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Evaluation of melt flow as a measure of low density polyethylene processability into blown films
Author(s) -
Plochocki Andrew,
Czarnecki Lech
Publication year - 1972
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.760120613
Subject(s) - low density polyethylene , materials science , melt flow index , die swell , composite material , blow molding , viscometer , extrusion , polyethylene , plastics extrusion , ultimate tensile strength , capillary action , viscosity , polymer , mold , copolymer
Melt capillary flow and extrudate swelling for low density polyethylenes (LDPE), differing in ease of heavy‐duty, blownfilm extrusion, have been employed as processability criteria. LDPE of good processability is characterized by a unique combination of melt fluidity, temperature, shear rate dependence and melt elasticity. These characteristics of flow are correlated with LDPE film blowing process variables such as maximum take‐up speed, film thickness scatter, and extruder temperatures profile. Intuitively, these melt flow criteria should be extended to Trouton's viscosity and the tensile strength of the melt. The limited development of the elongation viscometry techniques, however, has limited their application.