Chlorinated polyethylene (CPE) is a chlorinated modification product of high-density polyethylene (HDPE). As a processing modifier for PVC, the chlorine content of CPE should be between 35-38%. Due to its excellent weather resistance, cold resistance, flame resistance, oil resistance, impact resistance (CPE is an elastomer), and chemical stability, as well as its good compatibility with PVC, CPE has become the most commonly used impact toughening modifier in PVC processing. The performance of CPE is determined by two factors: 1. Molecular Configuration of HDPE Due to the different process conditions during the polymerization reaction of PE, there are certain differences in the molecular configuration and properties of its polymer HDPE. The properties of CPE after chlorination of HDPE with different properties also vary. CPE manufacturers must choose suitable HDPE special powder resins in order to produce qualified CPE resins. 2. Chlorination conditions, i.e. chlorination process CPE, as a PVC processing modifier, is usually formed by chlorination reaction using aqueous suspension chlorination method. The key conditions of this chlorination process are light energy, initiator dosage, reaction pressure, reaction temperature, reaction time, and neutralization reaction conditions. The principle of PE chlorination is relatively simple, but the chlorination mechanism is more complex. Due to the relatively small investment in equipment for producing CPE, many rudimentary small CPE production plants are already scattered throughout China. This not only causes pollution to the ecological environment, but also is one of the important reasons for the instability of CPE quality. At present, there are a large number of low-quality CPE on the market. Generally, there are two types of low-quality CPE. One is due to some production plants not having the technical conditions and outdated chlorination processes. Another method is to mix a certain amount of calcium carbonate or talc powder in CPE to engage in unfair competition. For the first type of low-quality product, users only need to identify the manufacturer to prevent use, but for the second type of low-quality CPE, many people do not have enough understanding of it. As is well known, the prices of calcium carbonate and talc powder are relatively low, usually between 400-500 yuan/ton, while the price of CPE is generally between 8500-9500 yuan/ton. Some unscrupulous manufacturers mix low priced substances into CPE and sell them at slightly lower prices than qualified products to win market share. Even some manufacturers purchase cheap agglomerated CPE from CPE production plants, which are crushed and then mixed with a certain amount of calcium carbonate or talc powder. After repackaging, they sell it at a lower price (lower than the normal CPE price), engaging in unfair competition to seek improper benefits. Usually, the price of this type of CPE ranges from 7000 to 8000 yuan/ton, and even worse, it is sold at a price of 5000 to 6000 yuan/ton. In the processing of PVC, these inferior CPE are used as modifiers for PVC processing. In order to achieve the purpose of impact resistance and toughening of PVC products, the amount of CPE will inevitably increase, which will lead to an increase in plasticization time, a decrease in equilibrium torque, and an increase in the time to achieve equilibrium torque. All of these will result in a decrease in the overall performance of the product and an increase in the scrap rate. Therefore, whether using cheap but low-quality CPE reduces or increases production costs is self-evident!

The vertical thickness deviation of PVC sheet is large ① The temperature control of the barrel is unstable, resulting in unstable melt flow rate. The temperature of the barrel should be adjusted to stabilize it. ② The unstable screw speed leads to unstable extrusion volume. The process parameters of the extruder should be adjusted to ensure stable extrusion. ③ The roller speed in the three roller calender is unstable. The speed of the three roller calender should be adjusted. ④ The traction speed is unstable, fluctuating fast and slow. The traction speed should be adjusted to ensure smooth operation. Uneven lateral thickness of PVC sheet ① The design of the molding mold is unreasonable, and the fabric flow in the cross-section is uneven. The mold should be modified to ensure even discharge from the mouth mold. ② The adjustment of the gap between the mold lips is unreasonable and uneven. The middle gap should be slightly smaller than the gap on both sides. ③ The gap deviation between the three rollers of the three roller calender is relatively large, and the gap between the three rollers should be made even. ④ The height selection and processing of the three rollers are unreasonable. The height of the roller surface should be appropriately adjusted. The surface of PVC sheet is rough and lacks luster ① Rough or sticky material on the three roll working surface. The working surface of the three rollers should be cleaned and polished to achieve a smooth surface. ② The roller temperature of the calender is too low, and the temperature of the three rollers should be appropriately increased. ③ The surface of the mold lip is not smooth and should be cleaned. ④ The filter screen is broken and should be replaced with a new one. The surface of the board has horizontal lines ① Uneven mixing of materials causes fluctuations in extrusion volume. It is necessary to switch to uniformly mixed materials and adjust the process parameters of the extruder to ensure good plasticization of the materials and even extrusion volume. ② The barrel temperature fluctuates significantly. The temperature control system of the machine barrel should be checked and adjusted to ensure the accuracy of temperature control. ③ The speed of the three rollers is unstable or there are scratches on the roller surface. The speed of the three rollers should be adjusted to ensure smooth operation; Replace the damaged roller or repair the surface of the roller. ④ The traction speed is unstable or the traction roller pressure is insufficient. The traction speed and tension of the traction roller should be adjusted to ensure smooth traction of the sheet metal. Longitudinal lines on the surface of the board ① The extrusion temperature is too low, resulting in poor plasticization of the melt. The body and nose temperature should be appropriately increased The gap between the mold lips is too small. It should be appropriately increased. ②The opening of the mold lip is generally equal to or slightly smaller than the thickness of the sheet, which is expanded after extrusion and stretched to the required thickness. ③ The traction speed is too fast. It should be slowed down appropriately. The traction speed should be slightly faster than the extrusion speed. Warping unevenness ① Improper control of roller temperature in the calender, especially when the temperature of the middle and lower rollers is too low. The roller temperature should be controlled within an appropriate range. ② The contact surface between the two ends of the board and the air is too large, and the cooling speed is too fast. The cooling speed is also fast at the thinner parts of the board. When forming, the board bends towards the part that cools first, generating internal stress. In order to reduce internal stress during molding, it is necessary to cool as evenly as possible and reduce stretching. bubble ①: The raw materials are damp and the moisture content exceeds the standard. The material should be kept low in moisture, and the body and nose temperatures should be too high, causing material decomposition. The processing temperature should be appropriately reduced. Surface black or discolored stripes and spots ① The temperature of the machine head is too high, causing the material to overheat and decompose. The head temperature should be appropriately reduced. ②There are dead corners inside the nose of the machine, causing the decomposition of stagnant materials. The machine head should be cleaned to eliminate dead corners. ③ There are impurities blocking the nose of the machine, causing stagnation

How to improve the hardness of the PVC pipe produced if it cannot meet the standard? Mainly considering raw materials and formulas. Please refer to the following for details: 1. The precipitation volume of filling material (calcium powder) should preferably be within 2.6-3.0. To balance both hardness and tear strength, calcium powder should not exceed 25 parts. In addition, an appropriate amount of nano calcium can be added to improve the strength; 2. The selection of stabilizers is crucial. Stabilizers (lead salt stabilizers, calcium zinc stabilizers, etc.) should have good thermal stability and stable internal and external lubrication balance. Do not use stabilizers that are too cheap 3. If the stability is insufficient, a small amount of metal soap can be compensated; 4. The amount of CPE used should not be too large, as excessive CPE usage can affect the hardness of the pipe; CPE should be selected with high molecular weight, standard chlorine content, no more than 35%, and no residue; 5. Lubricants cannot be used too poorly, they must be good, and PE wax is the worst for external lubrication. The total dosage is about 1.5 parts, not too much, so that when the product deforms under external forces, the PVC molecular chain connection is not easily damaged; 6. In terms of modification, CPE+ACR system, ACR+MABS system, or CPE+MABS system can be selected. 7. Titanium dioxide can affect tear strength, so it is recommended to choose a fine one. We have done chemical products for nearly 30 years. Our main products include PVC RESIN, CPE, STABILIZER, TIO2, PE WAX, PARAFFIN WAX etc.

PVC plastic is a multi-component plastic, and different additives can be added according to different uses. Due to different components, PVC products exhibit different physical and mechanical properties, which are suitable for different applications. The proportion of PVC plastic pipes in plastic pipes is relatively large. RPVC pipes are made by mixing PVC resin with stabilizers, lubricants, and other additives, and then extruding them into pellets using an extruder. They can also be extruded into shape using powder materials in one go. RPVC pipes have good chemical corrosion resistance and insulation, mainly used for conveying various fluids and as wire sleeves. RPVC pipes are easy to cut, weld, bond, heat and bend, making installation and use very convenient. SPVC pipes are made by adding a large amount of plasticizer, a certain amount of stabilizer, and other additives to PVC resin, and then extruding them into shape after granulation. SPVC pipes have excellent chemical stability, excellent electrical insulation, and good flexibility and coloring properties. This type of pipe is often used instead of rubber pipes to transport liquids and corrosive media. It is also used as cable sleeves and wire insulation pipes. We have done chemical products for over 30years. Our main products include PVC RESIN, CPE, TIO2, PE WAX, PARAFFIN WAX, STEARIC ACID, STEABILIZER ETC.

We have done chemical products for over 30 years. Our main products include PVC RESIN, CPE, PE WAX, STEARIC ACID, PARAFFIN WAX, STABILIZER ETC.

PVC storage continues to decrease slightly compared to the previous month As of now, the social inventory of PVC in China is 458000 tons, a decrease of 0.95% month on month and a year-on-year increase of 23.55%; Among them, in the East China region, there were 395100 tons, a decrease of 1.35% month on month and a year-on-year increase of 27.16%; In South China, there were 62900 tons, an increase of 1.62% month on month and 4.83% year-on-year. International PVC Resin market demand slows down The demand for PVC Resin in India has slowed down, and most customers have already completed their stocking needs for September. Moreover, downstream pipeline demand is currently tepid, leading to a decrease in enthusiasm to continue hoarding inventory at current prices. At the end of the month, the demand for foreign trade terminal orders was weak. As early expectations did not materialize, the performance of industrial fundamentals was weak, market prices fluctuated and decreased, and the atmosphere for foreign trade exports slowed down. The bearish future prices exacerbated the downward trend in foreign trade export prices; During the week, relevant financial policies were released, and the macro environment for commodities was positive. The market volatility rebounded, but market transactions remained flat with limited upside potential. Domestic calcium carbide prices continue to rise This week, the domestic calcium carbide market still saw a narrow upward trend, with mainstream trade prices in the Wuhai region rising to 3250 yuan/ton, and overall supply remains tight. The production enterprises started this week with instability, and there were occasional power restrictions in the Greater Wuhai region, resulting in unstable supply. Junzheng's maintenance is approaching its end, and the external sales of calcium carbide have decreased. Downstream, there is a regional shortage of goods. The price of raw material orchid charcoal has increased, presenting a situation of easy to rise but difficult to fall, providing certain cost support. Next week, the market is expected to enter a consolidation phase. Firstly, in terms of supply, there are plans to resume production of calcium carbide furnaces that have been discontinued in the early stage. Secondly, the high price of PVC has fallen, which has hindered the upward trend under cost pressure. Thirdly, the cost side of blue charcoal prices has increased, providing support for the price side. With the increase in supply, the market's supply shortage has eased to some extent, but the supply is still tight in the short term. Overall, the scale of PVC maintenance in China is gradually decreasing, and supply is gradually recovering. There are currently no intensive maintenance plans in other regions of Asia; There has been no increase in orders from domestic downstream product companies at the end of the month, and there is sufficient inventory of products. Demand has not improved. From the perspective of foreign trade, there is a delay in demand in India and Southeast Asia, and the expected prices for October are low; From the perspective of market supply and demand, there has been no improvement in the slow increase in supply and demand, and the competitive pressure in the foreign trade export market has increased. The domestic cost side remains strong supported by high energy levels, providing good support for the bottom of the market. We have done chemical products for over 30 years. Our main products include PVC RESIN, CPE, PE WAX, STEARIC ACID, PARAFFIN WAX, STABILIZER ETC.

During the extrusion process of PVC foam board, the problems encountered can be basically classified into four categories, One is the stability issue Secondly, the issue of melt strength The third issue is lubrication The fourth issue is decentralization These four types of problems, especially the first three, are mutually constrained and cross influenced, and sometimes it is difficult to distinguish them immediately from surface phenomena. It is necessary to observe and analyze the root cause of the problem in order to fundamentally solve it. Insufficient stability can affect the entire board surface, resulting in yellowing and high brittleness of the foam sheet. Insufficient melt strength can lead to large foam pores and long longitudinal bubbles in foam sheets. The direct way to determine whether the melt strength is insufficient is to press the sheet wrapped on the middle roller with your fingers behind the three rollers. When the melt strength is good, you can feel elasticity when pressing. If it is difficult to bounce after pressing, it indicates poor melt strength. Due to significant differences in screw structure and cooling methods, it is difficult to determine whether the temperature is reasonable. Generally speaking, within the allowable load of the extruder, it is better to have a lower temperature in the 3-5 zone. In order to obtain uniformly foamed products in foamed pipes, it is also necessary to ensure that PVC materials have good melt strength. The foaming agent developed by the company is designed to solve the problem of foaming products, which can effectively improve the quality of foaming pipes. Lubricants are divided into external lubricants and internal lubricants. External sliding is beneficial for demolding and is beneficial for the smoothness of the sheet surface. If there is too little external sliding, the temperature in zone 5 of the extruder is difficult to control and easy to rise, which can lead to high temperature of the confluence core, large bubbles, string bubbles, yellowing and other problems in the middle of the sheet, and the sheet surface is also not smooth; If there is too much external sliding, the precipitation will become severe, manifested in the structure inside the mold and the precipitation on the surface of the board. It can also be manifested as some individual phenomena that move back and forth irregularly on the board surface. Internal sliding is beneficial for plasticization and the fluidity of the melt. Insufficient internal sliding makes it difficult to control the thickness of the plate surface, manifested as the thickness in the middle and thin on both sides of the plate; The phenomenon of high temperature of the confluence core is prone to occur due to excessive internal sliding. Poor dispersion can lead to uneven surface of the board. Process temperature control issues: The four issues mentioned above are fundamental, fundamental, and deep-seated issues. Compared to the above four issues, process temperature control is much more intuitive and is a surface issue, but poor temperature control can trigger the emergence of fundamental problems. Increasing the processing temperature will reduce the material stability time and result in stability issues; The original lubrication balance will be disrupted. Generally manifested as insufficient external lubrication, especially in the later stage, it is necessary to increase the amount of external lubrication added; An increase in temperature can also lead to a decrease in melt strength, an increase in foam pores and a decrease in the number of foam pores in the foam sheet, making the sheet brittle and prone to fracture; The increase in temperature reduces the strength of the melt and also reduces the viscosity of the melt. The viscosity decreases and the shear dispersion ability decreases. For screws with weak dispersion ability, uneven dispersion may sometimes occur. We deal with pvc resin for more than 30years. Except pvc resin, we also have its relative additives, such as CPE, PE WAX,PARAFFIN WAX,TIO2, STEARIC ACID,STABILIZER,CACO3 and so on. One-stop purchase can save your time.

Heat stabilizer is one of the indispensable main auxiliaries for PVC processing. The number of parts used for PVC heat stabilizer is small, but its role is huge. The use of heat stabilizer in PVC processing can ensure that PVC is not easy to degrade and relatively stable. The commonly used heat stabilizers in PVC processing include basic lead salt stabilizer, metal soap stabilizer, organotin stabilizer, rare earth stabilizer, epoxy compound, etc. The degradation mechanism of PVC is complex, the action mechanism of different stabilizers is different, and the stabilization effect is also different. PVC stabilizer, action mechanism and application 1 Lead salt stabilizer Lead salt stabilizers can be divided into three categories: (1) Pure lead salt stabilizer is mostly a basic salt containing PbO; (2) The heat stabilizer with lubricating effect is mainly the neutral and basic salt of fatty acid; (3) Composite lead salt stabilizer, and solid and liquid composite stabilizer containing a synergistic mixture of lead salt and other stabilizers and components. Lead salt stabilizer has strong thermal stability, good dielectric properties, and low price. The reasonable ratio of lead salt stabilizer and lubricant can widen the processing temperature range of PVC resin, and the quality of processed and post-processed products is stable. It is the most commonly used stabilizer at present. Lead salt stabilizer is mainly used in hard products. Lead salt stabilizer has the characteristics of good heat stabilizer, excellent electrical performance and low price. However, lead salt is toxic and can not be used in products that contact with food, nor can it make transparent products, and it is easy to be contaminated by sulfide to generate black lead sulfide. 2 Metal soap stabilizer Stearic acid soap heat stabilizers are generally prepared by saponification of alkaline earth metals (calcium, cadmium, zinc, barium, etc.) with stearic acid, lauric acid, etc. There are many kinds of products, each with its own characteristics. Generally speaking, lubricating stearic acid is better than lauric acid, and the compatibility with PVC lauric acid is better than stearic acid. Metal soaps can absorb HCl, and some varieties can replace the Cl atom of the active site with fatty acid radical through the catalysis of metal ions, so they can play a different degree of thermal stability on PVC. In PVC industry, there is rarely a single metal soap compound, but usually a compound of several metal soaps. The common stabilizer is calcium zinc soap. According to Frye-horst mechanism, the stability mechanism of calcium/zinc composite stabilizer can be considered as follows: first, zinc soap reacts with allyl chloride on the PVC chain, and then calcium soap, zinc soap and chlorine chloride react to form unstable metal chlorides. At this time, the auxiliary stabilizer, as the intermediate medium, transfers the chlorine atoms to the calcium soap to regenerate the zinc soap, delaying the formation of zinc chloride which can promote the dehydrochlorination. Calcium and zinc stabilizers can be used as non-toxic stabilizers in food packaging, medical devices and drug packaging, but their stability is relatively low. When calcium stabilizers are used in large amounts, their transparency is poor and they are easy to spray frost. Calcium and zinc stabilizers generally use polyols and antioxidants to improve their performance, and transparent calcium and zinc composite stabilizers for hard pipes have appeared in China. 3 Organotin stabilizer Alkyl tin in organotin is usually methyl, n-butyl and n-octyl. Most of the products produced in Japan are butyl tin, and octyl tin is more common in Europe. This is the standard non-toxic stabilizer approved in Europe, while methyl tin is used more in the United States. There are three main types of organotin stabilizers commonly used: (1) Aliphatic acid salts mainly refer to dibutyltin dilaurate, di-n-octyltin dilaurate, etc; (2) Maleate salts mainly refer to dibutyltin maleate, bis (monobutyl maleate) dibutyltin maleate, di-n-octyltin maleate, etc; (3) Mercaptans, of which bis (thiocarboxylic acid) ester is the most used. Organotin heat stabilizer has good performance and is a good variety for PVC hard products and transparent products. In particular, octyltin has almost become an indispensable stabilizer for non-toxic packaging products, but its price is relatively expensive. Organic tin heat stabilizer (tin mercaptoacetate) has a good stabilizing effect on PVC. Especially the liquid organotin stabilizer can be better mixed with PVC resin than the solid heat stabilizer. The organotin stabilizer (tin mercaptoacetate) can replace the unstable Cl atoms on the polymer, making the PVC resin have long-term stability and initial color retention. The stability mechanism of tin mercaptoacetate was proposed: (1) S atom can replace unstable Cl atom, thus inhibiting the formation of conjugated polyolefins. (2) As a product of PVC thermal degradation, HCl can also accelerate the formation of conjugated polyolefins. Tin mercaptoacetate can absorb the HCl produced. 4 Rare earth stabilizer Rare earth heat stabilizers mainly include organic weak acid salts and inorganic salts of light rare earth lanthanum, cerium and neodymium, which are rich in resources. The types of organic weak acid salts include rare earth stearate, rare earth fatty acid, rare earth salicylate, rare earth citrate, rare earth laurate, rare earth octanoate, etc. The preliminary study on the action mechanism of rare earth stabilizer is as follows: (1) The special electronic structure of rare earth lanthanide elements (2 electrons in the outermost layer and 8 electrons in the secondary layer, with many empty orbits) determines that the energy difference of their empty orbits is very small. Under the action of external thermal oxygen or polar groups, the outer or secondary outer electrons are excited, which can coordinate with the unstable Cl on the PVC chain, and can form a coordination complex with the hydrogen chloride decomposed during the processing of PVC, At the same time, there is a strong attraction between rare earth elements and chlorine elements, which can control the free chlorine element, thus preventing or delaying the automatic oxidation chain reaction of hydrogen chloride and playing a role of thermal stability. (2) The rare-earth multifunctional stabilizer can physically absorb the oxygen in PVC processing and the ionic impurities contained in PVC itself, and enter the lattice hole of the rare-earth multifunctional stabilizer to avoid their impact and vibration on the parent C-Cl bond. Therefore, the activation energy of HCl removal from PVC can be increased by the action of rare earth multifunctional stabilizer, thus delaying the thermal degradation of PVC plastics. (3) Suitable anion groups in rare earth compounds can replace allyl chloride atoms on PVC macromolecules, eliminate this degradation weakness, and achieve stability. There are many studies on rare earth stabilizers in China. In general, the stability effect of rare earth heat stabilizers is better than that of metal soap stabilizers. It has good long-term thermal stability, and has extensive synergistic effects with other stabilizers. It has the advantages of good tolerance, free from sulfur pollution, stable storage, non-toxic and environmental protection. In addition, rare earth elements have a unique coupling effect with CaCO3 and promote the plasticizing effect of PVC, so the amount of CaCO3 can be increased, the use of processing aid ACR can be reduced, and the cost can be effectively reduced. The stabilizing effect of rare earth on PVC is characterized by its unique synergistic effect. The proper coordination of rare earth with some metals, ligands and co-stabilizers can greatly improve the stability.

Generally, most of the plastic masterbatches are added calcium carbonate, but they must be calcite crystal ores. Because the ores are different, although they are all calcium carbonate, some can be produced. Some cannot be produced. Talcum powder and calcium carbonate can be used. In terms of cost, calcium carbonate is lower than talcum powder. In terms of production technology, calcium carbonate is easier to process than talcum powder. Talcum powder and calcium carbonate shall be added to the polypropylene granule for packing belt, and the ratio is: polypropylene: talcum powder: calcium carbonate=70:25:5. For woven bags, calcium carbonate should be used. The addition amount can reach more than 30 portions. Pay attention to the temperature during processing. 1. Talc powder and calcium carbonate are used for filling, and their main purposes are: 1. increase dimensional stability (i.e., reduce shrinkage), 2. increase the rigidity of the material, 3. increase the heat resistance of the material, 4. reduce the cost of the material, etc., but there are also some defects: 1. increase the density, 2. poor use, impact toughness, 3. material luster has decreased. 2. Talc powder and calcium carbonate have the same particle size difference, generally 300 mesh, 600 mesh, 800 mesh, 1250 mesh and 2500 mesh, and of course, there are finer ones. Generally, 800 mesh and 1250 mesh can be selected for plastic, which can make the performance/price ratio the highest. 3. The price of talc powder fluctuates. Generally speaking, it is not a big problem to determine the price according to the number of items. For example, the price of 800 items is between 700 and 850 yuan, and that of 1250 items is between 1000 and 1280 yuan. It is abnormal for the price to be too high or too low. About the different use of talc powder and calcium carbonate: 1. The shape of talc powder is flaky, so it has higher rigidity, dimensional stability, heat resistance and good reinforcement effect. 2. Calcium carbonate is generally granular, so its rigidity and other aspects are not as good as talc powder, but its price is lower, and its whiteness is high, and its impact toughness of plastics is small. 3. Talc powder has nucleating effect on polypropylene, while calcium carbonate has no obvious effect on this aspect. 4. Calcium carbonate can generally be divided into light calcium carbonate and heavy calcium carbonate, but talc powder has no such distinction. Talc powder is ground from natural minerals.

PVC is widely used in shoe materials because of its high performance-price ratio. However, white soles often change color and turn yellow, especially in high temperature weather in summer. In order to prevent the soles from changing color and turning yellow, we should first identify the reasons for the color and turn yellow, and then apply the right medicine to the case. First, precipitation. Because there are a lot of plasticizers (generally 60~100PHR) added to the shoe material, but the compatibility of liquid plasticizers (especially chlorinated paraffin, liquid paraffin, white oil, etc.) with PVC is not very good. When the temperature rises, it is easy to precipitate to the surface of the shoe material, resulting in yellowing of the sole. Solution: use plasticizers with high molecular weight and good compatibility with PVC, such as polyester plasticizers; Use high mesh calcium powder to increase dispersion and oil absorption value; Reduce the use of stearic acid soap and stearic acid lubricant, and replace with polyol ester lubricant; Use some type 2 and 3 resin powder to increase oil absorption value; Add ACR resin to improve the uniformity of plasticization, make the surface compact and reduce the exudation. Second, lead pollution. When the temperature is high in summer, lead salt stabilizers, especially powdered trisalt and bisalt, are used. When the temperature is high, lead pollution or sulfur pollution, yellowing and discoloration will occur when sulfur elements (such as packaging cartons) are encountered. Solution: use lead salt stabilizer for PVC shoes or calcium and zinc stabilizer for soles; Reduce exposure to sulfur; Reduce storage temperature, etc. Third, the stability is insufficient. Insufficient stability of PVC will lead to the process from white to yellow to red to brown, and then the conversation will turn black. Stability is divided into light stability, thermal stability and oxygen stability. Solution: replace with high-quality stabilizer or increase the amount of stabilizer; Add an appropriate amount of ultraviolet light absorber; Add antioxidants, etc. PVC foam sole reference formula Formula 1: PVC 100, DOP 80-85, light calcium 60-65, AC 0.5-0.6, foaming regulator about 2.0, lead salt compound stabilizer (TG-38A) 3.8, PE wax 0.6, stearic acid 1.0, titanium dioxide 2.5 Formula II: PVC 100, DOP 90, light calcium 70, AC 0.8, foam conditioner 2.0 or so, lead salt stabilizer (TG-38A) 4.0, PE wax 0.5, stearic acid 1.2, titanium dioxide or toner appropriate Formula III: PVC 100, DIBP 85, light calcium 60, AC (TG-75) 0.5, foam conditioner 2.0 or so, calcium zinc composite stabilizer 4.0, PE wax 0.3, stearic acid 0.5, titanium dioxide or color powder appropriate.