china extruder machine is one of the types of plastic machinery. According to the material flow direction of the extruder and the angle of the center line of the screw, the extruder can be divided into a right-angle head and an oblique-angle head. The screw extruder relies on the pressure and shear force generated by the rotation of the screw, so that the material can be fully plasticized and uniformly mixed, and formed through the die.
Each type of product in the china extruder machine production line has its own operating characteristics, and a detailed understanding of its operating characteristics can give full play to the performance of the machine.
The extruder is one of the types of machines. Grasp the operating points of the extruder and use the extruder correctly and reasonably. The use of screw extruder includes a series of links such as installation, adjustment, commissioning, operation, maintenance and repair of the machine. However, the working system of the screw extruder is the extrusion system, but it has unique characteristics, and special attention should be paid to its characteristics when using the screw extruder.
2. Working principle of china extruder machine
Extrusion molding is a process in which a plastic material with a certain plasticity is continuously pressed out through a mouth under certain conditions to make it a product with a certain cross-sectional shape.
During the advance of the rubber material along the screw, due to the results of mechanical and thermal effects, the viscosity and plasticity of the rubber material have changed to a certain extent, and it has become a viscous fluid. According to the change of the rubber material in the extrusion process, the working part of the screw is generally divided into three parts: the feeding section, the compression section and the extrusion section according to their different functions.
The features of each section are as follows:
Feeding section: Also known as solid conveying section, this section starts from the feeding port to the melting of the rubber. After the rubber material enters the feeding port, under the pushing action of the rotating screw, it moves relative to the thread groove and the inner wall of the barrel, and forms a certain size of micelles.
Compression section: Also known as plasticizing section, this section starts from the beginning of melting of the rubber until all the rubber flows. The compression section accepts the micelles sent from the feeding section, compacts them, further softens them, and discharges the air entrained in the rubber compound to the feeding section.
Extrusion section: Also known as the metering section, the rubber material conveyed by the compression section is further pressurized and stirred, and the rubber material in the thread groove has been formed in a completely flowing state at this time. Due to the rotation of the screw, the rubber material flows and is uniformly extruded from the flow channel of the die with a certain capacity and pressure.
3. Maintenance and maintenance of jwell extruder
The installation, adjustment and commissioning of the china extruder machine are generally specified in the extruder's operating instructions. Here, the operating points, maintenance and maintenance of the extruder are briefly described as follows:
The operator must be familiar with the structural characteristics of the extruder they operate, especially the structural characteristics of the screw, the characteristics of the heating and cooling control instruments, the characteristics of the machine head and the assembly conditions, etc., so as to correctly grasp the extrusion process conditions and correct operate the machine. When making different plastic products, the operating points of the extruder are different, but there are also similarities. The following is a brief introduction to the same operation steps when extruding various products and the operating points of the extruder that should be noted.
1. Preparations before driving
- The china extruder machine is used for extruding plastics. The raw materials should meet the required drying requirements, and further drying is required if necessary. The raw materials are sieved to remove agglomerates and mechanical impurities.
2.Check whether the water, electricity and gas systems in the china extruder machine equipment are normal, ensure that the water and gas paths are unobstructed and leak-proof, whether the electrical system is normal, whether the heating system, temperature control, and various instruments work reliably. Auxiliary machine empty car low-speed test run to observe whether the equipment is running normally; start the vacuum pump of the setting table to observe whether the work is normal. Lubricate the lubricating parts of various equipment. If a fault is found, remove it in time.
3.Install the machine head and the setting sleeve. According to the variety and size of the product, select the head specification.
- The china extruder machine can be started after the constant temperature. Before starting the machine, the bolts of the machine head and the extruder flange should be tightened again to eliminate the difference in thermal expansion between the bolts and the machine head. The order of tightening the head bolts is to tighten diagonally. , the force should be even. When tightening the flange nut of the machine head, it is required to be tight around the same, otherwise the material will run out.
2.When driving, select and press the "ready to start" button, then connect the "start" button, and then slowly rotate the screw speed adjustment knob, and the screw speed starts slowly. Then gradually increase the speed, adding small amounts at the same time. When feeding, pay close attention to the indication changes of the host ammeter and various indicating heads. And according to the need to add enough material, the twin-screw extruder uses a metering feeder to feed the material evenly and at the same speed.
- When the output of the die is uniform and the plastic is good, the setting sleeve can be drawn. Judging the degree of plasticization depends on experience. Generally, the china extruder machine can be judged according to the appearance of the extruded material, that is, the surface is shiny, free of impurities, no foaming, coke and discoloration, and the extruded material is squeezed by hand to a certain degree. There are no burrs and cracks, and there is a certain elasticity, which means that the material is well plasticized. If the plasticization is poor, the screw speed, barrel and head temperature can be adjusted appropriately until the requirements are met.
4.During the extrusion production process of china extruder machine, it is necessary to regularly check whether various process parameters are normal according to the process requirements, and fill in the process record sheet. Check the quality of profile products according to the quality inspection standards, and take timely solutions if problems are found.
- Stop feeding, squeeze out the plastic in the china extruder machine, and when the screw is exposed, turn off the power of the barrel and the head, and stop heating.
2.Turn off the power supply of the extruder and auxiliary machines, and stop the operation of the screw and auxiliary machines.
3.Open the connection flange of the head of the china extruder machine and disassemble the head. Clean the perforated plate and various parts of the handpiece. In order to prevent damage to the inner surface of the machine head during cleaning, the residual material in the machine head should be cleaned with a copper sheet, and then the plastic adhering to the machine head should be ground off with sandpaper, polished, and coated with engine oil or silicone oil to prevent rust.
4.Cleaning of screw and barrel, after removing the machine head, restart the main engine, add parking material (or crushed material), and clean the screw and barrel. At this time, the screw is selected at a low speed to reduce wear and tear. After the stopped material is crushed into powder and completely extruded, compressed air can be used to repeatedly blow out residual pellets and powder from the feeding port and the exhaust port until there is no residual material in the barrel, then reduce the screw speed to zero and stop the extrusion. machine, close the main power supply and cold water main valve of the china extruder machine.
5.The safety items that china extruder machine should pay attention to when extruding are: electricity, heat, mechanical rotation and loading and unloading of heavy parts. The extruder workshop must be equipped with lifting equipment to assemble and disassemble heavy parts such as head and screw to ensure safe production.