PVC product quality
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The PVC drying system used in our factory combines air flow drying with cyclone drying, resulting in a consistently high and unstable level of impurity particles in the product. I would like to ask what the reason is? Thank you!
Our factory’s air filters have four layers of filtering material – do you have that?
I think it’s due to 1) problems with the system itself – there are dead zones and storage areas within it; 2) insufficient air flow in the system, resulting in high drying temperatures; 3) the material stays in the system for too long. This post was last edited by limingshuguang on 2009-4-15 at 22:32.]
What was said above is correct; the entire drying system needs to be cleaned. This post was last edited by limingshuguang on 2009-4-15 at 22:33.]
The last edit to this post was made by clq20040107 on 2011-10-12 at 11:16. The factor that has the greatest impact on the quality of PVC resin is impurities, and there are more than a dozen types of such impurities. 1. Is the polymerization additive system clean, mainly the HPMC tank? ； 2. Single-day rest quality: whether it contains impurities ； 3. Whether each piece of equipment has been repaired, accessed by people, or used in reverse ； 4. Removal of material trapped in dead corners within the stripping tower ； 5. Dry air filter ； 6. The accumulated material in the air flow tower is blown away ； 7. Regularly clean the drying bed ； There are a few more; I can’t remember them right now, I’ll look into it later. This post was last edited by ysy_jing on 2008-4-26 11:38.]
PVC drying systems generally include cyclone drying and fluidized bed drying. The combination of gas flow drying and cyclone drying you mentioned is not clear to me; the number of impurity particles in the product remains high and unstable – exactly how many are there? It is impossible to determine ； Process issues, management issues, or operational issues!
First, it is necessary to determine what type of impurity particles are present. Generally, black and yellow spots are caused by the resin changing color due to heat. Once the type has been identified, it is important to find out where the material is exposed to heat for extended periods of time; both steaming and drying processes can result in the appearance of such black and yellow spots. Material trapped in small dead corners can affect the quality of many batches of product. Sampling and analysis should be carried out in various locations, using the process of elimination. Last edited by limingshuguang on 2009-4-15 at 22:34.]
A cleaning hole can be added at the bottom of the air flow tower, allowing for cleaning without shutting down the system, which reduces the problems caused by impurities resulting from cleaning while the system is shut down