Multiply coated metal pipe for domestic supplies and effluents - has several unfilled and metal-filled plastics coatings with selective adhesiveness and electric conductivity

摘要

Metal pipe has plastics coating(s) to protect it against corrosion. The metal surface of the pipe is coated with a plastics matrix having embedded in it very finely divided predominantly pure metal particles so that there is, at statistically distributed discrete places of the metal surface, a selective adhesion of metal particles to metal surface; within the coating, the metal particles are electrically conductively connected with one another by means of further metal particles. Solid, i.e. unfilled, plastics layer is coated on the plastics/metal particles layer. The surface of plastics/metal layer has an irregularly mushroom-shape brought about by the use of metal particles of various sizes. This improves the firm anchoring of the layers. Firm adhesion of plastics layers to each other and to the metal pipe is ensured. The coated pipe is resistant to corrosion and mechanical and thermal stresses.