The hottest PVC processing aids in China have made

2022-08-08
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Major breakthroughs have been made in PVC processing aids in China

Beijing Institute of chemical industry, Shanxi Institute of chemical industry, etc. were the first to engage in the research of PVC processing aids in China. Shanghai coral chemical plant first realized industrial production in the early 1980s, and its brands are collectively referred to as acr201 and acr401 in China. PVC is one of the five general plastics in the world. In recent years, with the rapid development of China's national economy, PVC products have increased at a rate of more than 20% every year. In the late 1990s, with the development of China's PVC industry, especially the rapid development of plastic profile and plastic pipe industry, the demand for processing aids has also increased rapidly. At present, Shandong ranks first in output, followed by Jiangsu and Zhejiang

with the deepening understanding of processing aid manufacturers on PVC plasticization mechanism, PVC processing technology and PVC equipment, processing aid manufacturers have developed a series of processing aids for the defects of processing equipment and the performance defects of PVC products. These processing aids are essentially different from traditional processing aids, breaking through the limitations of traditional processing aids and solving a series of practical problems that traditional processing aids cannot solve. Specifically, PVC processing aids are making major breakthroughs in the following directions

(1) super plasticizing processing aids

are suitable for large amount of fillers, large amount of external slip, and weak shear force of equipment. It is necessary to greatly increase the shear force, strengthen plasticization, and improve the melt strength. The viscosity is very large, which can make up for the decline of melt viscosity caused by weak shear force of equipment and large amount of fillers in the formula, It breaks through the defects of traditional processing aids, such as low melt viscosity when the plasticizing speed is fast and slow plasticizing speed when the melt viscosity is high

(2) super melt strength processing aids

are suitable for use when the amount of filler is large, the shear force of the equipment is strong, and the melt strength needs to be greatly improved. This kind of processing aid is characterized by average plasticizing speed, but high melt viscosity, which is more than three times that of the traditional processing aid ACR-401

(3) lubricating processing aids

lubricants, especially external lubricants, can reduce the external friction between the melt and the metal surface, prevent the melt surface from cracking, and improve the surface finish of products. However, if the shear force of the equipment is weak and the plasticizing ability is not strong enough, the addition of external lubricants will cause poor plasticization of products, reduce the mechanical properties, and the addition of low molecular weight lubricants will cause precipitation and shorten the start-up time. In order to avoid precipitation and poor plasticization caused by excessive use of external lubricant, lubricating processing aids can be used

(4) processing aids to increase the hardness of PVC products

there are many factors that affect the hardness of PVC products. On the premise of unchanged formula, greatly increasing the shear and increasing the melt pressure can minimize the residue of various low melting point external slip agents in the products, so as to greatly improve the Vicat softening point and hardness of the products. This kind of processing aids is characterized by high glass transition temperature and low melting point. The lower melting point is to ensure the fast plasticizing speed, so as to extend the plasticizing experience of PVC, make PVC plasticize fully, and increase the Vicat softening point and hardness of PVC products by using the average glass transition temperature of low melting point

(5) ACR for pipe fittings

the processing of PVC pipe fittings requires that PVC melt must have the characteristics of full plasticization, high melt strength and good fluidity, but good fluidity and high melt strength are a pair of contradictions. Generally, when the melt strength is high, the fluidity is poor. Traditionally, adding various "vitamins" to metal materials is an effective way to enhance the fatigue resistance of metals. The processing aids overemphasize the melt strength and ignore the fluidity, resulting in poor surface gloss of PVC pipe fittings and butterfly spots in serious cases. In order to solve the above problems, pipe manufacturers added plasticizers, which significantly improved the gloss of pipe fittings, but greatly affected the mechanical properties. The new ACR for pipe fittings adopts a special formula, which greatly improves the fluidity of the melt while ensuring the strength of the PVC melt, and ensures that the surface gloss of the pipe fittings is greatly improved on the premise of good internal quality

in addition to the above-mentioned processing aids, there are also processing aids that can improve the surface gloss of products and the fillet strength of profiles. PVC processing aids have developed from traditional ACR-201 and ACR-401 to multi-function, and there are more and more types of products. Some defects of PVC products are matched with corresponding processing aids. Tailoring and measuring samples should be cut from test pieces with uniform thickness, and customization has become a major trend in the PVC processing aids industry. New processing aids this fund will help to develop new types of packaging materials and plastic products will emerge in endlessly

pvc pure resin is easy to decompose during processing, with poor fluidity, low impact strength and poor weather resistance. Therefore, various auxiliary materials need to be added in the processing process to improve its performance. Such as lubricants, heat stabilizers, impact modifiers, processing aids, etc. In the process of development and application of processing aids, according to the composition of products, they are roughly divided into the following categories: methyl methacrylate (MMA)/acrylate copolymer, mma/styrene copolymer, acrylonitrile/styrene, etc. at present, mma/acrylate copolymer is the most used and has the best effect

pvc processing aids were first developed by rohmhass company in the United States in 1958, and the first brand k-120 was launched in the same year. Since then, many foreign companies began to set foot in this field and develop similar products. After the 1970s, with the rapid growth of PVC products, processing aids have been widely used. At present, the main foreign manufacturers and related products include Mitsubishi P series, Kaneka PA series, rohmhass K series, bear F series, atofina P series, and LG Chemical PA series

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