FIELD: process engineering.
SUBSTANCE: method of making immediately PET granules with degree of polymerisation varying from 132 to 165 whereat melt after cutting in hot state is subjected to preliminary drying and drying/degassing. Cutting in hot state is performed at water temperature of 70-95°C and water-to-granule ratio making 8:1 to 12:1. Note here that fluid is completely retained unless entering pre-drier while circulation water in the latter is separated for faster than 10 s. Besides, this invention relates to PET pellets thus produced with degree of polycondensation not more than 2% lower than that polycondensation of heavy melt. Melt feature degree of polymerisation varying from 132 to 165. Degree of crystallisation of PET pellets makes smaller than 38% (method of density measurement). Besides, invention covers the device for making above described pellets.
EFFECT: ruled out decrease in degree of polycondensation.
19 cl, 2 dwg, 3 ex
