Comparative investigation of molded thickness and surface density on the structures and mechanical properties of lightweight reinforced thermoplastic composites

Lightweight reinforced thermoplastic (LWRT) is a newly developed porous material. The low density, high rigidity, design flexibility and sound absorption of LWRT facilitate its application in the automotive industry. Fibers are bonded with a matrix and air is imported by deconsolidation, which is not only economical but also environmentally friendly. In this work, film stacking and non-woven methods were employed as the impregnation techniques to manufacture LWRT. The molded thickness and surface density of LWRT were varied to study their influences on the structures and mechanical properties. Different lengths of fibers in LWRT were selected and 7 % PP-g-MAH was added to the matrix and compared with unmodified matrix. The mechanical properties decreased with the increase in molded thickness and the decrease in surface density. With higher fiber length, the strength and stiffness increased, while the toughness exhibited a maximum value at 80 mm fiber length. The strength and stiffness of LWRT were also enhanced when 7 % PP-g-MAH was added.