Using Thermoplastic (HDPE) Liners and Glass Fiber Reinforced Thermosetting and Thermoplastic Structural Wall Matrices to Produce Filament Wound Pressure Vessels

Polymer composites are an excellent alternative to replace more traditional materials in the fabrication of pressure cylinders for common applications. They minimize the weight and improve the mechanical, impact and corrosion behavior, which are relevant characteristics for almost all current and future large scale pressure cylinder applications, such as liquid filters and accumulators, hydrogen cell storage vessels, oxygen bottles, etc. A new generation of composite pressure vessels has been studied in this work. The vessels consist on a thermoplastic liner wrapped with a filament winding glass fiber reinforced polymer matrix structure. A conventional 6-axis CNC controlled filament winding equipment was used to manufacture the thermosetting matrix composite vessels and adapted for production of thermoplastic matrix based composite vessels. The Abaqus 6.4.2 FEM package was used to predict the mechanical behavior of pressure vessels with capacity of approximately of 0.068 m3 (68 liters) for a 0.6 MPa (6 bar) pressure service condition according to the requirements of the EN 13923 standard, namely, the minimum internal burst pressure. The Tsai-Wu and von-Mises criteria were used to predict composite laminate and thermoplastic liner failures, respectively, considering the elasto-plastic behavior of the HDPE liner and the lamina properties deducted from the micromechanical models for composite laminates. Finally, the results obtained from the simulations were compared with those obtained from the experimental pressure tests made on the thermoplastic liners and final composite vessels.