Optimum process variables for the production of coir pith particle board

Particle boards of size 250 mm x 250 mm and 12 mm thick with 0.9 g/cm(3) density were made using coir pith, a waste disposed from the coir fibre industries, of 0.45, 0.80, 1.20 and 2.10 mm particle size with phenol formaldehyde and urea formaldehyde resins. The response to the process variables, viz., proportion of resin, curing temperature and curing duration were found to follow a second-order model for the modulus of rupture of the boards. The higher strength characteristics were found for the boards made from the larger particle size of the coir pith and higher levels of the process variables. The levels of the variables, proportion of resin, curing temperature and curing duration of 16.7%, 138 degrees C and 26 min, respectively, were found to be optimum for phenol formaldehyde resin. The levels of proportion of resin, curing temperature and curing duration of 20.4%, 139 degrees C and 17 min, respectively, were optimum for the urea formaldehyde resin. (C) 1999 Silsoe Research Institute.