The screw and barrel are the most critical and soul parts of the injection molding machine, which are often called the heart of the extruder. It is in this part that the plastic (rubber) changes from the glass state to the viscous state and then is made into various products through the die and auxiliary machines.
It can be seen from the analysis of the extrusion process that the extruder screw should be evaluated at least from the following aspects:
1. The output of the extruder screw
Output refers to the output or extrusion volume through a given head under the premise of ensuring plasticizing quality.
2. Chemistry and mechanics of extruder screw
Reduce energy consumption and reduce the burden on the main and auxiliary cooling systems. Even polyethylene and polypropylene, which are both polyolefins, are not the same.
3. Unit consumption of extruder screw
Unit consumption refers to the energy consumed per kilogram of plastic (rubber) extruded. It is more important to match the size of the head resistance and the performance of the extruder screw. If it is not done well, the quality of the products made are also different. For example, low temperature extrusion is a current development trend, which can improve the quality of extruded products (such as reducing internal stress, etc.). Preheating and non-preheating also have an effect on the processing performance and the radial temperature difference.
4. The adaptability of the extruder screw
The adaptability of the extruder screw refers to the adaptability of the screw to process different plastics, match different heads and different products. The former is amorphous plastic, even polyethylene. Therefore, different screw designs should be adopted to adapt to different materials without obvious melting point and electrical properties.
5. Difficulty in manufacturing extruder screw
A good extruder screw must also be easy to manufacture and have low cost.
6. Feeding section of extruder screw
This section of the screw groove has a fixed depth and its function is to be responsible for preheating and plastic solid conveying and pushing. It must be ensured that the plastic starts to melt at the end of the feed section.
Our conveying screw element is a self-sweeping extruder screw assembly, which opens longitudinally and closes laterally. It has a strong conveying effect. Its aterial residence time is short. Its self-cleaning is good and high pressure can be built up in a short axial distance.
The conveying element is mainly a threaded structure and its function is to convey the material and give the material a certain thrust, so that the material can overcome the resistance encountered in the flow channel. The conveying screw element is the most popular extruder screw element at present with strong conveying function, short residence time and good self-cleaning.
In terms of production specifications, LESUN not only provides general extruder screws and standard twin-screw extruder accessories produced by manufacturers, but also provides design and manufacturing services for special extruder accessories according to customer requirements. At the same time, we also provide surveying and mapping business and processing business of accessories for major extrusion press companies. If necessary, welcome to contact us.