SCREW DESIGNS HAVING IMPROVED PERFORMANCE WITH LOW MELTING PET RESINS

摘要

Disclosed is a process for a melt processing a polyethylene terephthalate. The polyester particles have at least two melting peaks. The polyester particles may have an It. V. at their surface which is less than 0.25 dL/g higher than the It. V. at their center. The polyester particles may have not been solid stated. The melt processing device comprises a screw with a total length (9), L, a feed zone length (3) in the range from 0.1 SL and 0.45L, a taper angle, in the range from 0.5 degrees and 5.0 degrees and a compression ratio, CR, in the range from 2.0 and 5.0.