Excerpt: Li Xiuquan Studio! !
1. The design formula should be comprehensively screened in many aspects. 1. Ensure the specified physical characteristics. The so-called physical properties are generally in the following aspects: tensile strength, tear strength, modulus stress, hardness, wear, fatigue and fatigue damage, resilience, elongation at break and so on.
2. In the process of rubber compound processing, the performance is excellent, which ensures the high yield and material saving of products.
3. Low cost and cheap price.
4. The raw materials used are easy to buy.
5. High productivity, convenient processing and less energy consumption in the manufacturing process.
6. Meet the requirements of environmental protection and health and safety.
1. Fully understand various rubber characteristics.
Physical characteristics of natural rubber;
A. Natural rubber softens slowly after heating, completely softens to a molten state at 130- 140℃, gradually hardens when the temperature drops to zero, and becomes brittle at -70℃. The rebound rate of natural rubber can reach 50-85% in the range of 0- 100 degrees, and it still maintains normal performance when it rises to 130 degrees. The highest elongation can reach 1000%. Natural rubber is a kind of crystalline rubber with strong self-reinforcement and excellent mechanical properties. The tensile strength of pure rubber reaches1.7-25-35 MPa, reinforced vulcanized rubber reaches 25-35 MPa, and bending reaches more than 200,000 times. This is because natural rubber has small hysteresis loss and low calorific value. Natural rubber has good air tightness. The aging resistance of natural rubber is poor, and rubber without antioxidant will crack when exposed to strong sunlight for 4-7 days. With a certain concentration of ozone, it cracked in a few seconds.
Natural rubber has good alkali resistance, but it is not resistant to strong acid. Resistant to polar solvents, so it is not resistant to nonpolar solvents and has poor oil resistance.
With the cooperation of natural rubber, the amount of sulfur and accelerator in common vulcanization system is 2.0-2.4 and 1.2-0.5, respectively. Semi-effective vulcanization system sulfur 1.0- 1.7
2.5- 1.2 accelerator, 0.4-0.8 sulfur in effective vulcanization system and 5.0-2.0 accelerator. Ordinary sulfur system has more sulfur cross-linking health, but single sulfur is less healthy. Polysulfide has low energy, poor stability, poor heat resistance and aging resistance. But the comprehensive physical and mechanical properties are good. Ordinary sulfur curing system is easy to spray sulfur after adding sulfur for a long time, which can be replaced by insoluble sulfur to improve the physical and mechanical properties of vulcanized semi-finished products and solve the problem of glue return at high temperature. The tensile stress, modulus stress and elasticity can be improve, and that use of tread rubber can also improve wear. But there is a disadvantage, sulfur is fast and easy to burn.
Effective vulcanization system will not cause vulcanization reversion, and is generally used to manufacture excellent products with low creep rate, high elasticity and low heat generation. The dosage of sulfur is generally 0.6-0.7 parts, zinc oxide is 3.5-5 parts, and TMTD and N, N- dimorpholine disulfide are generally used as sulfur carriers. The aging performance of the effective curing system has also been greatly improved.
Semi-effective curing system has the mechanical and physical properties of sulfur curing system, and effective curing system has low creep, elasticity and heat generation. The phenomenon of vulcanization reversion is between the two. Qiu Lan can be used, but it is easy to burn by spraying frost. DTDM is a common sulfur donor. When DTDM can completely replace sulfur in vulcanization, an effective vulcanization system will be formed. Its advantages are long scorching time, no frost spraying, no pollution and good physical and mechanical properties of vulcanized rubber. In the all-natural rubber formula, the rubber compound has wear resistance, dynamic performance, aging resistance and reversion resistance. The bending performance is obviously improved. The dosage of DTDM in natural rubber is 0.5 phr, which is equivalent to 1 phr sulfur. It is equivalent to 0.6-0.8 part of sulfur in 70/30 natural/cis-butyl rubber. 50/50 is equivalent to 0.5 part sulfur. The dosage of DTDM should not exceed 1 phr.
Natural rubber can be vulcanized with organic peroxide. Dicumyl peroxide is the most commonly used. DCP has good thermal stability, high temperature aging resistance, small creep, small compression set, good dynamic performance and good reversion resistance. Disadvantages are slow vulcanization speed, easy scorching, low tear strength, incompatibility with anti-ozone agent, and easy scaling of vulcanization mold. The optimum vulcanization temperature of natural rubber is 143℃, and the reversion phenomenon occurs above 150℃.
B styrene-butadiene rubber emulsion polymerization styrene-butadiene, solution polymerization styrene-butadiene and carboxyl styrene-butadiene. The content of styrene and butadiene determines the properties of the polymer. The copolymer with 23.5% content has the best balance of comprehensive properties, and the copolymer with 50-80% content is called high styrene-butadiene rubber.
Emulsion polymerization of styrene-butadiene mainly has the following points: 1. The vulcanization curve is flat, and the rubber compound is not easy to scorch; 2. Wear resistance, heat resistance, oil resistance and aging resistance are better than natural rubber, and the high-temperature wear resistance is good. 3. The processing molecular weight will not decrease after it is reduced to a certain extent, and it is not easy to overtraining. Vulcanization hardness changes little. 4. High filling can be achieved by increasing the molecular weight, and the processability of oil-extended styrene-butadiene is good. It is easy to be used with other unsaturated general rubber. Combining with natural styrene-butadiene can overcome the shortcomings of styrene-butadiene. Sulfur is the main vulcanizing agent of styrene-butadiene rubber, and its dosage is generally 1.0-2.5 phr less than that of natural rubber, and its vulcanization speed is slower than that of styrene-butadiene rubber. It can be accelerated by increasing accelerator or temperature. The amount of sulfur directly affects the physical and mechanical properties of vulcanizate. With the increase of sulfur content, the curing time is shortened and the crosslinking density is increased. Hardness, constant tensile stress and resilience of tensile strength will all increase, but elongation, permanent deformation, thermal aging and flexibility will decrease. The optimum vulcanization temperature of styrene-butadiene rubber is 150℃, which is different from natural rubber without reversion. High quality products can be obtained by vulcanization at 150 degrees. Vulcanization at 160- 175 can obtain good elasticity and deformation resistance. Solution polymerized styrene-butadiene has light color, good dimensional stability of extrudate, fast vulcanization speed and good vulcanization flatness, so it is resistant to bending, low temperature and high resilience. But the tensile strength is slightly lower.
High styrene butadiene styrene rubber has a certain reinforcing effect on rubber. It can be blended with diene rubber such as natural rubber, styrene-butadiene rubber, cis-butadiene rubber, isoprene-butadiene rubber and chloroprene rubber. Sulfur can be used for co-vulcanization. It has the following advantages: 1. It improves the hardness of rubber; 2. It has anti-aging; 3. It has good wear resistance; 4. It has good electrical insulation performance; 5. It is easy to color; 6. Easy to mix and process; 7. It has thermoplasticity and strong fluidity, and is suitable for manufacturing complex rubber products. 8. Good tearing performance at high temperature, easy demoulding and smooth surface. Disadvantages: low temperature difference, large permanent deformation and great dependence on temperature. With the increase of styrene content, the tensile stress, tensile strength, tear strength and wear resistance of SBR vulcanizate increased, while the permanent deformation and buckling cracking resistance decreased.
C. polybutadiene rubber is divided into solution polybutadiene rubber, emulsion polybutadiene rubber and polybutadiene rubber. The most commonly used is dissolved polybutadiene rubber, which can be divided into high cis, low cis and trans cis-1.4 polybutadiene rubber. The main physical properties of cis-polybutadiene rubber are 1. High elasticity is the most elastic rubber among all rubbers at present. It shows high elasticity in a wide range, and can maintain a little elasticity at -40 degrees. When it is used with natural rubber and styrene-butadiene rubber, its low temperature performance can be improved. 2. Molecules will soon return to their original state. Therefore, the hysteresis loss is small and the heat generation is small. 3. The low temperature performance is good, mainly because the glass transition temperature is about-105℃, while the natural rubber is -73℃ and the styrene-butadiene rubber is -60℃, so the tread mixed with polybutadiene rubber can still maintain its service performance in cold areas. 4. Excellent wear resistance is second only to NBR. 5. Excellent bending performance and good dynamic cracking performance. Compared with styrene-butadiene, it has good filling performance. Compared with polybutadiene rubber, natural rubber can be filled with more working oil and reinforcing filler. Carbon black has strong wetting ability. Carbon black can be well dispersed, which is conducive to reducing costs. 7. It is miscible with nature, styrene, butadiene and chloroprene. It still has high oil resistance when it is used in combination with butyl chloride below 25%. 8. The low Mooney viscosity of the compound has no effect on the die expansion and extrusion speed of the compound. 9. It has good fluidity in the mold. 10. Low water absorption, and can be used for water-resistant products such as wires. But cis-polybutadiene rubber also has many disadvantages: 1. Low tensile and tear strength. 2. Poor wet skid resistance. 3. When used on the tread, the pattern will collapse in the middle and late period; 4. Poor adhesion; 5. Poor processing performance, easy to fall off at high temperature. 6. Sulfur cools easily. 7. In the absence of reinforcing agent, the tensile strength is very low and basically has no practical value.
D. Isoprene rubber (IR) is called artificial natural rubber, which has similar chemical composition, overall structure and physical and mechanical properties to natural rubber. But it is different from natural rubber. Compared with natural rubber, it has the following advantages: 1. Uniform quality and high purity. 2. Short plasticizing time and simple mixing processing. 3. light color 4. Expansion and contraction are small, which is related to the molecular weight and gel content of isoprene rubber. 5. The fluidity of rubber compound is good, and the fluidity of isoprene rubber in injection molding or transfer molding is even better than that of natural rubber. But it also has the disadvantage of 1. The tensile strength of pure rubber compound is low. This is mainly due to the low molecular weight of isoprene rubber and low strength of raw rubber. 2. Compared with natural rubber with the same amount of carbon black, the tensile strength, modulus stress and tear strength are lower, and the hardness is also lower than that of natural rubber. The sulfur content of isoprene rubber is usually less than that of natural rubber 10- 15%, generally less than 2.5 phr. When the dosage is too much, the tensile strength decreases rapidly. Natural rubber contains fatty acids, protein and other substances, which play an activating role in the vulcanization process. Therefore, the amount of accelerator should be correspondingly increased by 10-20% to obtain vulcanized rubber with excellent performance. The accelerator is selected from sulfenamide as the main accelerator and Qiu Lan as the auxiliary accelerator. Compared with natural rubber, rubber compound has low tensile strength, low elasticity, high self-adhesion, poor adhesion, low stiffness and poor fluidity. In order to improve the processability of isoprene rubber and the physical and mechanical properties of its vulcanizate. It has been modified to some extent. Firstly, the modifier is added in the mixing stage, and secondly, the modified functional group is introduced in the polymerization stage.
E. Ethylene-propylene rubber, which can be divided into binary propylene, ternary propylene, modified ethylene-propylene rubber and thermoplastic ethylene-propylene rubber, is an amorphous and amorphous rubber. The monomer units of ethylene and propylene in the molecular backbone are randomly arranged, which loses the regularity of polyethylene or polyethylene. It's elastic rubber. Ethylene propylene rubber has excellent aging resistance, 1. Its ozone resistance is not only much better than ordinary rubber, but also better than butyl rubber, which is generally considered to have good aging resistance. Among them, EPDM has the best ozone resistance. 2. The weather resistance is good, and it can be dried in the sun for three years without cracking, among which EPM has the best weather resistance. 3. Good heat resistance, and can be used in the environment of 120 degrees for a long time. The maximum service temperature can reach 150 degrees. 2. It has chemical resistance. Such as alcohol, acid, strong alkali, oxidant, detergent, animal and vegetable oil, ketone and ester. , has great weather resistance. However, its stability to aliphatic and aromatic solvents such as gasoline and toluene is poor. Third, it has good electrical insulation, and its electrical properties are close to those of butyl, chlorosulfonated polyethylene and polyethylene. It is especially suitable for electrical insulation products and wires working in water. Four. Impact elasticity and low temperature performance. Elasticity is second only to natural rubber and cis-polybutadiene rubber. The lowest limit low-temperature service temperature reaches -50 degrees. Fifth, low density and high filling performance. Its specific gravity is around 0.87. A large amount of filler oil and filler can be added. 200 copies at most, which reduces the cost. 6.EPDM has good steam resistance, even better than its heat resistance. The resistance of EPDM vulcanized with peroxide to superheated water is better than that of vulcanized rubber vulcanized with sulfur. However, ethylene-propylene rubber also has many disadvantages. The curing speed is the slowest, so it can't be co-cured with diene rubber. Thus limiting its use. 2. Self-adhesion and mutual adhesion are poor, which brings great difficulties to the processing technology. Improper handling will lead to delamination and sponginess. 3. Poor probability resistance and steam tightness. 4. Poor oil resistance and solvent resistance to most hydrocarbons. In ethylene propylene rubber, EPDM is the most widely used. Because EPDM has a third monomer, the higher the content of the third monomer, the easier it is to co-vulcanize with diene rubber. 1, in the sulfur curing system, the general dosage is controlled at 1-2 phr because of the extremely low solubility of sulfur in EPDM. With the increase of sulfur content, the scorch of vulcanization is shortened and the vulcanization speed is accelerated. Tensile strength, modulus and hardness increase, while elongation at break decreases. Heat resistance decreases. In order to prevent frosting from promoting, three or more kinds should be used together. The dosage of each accelerator is strictly controlled below solubility. Increasing the dosage of zinc oxide and stearic acid can improve the activation degree, crosslinking density and reversion resistance. 2. Using sulfur donor and semi-effective curing system can improve heat resistance and high temperature compression deformation. To prolong scorch, but it is still easy to spray frost, various accelerators should be selected to reduce the dosage of Qiu Lan, such as the classic combination of m1.5 tmtd0.8 teddc0.8 dtdm0.8 sulfur. This is often said to prevent EPDM from frosting with March 8 accelerator. But there is no absolute, this is an excellent example.
F. Neoprene rubber is a kind of general special rubber, which not only has good physical properties of general rubber, but also has weather resistance, environmental resistance, oil resistance and chemical corrosion resistance, and occupies a special position in all kinds of rubber. It has the following characteristics: 1. The strength and elongation of chloroprene rubber are similar to those of natural rubber. Its raw rubber has high tensile strength and elongation at break, and it is self-reinforced rubber. The vulcanizate of pure rubber can reach 27.5MPA, and the elongation at break can reach over 800%. 2. Excellent anti-aging performance. Namely weather resistance, ozone resistance and heat resistance. Its performance is second only to EPDM and butyl rubber in general rubber. Better than natural, styrene-butadiene, cis-butadiene, butyl eye. It can be used at 90- 1 10 for 4-5 months. 3. Excellent durability is the best rubber for general use. Hydrogen chloride vapor decomposes at high temperature. 4. It has certain chemical resistance. And solvent resistance. Second only to butyl rubber in general rubber. 5. Electrical performance, its insulation performance is average, only suitable for use below 600 volts. Because of its weather resistance, aging resistance and flame retardancy, it is often used in low-voltage cables. 6. Water resistance and air permeability are better than other synthetic rubbers. The air tightness is second only to butyl, and it is 5-6 times larger than natural rubber. 7. It has good adhesiveness and is widely used as an adhesive. This kind of adhesive is characterized by high bonding strength and wide application range, but it also has many shortcomings, such as poor cold resistance, rubber losing elasticity due to temperature drop, rubber crystallization and brittleness. 2. crystallinity, long-term parking will cause the crystal to lose its viscosity. The synthesis method of chloroprene rubber is different from diene rubber. 1. No sulfur curing system is used. Even if sulfur is used, it plays an auxiliary role in vulcanization. 2. Metal oxides must be used. Although zinc oxide is also used in other rubbers, its mechanism of action is different. 3. Hardness, tensile strength, elongation and other general physical and mechanical properties can be obtained through the combination of fillers, softeners and other additives. 4. Special properties such as anti-aging properties can be obtained by antioxidants and other compounding agents. Its basic formula is neoprene, metal oxide, filler, antioxidant, softener and other processing AIDS. Because of its excellent weather resistance, chloroprene rubber is often used with natural rubber, Ding Qing rubber, cis-polybutadiene rubber and ethylene-propylene rubber. Neoprene rubber is widely used to manufacture rubber hose, adhesive tape, wire sheath, printing cots, rubber sheets, various gaskets, adhesives and so on.
G NBR is famous for its excellent oil resistance, second only to special rubber, polysulfide rubber, polyacrylate and fluororubber. Cis-polybutadiene rubber can be divided into ordinary butyl rubber and special butyl rubber. Universal butadiene-acrylonitrile rubber is mainly a copolymer of butadiene and acrylic acid, which is widely used. A special type is a copolymer in which a third monomer is introduced. The letter of Butyrine is Butyrine, the first two digits indicate the content of alanine, and the third O is Butyrine (polluted) 1- Hard Butyrine pollution-free 2- Soft Butyrine 3- Hard Butyrine micro-polluted 4- Polybutyl 5- Hydroxybutyl 6- Liquid Butyrine 7- Irregular Liquid Butyrine. The fourth digit represents Mooney viscosity. Ding Jing has the following properties, 1. Physical and mechanical properties. It is an amorphous polymer. It must be reinforced to be of use value. The elasticity is lower than natural rubber, but better than butyl rubber. With the increase of acrylic acid content, the elasticity decreases, the wear resistance increases and the oil resistance also increases. The worse the compatibility with natural rubber. 2. Excellent oil resistance. 3. The cold resistance is worse than other general rubbers, and the higher the acrylic acid eye content, the worse the cold resistance. 4. The heat resistance is better than that of ordinary rubber, and the higher the acrylic acid content, the better the heat resistance. 5. Good steam tightness, the same as butyl rubber. The higher the propane eye content, the better the vapor density. 6. Resistant to chemical corrosion, alkali and weak acid. 7. Good water resistance, the higher the acrylic eye, the worse the water resistance. 8. Poor electrical insulation, it is semiconductor rubber. Cis-1,4-polybutadiene rubber is very polar, and its compatibility is generally not very good. However, it is very effective for polar compounds. It is also often used with natural rubber, styrene-butadiene rubber and cis-butadiene rubber. 1. Combined with phenolic resin, the tensile strength, tear resistance, wear resistance and hardness of vulcanized rubber can be improved, and the heat resistance, bending resistance, electrical insulation and chemical corrosion resistance can be improved. 2. The combination of polyamide resin can obviously improve the tensile strength, wear resistance, cold resistance, oil resistance and solvent resistance of vulcanized rubber. 3. The combination of NBR and 20-30 parts ABS can improve its wear resistance, strength and extrusion performance. 4. The processability and low temperature performance can be improved when it is combined with natural rubber, but the more natural rubber is used, the greater the oil resistance. A small amount of natural rubber plays the role of plasticizing tackifier. 5. Used in combination with styrene butadiene, often used in combination with styrene butadiene rubber to improve cold resistance. In the formula of oil-resistant base course, NBR/SBR is 60/40, and its oil resistance is equivalent to that of chloroprene rubber. 6. In order to improve the wear resistance, cold resistance and bending resistance of butyl eye, butadiene rubber can be used appropriately, and the amount of butadiene rubber should be increased when the oil resistance requirement is not high. 7. In order to maintain its weatherability, it is sometimes used with chloroprene rubber, because the vulcanization systems of the two rubbers are different, and it is difficult to achieve the best state. When the sulfur-adjusted neoprene exceeds 20 parts, 4 parts of magnesium oxide and 5 parts of zinc oxide are needed. 8. In order to improve the weather resistance and heat resistance of NBR, a small amount of EPDM can be properly mixed in 10%, and the effect is obvious. When it is increased to 20 phr, the weather resistance is obviously improved. 9. The product combined with chlorinated butyl rubber has the characteristics of oil resistance, heat resistance, aging resistance and corrosion resistance. 10. It can be used as a colorful product with chlorinated polyethylene rubber, which can improve ozone resistance, weather resistance and aging discoloration. 1 1. Combined with epichlorohydrin rubber, its static and dynamic ozone resistance can be improved.
H. butyl rubber abbreviation IIR butyl is a linear gel-free copolymer. It consists of isobutylene and a small amount of isoprene. The characteristic of butyl rubber is 1. Its air permeability is excellent, which is the lowest among hydrocarbon rubbers. This is one of the most important features. 2. Heat resistance, butyl rubber has excellent heat aging resistance, thermal oxidation aging reduces the price, and aging tends to soften. 3. Weather resistance: The weather resistance of butyl rubber reinforced with carbon black is very outstanding, and it will not be damaged by long-term sun exposure. 4. Excellent ozone resistance. It is 10 times better than natural and styrene-butadiene rubber. 5. Resistant to animal and vegetable oils. Compared with general synthetic rubber, it has better electrical properties. 7. Water absorption, butyl rubber has low water permeability at room temperature and excellent water resistance. The water absorption at room temperature is lower than that of other rubbers 10- 15 times. Butyl rubber also has disadvantages. 1. Butyl rubber is 3 times slower than highly unsaturated rubber such as natural rubber, and needs to be vulcanized at high temperature or for a long time. 2. Self-adhesion and poor mutual adhesion. 3. Poor compatibility, poor compatibility with general rubber, not suitable for use together, but can be used together with ethylene propylene rubber, polyethylene, etc. 4. The reinforced masterbatch needs heat treatment to improve its performance.
1. Rubber powder: waste rubber products are processed into rubber powder and converted into reclaimed rubber. The processes of desulfurization, water washing, drying, refining and tabletting are omitted. The addition of rubber powder can reduce the cost, improve the fatigue performance of rubber and improve the shrinkage and fluidity of rubber compound. However, the tensile strength decreased slightly. The production method includes normal temperature grinding, low temperature grinding and superfine grinding. 12-47 mesh rubber powder can be obtained by normal temperature grinding, 47-200 mesh rubber powder can be obtained by low temperature grinding, and more than 200 mesh rubber powder can be obtained by ultra-fine grinding. The properties of rubber powder are different with different raw materials. The smaller the particle size of rubber powder, the closer it is to the rubber compound without rubber powder. After adding it, its stretchability and tearing property are obviously reduced. The basic formula should be improved after adding rubber powder. 1. Add the third substance. Resorcinol and modified phenolic resin are added into the mixture. It can relieve the tension and tear reduction caused by the use of rubber powder. The effect is more obvious when it is added in plastic surgery training. 2. Adjust the curing system, because the rubber phase moves from rubber phase to rubber powder phase in the curing process, which leads to the reduction of sulfur concentration at the interface between rubber phase and rubber powder and the cross-linking strength at the interface. Therefore, the average crosslinking density of rubber is not enough. Physical and mechanical properties will also be degraded. The following measures should be taken. 1. Increase sulfur concentration. 2. Adopt vulcanization accelerator. 3. Adopt sulfur-free curing system such as peroxide. 4. Reinforce with inorganic reinforcing agent such as high styrene.
J. Reclaimed rubber has a certain reinforcing effect, which is easy to coagulate with raw rubber and compounding agent, and has good processability. It can replace part of raw rubber and reduce the cost of mixed rubber. Reclaimed rubber is a high-quality reclaimed rubber produced by adding softener, activator, tackifier and antioxidant to rubber powder. It has good plasticity 1. It is convenient to mix raw rubber and compounding agent, saving working hours and reducing power consumption. 2. The shrinkage rate is small, which can make the product surface smooth and the size accurate. 3. Good fluidity, easy to make model products. 4. Aging resistance, but poor heat resistance and solvent resistance. 2. Silica is a white reinforcing agent, and its reinforcing effect is better than any other white reinforcing agent. The rubber compound reinforced with silica has high tensile strength, tear strength, modulus stress and wear resistance, but its hardness also increases. The structure ratio of silica is higher than that of carbon, which will also increase the viscosity of the compound. The siloxane or silanol group of silica has strong hydrophilicity and water absorption. Long-term water absorption will reduce the Mooney viscosity of the compound, thus shortening the scorch time, and the accelerator will be absorbed into the silica compound, thus delaying the vulcanization of the compound. When the PH value is above 8, the vulcanization speed is very fast, and when the PH value is below 5, the vulcanization speed is very slow. Coupling agent should be properly added to the formula of instant white carbon black. After adding it, the viscosity of the compound decreased, the curing time was shortened, and the tensile stress, tear strength, tensile strength and wear resistance were improved. The heat generation, permanent deformation, elongation and hardness of vulcanized rubber decreased little. 3. Clay, which is full of semi-reinforced minerals. Good processability and smooth extruded products. Because of the high adsorption rate of DPG, it has certain influence on the rubber compound and will delay the vulcanization speed. 4. Light calcium carbonate is easily dispersed in the rubber compound. Does not affect the curing speed, but must consider the quality.
Plasticizers include petroleum filler, coal tar plasticizer, rosin plasticizer, fatty oil plasticizer and synthetic plasticizer.
Aromatics, plasticizers and hardeners are sometimes added to some special products.
In order to reduce the cost, it is necessary to add compatibilizers to rubber, such as rubber powder, calcium carbonate, clay, ointment and so on. Different solubilizers have different characteristics and have different effects on physical properties, so the formula should be adjusted appropriately.
Modern non-high-tech formula design rarely uses traditional formula design mode. It omits the design of basic formula, and is generally modified on the basis of defective formula of similar products. Many experiments done by predecessors were omitted, and some unexpected problems in sulfur process were avoided.