Abstract: A scraper (14) arranged between two parallel side members (12) of a scraper frame, having a metal structure (51) in the shape of a comb (52) with teeth facing downwards and a flexible blade (59) covering the teeth (52) and bonded to the structure (51). A first portion (51a) of the structure (51) is perpendicular to the longitudinal members (12) and at least a second portion (51b) integral with an end of the first portion (51a) forms an elbow with the latter, the flexible blade (59) being bonded to the elbows's inward facing surface. The invention is for use especially in blasting plants using powder or granular materials.

Abstract: A method and apparatus for sending a coating material (C) under high pressure into an openable mold (2, 3) which is closed and filled with a moldable material. A chamber (6) is used having one end (7) open toward the inside of the mold and an injection duct (14) emerging in the chamber (6). A piston (38) which can move in the chamber (6) from a first position in which the piston blocks the open end (7) of the chamber, is moved as far as a second position beyond the injection duct (14) in relation to the open end (7) of the chamber. The coating material (C) is injected into the chamber (6) via the injection duct (14) under a first pressure (P0); and with the mold remaining completely closed, the piston (38) is moved toward the first position by applying thereto a force (F2) corresponding, inside the chamber (6), to a second pressure (P2) which is greater than the first pressure (P0). Only thereafter is the mold (2, 3) opened.