PVC “fish eye” problem, urgent help needed

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Recently, there have been sudden fluctuations in the \"fish eye\" indicator: first, the value was above 90 for samples taken from two reactors, then it was three reactors, and subsequently it kept changing to other reactors – sometimes several, sometimes twenty or thirty, sometimes above 90. Moreover, this phenomenon did not occur in every reactor, and there was no pattern to it at all. Inspection results: 1. Each reactor was opened for inspection, and the reactor walls were clean. 2. The discharge pipeline and the raw material pipeline leading to the reactor were checked for any accumulation of material. 3. Inspection of the recovered monomer shows no PVC material. The above rules out the possibility of fish-eye effect caused by secondary polymerization. 4. Monomer analysis parameters are normal: pH 6.5, with high-boiling substances at 5–25 PPM. 5. All parameters of the soft water are within normal ranges: pH is 6.7, and conductivity is ≤10^6. The dispersant and initiator were checked and found to be normal, and the mixture was re-prepared 5 or 6 times. 7. The reaction temperature is maintained stably, eliminating the possibility of local overheating. 8. There is no error in raw material measurement. Measures were taken: the amount of initiator was reduced to minimize the rapid particle formation at the beginning of the reaction. It doesn’t work. I really don’t know what else hasn’t been clarified. I’m on the verge of breaking down; please, fellow sailors, help me out and analyze it. Our method for preparing the initiator is as follows: first add 500 units of room temperature water, then add the dispersant, and finally pour in the initiator (EHP:CNP=5:1), after which it is left to settle for use. The method for preparing the dispersant is as follows: first add normal temperature water, then add the dispersant, raise the temperature, lower it again, and finally transfer it to a tank for use.