二次注塑成型尼龙6的界面结晶行为及其对界面强度的影响

Interfacial Crystalline Behavior of Over-Injection Molded Polyamide 6 and Its Effect on the Bonding Strength

利用偏光显微镜(POM),广角X射线衍射(XRD),力学测试以及扫描电子显微镜(SEM)通过控制二次注塑过程中熔体温度(T2melt)和模具温度(T2mold)研究了尼龙6(PA6)在连接界面处的结晶行为及其对界面强度的影响。结果表明,在高T2melt和T2mold下,二次体在连接界面处有横晶生成,并且随着T2melt和T2mold的升高,二次体和一次体皮层晶型发生了明显的变化,二次连接件的界面接合强度得到不同程度的提高。

The interfacial crystalline behavior of over-injection molded polyamide 6（PA6） and its effect on the bonding strength by controlling the melt temperature and mold temperature were studied. The experimental results show that the interfacial bonding strength increases with increasing the secondary injection melt temperature （T2melt） and mold temperature （T2mold） when the first molding conditions are fixed, due to the trans-crystals formed at the interface. According to X-ray diffraction （XRD） data, the increase of T2melt and T2mold leads to the difference in crystallinity and crystal form of PA6 in the surface of both the first and secondary injection molded parts.