Abstract As the demand for the lightweight and recyclability in automobile industry increases, continuous fiber reinforced thermoplastics (FRTP) have received extensive attention due to their excellent mechanical properties and fully recoverability. One of the ongoing challenges is to achieve sufficient joint strength in spite of the inertness (i.e. lack of functional groups) of some thermoplastics. In this current work, two joining techniques, including fusion bonding and hotmelt film were applied to bond continuously glass fiber reinforced polypropylene (PP/GF) composites. Firstly, operating procedures during the fusion bonding process of PP/GF laminates were focused and assessed. Tests were carried out to investigate the effects of fusion temperature, ply sequence of PP/GF substrates and fusion depth on lap-shear joint strength. The cross-section microstructure and fracture surface were observed by optical and scanning electron microscopy. Then, the adhesion of bonded PP/GF specimens using thermoplastic adhesive film was further investigated. The lap-joint strength and failure mode was compared with fusion-bonded counterparts. The results suggested that fusion-bonded of PP/GF exhibited higher joint strength while joining with hotmelt adhesive film experienced shorten processing period and lower molding pressure. Therefore, fusion bonding and hotmelt adhesive film provide low-cost, feasibility and recyclable adhesion methods, which are promising for joining of continuous fiber-reinforced thermoplastic composites.

中文翻译：

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通过熔接和热熔胶膜连接连续玻璃纤维增​​强聚丙烯层压板的研究

摘要 随着汽车工业对轻量化和可回收性需求的增加，连续纤维增强热塑性塑料（FRTP）因其优异的机械性能和完全可恢复性而受到广泛关注。尽管某些热塑性塑料具有惰性（即缺乏官能团），但持续存在的挑战之一是实现足够的接合强度。在目前的工作中，两种连接技术，包括熔接和热熔膜，被应用于连续玻璃纤维增​​强聚丙烯 (PP/GF) 复合材料的粘合。首先，对PP/GF层压板熔接过程中的操作程序进行了重点和评估。进行了测试以研究熔合温度、PP/GF 基材的层顺序和熔合深度对搭接剪切接头强度的影响。通过光学和扫描电子显微镜观察断面微观结构和断口表面。然后，进一步研究了使用热塑性粘合膜粘合的 PP/GF 试样的粘合性。将搭接接头强度和失效模式与熔结接头进行了比较。结果表明，PP/GF 熔接具有较高的接合强度，而与热熔胶膜接合则具有较短的加工周期和较低的成型压力。因此，熔接和热熔胶膜提供了低成本、可行性和可回收的粘合方法，有望用于连续纤维增强热塑性复合材料的连接。进一步研究了使用热塑性粘合剂膜粘合的 PP/GF 样品的粘合性。将搭接接头强度和失效模式与熔结接头进行比较。结果表明，PP/GF 熔接具有较高的接合强度，而与热熔胶膜接合则具有较短的加工周期和较低的成型压力。因此，熔接和热熔胶膜提供了低成本、可行性和可回收的粘合方法，有望用于连续纤维增强热塑性复合材料的连接。进一步研究了使用热塑性粘合剂膜粘合的 PP/GF 样品的粘合性。将搭接接头强度和失效模式与熔结接头进行了比较。结果表明，PP/GF 熔接具有较高的接合强度，而与热熔胶膜接合则具有较短的加工周期和较低的成型压力。因此，熔接和热熔胶膜提供了低成本、可行性和可回收的粘合方法，有望用于连续纤维增强热塑性复合材料的连接。结果表明，PP/GF 熔接具有较高的接合强度，而与热熔胶膜接合则具有较短的加工周期和较低的成型压力。因此，熔接和热熔胶膜提供了低成本、可行性和可回收的粘合方法，有望用于连续纤维增强热塑性复合材料的连接。结果表明，PP/GF 熔接具有较高的接合强度，而与热熔胶膜接合则具有较短的加工周期和较低的成型压力。因此，熔接和热熔胶膜提供了低成本、可行性和可回收的粘合方法，有望用于连续纤维增强热塑性复合材料的连接。