Vented injection molding machine and method
US4112519A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 8, 1976 |
| Grant date | Sep 5, 1978 |
| Priority date | — |
| Expiry date | Jul 8, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/812
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Injection molding apparatus is disclosed for molding degradable synthetic resinous materials such as nylons. A vented injection molding machine includes a barrel, a rotatable reciprocable screw and means for preventing ingestion of a deleterious atmospheric gas such as oxygen. The particular apparatus whereby exclusion of the atmospheric gas may be effected includes a conduit having a terminal end thereof positioned at the vent opening of the injection molding machine barrel. The conduit communicates with a source of inert gas and directs a pressurized current of inert gas into the vent opening during the transient time interval between the end of the injection portion of the molding machine cycle and the plasticization portion of the machine cycle. If desired, the inert gas may flood the vent opening continuously. Both nitrogen and carbon dioxide are suitable inert gases for use with nylon materials.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.