Improving vibration joint weld joint strength through process and equipment modification

摘要

Vibration welding is a process used to join thermo plastic components. Currently, under optimised low pressure welding, the weld strength of butt joints of un reinforced polymer can be equivalent to the strength of unwelded material. However, in short glass fibre reinforced polymer, the optimised weld strength is significantly lower than that of unwelded material and is closer to the strength of the resin matrix. This lower strength is attributable to the unfavourable orientation of the short glass fibres in the weld zone. The fibres tend to align parallel and in the plane of the weld zone and thus provide no reinforcement in the direction perpendicular to the weld zone. In the present work the impact of various modifications to the existing vibration welding technology was examined, with the objective of increasing the current achievable weld strength of glass reinforced nylon. The introduction of a secondary vibratory motion perpendicular to the weld plane during welding resulted in strengths 20 percent higher than those of samples welded using the standard vibration welding process.