家具用 中密度纖維板의 壓縮 粘彈性에 關한 硏究 ( II ): 利用 含水率別 크리이프 및 應力弛緩 擧動 變化

A Study on the Compressive Viscoelasticity of Medium Density Fiberboard for the Furniture ( II ): Variation of Creep and Stress Relaxation Behavior of MDF with In-use Moisture Content

This experiment was carried out to examine the domestic MDF as substitute for the imported MDF and the long term service performance of furniture made of MDF by investigating the creep and stress relaxation behavior of both MDF at 3-staged moisture content level under significant loading level according to each physical properties and fiber element mixture as composition of the composite. Main results are as follows: Domestic MDF constructed with incomplete tracheid cell, wood fiber and even bark has lower specific gravity, internal bonding strength and MOR and has higher vapor and water absorption causing higher thickness swelling due to probably lower effective resin content or packing degree than the imported MDF of which the main composition is tracheid cell. So the former has not shown the material homogeneity as homogeneous continuum, normal creep and sound relaxation behavior as composite. Moisture content has great influence on the viscoelasticity of MDF as a wood-fiber based material. Intermediate MC maintain the internal resistant strngth of MDF but low MC causing micro crack and high MC causing fiber loosening showed significant lessening the load resistivity of the board. esp. domestic MDF