Final product strength is dependent on material properties after processing, which can include secondary operations, such as ultrasonic welding. In this paper, it is shown that non-visible surface contamination can have a profound negative impact on the quality of an ultrasonic weld. Acrylonitrile–butadiene–styrene (ABS) was contaminated with commonly used chemicals in the polymer processing industry. These included mold releases, cutting fluid, and lotion. The contamination was identified using Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). The contaminated ABS was ultrasonically welded, then analyzed by pressure decay, tensile strength, cross-sectional microscopy, and scanning electron microcopy with energy-dispersive X-ray spectroscopy (SEM/EDS). Of the contaminates tested, the mold releases (FDA silicone and zinc stearate) had the largest negative effect on the weld, which was a 45% decrease in maximum load. Conversely, cutting fluid had the least effect; statistically, it displayed no difference in strength when compared to the non-contaminated samples.

最终产品强度取决于加工后的材料特性，其中可能包括二次加工，例如超声波焊接。本文表明，不可见的表面污染会对超声波焊接质量产生深远的负面影响。丙烯腈-丁二烯-苯乙烯 (ABS) 被聚合物加工行业中常用的化学品污染。这些包括脱模剂、切削液和乳液。使用具有衰减全反射率的傅立叶变换红外光谱 (FTIR-ATR) 识别污染。污染的 ABS 被超声焊接，然后通过压力衰减、拉伸强度、横截面显微镜和扫描电子显微镜与能量色散 X 射线光谱 (SEM/EDS) 进行分析。在测试的污染物中，脱模剂（FDA 有机硅和硬脂酸锌）对焊缝的负面影响最大，最大载荷降低了 45%。相反，切削液的影响最小；从统计上看，与未受污染的样品相比，它在强度上没有差异。