A study on the properties of rapidly prototyped wood-plastic composites based on selective laser sintering

Materials for polypropylene / wood-powder composite are prepared in the way of alkalization, drying and mixing. Test pieces or specimens are made in the shaper with selective laser sintering before their mechanical properties are to be tested or measured and an analysis made of them with scanning electron microscope (SEM). The experimental findings show that before the use of MAH both the tensile strength and flexible strength are lower than those of the pure polypropylene (PP) when wood powder is filled into polypropylene, whereas both its tensile modulus and flexible modulus gradually rise with the increase in the content of wood powder. When MAH is used as the combining agent, the tensile strength, flexible strength, impact strength and flexible modulus of the wood-plastic composite with higher wood powder mass fraction of 40% vary with the changes of MAH contents, and when the contents of MAH fall into the range from 1.5% to 2.5%, the above values of the composite are normally the highest. SEM photos of the fractured surface of the composite show that the existence of combining agent not only strengthens the interaction between wood powder and the base material, but also influences the mechanical anchorage on the interface of the wood powder and the base material, which is helpful to the improvement of the mechanical properties of the composite.