Process for tubular water-bath polypropylene films
US4203942A · kind A · utility
12Cited by
10References
4Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1977 |
| Grant date | May 20, 1980 |
| Priority date | — |
| Expiry date | Dec 9, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/9258
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Substantial and commercially important increases in polypropylene film production rates without adversely affecting film quality are obtained in a tubular water film process. The improvements comprise modifications in the die lip, in the mandrel air (fluid) slot affecting the cooling gas velocity, and in the upper bubble pressure control. The improvements are especially useful to obtain mill rolls 60 to 80 inches wide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.