Modernization and mass production are only in the last forty years. At present, in addition to some recycled plastic particles in the process of high pressure requirements of materials, or should not use screw extrusion materials (such as polytetrafluoroethylene plastic, etc.) still use the piston extruder, other mainly used screw extruder, and countries have formed a series of production. In the 1930s, the first plunger injection molding machine with a higher level of mechanization appeared.
In the 1940s, screw extruders began to be used as preplasticizing devices for injection molding. Until 1956 reciprocating screw injection molding machine, recycled plastic particles make plastic molding technology began to advance by leaps and bounds, thus marking the plastic molding technology has developed to a new historical stage. The recycled plastic pellet calendering machine was developed on the basis of the rubber calendering machine, which also appeared about the middle of the 19th century. In the 1970s, the wide, high precision, high productivity and high automation of Z-type and S-type and reducing diameter, multi-roller plastic calendering molding machine appeared, which also marked that the plastic calendering molding technology has reached the level of modernization.
In the 1970s, the whole plastic industry has entered a new period of development, plastic molding processing equipment technology level, varieties, specifications and output have been rapid development, and tend to mature. At present, plastic molding processing equipment has developed into a complete category, standardized, serialized, and higher degree of automation products. It includes plastic raw material preparation equipment, plastic molding equipment, plastic secondary processing equipment, plastic recycling equipment and other equipment types.
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