Process for thermoforming a hollow plastic article using an extendible porous male mold assembly
US4085177A · kind A · utility
10Cited by
8References
3Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1975 |
| Grant date | Apr 18, 1978 |
| Priority date | — |
| Expiry date | Jun 3, 1995 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2949/3032
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Process for thermoforming hollow articles having large length to diameter ratios. A male mold assembly having an extendible head portion formed of a porous metal is employed with the male mold being passed through the plane of a heated plastic sheet while a vacuum is drawn through the porous metal head portion to draw the sheet against the male mold. The extendible head portion is extended to increase the depth of the formed article.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.