In this study, the compatibility of sawdusts and bark particles prepared from 6 Korean species: pitch pine, Korean pine, Larch,acacia, Italy poplar and oak, and fine chip particles prepared from Malaysian oil palm(fermented or nonfermented)as well sqwdust particles of German spruce on the wood-gypsum composites for shear strength was examined with the addition of hardening retardant(Retardan P). In addition, the actual board thickness, the board density and the bending strength on the gymsum bonded-German larch(Larix decidua)particleboard were studied according to the addition levels of hardening retardant. The results obtained in this study were as follows; 1. It is possilble to classify the composites combined with sawdusts into 3shear strength groups according to the addition levels of hardening retardant up to 0.02%, Korean pine and larch belonged to the strength increasing group, Pitch pine, Italy poplar, oak, non-fermanted oil palm and spruce belonged to the strength decreasing group. Acasia and femented oil palm didn t show any strength decrease at the addition of 0.01%, but showed a dlight strength decrease atthe addition of 0.02%. 2. Bending strength of the 3layer gypsum bonded-larch particleboard showed a decreasing trend. which might be caused by the decrease of board density from the poor thickness control due to a precure, at the addiction of less than 0.04% of hardening retardant. In the range of addition levels of 0 to 0.08% of hardening retardant, the highedt bending strength was shown at the addition df 0.04%.
1. 緖論
2. 材料 및 方法
3. 結果 및 考察
4. 結論
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