Single screw extruder single screw extruder plate

Single screw extruder single screw extruder, plastic sheet extrusion speed from the extruder material handling and flow rate are of para sticky fluid analysis, the plastic flow rate (ie extrusion speed) and screw speed is proportional, since convenient adjustment screw speed is characterizing the extrusion process extrusion speed important operating variables. Thus, in general, increase extruder screw speed is modern increase production capacity, to achieve an important means of high-speed extrusion. However, analysis showed that the length of the plastic melt, increasing the screw speed, on the one hand due to enhanced shear, the viscosity increased heat dissipation; on the other hand, in the absence of head pressure control, the screw speed increases, increase the flow rate, the material in the machine stays shortened. And the impact of the latter than the former, due to the melting of the segment length was extended to all but destroy the normal extrusion process. So when you need to increase the screw speed to increase the extrusion rate, it must also increase the heating temperature or the use of the control head pressure to achieve the purpose. Plastic extrusion speed or quality of plastics and plastic materials and temperature control related to the use of a variety of plastic plasticizing temperature vary. If you want fast extrusion plastic, only material quality, appropriate temperature, can be achieved. In addition, the extrusion speed and extrusion thickness is closely related to the normal extrusion process, a large amount of plastic extrusion slow; on the contrary, the extrusion rate soon, under the premise of guaranteeing quality, may be appropriate to increase the extrusion rate . Third, the pulling speed extruded products by traction device drag through the nose, in order to ensure product quality, uniformity and stability requirements for towing speed, coordination and screw speed, in order to ensure uniformity of thickness and extruded products diameter. If the pulling speed is unstable, easy to form extruded layer bamboo-like, while pulling out of large thickness is too slow, and the heap of plastic or empty pipe phenomenon; traction too fast, easily lead to pull out of thin attenuation, even unglued drain bag phenomenon. So the normal extrusion process, we must control the pulling speed. Fourth, the cold plastic extrusion molding process of the cooling system is also very important one. Generally divided into screw cooling body cooling, and cooling the product. 1. Cooling screw cooling action of the screw is to eliminate friction overheating, stable extrusion pressure to plastic stir, improve the quality of plastics. But its use must be appropriate, especially not over even otherwise, the barrel suddenly cooled plastic melt can lead to serious accidents. The screw cooling prior to extrusion is absolutely prohibited, or will lead to serious equipment accident. 2. The cooling effect of the cooling body is to increase the barrel body heat, in order to overcome the frictional heating hot formed, because the temperature in the extrusion process, even when cut off the heating power can not be stopped, so that a reasonable The temperature can not be long-term maintenance, the need to increase the heat, leaving the barrel to cool down in order to maintain the extrusion process of thermal equilibrium. Body cooling is carried out segments, mainly cooling fan based, taking into account the different functions of each segment of the body, for all of the segments with particular attention to the use of cooling products, cooling products 3. cooling is to ensure that products geometry and internal structure important measures. Plastic extruded layer after leaving the head, should be cooled immediately, otherwise it will deform under gravity. For PVC and other non-crystalline material can not consider the problem of crystal, plastic products can be quenching method, direct cooling water to the cooling water tank through the cold, no deformation. The cooling of the polyethylene, polypropylene and other crystalline polymer to crystallize the issue should be considered, if rapid cooling method, will adversely affect the plastic tissue, resulting in stress, which led to cracking of the product in the future One of the reasons, we must take it seriously in the extrusion process; polyethylene, polypropylene and other crystalline plastics extrusion cladding is appropriate to gradually cool to lukewarm water cooling method, generally depending on the device and set of auxiliary facilities, cooling tank should be divided segmented, the water temperature can be plastic extruded layer into the first stage tank 75 ℃ ~ 85 ℃ temperature began piecewise reduce the water temperature, until room temperature, the temperature difference between the temperature of each segment smaller and more reasonable. Fifth, the extrusion process of the technical requirements