Production of biaxially drawn film of polyamide blend
US4098860A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1976 |
| Grant date | Jul 4, 1978 |
| Priority date | — |
| Expiry date | Aug 4, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2077/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for preparing a biaxially stretched film of polyamide blend, which comprises (1) extruding a polyamide blend in melt to make an unstretched film and (2) stretching the unstretched film first in a machine direction with a stretch speed of about 40,000 to 60,000,000 %/minute in a draw ratio of about 2 to 6 and then in a transverse direction with a stretch speed of about 500 to 100,000 %/minute in a draw ratio of about 2 to 6, or (2') stretching the unstretched film first to make a uniaxially stretched film having a plane orientation index of about 0.6 to 1.5 and then stretching the uniaxially stretched film in a direction being substantially at a right angle to the direction at the previous stretching, said polyamide blend comprising an aliphatic polyamide and a polyamide containing in the molecule at least about 70 mol % of the repeating units constituted with metaxylylenediamine or its mixture with paraxylylenediamine (of which the content is not more than about 30 mol % based on the combined amount of metaxylylenediamine and paraxylylenediamine) and at least one .alpha.,.omega.-aliphatic dicarboxylic acid having 6 to 10 carbon atoms in a proportion of about 97 : 3 to 80 …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.