热塑性聚氨酯弹性体内衬软管接缝热封性能及机理

Performance and Mechanism of TPU Liner Joint with Hot Sealing

以热塑性聚氨酯(TPU)膜为密封材料,通过热封装置进行内衬软管接缝的焊接实验,以探究塑料膜热焊接性能和机制。结果表明,在焊接温度240~320℃条件下,升高温度不改变分子链官能团,但会影响分子链运动的强弱;焊接温度的升高会减少分子链段中的缠结交联点,降低拉伸强度;热风焊接过程可按膜受热熔融、界面对流、缠结和冷却凝固四个阶段进行,控制阶段为受热熔融和缠结阶段。

Thermoplastic polyurethane(TPU)membrane was selected as sealing material,the welding experiment of liner joint was carried out through hot sealing device to study the performance and mechanism of plastics thermal welding.The experimental results show that the functional group of molecular chain is not infected by welding temperature during 240~320℃,but the strength of molecular chain movement is changed.With the increase of welding temperature,the entanglement points in molecular chain segment and the tensile strength are reduced.The hot air welding process can be carried out in four stages,such as,melting,interfacial convection,entanglement and cooling solidification,the melting and entanglement are the control stages.