The Charpy impact test was conducted to determine the
amount of energy absorbed by the hybrid composites during
fracture. The results of the Charpy impact test are presented in
Fig. 8. It is observed that the value of Charpy impact strength is
higher in woven samples (51.41 kJ/m2) compared with the UD
samples (41.24 kJ/m2) and mat samples (24.64 kJ/m2). The
impact properties of composites depend on the interlaminar and
interfacial adhesion between the fibre and the matrix. In this
study it was found that the impact strength of kenaf–Kevlar
hybrid composites is in similar trend as the tensile properties.
This is in contrast with the observation of Van der Oever et al.
[40] that the Charpy impact strength decreases with increasing
fibre internal bonding and enhanced fibre–matrix adhesion,
which is opposite to the trend for the tensile and flexural properties.
The impact toughness of kenaf/glass hybrid composites
was found to be influenced by the fibre orientation [41]. It was
found to be affected by fibre orientation in glass fibre reinforced
polymer matrix composites [42]. In determining the influences
of weaving architectures on the impact resistance of multi-layer
fabrics, Yang et al. [43] found that the weaving architectures
and fabric firmness are less influential on the overall ballistic
protection of multi-ply systems compared to the single-ply
cases.
Generally, based on the above discussion, it was found
that the effect of fibre orientations is important to the
mechanical properties of hybrid composites as well as for
ballistic resistant application [44]. Kenaf–Kevlar hybrid composites may find applications as alternatives to current
spall-liners which are aimed at protection from impact by
small fragments.