Process for extruding a modified high molecular weight poly(ethylene terephthalate) resin
US4409167A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1981 |
| Grant date | Oct 11, 1983 |
| Priority date | — |
| Expiry date | Dec 21, 2001 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2067/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Poly(ethylene terephthalate) resin and blends of poly(ethylene terephthalate) resin with other polymers are extruded while being coupled with an organic diisocyanate under conditions where carbon dioxide gas is vented smoothly, as it is formed. The extruder has a number of zones designed to perform specific functions. The temperature in the kneading zone and in the venting zone must be maintained at about 280.degree.-320.degree. C. to bring about rapid reaction and to permit efficient gas evolution and removal without thermally degrading the polymeric material. The extruded article is free of trapped gas bubbles and other imperfections. This process is particularly suitable for making PET billets, which then are stretched to form strapping useful in packaging applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.