Molding process for articles having an irregular shaped internal passage
US4743481A · kind A · utility
42Cited by
12References
16Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 26, 1986 |
| Grant date | May 10, 1988 |
| Priority date | — |
| Expiry date | Nov 26, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1352
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for making an article having an irregular internal passage utilizes a hollow polymer preform. The preform is filled with a relatively incompressible filler material such as a powder or a fluid, which supports the preform when it is placed in a mold, e.g. an injection mold. The filler enables the preform to withstand high molding pressures and prevents deflection and movement of the internal passage within the preform. The shell, a layer of a polymer material is then molded about the preform. After the final article has been formed, consisting of the preform and shell, the filler is removed for possible reuse.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.