Method of and apparatus for producing a product with a coating layer
US5174933A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 1990 |
| Grant date | Dec 29, 1992 |
| Priority date | — |
| Expiry date | Dec 6, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/0854
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A cavity pressure is sequentially changed, by relatively displacing two mold dies forming a mold cavity, to a molding presure at which a product is molded in the mold cavity, a coating pressure lower than the molding pressure at which fluidized thermosetting plastic material is injected to form a coating layer, a curing pressure between the coating pressure and molding pressure at which the coating layer is cured, and a finishing pressure between the coating pressure and curing pressure at which the coating layer thermosets. The changing of the cavity pressure to the coating pressure is initiated a predetermined time later than a termination of a drop in pressure from the molding pressure due to shrinkage of the product. The changing of the cavity pressure to the curing pressure is initiated at a peak of an increase in relative displacement between the two mold dies caused by injecting a fluidized thermosetting plastic material in the mold cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.