Hot-runner mold and injection molding method making use of the same
US4212624A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1978 |
| Grant date | Jul 15, 1980 |
| Priority date | — |
| Expiry date | Jun 7, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/2796
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A mold suitable for use in simultaneous molding of a large number of articles at a time by hot-runner molding technique. The mold has a hot-runner block in which disposed are a plurality of gates through which the molten resin is delivered to the molding cavities formed in a cavity block which is usually kept at a low temperature. The gate area of the hot-runner block is kept in contact with the cavity block, for the safe deliver of the resin to the molding cavities, in the injection step and, therefore, is cooled by the cavity block. Consequently, when the injection is completed, the gate area has been cooled to such a low temperature as to cause a solidification of the resin in the gate area. The hot-runner block is then separated from the cavity block and brought into contact with a hot gate-temperature recovering block, so that the gates are heated to remelt the solidified resin, before the next batch of injection is performed, so as to recover the fluidity of the resin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.