塑料的切削加工（Cutting of plastics）.docVIP

塑料的切削加工（Cutting of plastics） The production method of plastic parts by direct forming, but some pieces of plastic molding directly or on its accuracy is difficult, must be cutting. The cutting of plastic parts generally used metal processing equipment. Because the plastic and metal properties vary greatly, and the plastic variety, different kinds of properties are quite different, so cutting the plastic parts with its own features. [editor this paragraph] affects the performance of plastic machining thermal property And compared to metal, plastic heat capacity of small, poor thermal conductivity (the thermal conductivity of metal only 3/1000 or less), coefficient of thermal expansion (1.5 to 20 times larger than the metal). Therefore, in the cutting process caused by friction heat transmitted to the main tool. Even a small amount of heat to the plastic parts, plastic parts due to the incoming internal, prone to overheating, causing discoloration, plastic melting, even burning. But the temperature is too high, the plastic elastic deformation intensifies, influence the surface quality and dimensional accuracy of plastic parts, cause the workpiece to bounce is serious, even caused the accident. Therefore, often used in the processing of the coolant (generally use compressed air to reduce temperature). Modulus of elasticity The only 1/10 to the elastic modulus of plastic metal 1/16, cutting tool and fixture, if the pressure is too large, it will cause a large elastic deformation, affect the machining precision of plastic parts, can cause severe processing difficulties. Therefore in the cutting process, reasonable tool parameters, edge sharp, cutting dosage should be appropriate to reduce the cutting force. The clamping force is not too large. The characteristics of plastic cutting In the high-speed cutting, cut down the plastic debris in glue melting state, cold hardening. In the process, debris easily adhere to the tool, thereby changing the angle of the cutting tool,