Process Analysis of Manufacturing Thermoplastic Type-IV Composite Pressure Vessels with Helical Winding Pattern

Composite pressure vessels (CPVs) are widely employed for the high-pressure storage and transportation of hydrogen due to their extraordinary lightweight characteristics. Thermoset CPVs are the market standard due to easy and reliable production. The use of thermoplastic composites for CPV manufacturing via laser-assisted tape winding presents advantages with regard to out-of-autoclave and clean processing, recyclability and design freedom concerning the winding layup. The complex interactions of multiple process parameters like laser power, irradiation incidence angle and tape feed rate along the winding path influence the bonding quality within the composite laminate and require a thorough understanding, especially for helical winding patterns covering cylinder and dome parts of the pres sure vessel. In this work, helical circuits of composite tape were placed on a thermoplastic liner with systematically varied process parameters. The temperature distribution governing the bonding quality between the tape plies was monitored and processed for data analysis. An empirical model characterizing the influences of process parameters on the nip point temperature was created highlighting differences in temperature variation on cylinder and dome parts. Tape feed rate profiles were also taken into account to identify action fields for the development of an optimized process for thermoplastic CPV manufacturing.