How to improve PVC resin quality?
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Our factory has recently paid special attention to the quality of PVC resin. The analysis index of the resin produced is tested as: Appearance 0.52-0.54 (there is still no effect by adjusting the dispersant system) Oil absorption 20-24 Moisture content 0.25-0.40 Whiteness 79-81 (cannot be improved) Fish eye 10-18 (basically greater than 15, recently hundreds of tons of resin have been classified as non-premium grade resin due to fish eye exceeding the standard) The dispersants used in our factory are four composites: Two types of initiators: PVA, GH20, F50, and 02: EHP, CNP and other additives: ammonium bicarbonate and zinc acid are mixed, ammonium bicarbonate concentration is 10%. Could you please give me some advice on the first and second aspects, what aspects can be used to improve the quality? You can also send me some information for reference, preferably the polymerization kettle recipe. Thanks in advance! ~~~~~~~ This post was last written by wang * neng edited on 2009-2-9 11:28 ]
Overall, it seems that the quality of the monomer is not good. Reduce the reaction temperature by 0.5 degrees and take a look!
There are many factors that affect the quality of PVC! First of all, everyone must admit that: The quality of the ethylene method is superior to that of calcium carbide! But what’s the advantage? Why is it excellent? First of all, I think it’s still a problem with the processing route! Because the raw material route of calcium carbide method is relatively long, the raw materials are not pure enough. ； Secondly, the harmful factor of mercury is introduced into the calcium carbide method. ； The last step is our choice of equipment and materials. In fact, the chemical industry is very simple, just like cooking! It is necessary to select raw materials, then clean the raw materials, and then obtain the final product through processing under various conditions! This is a big problem that requires systematic sorting and rethinking. There is still a lot in the calcium carbide production process that requires us to make progress bit by bit and optimize it slowly! !
What is the quality of the monomer? Does the water content of the monomer exceed the standard? How much terminator should be added? What are the stripping and drying temperatures? Finally, can you introduce the mixture of ammonium bicarbonate and zinc acid?