The main body of the plastic extruder is an extruder，consisting of an extrusion system, a transmission system (Single Screw Gearbox and motor) and a heating and cooling system.
The extrusion system includes a screw, a barrel, a hopper, a handpiece, and a mold. The plastic is plasticized into a uniform melt through an extrusion system, and the extruder is continuously extruded under the pressure established in the process.
⑴Screw: It is the most important part of the extruder. It is directly related to the application range and productivity of the extruder. It is made of high strength and corrosion resistant alloy steel.
⑵Barrel: It is a metal cylinder. It is generally made of alloy steel with high heat resistance, high compressive strength, strong wear resistance and corrosion resistance or composite steel pipe lined with alloy steel.
⑶Hopper: The bottom of the hopper is equipped with a cutting device to adjust and cut the flow. The side of the hopper is equipped with a sight hole and a calibration metering device.
⑷Head and die: The machine head consists of an alloy steel inner sleeve and a carbon steel jacket. The machine head is equipped with a forming die. The function of the machine head is to convert the rotating plastic melt into parallel linear motion, and evenly and smoothly introduce the mold sleeve. Medium and give the plastic the necessary molding pressure.
The function of the drive system is to drive the screw, which supplies the torque and speed required by the screw during the extrusion process, usually consisting of a motor, a Plastic Extrusion Gearbox and a bearing. Under the premise that the structure is basically the same, the manufacturing cost of the Screw Barrel Gearbox is roughly proportional to its external dimensions and weight. Because the shape and weight of the twin screw extruder gear reduction are large, it means that there are many materials consumed during manufacturing, and the bearings used are also relatively large, which increases the manufacturing cost.
In the same screw diameter extruder, the high-speed and high-efficiency extruder consumes more energy than the conventional extruder, and the motor power is doubled. It is necessary to increase the frame number of the industrial ZLYJ330B Gear reducer. But a high screw speed means a low reduction ratio. Therefore, the increase in the volumetric weight of the China ZLYJ173C Gear Reducer unit is not linearly proportional to the increase in motor power.In terms of unit output, the motor power of the high-speed high-efficiency extruder is small and the weight of the reducer is small, which means that the unit production cost of the high-speed and high-efficiency extruder is lower than that of the ordinary extruder.
Heating and cooling device
Heating and cooling are essential for the plastic extrusion process.
(1) The extruder usually uses electric heating, which is divided into electric resistance heating and induction heating. The heating piece is mounted on the fuselage, the neck and the machine head. The heating device heats the plastic in the cylinder from the outside to raise the temperature to achieve the temperature required for the process operation.
(2) The cooling device is set to ensure that the plastic is in the temperature range required by the process. Specifically, it is to eliminate the excess heat generated by the shear friction of the screw rotation, so as to avoid the decomposition of the plastic, the scorch or the setting of the plastic is difficult.
With Best Regards,
Cherry Zhang ( Sales Department; Miss. )
NER GROUP CO.,LIMITED
Yantai Bonway Manufacturer Co., Ltd
Add:No.5 Wanshoushan Road Yantai city Shandong Province, China