Reasons for color change of PVC foaming regulator

1. Firstly, it is necessary to judge whether there is a problem with the foaming agent itself. PVC foaming regulator uses the gas generated by the thermal decomposition of the foaming agent to cause pores. When the processing temperature cannot reach the decomposition temperature of the foaming agent, it will not foam. Different kinds of foaming agents have different decomposition temperatures. Even if the same foaming agent is manufactured by different manufacturers, the decomposition temperature is not completely the same, and not all PVC is suitable for foaming, so it is necessary to choose a material with a relatively low degree of polymerization, which has a low processing temperature

2. The decomposition temperature of normal foaming agent is higher than the processing temperature of PVC. If no appropriate auxiliary agent is added, the result is that PVC has decomposed (yellowing or blackening) and ACR has not decomposed (foaming). Therefore, a stabilizer must be added to keep PVC stable. On the other hand, an auxiliary agent that promotes AC foaming is added to reduce the AC decomposition temperature to match it. There are also additives to make the foam pores small and dense, that is, to avoid continuous large bubbles to reduce the strength of products. Since the temperature is low and no longer yellow, it can be determined that the temperature is high, which causes the decomposition of PVC to turn yellow. In addition, the decomposition of PVC is a self promoting reaction, which means that the substances decomposed further promote the decomposition. Therefore, it is often seen that the temperature is not high, and a large amount of decomposition occurs when the temperature is slightly higher