Method of forming a textured pattern on a metal plate which pattern is transformed to a plastic part, and a press plate and plastic part produced thereby

A method for producing a generally uniform textured pattern on at least one surface of a metal press plate used to impress said uniform pattern on a work piece, comprising the steps of:

• providing a metal plate having a hardness of Rockwell C40 or less;
• projecting a stream of substantially spherical balls at a generally right angle to the surface of the steel platen at a velocity sufficient to create an impression on said surface;
• and
• causing said stream of substantially spherical balls to impact at generally said right angle to the surface of the steel platen, such that each ball creates an impression on the surface of the steel platen to create the generally uniform pattern each of said impressions having a relief ranging from 0.02 to 2.0 millimeters;
• each of said balls formed from a material having a substantially uniform diameter ranging between 0.50 and 1.0 millimeters, a surface hardness ranging between Rockwell C40 and C65, a core hardness ranging between Rockwell C35 and C65, and a case hardness greater than Rockwell C45.

A method for imparting a textured surface on a plastic part, comprising the step of:

• providing a metal plate;
• projecting a stream of spherical steel balls against a surface of said metal plate at an angle substantially perpendicular to said surface, said balls having a hardness greater than the surface of said plate and having a velocity sufficient to create an impression in said surface;
• each steel ball having a substantially uniform diameter in the range of 0.5 and 1.0 millimeters, said steel balls imparting a generally uniform rough texture to said surface of the plate;
• providing a plastic part;
• and
• transforming said texture to said plastic part by pressing said surface of said plate on said plastic part to provide a texture on the surface of said part, such texture corresponding to the texture on said surface of said plate.