The wide application of plastic products has promoted the rapid development of plastic machinery industry,?Extruder can be divided into single screw, twin screw and multi screw extruder according to the number of screws. And how to choose the satisfactory extruders and what matters to note when buying extruders are always a puzzling problem for users. Now let’s look at what matters we need to pay attention to when choosing extruders.
1. The rotational speed of the screw is the most critical factor affecting the productivity of an extruder. Screw speed is not only to improve the extrusion speed and extrusion volume of material, but also to make the extruder achieve good yield effect and achieve good plasticizing effect. In the past, the main way to increase extruder output is to increase the screw diameter. Although the diameter of the screw increases, the material extruded in the unit time will increase. But the extruder is not a screw conveyor. In addition to extruding materials, screws should be extruded, stirred and cut to make plastic plasticized. Under the premise that the screw speed is constant, the screw mixing and shearing effect of the large diameter large screw grooves is not as good as that of the small diameter screw.Therefore, the modern Extruder mainly improves the productivity and the quality of pipe making by increasing the screw speed. When the screw diameter is constant and the screw speed is increased, the torque of the screw will increase. When the torque reaches a certain level, the screw will be broken. However, through improving the material and production process of the screw, the screw structure is designed reasonably, the length of the feed section is shortened, the flow velocity of the material is improved and the extrusion resistance is reduced, and the torque can be reduced and the bearing capacity of the screw can be improved.
2. Screw structure is the main factor affecting the productivity of extruder. If there is no reasonable screw structure, it is not successful to simply increase the screw speed to increase the extrusion volume and violate the objective law. The design of high speed and high efficiency screw is based on high speed. The plasticizing effect of the screw at low speed will be worse, but the plasticizing effect of the screw is improved gradually after the screw speed is raised, and the optimum effect is achieved when the speed of the screw is reached. At this time there is a higher capacity and qualified plasticizing effect.
3. The improvement of the barrel structure is mainly to improve the temperature control of the feed section and set up the feed trough. Whether the temperature of the water jacket is reasonable is very important for the stable work and efficient extrusion of the extruder. The high temperature of the water jacket will soften the raw material, even melt the surface of the raw material, and weaken the friction between the raw material and the inner wall of the cylinder, thus reducing the extrusion force and the extrusion quantity. But the temperature can not be too low, the low temperature of the barrel will make the screw rotating resistance too large, more than the bearing capacity of the motor will cause difficulty in motor starting or unstable speed. Beier machine uses advanced sensors and control techniques to monitor and control the water jacket of the extruder, so that the temperature of the water jacket is automatically controlled within the optimum range of process parameters.
4. Under the premise that the structure is basically the same, the manufacturing cost of the reducer is directly proportional to its size and weight. Because the shape and weight of the reducer is large, it means that the material consumed during manufacture is large, and the bearing used is larger, which makes the manufacturing cost increase. In the extruder with the same screw diameter, the high speed and high efficiency extruder consumes more energy than the conventional extruder, doubles the power of the motor, and the seat number of the reducer is necessary. But high screw speed means low deceleration ratio. The same size reducer, low deceleration ratio and large deceleration ratio, gear modulus increased, reducer capacity to load also increased. Therefore, the increase of the volume and weight of the reducer is not linearly proportional to the power of the motor. If the extruder is used as the denominator, divided by the weight of the reducer, the number of extruders with high speed and high efficiency is small, and the ordinary extruder is large. With the unit output, the motor power of the high speed and high efficiency extruder and the weight of the reducer are small, which means that the unit production cost per unit output of the high speed and efficient extruder is lower than that of the ordinary extruder.
5. The high speed extruder is prone to vibration. Excessive vibration is very harmful to the normal use of the equipment and the service life of the machine. Therefore, multiple measures must be taken to reduce the vibration of extruders so as to improve the service life of the equipment. The most easily generated vibration part of the extruder is the high speed shaft of the motor shaft and reducer. First of all, high speed extruders must be equipped with high quality motors and reducers to avoid vibration due to vibration of motor rotor and reducer shaft. The second is to design a good transmission system. Attention should be paid to improving the rigidity, weight and quality of machining and assembly, and also an important link to reduce the vibration of extruders. When a good extruder is used, it does not need to be fixed with anchor bolts, and basically there is no vibration. This depends on the rigidity and weight of the frame. Besides, we should strengthen the quality control of the processing and assembly of the components. For example, when machining, the parallelism of the upper and lower planes of the rack can be controlled, the verticality of the installation surface of the reducer and the plane of the rack.
6. The production operation is basically a black box, can not see the inside of the situation, only through the instrument to reflect, so the precision instrument will make us more aware of its internal situation, so that production can be faster and better production effect.