An instrument for online measurement of structural orientation in translucent polymer sheets

摘要

In many applications of polymer materials, a hightensile strength is required. There is a definite correlation betweenthe degree of orientation of molecular chains achieved in theorientation process and the tensile strength obtained. In this work,we describe design and fabrication details of a device, 'Laser basedpolymer orientation grader', for online measurement of the degreeof orientation to obtain a high consistent tensile strength as output.This instrument has been designed making skilful use of theoptical anisotropic property of the oriented polymer strip. Theprinciple is based on the fact that the spatial distribution of laserlight passing through the translucent polymer sheet depends on thedegree of orientation of long chain molecules in the sheet. Themethod has potential online application in monitoring andcontrolling of anisotropy in manufacturing processes.