Hemp fibre as alternative to glass fibre in sheet moulding compound. Part 2 : impact properties

This paper describes the results of falling weight impact tests on natural fibre reinforced polyester composites fabricated using a conventional sheet moulding compound (SMC) process. The influence of hemp fibre and CaCO3 filler content on the penetration energy of hemp fibre reinforced sheet moulding compound (H-SMC) is reported and compared with glass fibre reinforced sheet moulding compound (G-SMC). To evaluate the influence of fibre/matrix interfacial adhesion on the impact behaviour of these H-SMCs, the hemp fibres were treated with alkaline and silane treatments, as well as a combination of these treatments. A simple mechanistic model is proposed for these natural fibre composites and is used to obtain more insight into the impact behaviour of the composites as well as to provide guidelines to compare the experimental data with theory.