Whether plasticizing extruder molding machines and plastic processing into a certain shape. Although, they have similar function, the differences between them still exist.
Popular point said, injection molding machine is through the plastic particles into a closed cavity, after happy and full of cavity, the suspension of work, by cooling the plastic shaped into a certain shape, open mold after work again. For example, plastic cups, plastic containers, plastic shell of various complicated situation, and so on. Extruder is obtained by adding plastic particles, happy and through continuous continuous extrusion die, such as plastic pipe, plastic board, plastic and so on. What specific plastic, two kinds of machine most of the plastic can be processing, such as PPPEABSPVC and so on. But processing different materials, screw structure is not the same.
1. Squeezing extrusion system, including screw, barrel, hopper, the nose, and mould, plastic plastic into homogeneous melt by extrusion system, and established in the process, under pressure by the screw continuous extrusion head.
Screw (1) : is it a squeeze molding machine zui main part, it is directly related to squeeze molding machine and the application scope of productivity, is made from high strength and corrosion resistance of alloy steel.
(2) the barrel: is a metal cylinder, generally with heat resistant, high crushing strength, strong wear resistance, corrosion resistance of alloy steel or lining made of alloy steel composite pipe. Barrel and screw, implementation of plastic crushing, softening and melting and plasticizing, exhaust and compaction, and to the continuous uniform conveying rubber molding system. General barrel length is the diameter of 15 ~ 30 times, in order to make fully heating and fully plastic into a principle.
(3) the hopper: at the bottom of the hopper is equipped with cutting device, in order to adjust and stop the flow of material, the side of the hopper is equipped with sight hole measuring device and calibration.
2. The role of the transmission system transmission system is a screw driver, and supply the screw in the required torque and rotational speed in the process, usually composed of motor, reducer and bearing, etc.
3. The heating cooling device heating and cooling is necessary for plastics extrusion process can be.
(1) now squeeze molding machine with electric heating, usually divided into resistance heating and induction heating, heating tablets in the fuselage, machine neck, in all parts of the nose. Heating device by the plastic inside the external heating tube, heating, in order to achieve the temperature of the process operation need.
(2) the cooling device is to ensure that the plastic in the temperature range of technical requirement. Specifically to rule out the screw rotating the excess heat generated by the shear friction, in order to avoid high temperature make plastic decomposition, charred or difficult to finalize the design. Barrel cooling into the water and air cooling two, general small and medium-sized squeeze molding machine adopts air cooling is more appropriate, large use water more or two forms combined with cooling; Screw water cooled mainly adopts center, the purpose is to increase the rate of solid conveying material, the quantity of adhesive stability, improve the quality of products at the same time; But the cooling in the hopper, one is to strengthen the transport of solid materials, prevent make jam the material plastic grains sticky with heating, 2 it is to guarantee the normal work of the transmission parts.
This is the general differences and similarities between extrusion machine and injection molding machine.
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