Mottled appearance injection molding methods
US4042660A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 14, 1976 |
| Grant date | Aug 16, 1977 |
| Priority date | — |
| Expiry date | Jan 14, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C45/581
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A molding system for producing articles of mottled appearance includes a plasticizing unit having an inner bore which communicates with a mold cavity. A feed screw is mounted within the bore and is connected to fluid-actuated motors for rotary and translational movement within the bore. A spreader device is positioned in a heated part of the bore ahead of the feed screw. The screw is rotated to feed and soften molding materials of diverse coloration and is subsequently translated to push the materials through the spreader device such that final plasticization occurs. A bridging conduit is provided between the rotary and translational motors to divert a controlled amount of fluid from the latter to the former during a pushing operation, to rotate the screw forwardly at a controlled rate or to hold pressure on the screw to prevent backward rotation or to limit the amount of backward rotation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.