Plastykote® is a high machanical resistance anticorrosive coating for steel pipes. Plastykote® is the recommended option for pipeline laying in aggressive or stony soils when there is high risk of damage for an anticorrosive coating of epoxydic type.
Its two versions respond to different levels of service temperature:
THREE LAYER POLYETHYLENE
The three layer polyethylene system is used when the pipeline operation temperature is no higher than 80°C. It is made up of first epoxy layer, applied directly on the previously blasted and heated steel, a layer of adhesive, whose function is to achieve adherence between this first layer and the third one and the last one of polyethylene. Its usual thickness is from 1.5 mm to 3 mm.
THREE LAYER POLYPROPYLENE
Should a pipeline with a higher service temperature range be coated, this is the option to consider. It is made up of a first epoxy layer, applied directly on the previously blasted and heated steel, a layer of adhesive whose function is that of achieving the bonding between this first layer and the third one and the last one of polypropylene. The adhesive, like the external layer, is based on polypropylene instead of polyethylene. It can be used with service temperatures of up to 140°C and its usual thickness is of 1.5 mm to 3 mm.
The metod is similar for all the Plastykote® coatings. The pipe surface si blasted, heated and electrostatically covered with an epoxy primer. Next, a layer of copolymer and another one of polyolefin are applied by extrusion in an enveloping manner.