Injection molding with periodic forces to the material in the mold
US5851474A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Apr 10, 1996 |
| Grant date | Dec 22, 1998 |
| Priority date | — |
| Expiry date | Apr 10, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/0082
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An injection moulding process for moulding a material in a mould having a mould cavity and at least one channel communicating with the mould cavity, each channel entering the mould at a respective mould inlet includes the steps of heating inner surface areas of the mould to a temperature above the heat distortion temperature of the material; supplying the molten material into the mould by way of at least one channel and subjecting the molten material to a propelling force, sufficient to propel it through the channel into the mould; causing the molten material in the mould to solidify; applying periodic forces to the material in the mould at a plurality of spaced-apart regions, first and second of the regions being located either side of molten material in the mould cavity, the periodic force being applied with a difference in phase so as to cause shear of molten material within the mould cavity between the first and second regions; cooling the mould below the heat distortion temperature of the resin while or after applying the periodic force; and then opening the mould, and removing the moulded article.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.