Production of Coir Fibre-Reinforced Natural Rubber Composite Using Vacuum-Assisted Resin Transfer Moulding (VARTM) Process for Roofing Insulation Applications in Buildings

This research paper aims to produce a coir fibre-reinforced natural rubber composite using a Vacuum-Assisted Resin Transfer Moulding (VARTM) process for building roofing applications. Using coir fibre as a reinforcement in different applications is a much-researched feature because it is a readily available natural fibre. Coir fibre is a low-cost material with a high strength-to-weight ratio. The thermal properties of a composite mainly depend on volume fraction, arrangement of fibre reinforcement, and the production process. The novelty of this research lies in using the VARTM process for producing composite materials while allowing precise control over the resin infusion process, resulting in uniform distribution of natural rubber latex throughout coir fibre reinforcement. This research addresses challenges in existing manufacturing processes for coir fibre-reinforced composites, such as poor resin distribution and inadequate fibre-matrix interaction. By utilising VARTM, the primary purpose of this research is to overcome these challenges and achieve a high-quality composite with improved mechanical and thermal properties. The methodology includes a state-of-the-art review and analytical, numerical, and experimental analysis. Expected outcomes comprise an improved manufacturing process for developing natural bio-composite material. Research significance lies in the potential for creating a sustainable and eco-friendly composite. Analytical calculations and numerical simulations validated the experimental thermal conductivities. However, experimental results have deviated from the analytical and numerical results due to the limitations of theoretical equations available in the literature. Hence, the underlying reasons for this difference have been discussed in detail. According to this research, the VARTM method manufactured 4cm coir fibre length and 275g coir fibre weight sample was selected as the best sample for roofing insulation in a building. The lowest thermal conductivity of the specified sample was 0.08W/(mK), and the respective tensile stress was 0.19MPa.