Microleakage of preheater into the system of hazar

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Microleakage of preheater system for conversion and prevention measures against

, Is the national quality testing standards approach. Whiteness higher resin color that the more shallow, less decomposition of HC1, the higher the thermal stability of the resin, whereas the lower. Congo red method is to weigh a certain amount of PVC resin placed in the oil bath 180 ℃, the gradual decomposition of the released HC1 pH value of the test paper to change color in time to begin to quantitatively show that the resin can be released l_ thermal decomposition speed,[link widoczny dla zalogowanych], the faster The shorter the time that the more easily biodegradable, the lower the thermal stability of the resin, the higher the contrary. 2 to improve the thermal stability of PVC resin, PVC resin, measures the thermal stability of the whiteness of the aging process and plastic products for the transparency of products is essential to improve the thermal stability of resin processing helps prevent discoloration, resulting in more high, more high-quality products. PVC molecules in the number of irregular structure is the main reason for poor thermal stability, such as branched-chain, the internal double bond, end double bonds,[link widoczny dla zalogowanych], peroxide, the first one connections, resulting in the formation of the defect structure due to a raw material impurities, polymerization temperature control and residual monomer formulation and thus improve the thermal stability of PVC resin are mainly two ways: ① preventive stabilization techniques; ② degradation of the stability of the technology end. The former is to improve the purity of the synthesis of vinyl chloride monomer to reduce the post-resin synthesis of small molecular mass of irregular chain and the formation of substances; the latter for the preparation of the post-resin, the main recipe by adding or adjusting pH value of the regulator, heat PVC stabilizer additives to optimize the molecular structure and thermal decomposition or to improve the resin's thermal stability. Dongfeng Liuzhou Chemical Industry Co., Ltd. (hereinafter referred to Liuzhou company) production of PVC resin as technology, operations, equipment, scale, and many other influences, the whiteness of thermal aging has been less satisfactory, largely maintained at 66%, reaching less than the national standard (whiteness ≥ 74%),[link widoczny dla zalogowanych], both part of the high-end products can not meet the needs of users, but also likely to cause discoloration in the drying process to increase the product rate. Therefore, Guangxi Liuzhou company decided to overcome this difficulty, through joint analysis, research, and learn from the experience of brothers and manufacturers decided to use the first ② ways heat stabilizer is added to the test method. Heat stabilizers used in Chemical Technology Development Co., Ltd. Guiyang Kaitai production of \and processing in commonly used heat stabilizers, proved that this stabilizer has multiple effects, such as the effectiveness of prevention and stability, effectiveness of passive stability, but also to maximize the degree of polymerization and reduce residual VCM, it can improve the PVC whiteness of the thermal aging. 3 test process and results in June 2004 Liuzhou Company engineers and group leaders had a \Test methods are: material added each tank of liquid zinc 2.3kg, about 0.05% of the amount of material, feed material together with the other before the join. Tested a total of 9 vessels, sampling and analysis of the more typical 5 reactor, the results in Table 1. ** Table 1PVC test the performance of resin were produced PVC-SG5-based resin (a product). As can be seen from Table 1, add the liquid after the aging of zinc by the whiteness of 66% to an average of 75.9%,[link widoczny dla zalogowanych], an increase of about 10%, thermal stability time is greatly extended, has reached the national standard GB5761 --- 93 quality requirements ( that whiteness ≥ 74%), apparent density and also improved plasticizer absorption, and other quality indicators of no influence on the reaction time, temperature control, discharging operation, drying process, also without any effect, indicating test achieved some results. 4 goals and plans for future after the end of the experiment, Liuzhou company immediately conduct a careful summary, on the one hand with manufacturers to contact the exchange and communication; other organizations related to production, technology, quality inspection department analysis, discussion, and agreement was reached consensus, the end of 2004 began to put 8 to expand testing techniques used in actual production, after nearly 3 months of use, production of PVC-SG5 greatly improved the quality resin, aging whiteness has been stable at 74% or more, by plasticizer absorption has been stable at 23 - 25g, impurity particles has been stable at 20 below,[link widoczny dla zalogowanych], a product rate reached 96%, qualified rate of 99% or more, by the customers. And the low price of resin, the device is simple to run, to continuously enhance the quality and credibility of the resin product and market competitiveness has played a positive role. Is proposed to deepen the test, the thermal stability and heat terminator compound used to enhance the whiteness of the resin to 80% or more. . (Guangxi Liuzhou Dongfeng Chemical Co., Ltd.. Yuan Jie Cai)