Apparatus for coinjection molding of preforms for multi-layer containers
US5040963A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1990 |
| Grant date | Aug 20, 1991 |
| Priority date | — |
| Expiry date | Apr 24, 2010 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/26
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A multi-cavity injection mold, for simultaneously injection molding a plurality of multi-layer articles, having a single hot runner manifold system for the sequential supply of first and second molten molding materials to the cavities of the mold with each of the materials being supplied simultaneously to all cavities in equal quantities. The invention also provides a core rod for each cavity in which a concavity is provided, adjacent the entry point of the materials into the cavity, to prevent the first injected material in an injection cycle from being washed from the end of the core rod by the second injected material, a buffer of the first injected material in the neck region of the preform to compensate for variations in temperature of the cavities and material being distributed to different parts of the mold and the use of the first part of the metered quantity of the first to be injected material from the next injection cycle to seal the preform at the end of the injection cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.