Effects of fabric structure on the formability characteristics of thermoplastic composites under various process conditions

Abstract

Thermoplastic composites are broadly utilized for structural and automotive applications due to their higher specific strength and modulus, higher strain to failure, recyclability, and unlimited shelf life. This study investigates the effects of fabric structure on the forming behaviour of glass fabric reinforced polypropylene composites during the sheet forming of a doubly curved shape. Stamp forming, a novel thermoforming technique, is mostly used for hemispherical forming of thermoplastic composites. The study also investigates the influence of process parameters such as die temperature, blank temperature, and blank holder force on sheet formability. Forming ratio, thickness distribution, material draw-in, and punch force were used for the evaluation of the formability of composites. Conventional and novel plain weave glass fabric reinforced polypropylene composite laminates were fabricated using the film stacking technique. Thermo-stamp forming experiments were conducted on the basis of the Taguchi’s L9 orthogonal array. Experimental results revealed better forming characteristics by the novel glass fabric reinforced composite than for the conventional glass fabric reinforced composite. Production of defect-free components under high die temperature, low blank holder force, and medium blank temperature process condition was observed.