Method for manufacturing a multi-layer plastic product
US5851456A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 28, 1997 |
| Grant date | Dec 22, 1998 |
| Priority date | — |
| Expiry date | Mar 28, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF05C2225/08
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and apparatus for manufacturing a multi-layer plastic product comprised of a hollow plastic core and an outer plastic layer formed on the core are provided. A mold has a plurality of segments and is provided with a plurality of supply ports arranged in a desired pattern. The mold is assembled with the hollow plastic core located in a mold cavity, and, then, a molten plastic material is supplied into the mold cavity through the plurality of supply ports. Then, the mold is set in its clamped condition to carry out shaping of the molten plastic material into the outer layer having a desired shape. Since the molten plastic material is supplied through a plurality of supply ports, the pressure inside the mold cavity during supply and shaping steps is maintained at a relatively low pressure level, preferably 200 kg/cm.sup.2, which is much lower than an ordinary pressure level used in injection molding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.