Scrapless forming of plastic articles
US4005967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 1976 |
| Grant date | Feb 1, 1977 |
| Priority date | — |
| Expiry date | Jan 21, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/716
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Apparatus for rapidly making thermoplastic containers wherein the resultant containers can, if desired, be multilayered for vapor or gas barrier or other reasons, or be oriented for toughness and improved stress crack resistance. The apparatus takes a measured amount of thermoplastic material which is lubricated, heated and forged into a desired shape preform with a predetermined lip configuration. The center portion of each said preform is maintained at a forming temperature while the peripheral portion thereof is clamped and rapidly brought below the softening point of the plastic resin. The preform can then be immediately thermoformed into a container having a desired shape and size, and cooled. If desired, the preform can be forged, cooled and recovered for a subsequent thermoforming operation or can be a finished article itself.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.