Wolf Michael, Drummer Dietmar
Institute of Polymer Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Am Weichselgarten 10, 91058 Erlangen, Germany.
Polymers (Basel). 2022 Jul 29;14(15):3083. doi: 10.3390/polym14153083.
Multi-material designs enable more efficient use of material-specific properties, which is necessary for sustainable and resource-saving production. However, multi-material polymer joints confront conventional joining methods with major challenges. Therefore, novel joining processes such as joining using pin-like structures are required. Investigations into this innovative process have provided initial findings of, for example, the design criteria of the pin-like structures depending on the material combination. For further optimization of the process, the filling behavior and the shrinkage effects occurring in pin-like joining are herein investigated. These have a decisive influence on the resulting bond quality. To identify the correlations, the joining step was carried out on the one hand using vibration welding technology with and without pre-heating of the structured-partner. On the other hand, the injection molding process was used to realize filling of the structures, as well as cooling under increased pressure. The investigations show that the shrinkage behavior clearly influences the filling degree and the bond properties of the multi-material joint. For shrinkage-intensive materials, filling and cooling under pressure is essential to achieve high mechanical bond strengths, whereas for materials with low shrinkage, the pressure during the joining step is negligible.
多材料设计能够更有效地利用材料的特定属性，这对于可持续和节约资源的生产而言是必要的。然而，多材料聚合物接头给传统连接方法带来了重大挑战。因此，需要诸如使用针状结构进行连接等新型连接工艺。对这一创新工艺的研究已经得出了一些初步结果，例如针状结构的设计标准取决于材料组合。为了进一步优化该工艺，本文研究了针状连接中出现的填充行为和收缩效应。这些对最终的粘结质量具有决定性影响。为了确定其中的相关性，一方面采用振动焊接技术进行连接步骤，对结构化部件进行预热和不预热处理。另一方面，使用注塑工艺来实现结构的填充以及在增压下冷却。研究表明，收缩行为明显影响多材料接头的填充程度和粘结性能。对于收缩强烈的材料，在压力下填充和冷却对于实现高机械粘结强度至关重要，而对于收缩率低的材料，连接步骤中的压力可以忽略不计。
