How to make a qualified twin screw screw
　　 1. The twin screw should be able to sweep the entire inner surface of the screw closely to obtain good heat conduction, mixing effect and narrow residence time.

　　 2. The radial gap between the screw and the barrel (barrel) should be less than 0.003 times the screw diameter.

　　 3. A streamlined design is adopted to avoid dead ends.

　　 4. When the plastic contains solid filler particles that require high-stress crushing, a dispersing and mixing unit should also be used. The dispersion mixing unit also ensures that unmelted plastic particles are not transported to the end of the screw. Therefore, even if there are no solid filler particles in the plastic, the dispersion mixing unit is very useful.

　　 5. The configuration of the distributed mixing section should take into account the reduction of the consistency difference and the non-uniformity of the melt temperature. The preferred position of the mixing section is at the end of the screw.

　　 6. When plastics are packed with densely corrosive fillers, such as dioxide erosion, glass, etc., the screw and barrel (barrel) should be made of wear-resistant materials.

　　 7. When extruding PVC, fluoroplastics or other plastics that can corrode the exposed gold shavings, the screw, barrel (barrel) and head should be made of corrosion-resistant materials.

　　 8. The mixing section should have low pressure drop and excellent forward pumping capacity.

　　 9. In order to improve the conveying performance of the material and reduce the hanging material, the radius of the rounded corner of the thread groove should be larger, and the multi-thread and small pitch should be avoided to reduce the screw friction and improve the conveying capacity.

　　 10. When the screw uses a coating, a coating with low friction should be given priority. This will improve the conveying performance of the screw, resulting in higher output and better stability, and the screw is also easier to clean.

　　 The above ten methods are necessary for making a qualified screw and can be used for reference.