▎ 摘　　要

NOVELTY - A powder coating comprises 0.1-0.2 pt. wt. synthetic ultrafine aluminum silicate powder, 0.1-0. 2 pt. wt. aluminum oxide (C), 2-4 pts. wt. negative ion powder, 0.05-0.08 pt. wt. single-layer graphene powder, 0.5-1 pt. wt. xenotime powder, 20-30 pts. wt. epoxy resin, 20-30 pts. wt. polyester resin, 3-5 pts. wt. additive, 20-40 pts. wt. calcium carbonate powder and 5-25 pts. wt. colorant. The powder coating has resistivity of 89-94 Ω.m. USE - Powder coating used in workpiece for improving powdering efficiency of double-faced groove hollow pipe in spraying method (claimed). ADVANTAGE - The powder coating has large coating coverage rate, no sagging on the surface and excellent surface leveling. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for spraying method for improving powdering efficiency of double-faced groove hollow pipe, which involves (S1) placing a workpiece in a rotary clamping cylinder of transmission device which performs transmission at intervals, (S2) mounting two groups of electrostatic spray guns in the two groups of up-down moving devices, (S3) spraying the powder coating material in the workpiece through group (A) of electrostatic spray guns up and down, (S4) transmitting once the transmission device, rotating the rotary clamping cylinder at 180°, aligning the group (B) of electrostatic spray guns with spraying up and down in the workpiece, (S5) curing the sprayed workpiece in oven, and (S6) cooling. In step (S2), the horizontal distance between the workpiece and the electrostatic spray guns is 15-20 cm.