▎ 摘　　要

NOVELTY - Additive manufacturing process involves applying successive layers of a powdered polymer material (M) at portion bed of a selective laser sintering printer, heating the layer of powdered polymer material (M) to be printed at a processing temperature (Tp), and selectively sintering each layer prior to deposition of the subsequent layer, and maintaining the printed portion and unsintered material (M1) at portion bed temperature (Tb) until the three-dimensional article is completed. The material (M) has particle size of d50 of 20-100 mu m, as measured by laser scattering in isopropanol, and comprises at least one semi crystalline polymer or copolymer (P). The component (P) has melting temperature of 230 degrees C or more. The portion bed temperature (Tb) is lesser than the processing temperature (Tp). The glass transition temperature (Tm), portion bed temperature (Tb) and melting temperature (Tm) of the component (P) satisfy specific relation. USE - Additive manufacturing process used for forming three-dimensional article (claimed). Uses include but are not limited to implantable device, medical device, dental prostheses, brackets and complex shaped components used in aerospace industry and under-the-hood components in automotive industry. ADVANTAGE - The method provides the three-dimensional article having excellent mechanical properties such as stiffness, compression strength, impact strength, tensile and flexural strength, elongation at break and heat distortion. The powder can be reused in laser sintering three-dimensional printing process, without impacting the appearance and mechanical performances of the resulting printed article. By reducing the temperature of the portion bed (Tb), the polyphenylene sulfide has excellent stability, longevity and recyclability, and reduces the energy consumption during the printing process. DETAILED DESCRIPTION - Additive manufacturing process involves applying successive layers of a powdered polymer material (M) at portion bed of a selective laser sintering printer, heating the layer of powdered polymer material (M) to be printed at a processing temperature (Tp), and selectively sintering each layer prior to deposition of the subsequent layer, and maintaining the printed portion and unsintered material (M1) at portion bed temperature (Tb) until the three-dimensional article is completed. The material (M) has particle size of d50 of 20-100 mu m, as measured by laser scattering in isopropanol, and comprises at least one semi crystalline polymer or copolymer (P). The component (P) has melting temperature (Tm) of 230 degrees C or more. The portion bed temperature (Tb) is lesser than the processing temperature (Tp). The melting temperature (Tm) and glass transition temperature (Tm) of component (P) are measured by differential scanning calorimetry at 20 degrees C/minute according to ASTM D3418. The glass transition temperature (Tm), portion bed temperature (Tb) and melting temperature (Tm) of the component (P) satisfy the relation: Tg not less than Tb not less than Tm-40 degrees C. The processing temperature (Tp) is in the range of (Tm-40 degrees C)-(Tm) (excluding Tm-40 degrees C and Tm). INDEPENDENT CLAIMS are included for the following: (1) recycled powder material; and (2) blend of powder materials.