A phenomenological study of the hot-tool welding of thermoplastics - Part 3. Polyetherimide

A hot-tool welding machine was used to study the weldability of polyetherim ide, a high-temperature amorphous thermoplastic. Weld strength data are rep orted for two specimen thicknesses. In these experiments, the outflow in th e melting phase was controlled by means of stops, the thickness of the molt en film was controlled by the heating time, and the outflow during the fina l joining phase was also controlled by displacement stops. Strength data fo r butt welds are reported for a series of tests in which the hot-tool surfa ce temperatures, the heating times, and the displacement stop positions wer e varied, but the pressure was not. Within the range of the weld process pa rameters investigated, the highest weld strength achieved was of the order of 85% of the base strength of the material. This is lower than the 100% we ld strength that can be achieved in this material by vibration welding. (C) 2000 Elsevier Science Ltd. All rights reserved.