According to foreign data reports, a problem often encountered in the extrusion and injection molding of plastic products is the rapid wear and corrosion of the screw and barrel, and in many cases it takes about six months or even two or three months. Within a certain period of time, the screw and barrel are worn and corroded to the point where they need to be replaced. This forces the plastic molding industry to have to conduct more and more in-depth research on the wear- and corrosion-resistant strengthening measures of the screw and barrel.

In the past three years, in order to improve the wear resistance and corrosion resistance of screws and barrels, great progress has been made in the study of the corrosion and corrosion enhancement measures for screws and barrels, mainly in the following: The development of the material, the new mechanical manufacturing process technology and the new heat treatment process technology were transplanted into the screw and barrel manufacturing process. The simple case in this regard is: in the fifties, the use of medium carbon steel, alloy steel surface quenching, chrome plating or quenching followed by chromium plating and other measures; later, the use of alloy steel, nitrided steel and other materials for gas Nitriding treatment; After entering the 1970s, in addition to the continued use of nitriding steel for gas nitriding treatment, more and more examples of nitriding process, the use of medium carbon steel, alloy steel chrome plating process There is a clear increase; new processes for spraying and surfacing wear-resistant and corrosion-resistant alloys on the top surface of screw ribs and even the spiral surface of the screw are widely used. In some special cases, pure nickel is used to make the screw; For the cylinder, a new process using a cast iron, medium carbon steel, or alloy steel to fabricate the barrel body and then casting a special alloy lining resistant to wear and corrosion on the inner wall of the barrel is widely used.