MATERIALS AND METHODS
The study used coconut coir as the main raw material and recycled rubber as the secondary material. Before being used, both materials have to undergo several processes. The coconut coir has to undergo several pre-treatment processes. Initially, it was crushed to obtain small grain, soaked in water, washed and dried before it was ready to be used. The processed coconut coir was added with recycled rubber particles and evenly mixed together using polyurethane as the binder, prescribed as in Table 1 and 2. Here, the percentage of polyurethane varies in order to investigate the influence of resin on the performance of coconut coir composites. The composite boards were prepared in two diameters, e.g. 100 mm for low frequency and 28 mm for high frequency. The samples were compacted by hot press machine to produce the composite fiber boards.