Investigation on the weldline strength of thin-wall injection molded ABS parts
Investigation on the weldline strength of thin-wall injection molded ABS parts
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DOI：
10.1016/j.icheatmasstransfer.2007.01.005
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发表时间：
2007-04-01
影响因子：
7
通讯作者：
Chen, Shia-Chung
中科院分区：
文献类型：
--
作者：
Chen, Chun-Sheng;Chen, Tsyr-Jang;Chen, Shia-Chung
众所周知，熔接缝降低了传统注塑件的机械性能。然而，目前对薄壁注塑件熔接缝强度的系统研究和报道还很少。研究了工艺条件对丙烯腈-丁二烯-苯乙烯共聚物(ABS)薄壁零件熔接痕强度的影响。相关参数包括熔体温度、模具温度、注射速度和保压压力。对不同厚度(1.0 mm、1.2 mm和2.5 mm)的试件进行了拉伸试验。给出了单浇口浇注试件(无熔接痕)和双浇口浇注试件(有熔接痕)的抗拉强度比较。实验结果表明，熔体温度越高、模具温度越高、注塑速度越快、保压压力越低，焊缝试件的机械强度越高。较高的熔体和模具温度不仅降低了残余应力，而且有助于分子链的扩散，从而在熔接缝界面上实现了更高的表面结合程度。另一方面，较高的堆积压力会导致较高的残余应力形成，从而降低分子键合率。此外，零件厚度对熔接缝强度也有显著影响。回归分析与拟合模型相结合，似乎能很好地将工艺条件与焊缝强度降低联系起来。(C)2007爱思唯尔有限公司。所有比赛已预留。
It is well known that the weldline reduces the mechanical performance of the conventional injection molded parts. Yet, systematic researches and reports on weldline strength of thin-wall molded parts are still insufficient. This study investigates the influence of processing conditions on the weldline strength of thin-wall Acrylonitrile Butadiene Styrene Copolymer (ABS) parts. The relevant parameters include melt temperature, mold temperature, injection speed and packing pressure. Tensile tests on specimens of different thickness (1.0, 1.2 and 2.5 mm) are conducted. Comparisons on tensile strength for single-gate molded specimens (without weldline) with those of double-gate molded specimens (with weldline) are presented. From the experimental results, it was found that weldline specimens molded at higher melt temperature, higher mold temperature, faster injection speed and lower packing pressure would result in better mechanical strengths. Higher melt and mold temperatures not only lower the residual stress but also help the diffusion of molecular chains leading to a higher degree of surface bonding at the weldline interface. On the other hand, high packing pressure leads to higher residual stress formation and reduces the molecular bonding rate. In addition, part thickness also exhibits significant effect on weldline strength. A regression analysis combined with fitting model seems to correlate process conditions and weldline strength reduction quite well. (c) 2007 Elsevier Ltd. All fights reserved.