The injection of additives during injection is stable, and the relationship between temperature and melt viscosity of ABS plastic is different from other amorphous plastics. When the temperature rises in the melting process, the melting actually decreases very little, but once it reaches the plasticizing temperature (the temperature scale suitable for processing, such as 220～250℃), if the temperature rises blindly, the heat resistance will not be too high. The thermal degradation of ABS instead increases the melt viscosity, making injection molding more difficult, and the mechanical properties of the parts are also reduced. Therefore, although the injection temperature of ABS is higher than that of plastics such as polystyrene, it cannot have a looser temperature-increasing scale like the latter. In some injection molding machines with poor temperature control, when ABS parts are produced in a certain quantity, yellow or brown coking particles are often found on the parts more or less, and it is difficult to use new materials for air injection, etc. Ways to eradicate it out. The reason is that ABS plastic contains butadiene. When a certain plastic particle adheres firmly to the surface of the screw groove that is not easy to wash at a higher temperature, it will be degraded when it is subjected to a long-term high temperature effect. And carbonization. Since the high temperature operation makes difficult ABS may cause problems, it is necessary to limit the furnace temperature of each section of the barrel. Of course, the applicable furnace temperature of different types and compositions of ABS is also different. Such as the plunger machine, the furnace temperature is maintained at 180 ~ 230 ℃; the screw machine, the furnace temperature is maintained at 160 ~ 220 ℃. It is particularly worth mentioning that because the processing temperature of ABS is relatively high, it is sensitive to changes in various process factors. Therefore, the temperature control of the front end of the barrel and the nozzle part is very important. Practice has proved that any small changes in these two parts will be reflected on the parts. The greater the temperature change, the disadvantages such as welding seam, lack of gloss, flashing, sticking, and discoloration will be caused.