A phenomenological study of the hot-tool welding of thermoplastics. 4. Weld strength data for several blends

A hot-tool welding machine was used to study the hot-tool weldability of se veral commercial thermoplastic blends: a blend, ABS, of acrylonitrile-butad iene-styrene; a blend, PC/ABS, of polycarbonate (PC) and ABS; a blend, PC/P ET, of PC and poly(butylene terephthalate) (PBT); a blend, M-PPO, of poly(p henylene oxide) (PPO) and HIPS; a blend, PPO/PA, of PPO and polyamide 6,6; 30GF-MPPO, a 30 wt% glass-filled grade of M-PPO. Weld strength data are rep orted for a specimen thickness of 3.2 mm. In these experiments, the outflow in the melting phase was controlled by means of stops, the thickness of th e molten film was controlled by the heating time, and the outflow during th e final joining phase was also controlled by displacement stops. Strength d ata for butt welds are reported for a series of tests in which the hot-tool surface temperatures, the heating times, and the displacement stop positio ns were varied, but the pressure was not. The maximum relative weld strengt hs demonstrated are 100% in ABS, 91% in PC/ABS, 98% in PC/PBT, 80% in M-PPO , 100% in PPO/PA and 77% in 30GF-MPPO. A maximum relative strength of 38% w as obtained in hot-tool welds of PC/ABS to M-PPO. (C) 2001 Elsevier Science Ltd. All rights reserved.