COMPREG MADE FROM RUBBER WOOD VENEER

Abstract

Rubber wood (Hevea brasiliensis Muell & Agr.) is suggested on as a new raw material for the manufacturing of compreg to aim at a new product in Thailand. Some factors affecting the resin retention in rubber wood veneer were examined by using the factorial experimental design (completely randomized technique). The three factors chosen were the concentration of phenol formaldehyde resin at three levels, (viz.) 20%, 30%, and 40%, soaking time at 5, 10, and 15 hours, and the veneer condition either air-dried or green. The results of this study indicated that the green veneer treated with a 40% resin solution and soaked for 10 hours produced a high quality compreg since the veneer showed a resin retention of 33.18%. The average of modulus of rupture and modulus of elasticity in a static bending test of parallel-laminated compreg were 126.16 MPa, and 14.22 GPa respectively, this was highly significantly (P <0.01) different from the values of the cross-laminated compreg and the solid rubber wood. The average modulus of hardness of cross-laminated compreg was 98.32 MPa, not significantly (P <0.05) different to 87.38 MPa for the parallel-laminated compreg. Values for both compregs were. however highly significantly different to those for solid rubber wood. The physical properties of both the compregs, such as specific gravity, water absorption, swelling, and recovery of thickness similar.