Plasticator wear-resistant barrel

Plastic top plates are made from several different types of thermoplastics. Many are molded from acetal or low-friction acetal. Low-friction acetal is a blend of acetal with another plastic with a very low coefficient of friction. The plastic used must have good corrosion resistance and the plastic must also have good wear resistance in conditions where there is little or no lubrication. The barrels of the top plates must be molded very accurately, for the same reasons that the barrels of steel top plates must be curled very accurately. 

Some aspects of plastic wear are hardly even discussed in manufacturer s literature plastic abrasivity, plastic abrasion resistance, and plastic erosion resistance. The manufacture of many plastic products involves the use of injection molding or extrusion equipment. If a plastic contains inorganic fillers such as glass or carbon fiber reinforcement, they can be veiy abrasive to parts that contact the melted plastic extruder barrels, screws, molds, and check valves. 

Pins transfer the tensile loads from the barrels of one top plate to the barrels of the next top plate, and they must do so while the pins are mming in the barrels. The pins in flat-top chains act as both beams and bearings. Pins need high surface hardness to resist wear when the joints flex and they need high strength to earry the conveyed loads. The pins in stainless steel and plastic flat-top chains are usually made from stainless steel to provide the needed eorrosion resistance. 

Extruder Barrel n (extruder cylinder) A thick-walled, cylindrical steel tube, lined with a special hard alloy to resist wear that forms the housing for the extruder screw and contains, between itself and the screw, the plastic material as it is conveyed from feed hopper to die. Barrels are usually surrounded by heating and cooling media, such as electrical heater bands, cast-in-aluminum calrods and tubing for coolant, induction heaters, or, rarely, by a compartmented jacket for the... 

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