Roughening workpiece surface involves roughening beneath liquid coating using compressed air needle device with needles with conical free surfaces facing workpiece surface

摘要

The method involves using a compressed air needle device (1) with needles (2) whose free surfaces facing the workpiece (4) surface to be roughened are of conical shape. The cone angle of the needle ends (2a) matches the desired roughness and the toughness of the surface. Roughening is performed beneath a liquid coating.