Patent · US Expired

Continuous moving bed reactor for manufacture of high molecular weight polyethylene terephthalate

US4361538A · kind A · utility

18Cited by
3References
2Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 17, 1981
Grant dateNov 30, 1982
Priority date
Expiry dateMar 17, 2001

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08G63/80
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

High molecular weight polyethylene terephthalate (PET) is obtained by solid state polycondensation of low molecular weight polymer granulate or chips. The present invention relates to a moving bed reactor wherein the crystallized, low molecular weight polymer granulate or chips move by gravity flow from the top to the bottom of a cylindrical, vertical reactor. By means of an automatic sampling system, samples of the polymer chips are taken from different points in the moving bed and analyzed to continuously establish the intrinsic viscosity, i.e. molecular weight, of the chips. A countercurrent flow of cold and/or heated gas and the chip residence time are then adjusted in response to the viscosity profile in the reactor in order to control and achieve a desired chip quality.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.