열압밀화재를 위한 마이크로파의 효과

Effect of Microwave Irradiation on Compressed Wood by a Hot Press

This paper deals with an effect of microwave irradiation for compressed wood by a hot press of sonamu(Pinus densiflora) to improve the physical properties. Specimens lOOmm(L) by 20mm(R) by 20mm(T) of sap wood in air-dried and water-saturated conditions were used. Specimens were irradiated by microwaves of O.9kW(2450MHz) and hot-compressed to the radial direction. Moisture content remarkably decreased with the irradiation time of microwave increased. In the water saturated specimens, wood temperature steeply increased as the wood moisture decreased by microwave irradiation. From the consideration of compressive stress, wood can be regarded as a plastic material in a wet condition. This may be due mainly to the softening of the matrix components in the cell walls when heated in the water saturated conditions. Recovery of the set of compressed wood is considered to show the minimum value for the high temperature and high pressure above 1 atm in wood which is water saturation. Improvement in abrasion resistance and hardness were recognized in water saturated wood. These results show that microwave irradiation is suitable to plasticize of wood specimen impregnated with water, can be improve to physical properties of wood as the pretreatment for heat compression.