Abstract: A method of manufacturing a 3-dimensional model object by a powder bed fusion method using a resin granular material, in which the resin granular material comprises a resin powder (A) and a flow aid (B), a sphericity of the resin powder (A) is 80 or more and 100 or less, the resin powder (A) has a D80 particle size of 60 ?m or less and a D20 particle size of 1 ?m or more, the flow aid (B) is contained at an amount of more than 0.01 part by mass and less than 5 parts by mass with respect to 100 parts by mass of the resin powder (A), and steps (a) to (c) are performed in this order repeatedly.

Abstract: A polymer powder includes a polyamide, wherein a melting point determined in differential scanning calorimetry is 190° C. or higher, a difference between the melting point and a melting onset temperature, which is defined in differential scanning calorimetry as a lowest temperature among temperatures at each of which a first temperature differential value of Heat Flow (W/g) observed between a peak top temperature of an endothermic peak, observed when 10 mg of powder is heated at a rate of 20° C./min from 30° C. in a nitrogen atmosphere, and a temperature point of ?50° C. from the peak top, becomes ?0.2 (W/g.° C.), is less than 30° C., and a D50 particle size is 1 ?m or more and 100 ?m or less.

Abstract: A method produces polyamide fine particles by polymerizing a polyamide monomer (A) in the presence of a polymer (B) at a temperature equal to or higher than the crystallization temperature of a polyamide to be obtained, wherein the polyamide monomer (A) and the polymer (B) are homogeneously dissolved at the start of polymerization, and polyamide fine particles are precipitated after the polymerization. Polyamide fine particles have a number average particle size of 0.1 to 100 ?m, a sphericity of 90 or more, a particle size distribution index of 3.0 or less, a linseed oil absorption of 100 mL/100 g or less, and a crystallization temperature of 150° C. or more.

Abstract: A method produces polyamide fine particles by polymerizing a polyamide monomer (A) in the presence of a polymer (B) at a temperature equal to or higher than the crystallization temperature of a polyamide to be obtained, wherein the polyamide monomer (A) and the polymer (B) are homogeneously dissolved at the start of polymerization, and polyamide fine particles are precipitated after the polymerization. Polyamide fine particles have a number average particle size of 0.1 to 100 ?m, a sphericity of 90 or more, a particle size distribution index of 3.0 or less, a linseed oil absorption of 100 mL/100 g or less, and a crystallization temperature of 150° C. or more.