High molecular polymer powder material

Abstract

A high molecular polymer powder material is characterized by comprising the following components in percentage by mass: 80-99.8 percent of high molecular polymer substrate, 0.1-5 percent of adhesion promoting resin and 0.1-15 percent of melt flow assistant. A mechanical mix process or an extrusion blending repulverizing process is adopted to uniformly mix the high molecular polymer substrate, theadhesion promoting resin and the melt flow assistant to obtain the high molecular polymer powder material; wherein the high molecular polymer powder material has excellent melt flow, and the melt flowrate thereof is at least 20% higher than the same polymer substrate without the addition of melt flow assistant, as measured according to ASTM 1238 (2015) at 160 DEG C under a load of 0.325 kg. The invention makes use of the self-leveling property of the melted high molecular polymer powder material with good melt fluidity, realizes accurate and rapid leveling of the substrate, improves the production efficiency, reduces the cost, and improves the accuracy and surface quality of the sintered workpiece.

Description

technical field [0001] The invention relates to the technical field of additive manufacturing, in particular to a polymer powder material. Background technique [0002] Selective laser sintering is a method of manufacturing three-dimensional objects by selectively fusing multiple layers of powder, which allows machining without tools but only by laser sintering multiple overlapping layers of powder according to the three-dimensional image of the object to be produced, to get a 3D solid. This method is mainly accomplished using thermoplastic polymers, and patents US6136948 and WO9606881 describe in detail the method of using powdered polymers to manufacture three-dimensional objects. [0003] At present, when selective laser sintering of polymer powder materials with a melting point higher than 200 °C requires a higher temperature sintering environment, the process currently has the following four disadvantages: 1. The high temperature of the sintering environment easily lea...

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Problems solved by technology

[0003] At present, when selective laser sintering of polymer powder materials with a melting point higher than 200 °C requires a higher temperature sintering environment, the process currently has the following four disadvantages: 1. The high temperature of the sintering environment easily leads to oxidation of the material, making the manufacturing process difficult. The mechanical and mechanical properties of the parts are reduced and the color of the parts is deteriorated, and the reusability of the powder materials is reduced at the same time; 2. The high temperature of the sintering environment requires the equipment to have better heating, heat preservation, heat insulation, sealing and other properties, which greatly improves the manufacturing and maintenance of the equipment. Use and maintenance costs; 3. High sintering ambient temperature will consume more energy and require longer cooling time, which affects processing efficiency and increases manufacturing costs. At the same time, high temperature operation also brings safety hazards; 4. Sintering ambient temperature High, the workpiece is more prone to warping and deformation, which affects its dimensional accuracy; therefore, the method of low-temperature sintering of polymer powder materials by using a substrate plus a support came into being, but the existing method of using a substrate plus a support for low-temperature sintering with a high melting point The method of polymer powder materials requires a lot of time to calibrate and level the substrate, which greatly reduces the production efficiency, and the error of substrate calibration and leveling is too large, which often becomes a factor that affects the accuracy and surface quality of the sintered workpiece. The key factor is that the substrate has a large loss during use, the service life is short, and the cost of the substrate is high, which further increases the production cost. The above reasons have made it difficult to popularize the method of substrate plus support and low-temperature sintering of high-melting point polymer powder materials.

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