Cold runner system for sandwich molding
US6824726B2 · kind B2 · utility
0Cited by
6References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 24, 2002 |
| Grant date | Nov 30, 2004 |
| Priority date | — |
| Expiry date | Jan 21, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2101/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of sandwich molding, in which a first thermoplastic material is injected into a mold cavity followed by the injection of a second thermoplastic material expanding within the first thermoplastic material, eliminates the need for heated runner systems communicating from the injection nozzle of the injection molding machine to the mold cavity by employing a cold runner having sufficiently slow solidification time to allow subsequent injections from two injection sources. The backflow into the inactive branch is prevented by maintaining the injection nozzle against the mold until molding is complete.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.