Method of manufacturing polyester granules with improved photochemical and thermal stability, and its application
US6274659A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 17, 1998 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Jun 17, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2467/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The process for production of a heat-stable and light-fast product consisting of multifilaments, monofilaments or flock for textile and industrial applications includes mixing from 0.2 to 0.5% by weight, based on the amount of product, of a UV absorber having a melting point of from 135 to 145.degree. C. and a colorant having a melting point greater than 180.degree. C. with a polyester powder at room temperature to form a starting mixture; feeding from 1 to 100% of the starting mixture and from 0 to 99% by weight PET granules into a cooled feed zone of a twin-screw extruder; operating the twin-screw extruder to melt, knead and homogenize the feed to form polymer strands, which are then cooled and cut to form a compound; and subsequently melt-spinning the compound to form the product. When the product is made by this method the UV absorber is incorporated in the product, thus avoiding the additive-related manufacturing problems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.