FIELD: technological processes.
SUBSTANCE: invention relates to a method and an apparatus for molding, crystallising and increasing molecular weight of polymer particles, particularly particles of polyethylene terephthalate. Method of producing polyethylene terephthalate particles comprises providing polyethylene terephthalate (PET) melt having temperature of 230–310 °C, cutting of molten PET particles onto granules at fast cooling with cooling liquid, drying of obtained solid particles, movement of solid particles into crystallization reservoir, introduction of PET solid particles with hot inert gas or air into contact. Used device for producing particles of solid crystallized polymer includes a molding device for molding molten polymer in a quick cooling chamber, coolant removal device, grate, crystallizer, pneumatic system for transportation with inert gas, reactor for solid-phase polycondensation of SSP.
EFFECT: invention does not require repeated heating of polyethylene terephthalate (PET) granules after cutting and crystallisation in the underwater cutting section (UWC); in existing solid-phase polycondensation (SSP) technologies, in which UWC is used, high crystallinity of PET granules can be observed by cooling and repeated heating of PET granules, which reduces efficiency of by-products removal, such as acetaldehyde (AA), as well as reducing the rate of molecular weight increase reactions.
10 cl, 1 dwg, 1 tbl
Authors
Dates
2019-04-17—Published
2017-06-19—Filed