the outer coating ep powder of plastic-coated steel pipes is mostly sprayed with electrostatic guns.
electrostatic gun spraying: when spraying, the powder is under the action of the electrostatic generator to generate static electricity to make the powder adsorb on the steel pipe. the coating is dense and reliable in quality. this method is the current coating method. but in this way, it is required to configure a powder recovery system to collect the over-sprayed powder.
electrostatic gun extension rod spraying is adding a long rod based on the former, which is mainly used for internal coating, and the powder can be sprayed only when it goes deep into the steel pipe.