After the resin is filled into barrels, it is found that there are impurities or abnormal conditions such as dark appearance or water droplets. At this time, the cause should be found. Problems with particles or other impurities can arise for three reasons.
If the filter bag is broken during the resin pressure filtration, or the fineness of the filter bag is unqualified, the acrylic resin should be re-filtered at this time; the packaging barrel is not clean; the water in the packaging barrel or other original chemicals in the recycling barrel have not been thoroughly washed.
During resin pressure filtration, samples should be taken frequently to visually check whether the resin is clear and transparent. Use a scraper fineness meter to check whether the fineness is qualified. Before packaging, the quality of the packaging barrels, especially the recycling barrels, must be strictly checked.
Qualified packaging barrels should be placed in the warehouse to prevent water or sand and dust. Qualified resins must be packaged by the acrylic manufacturer after cooling down. The barrel cover should not be tightened immediately, otherwise the barrel will be easily deformed when transported when it is hot.
Appearance requirements of the packaging barrels: Tighten the lids of the large and small barrels, and at the same time, they must be covered with iron sheets or plastic covers.
The quality of the dripping process control has a great impact on the resin quality and production safety. The reason why the reaction dripping mixed monomers should be uniform and moderate is to make the reaction uniform and the material heat exchange good.
Therefore, the dropwise addition of mixed monomers of acrylic acid must have the best dropping speed requirements. Generally, the solid content is 50%, and the dropwise addition is completed in 2.5-3 h; the general solid content is 60%, and the dropwise addition is completed in 3.0-3.5 h; high The solid content (70%) should be added dropwise in 4.5-6 h. This is the empirical data accumulated in mass production. It is best not to arbitrarily change the monomer dripping time for various reasons.
Due to improper process operation, when the mixed monomer is added dropwise, there is a situation of flushing in the kettle, because the production reaction of acrylic resin is a solution polymerization reaction, which is an exothermic reaction.
There are two situations for the punching. One: if the dripping time and speed of the operating procedures are not strictly controlled, such as the dripping speed of the mixed monomer is too fast. In addition, the heat given by the heat-conducting oil in the jacket of the reactor is too large, which will cause the reaction liquid to heat up rapidly, and the reaction heat is too large, and too fast. If the acrylic acid is not cooled in time, it will inevitably cause a sharp rise in the pot and flushing.
At this time, emergency measures should be taken: immediately turn off the heat transfer oil, turn on a large amount of cooling water for rapid cooling, quickly stop stirring, and stop dripping the mixed monomer. At this time, the operator must pay attention to personal safety and be careful to prevent fires caused by combustibles.
The second is that the temperature is sometimes low when the mixed monomer is added dropwise. When the dripping speed is too fast, the temperature rises too fast, and the material in the kettle accumulates to a certain extent, the reaction is violent and the heat released suddenly increases. At this time, it is too late for normal heat dissipation and cooling.
At this time, the above emergency measures should also be taken until the stirring is not started, the cooling water is turned off, the temperature is slowly raised, and the mixed monomer is slowly added dropwise until it is normal. In the above two situations, the acrylic acid manufacturer must take appropriate measures, otherwise it will cause serious consequences.
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