COATING FOR THE INTERNAL SURFACE OF A PIPE, METHOD FOR APPLYING THE SAME ON SAID SURFACE, TWO-LAYERED SEMI-FINISHED PART USING SAID COATING AND METHOD FOR MAKING THIS PART

摘要

The present invention relates to a coating applied onto the internal surface of a pipe, wherein said coating consists of two coaxial tubular and film-type envelopes (2, 3) made of a thermoplastic polymer. The outer envelope (2) rests against the pipe (1) internal surface, while the inner envelope (3) is separated from the first by a coaxial main reinforcement layer (4) impregnated with a solidified polymeric binder. The inner envelope (3) is made in the shape of a multiple-component homogeneous system that comprises at least one polymer selected from the group of thermoplastic polymers having a relative stretching ratio of at least 200 % and a melting point of at least 100 DEG C. This homogeneous system also comprises a structural modifier of the selected polymer. The envelope (3) and the layer (4) are formed with unjoined edges in at least one place along the coating axis, wherein said edges (6, 7) are sealed together so that the envelope (3) and the layer (4) form a monolithic structure. The present invention also relates to a two-layered semi-finished part that comprises the inner envelope (3) linked to the reinforcement layer (4), wherein said envelope is obtained from the multiple-component homogeneous system having the above-mentioned composition.