Study On Mechanical And Machinable Properties Of Wood-plastic Parts Fabricated By Laser Sintering

Selective laser sintering, as one of advanced additive manufacturing technologies which is developed earlier than others, has got more attention from researchers and enterprises, because of its obvious advantages in rapid production of small-batch parts with complicated structures. With the application and popularization of selective laser sintering, available material becomes one of main factors affecting the development of this technology. It has been a main concern for researchers and carriers to develop green sustainable material with low energy-consumption, high performance and low cost for selective laser sintering.In response to the demand for the development of materials available for selective laser sintering, wood-plastic composite is employed as the material for selective laser sintering, which is cheap, recyclable, and environmentally friendly. In this paper, P-PES wood-plastic composite mixed by pine powder and modified polyether sulfone resin (PES) was prepared and SLS experiments were done. In the experiments, differential scanning calorimetry (DSC) is used for testing the glass transition temperature of the raw material and composite material, providing a basic reference for preheating temperature of SLS. Parametric scope of wood-plastic composite used for SLS was confirmed by tests.The main interfacial bonding mechanism of selective laser sintering with the material of P-PES wood-plastic composite powder is identified through the observation of fourier infrared spectrum testing curves and impact-section microstructure of wood-plastic SLS parts, and its effects on mechanical properties are analysized. The effects on mechanical properties of wood-plastic SLS parts were explored, including the proportion of raw materials, pine powder alkaline treatment, process parameters and environmental temperature variation. The mechanical properties of wood-plastic SLS parts in different periods were measured to get the information about the variation of mechanical properties in a certain time. Design of experiment (DOE) and Minitab software were employed to analyze the effects of SLS process parameters on wood-plastic SLS parts, the relevant mathematical models are obtained, besides the process parameters were optimized in order to improve the mechanical properties.Preliminary exploration was carried on, which was about the machinability of wood-plastic SLS parts. Post-treatment processes were proposed to improve the density of wood plastic SLS parts, mechanical properties and water resistant ability. Minimum dimension of P-PES wood-plastic composite produced through SLS were obtained, and holes less than 2mm were suggested to be produced by machining. Tenon structure, nails and glue combination were adopted to connect or assemble wood-plastic SLS parts. Nail holding power of board face and board edge were measured, including the original pieces, wax infiltration pieces and resin infiltration pieces.