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Extrusion characteristics of thermoplastic melts containing fluoropolymers
Author(s) -
Lee Eonseok,
White James L.
Publication year - 1999
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11419
Subject(s) - hexafluoropropylene , fluoropolymer , materials science , die swell , extrusion , tetrafluoroethylene , linear low density polyethylene , composite material , polyethylene , polyvinylidene fluoride , polytetrafluoroethylene , thermoplastic , high density polyethylene , polystyrene , copolymer , polymer chemistry , polymer
This paper investigates the influence of fluoropolymers on the extrusion characteristics of three different thermoplastic melts. The presence of a small amount of fluoropolymer reduced the pressure drops, extrudate swell, and retarded the onset of surface defects in linear low density polyethylene (LLDPE), while little or no effect was found in polystyrene (PS) and polyamide 12 (PA 12). Among the fluoropolymers investigated in this study, vinylidene fluoride‐hexafluoropropylene (VDF‐HFP) copolymer was the most effective additive in reducing the pressure drop and extrudate distortion of LLDPE, polyvinylidene fluoride (PVDF) intermediate, and tetrafluoroethylene‐hexafluoropropylene (TFE‐HFP) copolymer exhibited the least effectiveness. Contact angle measurements on the die surface indicated that all fluoropolymers preferentially deposit on the die surfaces during the extrusion of LLDPE and PS blends with small amounts of fluoropolymers.