Abstract: A method for powder spray-coating objects utilizes pneumatic conveyance of powder from an injector to a spraying system having a spray coating zone through which objects are consecutively conveyed in an automated system. Power conveyance is interrupted between the consecutive objects as object gaps enter the spray coating zone while the conveying air flow is maintained by injection of controlling air into a vacuum zone of the injector which reduces the injector vacuum to a degree causing interruption of powder conveyance. Flushing compressed air may be injected between the injector and the spray device of the spraying system to automatically flush powder to maintain system integrity. Equipment for powder spray coating of objects utilizing the above method is also disclosed.

Abstract: The invention concerns powder spray coating equipment comprising an air divider (16) to adjustably divide a total-air flow (6, 14) into a conveying-air flow (54, 57, 70) and a supplemental-air flow (56, 84, 86) in such manner that, when adjusting for a larger flow of conveying air, the flow of supplemental air shall be reduced in a predetermined ratio, and vice versa; further comprising an injector (76) to aspirate and to pneumatically convey coating powder by means of the flow of conveying air; and a supplemental-air intake (89) into the air/powder path (76, 82). The conveying-air path (54, 57, 70) and the supplemental-air path (56, 84, 86) each are fitted with at least one throttling duct each constituted by at least one channel (40, 42) in a rotatable shaft (34, 36) and by a bearing surface (39) covering the channel.