Apparatus for injection molding articles of thermoplastic materials
US5169648A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1991 |
| Grant date | Dec 8, 1992 |
| Priority date | — |
| Expiry date | Jul 24, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2995/0063
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and an apparatus of injection molding articles of thermoplastic material. The method includes initially forcing molten plastics material into an injection mold in an amount sufficient for forming the article. Subsequently, a flowable medium is forced into the injection mold with a pressure which distributes the plastics material uniformly over the surface of the mold cavity of the injection mold so as to form a hollow body. The hollow body is then cooled while the pressure of the medium is maintained. Finally, the pressure of the medium is released and the molded article is removed from the injection mold. The pressure of the medium in the mold cavity is controlled and/or varied at least temporarily until the plastics material has cooled. The apparatus for carrying out the method includes a pressure reservoir for the medium which is connectible to the injection mold through lines. The lines include control and/or regulating elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.