Method and apparatus for the injection of additives into plastics material
US4259277A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 16, 1978 |
| Grant date | Mar 31, 1981 |
| Priority date | — |
| Expiry date | Oct 16, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/0005
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention provides a method and apparatus for injecting an additive into a stream of homogenized plastics material. The apparatus includes a homogenizing means such as a screw conveyor for the plastics material and at least one injector for injecting an additive, usually a colorant, into the boundary layer only of the homogenized plastics material prior to the latter being subjected to mastication in a gear pump. The additive is injected into the plastics material at such a position in the boundary layer that as the material passes through the gear pump the additive is mixed substantially wholly with the boundary layer of plastics material and for this purpose the injection of additive is at a position such that it passes through the gear pump in the region of the intermeshing gears of the pump.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.