桉树木屑热压成型特性研究

RESEARCH OF HOT PRESS FORMING CHARACTERISTICS OF EUCALYPTUS SAWDUST

以桉树木屑为原料，在自制的成型模具上，利用万能力学试验机研究物料粒径、含水率、温度以及成型压强变化对物料密度和压缩功率的影响。试验结果表明：木屑在粒径较小时，颗粒间比表面积大，加强粘结剂和分子引力作用，成型效果较好；含水率增加会降低压缩功率，同时会导致成型质量降低，物料含水率为4％～12％时有较好的成型效果；提升物料温度在一定范围内可显著降低压缩功率，提高物料成型密度，温度也间接地改变物料含水率和粘结剂等因素来影响成型效果，在约100℃时成型效果最佳；增大压强有利于提高物料成型的质量，当压强达到100MPa后，增加压强对成型起到的作用甚微，成型质量保持在相对稳定的水平。

Using eucalyptus sawdust as raw materials, the effect of material property such as particle size, moistures, temperature and molding pressure on material density and compression power was studied on a self-made molding die using universal mechanical testing machine. The experimental results show that when the particle size of sawdust is smaller, the specific surface area between the particles is large, the binder and molecular gravitation are strengthened, and the molding effect is better. With the increase of moisture, the compression power and the molding quality decrease gradually. The sawdust has better molding effect when moisture is between 4% and 12%. Increasing the material temperature within certain range, the compression power can be reduced sharply, the material molding density is increased, the temperature also indirectly changes the moisture content of the material and other factors of binder to affect the molding effect, and the molding effect is the best at about 100℃. The growth of pressure is beneficial to improve the molding quality of materials. However, when the pressure reaches 100 MPa, increasing pressure has little effect on the molding, and the molding quality is maintained at a relatively stable level.