INFLUENCE OF SHEARING HISTORY ON THE RHEOLOGICAL PROPERTIES AND PROCESSABILITY OF BRANCHED POLYMERS .2. OPTICAL-PROPERTIES OF LOW-DENSITY POLYETHYLENE BLOWN FILMS

An investigation was performed to determine how optical properties of LDPE blown films changed when the material was subjected to extrusion shearing. In this study, shearing histories were given to the materials by designed extrusion shearing. Recognizable variations take place in haze and gloss of the blown film during the extrusion shearing. Such variations were expressed as a function of the processing index (PI), which was introduced in a preceding paper as a measure of the memory effect of shearing histories of LDPE. This means that the variations originate in a certain change in the cohesive state of the polymer molecules attributable to the shearing. Copyright © 1979 John Wiley & Sons, Inc.