Precipitated Silica is getting popular in products of rubber and tire manufacturing companies very fast these days. The need for Green tires which consume less energy has encouraged tire makers to use precipitated silica in their products. Also the increasing pressure on car manufacturing companies to produce cars to consume less energy and emit less CO2 gas has increased the demand for green tires rapidly in past few years. Alpine Chemie has been a top producer and supplier of precipitated silica for years. The quality of our products and its reasonable price has made us very well-known as a trustworthy and reliable company in tire and rubber industry. At alpine Chemie we produce different raw materials for tires such as Batch-off release agent. Alpine chemie will synthesize completely precipitated silica formulations that includes physical properties such as surface area, particle size and pH levels based on the demands of our customers.
What is Precipitated Silica?
Precipitated silica is a form of silica (Silicon dioxide with chemical formula of SiO2) which is made by precipitation from a solution containing silicate salts. The difference between precipitated and fumed silica is the type of silica and the applications. precipitated silica is produced in precipitation process while fumed silica is produced in flames. precipitated silica is used in tire and show industries while fumed silica is mostly used in cosmetic products and toothpastes. The precipitated silica is a silicic acid product including silica, a white powder, a sufficiently porous material and nanoparticles. Precipitated silica products are required to support the operation of different industrial types, like automobile tires, rubber, cosmetics, electronics, agriculture and others. The procedure of chemical response between the sodium silica solution and different types of acids like hydrochloric, sulfur, acetate and other silica acids can make this precipitate. It purvey a good finish, resistance and equilibrium at the required physico-chemical properties of the products. Appearance product characteristics: Powder or white lumps free Water absorption flow: minimum 250% Oil absorption value: 225% minutes. Moisture at 1100 C: 5-7% Sio2 silica material: 88-90% Application Silica precipitated is useful for improving bond strength and as a reinforced and thickened agent.
Precipitated Silica vs Carbon Black
The demand for green tires has increased the demand for precipitated silica instead of carbon black. Carbon black is produced by the incomplete combustion of heavy petroleum products in refineries. Not only this procedure is harmful to the environment by producing CO2 gas, carbon black by itself has lower efficiency in tires. Tire factories are trying to increase the ratio of silica to carbon black in their tires to increase the efficiency of tires.
benefits of precipitated silica
- Reduces rolling-resistance
- Reduces fuel consumption
- Higher tear strength
- Higher tensile strength
- Increases abrasion resistance
- Better dynamic properties
- Reduce heating
Process types precipitated silica production
Wet method: For the preparation of silicate, the process of silica precipitation is carried out by neutralization of sodium silicate solution with an acidic solution (H 2 SO 4) by filtration, drying, milling and granulation. It produces precipitated silica of the same size, which runs off at temperatures of 90-100 °
Dry method: This process is the vaporization and parsing of SiCl4 with hydrogen at a temperature of 1800-2000 ° C. Thus, silica powder products are formed.
Process steps precipitated silica production
The advancing of the precipitated silica takes place in several stages:
- The purveyance of raw materials
- The product formation
- The cleaning products
. 1. Adhesive: Supersil precipitated silica is beneficial to elevate bond resistance and as a fortify and thickening agent.The dispersed silica particles in a liquid adhesive cure rapidly when they come into contact with the solid surface. In natural and synthetic rubber adhesive
Precipitated silicic acid is used in shoe soles because of their wear and tear resistance, abrasion resistance, and for making joints with light colors or even transparent materials. Provides superior durability and elasticity as well as improved module. Acts as white reinforcement and facilitates the production of colored products.
We have recently introduced EVA quality for the EVA footwear market. The EVA quality can be incorporated as it gives good abrasion and modulus properties.
.3. Railway Pads :
Precipitated Silica is used for the following reasons in Railway Pads :
- furnish enhanced erosion resistance and strength.
- furnish better permanence and resilience and improved modulus.
4. Rubber Products
In industrial rubber ,precipitated silica admit better resistance and permanence on industrial Rubber Belts and Rubber Hoses together with improved heat resistance and tear strength. It also improves adhesion in wire and fabric coat compounds and allows for quick and easy processing, resulting in smooth finished surfaces in molded products.
The fortify efficacy of the surface of PPT silicic acid depends mainly on its particular surface area, which generally enhancement with the particular surface area. The stability values of the rubber increase, but the elasticity decreases, the tear strength decreases and they are wear-resistant. During mixing, it is difficult to diffuse high Mooney viscosity and easy ignition with high heat generation. Therefore, various formulations and different uses needed different particular surfaces. Likewise, the influence of the specific surface on the physical and mechanical properties of the vulcanized rubber is not constant.
Other applications of Silica
The oil absorption value reverberate the degree of the structure, the oil absorption value is large, the degree of the structure is small, the elongation of the vulcanization is in most cases larger, the tensile strength and the hardness are larger, in particular, the wear resistance is smaller, but the deformation rate is lower.
Decrease of calcination
The decrease in calcination at 900 ° C reverberate the surface hydroxyl group. If the hydroxyl group of the surface is too large, it is easy to cause the manufacturing of rubber combination and make them brittle. The processing trait is spoiled and the vulcanization is likely to decrease, and the surface hydroxyl group apply a strong sorption effect on the vulcanization accelerator, thereby lengthen the vulcanization time.
The decreasing in heating to 4 and 105 ° C reflects the amount of free water in the voids of the particles. If it is too small, it becomes difficult to refine the high-structure rubber. If the reduction in heating is zero, the silica is unusable. Generally, it should be set to about 6%.
The value of PH
The pH is about 7, the pH increases (the acid content decreases) and the curing rate of the compound increases.
The lower the content of soluble salt, the better. However, if we want to reduce the content of soluble salt, the production costs are considerably higher.
Silica as a rubber additive
Modern tire tread rubber is made by mixing and mending a various kind of commonly embedded organic and inorganic compounds as main ingredients: polybutadiene, aromatic oils and up to 30% by weight. Silane coupled with silane. The mixture is stirred strenuously and allowed to harden. The particle size of the silica additive is very important. The best rubber amplification occurs when the silica particles are less than about 50 nm in size. However, if 50 nm of particles were added directly to the mixture, the viscosity would be so great that mixing would be excluded. The optimal silica additive is thus a larger conglobate of small particles that are held together so loosely that they disperse during mixing and result in smaller particles. The surfaces of the 50 nm particles then combine with the tire components. Silica does not dissolve as molecular silica in the mixture. The product Degussa VN3 is a silica commonly used to make tire rubber. As discussed below, this material consists of particles of 20 to 150 microns, which themselves are agglomerates of submicron particles. The texture is similar to that of a raspberry, with the individual nodes of the bay corresponding to the particles with a diameter of ten nanometers. The gas adsorption surfaces measured for Degussa silicas are between 100 and 200 m 2 / g. This rather large value indicates that there is a large inner surface. The geometric surface of the agglomerates (assuming a smooth surface) would be only 0.3-0.01 rn2 / g
History of Precipitated Silica
Rubber and tyre industries were the first industries that started to use precipitated Silica in their products. PPG is an American company which introduced precipitated Silica to tyre industry in 1930s. Later other industries such as footwear, food and painting industries started using it in their products. Since the first time PPG introduced silica to tire industry the need for green tires with higher efficiency which have less rolling resistance and higher grip increased. The use of precipitated silica to produce tyres is becoming more popular everyday because it reduces fuel consumption and its effects on environment. as green tyres (which make cars consume less fuel) are becoming more popular, the demand for precipitated silica is increasing all around the world. Alpine chemie is one of the first companies that started to produce high quality precipitated Silica and supply it to all around the world.