Clad polymer buffer rods for polymer process monitoring

Clad polymer buffer rods consisting of a polyetheretherketone (PEEK) core a nd a cladding made of a heat resistance epoxy-aluminum composite are presen ted. The core has a uniform diameter or a taper shape. Ultrasonic measureme nt results indicate that the ultrasonic signal strength and signal to noise ratio of these clad rods are better than those of the non-clad PEEK rods f or both longitudinal and shear waves because of the improved ultrasonic wav e guidance in the core. Comparisons of these rods with those made of polymi de and high-density polyethylene are given. Applications of these buffer ro ds for ultrasonic monitoring of polymer extrusion at temperatures up to 200 degreesC and pressures up to 180 psi are demonstrated. The monitoring resu lts also reveal that within certain operating temperature and pressure rang e, clad polymer buffer rods show advantages over clad steel buffer rods. Cr own Copyright (C) 2001 Published by Elsevier Science B.V. All rights reserv ed.