Flame retardant, load bearing and thermal studies on satin weaved sunn hemp fibre and cashew nut shell de-oiled cake biosilica epoxy composites

This study aimed to create a high flame retardant, load bearing and thermally stable epoxy composite for various engineering applications. To achieve this, cashew nut shell de-oiled cake derived biosilica and satin weaved sunn hemp fibre was utilized as reinforcements along with epoxy resin. The biosilica is prepared using thermo-chemical process, whereas the satin weaved sunn hemp fibre was made using hand loom. Furthermore, the composites were manufactured by the hand lay-up method and characterized in line with the ASTM standards. According to the results, the lowest value of combustion rate is approximately 11.93 mm/min for the composite designation RSB3. The addition of sunn hemp fibre and 3.0 vol. % of biosilica composite (RSB2) yielded a tensile strength of 164 MPa, flexural strength of 204 MPa and modulus of 6.21 and 6.82 GPa, respectively. It is noted that the thermal conductivity improved marginally when the biosilica is added into the composite. Furthermore, adding cashew nut shell biosilica decreases the specific wear rate of the composites. Such natural fibre composite with high resistances to heat as well as mechanical load and thermal stability could be employed in automobiles, industries making consumer and electronic goods as well as sports applications.