Process for producing glass fiber reinforced thermoplastic compression molded materials and said molded materials
US4950532A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1986 |
| Grant date | Aug 21, 1990 |
| Priority date | — |
| Expiry date | Oct 30, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/65
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Fiber reinforced thermoplastic parts having good surface characteristics are produced by a process involving: preheating fiber reinforced composite to achieve at least a flowable viscosity of the polymer, and (2) molding under controlled rheological conditions. The preheating is conducted on composites that are predominantly amorphous thermoplastic polymers, copolymers, polyblends or alloys reinforced with continuous glass fiber strand reinforcing mat. The amount of the mat present in the laminate is less than around 40 weight percent of the composite. The temperature of preheating is at least greater than the glass transition temperature of the polymer and less than the degradation temperature of the polymer to expand the composite. The preheated composites are compression molded in an effective charge and at a pressure of at least around 500 to 6,000 psi, where at least one die surface of the mold is maintained at a temperature in the range of the glass transition temperature of the polymer to a temperature of 70.degree. F. (39.degree. C.) below the glass transition temperature of the polymer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.