A welding machine for thermoplastic polyimide (TPI) films: Novel apparatus and experimental investigations

摘要

The utilization of thermoplastic polyimide (TPI) films for aerospace structures has attracted considerable attention in recent decades due to excellent thermal stability, high glass transition temperature and good mechanical properties. As engineering materials, TPI films with limited product width require suitable welding with respect to insolubility and infusibility resulting from planar structure and wholly aromatic structures. This paper focuses on the development of a novel welding machine and investigation on ultimate strength of original and welded TPI films. The resistance welding machine is proposed with specific functions for overcoming the difficulties in welding TPI films. A series of experiments in combination of temperature and pressure are carried out to assess the quality of welded TPI films. Additional experiments on welded specimens from three existing welding machines are performed to compare and justify performance of resistance welding machine.