The USE of COFFEE Residue AS A Filler for NATURAL RUBBER

Coffee residue is the agricultural waste after extraction process in the coffee industry. It consists of most hemicellulose and fiber components. In this study, coffee residue is used as filler for natural rubber. It was crushed by wet ball mill for 2 hours and dried. Then the pre-crushed coffee residue was ground by vibratory mill and sieved to a controlled size of below 120 mesh. The prepared filler was characterized in terms of particle size, specific surface area, surface activity and pH-value. Rubber compounds were prepared by using internal mixer and two-roll mill. The effect of coffee residue on the properties of natural rubber were studied and compared with that of carbon black (reinforcing and semi-reinforcing grade) and calcium carbonate. Moreover natural rubbers filled with coffee residue/carbon black (reinforcing grade) hybrid at various ratios on the total filler content of 50 phr were studied. The scorch times and cure times of natural rubber compounds will be determined at 160°C as a function of filler loadings which were varied from 0 to 50 phr using a Moving Die Rheometer (MDR). Also, the Mooney viscosities of rubber compounds will be studied. Then the physical properties of rubber vulcanizates including tensile and tear strength, abrasion resistance and hardness will be determined.