Plastic extrusion is very important in the process of plastic production, so as the main equipment of plastic extrusion links: the selection and use of plastic extruders, is very important. Correct and reasonable use of extruder can give full play to the efficiency of the machine, maintain good working condition, and prolong the service life of the machine. Correct selection of extruders can better meet the needs of plastic manufacturers, reduce costs, and increase the profits of manufacturers.
Therefore, Jerry Shaw technicians in view of the above situation, the classification of extruders were summarized, hoping to provide help to everyone.
The core equipment of extruder is screw, so extruder can be divided into single screw extruder, twin screw extruder and multi-screw extruder according to the number of screw. At present, the single screw extruder is the most widely used and suitable for extrusion processing of general materials. The main sign of the development of single screw extruder is the development of its key component screw. In recent years, a large number of theoretical and experimental studies have been carried out on the screw. Up to now, there are nearly 100 kinds of screw, including separation type, shear type, barrier type, shunt type and wavy type.
Although the single screw extruder has been more perfect in recent years, with the continuous development of polymer materials and plastic products, the plastic industry is now demanding higher and higher quality of plastics, and more and more varieties of plastics are needed. Therefore, better processing technology is needed to produce higher-level plastic products, so a lot of them are needed. Plastics manufacturers began to shift their objectives to twin screw extruders.
Compared with single-screw extruder, twin-screw extruder has the following advantages: less heat generated by friction, more uniform material shear, screw conveying capacity, more stable extrusion, materials in the barrel mixing uniform and other characteristics, so it is welcomed by the majority of plastic production enterprises.
Especially SJSZ series conical twin-screw extruder has the characteristics of forced extrusion, high quality, wide adaptability, long life, low shear rate, difficult material decomposition, good mixing plasticization performance, powder direct molding, temperature control, vacuum exhaust and so on. It is suitable for the production of products such as pipes, boards and profiled materials.
The twin-screw extruder has good feeding characteristics, is suitable for powder processing, and has better mixing, exhaust, reaction and self-cleaning functions than single-screw extruder. The most outstanding feature of twin-screw extruder is that it is more stable and more balanced when processing plastics and blends with poor thermal stability.
In recent years, twin-screw extruders have developed greatly abroad. Various types of twin-screw extruders have been serialized and commercialized. There are also many manufacturers, which are roughly classified as follows:
According to the relative position of two axes, there are parallel and conical points.
According to two screw meshing procedures, there are meshing type and non meshing type.
According to the rotation direction of the two screws, there are identical and opposite directions, and in the opposite direction, there are inward and outward points.
According to the screw rotation speed, there are high speed and low speed points.
According to the structure of screw and barrel, there are integral and combined parts.
Single-screw extruder and twin-screw extruder have their own advantages and disadvantages. Choosing the type of extruder suitable for the production needs of enterprises can not only improve production efficiency, but also reduce the production cost of enterprises.
