Influence of solid-state polycondensation processing on PET pellets and preforms quality
Four commercial water bottle grade polyethylene terephthalate(PET)resins were compared in a preform extrusion molding trial on a single cavity molding machine.Colour,haze,intrinsic viscosity(Ⅳ),crystallinity,oligomer,acetaldehyde(AA)and 2-methyl-1,3-dioxolane(MDO)content were all compared before and after pre-forming.The influence of Solid-state polycondensation(SSP)processing could be seen in the oligomer,AA and MDO levels-longer SSP residence times and higher temperatures favoured lower values,while SSP processing under air with higher antimony(Sb)content led to darker and yellower preforms as well as higher haze level.No signifi-cant difference was observed in the melting behaviour of spherical and cylindrical pellets and the Ⅳ drop was the same for all PET resins.All results show SSP is an integral part in the PET processing chain.
万方数据
维普
