US4859390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of polyamide mouldings
Assignee: Bayer AG
•
Filing: 1987-11-04
•
Granted: 1989-08-22
•
Expires: 2007-11-04
Abstract
Abstract A process for the production of polyamide mouldings, characterized in that a polyamide melt is extruded through nozzles to form strands, which at a temperature of from 25 DEG C. below to the respective polyamide softing point in a ratio of from 1:1.5 to 1:8 are stretched and granulated, and the granulate is worked-up in a known manner to produce injection mouldings.
Inventors
- 👤 Karl H. Fritsch
- 👤 Peter Bier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:33
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/12; B; B29; B29B; B29B9/00; B29B9/02; B29B9/06; B29C; B29C55/00; B29C55/02; B29C55/04; B29C55/06; B29C45/00; B29K; B29K2077/00; C08J2377/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
129 words
A process for the production of improved polyamide mouldings, wherein the polyamide of a relative viscosity of from 2.0 to 5.0 measured as a 1% by weight solution in m-cresol at 25° C., is first melt extruded through nozzles of 1-8 mm to form solid strands, which at a temperature of from 25° C. below the respective polyamide softening point are stretched longitudinally in a ratio of from 1:1.5 to 1:8, the strand being passed on stretching through two heating zones with temperatures adjusted from 25° C. to 300° C., the heating zones lying between stretching roller pairs, the strands then being granulated, and the granulates are then injection moulded at temperatures not exceeding 280° C. to product polyamide having improved resistance to breaking and higher elongation at break.
Claim 2
Dependent Claim
129 words
A process for the production of improved polyamide mouldings, wherein the polyamide of a relative viscosity of from 2.0 to 5.0 measured as a 1% by weight solution in m-cresol at 25° C., is first melt extruded through nozzles of 1-8 mm to form solid strands, which at a temperature of from 25° C. below the respective polyamide softening point are stretched longitudinally in a ratio of from 1:1.5 to 1:8, the strand being passed on stretching through two heating zones with temperatures adjusted from 25° C. to 300° C., the heating zones lying between stretching roller pairs, the strands then being granulated, and the granulates are then injection moulded at temperatures not exceeding 280° C. to product polyamide having improved resistance to breaking and higher elongation at break.
Claim 3
Dependent Claim
13 words
A process as claimed in claim 1 wherin the stretching ratio is <1:5.
Claim 4
Dependent Claim
30 words
A process as claimed in claim 1, wherein said stretching is carried out at a temperature of from 20° C. to 80° C. below the softening point of the polyamide.
Claim 5
Dependent Claim
15 words
A process as claimed in claim 1 wherein the polyamide contains nucleating and release agents.
Claim 6
Dependent Claim
19 words
A process as claimed in claim 4 wherein the polyamide contains microtalcum or fine grained polyamide and/or amide wax.
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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) | 1992-08-21 | 1993-02-20 | 1993-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-21 | 1997-02-20 | 1997-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-21 | 2001-02-20 | 2001-08-22 | $7700.00 | Window Closed / Lapsed |