Study On The Improvement On The Salix Gypsum Particle Board's Property

By adjusting the amount of addtive,the structure pattern on the board's cross section , ratio of materials as well as the value of molding pressure ,the paper mainly studys on how to improve the quality of Salix Gypsum Particleboard (SGP),which is composed of gypsum as adhesive and Salix,a kind of shrub inhabitating western desert region of our country.To circumstantiate, the effects of above elements on the board's property,such as Tensile Strength(MOR),Inner Bond(IB) ,Thickness Swelling(TS) are focused on in this paper in order to improve the quality of Salix Gypsum Particleboard .The result shows that, 1. Borax is a sort of retarder during the hydration of gypsum,which can prolong this process. As a consequence, the hydration of gypsum can be changed by putting into borax when making Salix Gypsum Particleboard.As an essential substance in actual production,borax has negative effect on board's strength,as a result, in order to ensure normal production,the amount of borax added must be controlled in a certain scope as small as possible. 2. Appropriate amount of white cement can increase the bending strengthen of gypsum itself ,which can reach its peak at 10 percent(white cement to gypsum).On the other hand, white cement has little effect on the hydration of gypsum ,but it does have good on TS. 3. To add proper amount of Urea Formaldehyde(UF)can enhance the MOR,IB, Screw Holding Power(SHP) of the board,while affecting little on TS. 4. The three-layer board's comprehensive property is superior to that of the single –layer board .The degree of eveness while paving is highly demanded if three-layer board is adopted .Under such circumstances,it is preferable to use middle-sized particles as surface materials and large-sized ones for the inner so as to obtain high strength.5. The board's MOR, SHP and TS climb with the increasing wood gypsum ratio.6.The board's MOR,IB and SHP climb with the increasing wood gypsum ratio,while drop down with the MOE . 7. The board's MOR and MOE rise with the increasement of molding pressure . 8. According to the results of the experiments, Salix Gypsum Particleboard of high quality can be made using following parameters, the amount of borax added:0.5%the amount of white cement added:10%the amount of UF added:6%the structure pattern on the board's cross section:single-layerthe ratio of wood to gypsum:0.30the ratio of water to gypsum:0.30molding pressure:2.0 MPa...