The screw of the parallel twin screw extruder in the same direction is designed based on the principle of integration, and can be replaced and combined according to different material needs. When disassembling the screw, the material inside the main machine should be drained as much as possible (if the material is high viscosity plastic such as PC or medium viscosity plastic such as ABS and POM, PP or PE material can be added to clean the chamber before parking). Then, the main machine and various auxiliary machines should be stopped, and each section of the electric heater can still maintain normal operation. Then, the screw should be replaced according to the following steps.

Plastic modification is a method of improving the quality of plastics by adding additives, fillers, etc. to alter their properties. Meanwhile, plastic modification is also the most effective way to reduce the cost of plastics. The elements of formula design in plastic modification mainly include material selection, compounding, dosage, and mixing method. The interaction between various elements can be either mutual assistance or mutual cancellation. Therefore, designing a high-performance, easy to process, and low-cost formula is not an easy task.

Nylon (PA) has a series of excellent properties such as high mechanical strength, chemical resistance, oil resistance, wear resistance, self-lubricating, and easy processing and molding, and has become one of the widely used thermoplastic engineering plastics both domestically and internationally.

Thermoplastic elastomers, abbreviated as TPE or TPR, are also referred to by many as SBS, a specific type of elastomer. But in reality, there is no unified name for thermoplastic elastomers both domestically and internationally, and most of the time they are represented by the English abbreviation TPE.

PVC needs to add additives in processing in order to produce various products that meet people's needs, such as soft, hard, transparent, good electrical insulation, foaming, etc. When selecting the variety and dosage of additives, it is necessary to comprehensively consider various factors, such as physical and chemical properties, flowability, and formability, in order to ultimately establish an ideal formula.

Coupling is an important connecting device between the main motor of the extruder and the gearbox. Currently, nylon rod couplings and safety couplings are commonly used on the market. Nylon rod couplings have a simple mechanical structure and low cost, but the torque is not accurate. They rely entirely on the shear force of the torque greater than that of the nylon rod. When the nylon rod is cut off, it needs to be reattached.

Thermoplastic elastomer is an environmentally friendly low-carbon composite material that possesses the characteristics of rubber (high elasticity, compression permanent deformation, etc.), as well as the processing characteristics of plastic (simple process). In most regions, the abbreviation TPE is commonly used to refer to thermoplastic elastomers. Another theory is that TPE is the general term for thermoplastic elastomers, TPU is thermoplastic polyurethane, TPV vulcanized thermoplastic elastomers, and TPR is generally considered as shoe sole material in China.

1 Overview of modified plastics for vehicles; 2 Automotive use and modification of PP; 3 Automotive use and modification of PA; 4 Automotive use and modification of ABS; 5 Vehicle use and modification of other plastics; 6 Conclusion

The main components of automobile lights are composed of reflectors, lenses, casings, light sources, electronic circuits, and installation accessories. With the development trend of lightweight automobiles, the proportion of plastics in automobiles is getting higher and higher.

With the development of industries such as automobiles, machinery, electronics, and aerospace, the requirements for material properties are becoming increasingly high. Developing high-performance and multifunctional modified nylon (PA) special materials has become a major research and development topic.