PROCESS FOR PELLETIZING ULTRA-HIGH MELT FLOW POLYMERS

摘要

Disclosed is a process for pelletizing high melt flow crystalline polymers to produce crystalline pellet products. The process includes feeding a polyolefin granular or pelleted polymer into a melting/mixing mechanism to provide a molten polymer material. The molten polymer material is optionally passed through a melt pump and through a die to form a plurality of molten polymer strands. The plurality of molten polymer strands then are passed through or along a water trough declined with respect to the direction of the horizontal arrays where they are sprayed with cool liquid a plurality of times in such a manner that the sprayed cool liquid creates turbulent flow and disturbs a thin film of hot water and/or steam that forms around each molten polymer strand as it is cooled without undesirable axial acceleration of the polymer strands. Subjecting the molten polymer strands to such a cooling procedure produces cooled polymer strands, which then are fed to a cutting mechanism and cut into pellets. The process produces ultra high melt flow crystalline polymer pellets which are uniformly compounded.