900550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of enhancing flexure of plastic hinges
Assignee: Dow Chemical Co
•
Filing: 1970-04-24
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Granted: 1975-08-19
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Expires: 1990-04-24
Abstract
Abstract Plastic hinges having increased flexure longevity are formed by compressing a normally solid plastic member in the region of desired flexure at low temperature and at low compression rates to achieve cold flow of the plastic in the compressed region. The resulting plastic hinges are particularly useful in unimolded plastic containers.
Inventors
- 👤 Bruce L Oliver
- 👤 Ben W Heinemeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:52
CPC Classifications
B; B29; B29C; B29C53/00; B29C53/02; B29C53/04; B29C53/06; B29C37/00; B29C37/0053; B29C37/0057; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0608; B29K2023/065; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24479; Y10T428/2457
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
46 words
A METHOD FOR PROVIDING PLASTIC HINGES HAVING IMPROVED TENSILE STRENGTH AND INCREASEDFLEX LIFE WHICH COMPRISS COMPRESSING A GROOVE-FORMING DIE INTO A NORMALLY SOLID, THERMOPLASTIC ORGANIC POLYMER AT A COMPRESSION RATE LSS THAN ABOUT 2000 MILS/SECOND, THE TEMPERATURE OF THE POLYMER BEING BELOW THE SOFTENING POINT THEREOF.
Claim 2
Independent Claim
46 words
A METHOD FOR PROVIDING PLASTIC HINGES HAVING IMPROVED TENSILE STRENGTH AND INCREASEDFLEX LIFE WHICH COMPRISS COMPRESSING A GROOVE-FORMING DIE INTO A NORMALLY SOLID, THERMOPLASTIC ORGANIC POLYMER AT A COMPRESSION RATE LSS THAN ABOUT 2000 MILS/SECOND, THE TEMPERATURE OF THE POLYMER BEING BELOW THE SOFTENING POINT THEREOF.
Claim 3
Dependent Claim
39 words
The method according to claim 1 which comprises compressing a groove forming die into a normally solid, olefin polymer at a compression rate less than about 2000 mils/second, the temperature of the polymer being below the softening point thereof.
Claim 4
Dependent Claim
40 words
The method according to claim 2 wherein the polymer is a high density polyethylene having a melt index in the range from about 0.1 to about 20 decigrams/minute and the compression rate is from about 5 to about 1000 mils/second.
Claim 5
Dependent Claim
15 words
The method according to claim 3 wherein the compression rate is less than 500 mils/second.
Claim 6
Dependent Claim
16 words
The method according to claim 4 wherein the compression rate is from 200 to 300 mils/second.
Claim 7
Dependent Claim
24 words
The method according to claim 1 wherein the groove-forming die is preheated to a temperature in the range from about 75*F to about 210*F.
Claim 8
Dependent Claim
10 words
A plastic hinge provided by the method of claim 1.
Claim 9
Dependent Claim
21 words
The method according to claim 1 wherein the temperature of the polymer is within the range from about 60* to 140*F.
Claim 10
Dependent Claim
21 words
The method according to claim 1 wherein the temperature of the polymer is within the range from about 70* to 90*F.
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) | 1978-08-18 | 1979-02-17 | 1979-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-18 | 1983-02-17 | 1983-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-18 | 1987-02-17 | 1987-08-19 | $7700.00 | Window Closed / Lapsed |