The Study On The Composite Made By Wood Fiber Mixed With Corn Stalk Skin Flake

In this paper, the technology of composite board made by wood fiber/corn stalk skin flake and modified UF resin was studied. In consideration of the shape and density difference between wood fiber and corn stalk skin flake, the mixing-uniformity of mixed materials with the resin and without the resin were discussed during the vibration of transporting and under different forming methods by simulate the real production process. By using orthogonal experiment, the effect of the factors such as pressing time, pressing temperature, resin content and mixing ratio of wood fiber/corn stalk skin flake on the appearance and main physical and mechanical properties of composite were studied. Based on the result orthogonal experiment, the effect of resin content and mixing ratio on the physical and mechanical properties of composite were investigated further. In the end of the paper, the bonding property between wood veneer/corn stalk skin treated by acid and alkali were studied finally. The bonding property was surveyed and analyzed by SEM, the dynamic mechanical properties and thermal stability of composite were analyzed by dynamic mechanical thermal analysis of DMA and thermo gravimetric analysis of TGAtoo.The results show that, the mixing ratio of mixed material with the resin and without the resin has changed in the different positions (up surface, middle position and lower surface) during the vibration of transporting, but the mixing-uniformity of mixed material with the resin was better than that of without the resin. The mixing ratio of different parts in the flat blank formed by airflow forming and mechanical forming was changed too. The percentage of corn stalk skin flake was higher in the position that near with the forming head. The orthogonal experiment result shows that the mixing ratio of wood fiber/corn stalk skin flake and resin content have the significant effects on the24h TS and MOE of composite, hot pressing time has the significant effects on the24h TS, hot pressing temperature has the obvious effects on the appearance quality of composite, the higher the temperature, the corn stalk skin flake in the mixed material was more carbonized and this caused the color of the composite was more dark. With the increasing of the resin content and wood fiber ratio in the mixed material, the mechanical properties of the composite were increased significantly. Observed by SEM and analyzed by DMA, the increase of rigidity of composite was found by increasing of the percentage of wood fiber. TGA testing data shows that in a certain mix ratio and the resin content, heat stability of the composite is better. The bonding strength between wood veneer/corn stalk skin was improved by the treatment of acid and alkali to corn stalk skin and the alkali treatment has a better bonding strength.According to the results, the best technology of wood fiber of/corn stalk skin flake composite was got as below:resin content is10%, hot pressing temperature is130℃, hot pressing time is3min (composite thickness is10mm), the ratio of corn straw skin flake with wood fiber was5:5or4:6as proposed. The basic physical performance of composite can meet the quality requirements of indoor fiberboard of the national standard of GB/T11718-2009.