Main product (crumb rubber)
Crumb rubber is the main type of products from processing of automobile tyres. Due to the fact that automobile tyres are subject to prolonged tremendous loads during their life-time, production of new tyres uses high-quality components (natural, synthetic rubbers, emollient oils, fillers, etc.) together with latest technologies. tyre rubber is practically the strongest and most durable of all types of rubber used; it has many important qualities (elasticity; resistance to acids and alkalis; bending strength, stretching, abrasion, etc.). During mechanical processing of tyres into crumb, the physicochemical composition of rubber practically does not change, and the use of efficient equipment for crushing and grinding allows to obtain high-quality finely ground crumb rubber of various milling with a particle size from 0.1 to 5 mm, depending on the requirements of the consumer. The equipment that we want to use in production of crumb rubber allows us to obtain the final product, completely free of impurities (their share is less than 1%) and complying with the technical requirements. Products obtained during such processing are: a) rubber powder TU 2519-001-510 09273-2001; b) crumb rubber TU 2511-001-81862491-2008; c) crumb rubber tyre (CR) TU 2519-001-59740985-05
Scope of application for crumb rubber
To understand how interesting and versatile the product is to consumers, let us describe uses of crumb rubber in Russia. At present, depending on granularity, crumb rubber is used as a raw material for the following purposes:
1) granules from 0.1 to 0.45 mm in size are used as a component (5 ... 10%) in rubber compounds for the manufacture of new automobile and industrial tyres as well as other rubber products. The use of crumb rubber with a high specific surface area value (25003500 sq.cm / g), obtained by mechanical grinding, increases the resistance of tyres to bending and impact forces, increasing their service life. For the manufacture of the regenerate, crumb rubber of up to 2 mm is used. Regenerate is widely used in rubber compounding and in the production of new tyres as a substitute for natural rubber, but at the same time the regenerate from tyre crumb is 4 times cheaper than its natural equivalent;
2) granules with a particle size of up to 0.6 mm is used as a component (up to 50 ... 70%) in the manufacture of rubber footwear and other rubber products. Physical properties of such products (strength, resistance to deformation) practically do not differ from properties of rubber products made from natural rubber;
3) granules with particle sizes of up to 1.0 mm can be used for the manufacture of composite roofing materials (asphalt roll roofing and rubber roof tiles), rail pads, rubber-bitumen mastics, vulcanized and non-vulcanized roll waterproofing materials. Also, rubber powder is used in the manufacture of asphalt rubber shingles (roofing felt) for roofing. Thiokol (polysulfide) mastic, a mixture of a base material and rubber granules (less than 1 mm in size), forms a resistant coat, used both as a building and decorative material. It is possible to use thermoplastic rubber (synthetic thermoplastic obtained using rubber powder as a filler), as a sealant for joints between building frames, waterproofing material for slate roofing tiles, and also for repairing metal roofs, for bituminous waterproofing sealants such as pipe dope, for anti-filtration screens, as sealant of manure settling tanks on livestock and poultry farms. The material has a high resistance to acids and alkalis, including concentrated ones;
4) rubber granules with particle sizes from 0.5 to 1.0 mm, are used as an additive to modify petroleum bitumen in asphalt concrete mixtures (based on the "Application guidelines for asphalt concrete mixtures with polymers from industrial waste" (Appendix No. 3) and " Technical recommendations on the construction of road structures using asphalt concrete No. TR 103-07 (Appendix No. 4)) used in the construction of motorways. Such components improve the deformation and frictional properties of road surface and make it possible to increase its durability, as well as their impact resistance and resistance to temperatures flactuations. At the same time, the lifetime of the roadway is increased by 1.5-2 times. Also, a mixture of coarse rubber granules, metal and textile cords up to 50% by weight with mineral additives can be incorporated into the substrate, which in turn significantly improves the physical and mechanical properties of the entyre surface;
5) rubber granules with particle size of less than 3 mm are used in the production process of structural fiber-reinforced concrete. Metal and textile cord in a certain proportion are mixed with crumb rubber and added to a dry cement-sand mixture in the ratio of one to two. Fiber-reinforced concrete for construction is used for deep foundations in places of intense flow of people, as well as by virtue of its properties, in regions with harsh climatic conditions, including territories with permafrost;
6) crumb rubber is also involved in the creation of coatings and polymeric binders for different types of sports surfaces for basketball, volleyball, badminton, etc. Also, football fields with artificial turf are covered with crumb rubber with a particle size of 1.0 to 2.5 mm;
7) the use of crumb rubber in the construction of playgrounds for children is gradually gaining popularity (according to GOST R EN 1177: 1998, "Impact attenuating playground surfacing. Safety requirements and test methods"), as well as various equipment for playgrounds;
8) Crumb rubber is also used in anti-slip surfaces and other outdoor surface areas. Adding processed crumb rubber makes surfaces more durable and practical;
9) Production of rubber tiles is considered to be yet another area of application for crumb rubber. Such tiles have high durability, hardness, impact attenuating, shock-absorbing and orthopedic properties. The proportion of crumb rubber in the production of rubber tiles and pavers is more than 80%;
10) the use of crumb rubber as a filling for various types of sports equipment, for example, punching bags;
11) rubber powder produced on the basis of crumb rubber is used in oil and gas services industry. Composite material, based on micronised rubber powder with a high specific surface value (2500-3500 sq.cm / g) and organic additives, is used as a sorbent for collecting crude oil and liquid petroleum products from the surface of water and soil, for sealing oil wells (tamponage), etc. The mass ratio of absorbed oil or oil products by this sorbent is 6.5-7 to 1, although the raw materials for the production of its main component of micronised rubber powder, worn tyres and technological rubber waste, have a mass ratio of more than 1.3. As a result of sorption of oil or liquid petroleum products, sorbents are collected on the surface of water into large agglomerates weighing up to several kilograms, which remain afloat regardless of the physical states of water for several months and are relatively easy to collect, leaving no traces, even in the form of thin oil films. Sorbents are non-toxic and environmentally friendly;
12) is very effective is the use of rubber powder in the manufacture of anti-corrosion pastes, which are applied to the undercarriage of cars and other metal products to protect them against corrosion. There are other possible applications of crumb rubber not only as a base material but as a component of composites, and as a material which is a basic material in the production of rubber powders, etc.
An integral part of the production of crumb rubber are secondary products such as textile and metal cords.
1. Metal cord
In the manufacture of automotive tyres, and specifically the bead wire of the bead filler, carbon steel wire according to GOST 14959 and GOST 1050 steel is used, which is then coated with brass. The final product is called brass plated steel wire and corresponds to GOST 26366-84 "Brass-plated steel wire for bead rings of tyres". This product is a metal cord, which, depending on the type of car tyre and its manufacturer, constitutes 15-20% of the total weight of raw materials. The technology of drawing out the steel belt during first stages of processing, in principle, makes it possible to extract most of the wire in an unchanged form, even without breaking it. In the further process of crushing rubber and complete removal of impurities, the remnants of fine wire are converted into metal shavings. Metal cord is a commercial by-product, and is a form of scrap metal as per categories "steel ropes and wires (13A) and "steel shavings" (16A).
2. Textile cord
Apart from metal cord, there are also polymer and textile yarns that have impact attenuating and high-strength properties. During tyre recycling, the textile part of the cord is separated from crumb rubber and forms an independent secondary product in the process. Textile cord is used as a basic material for the manufacture of heat and sound insulating plates, for sealing oil wells (tamponage) when drilling, as a reinforcing filler in the manufacture of composite elastomers, can be used as a filler in the manufacture of roofing slates, waterproofing pastes. It is also possible to use textile cord as a filler for a variety of sports equipment.
Just as there are numerous applications for recycled rubber mentioned above, the market today is not limited by them and is set for further expansion, both in terms of volume and uses. It should be said that in its essence crumb rubber is a universal raw material, as it is made from automobile tyres, which is hydrocarbon-based, and the field of application of hydrocarbons in the modern world has great potential. An important role is played by the fact that the crumb rubber is a product of recycling, thereby saving irreplaceable natural resources. Possible strategies for market development can be divided into two main parts: I. Increasing the sales volume due to existing areas of application; II. New segment development thanks to advances in materials research, conducted by domestic and foreign scientists. One of the most promising large-scale applications of crumb rubber in our country can be road construction.
At the moment, there is a certain demand for the use of crumb rubber as an additive for the modification of petroleum bitumen in asphalt mixes, in order to improve the friction properties of the road surface. The necessary documentation was developed as early as February 1, 1989, and approved by the Ministry of Avtodor of the RSFSR, under the name "Technical Instructions for the Construction of Road Surfaces with a Rough Surface No. VSN 38-90. "Transport" 1990" and includes two appendices "Guidelines for the construction of asphalt concrete surfaces with the use of crushed rubber" (Appendix No. 1) and (Appendix No. 2). The use of crumb rubber in the construction of road surfaces not only improves their frictional properties, but also greatly increases the service life of such road surfaces. This makes it possible to allocate budget funds more efficiently for this type of work. In our country several experimental road sections have been built in the Novoanninsky district of the Volgograd region, in the Moscow region and on the territory of the Sochi district of the Krasnodar region. At the legislative level, the use of crumb rubber in road paving is not mandatory at the moment (unlike other countries, for example, in the United States after the adoption of the law on the disposal of automobile tyres, road companies are obliged to use rubber waste in road construction and only under this condition receive government order. The service life of such roads as a result of proper legislation is extended to 15 years), this is due to the lack of enterprises producing this type of product (Should such a bill be passed in the near future, this will result in sharp increase in prices for granulate, due to its low supply, and the additional burden on the budget of the Russian Federation). The launch of our enterprise will significantly increase the volume of the market and, in our opinion, will contribute to the adoption of this bill. Another important indicator for the use of crumb rubber is the implementation of Sport for Social Development state programmes. With regards to that, our product is in demand from manufacturing of synthetic surfaces in sporting arenas, volleyball and basketball courts, football pitches with artificial turf, to the equipment of school gymnesiums, etc.
It is worth noting that there are numerous promising areas for the development of the crumb rubber market, such as: a) using it as a raw material for the manufacture of railway sleepers, which contributes to an increase in the life of the sleepers, reducing its weight, increasing its ability to withstand higher compression loads with no visible deformation after decompression and, moreover, saves natural resources (wood); b) manufacture of median deviders on federal and regional motorways, etc. From the above, it can be concluded that despite the existing opportunities, the prospects for market development in the use of crumb rubber have a good medium-term and long-term potential. Environmental importance of processing various types of solid household waste, and in recognition of the need for continuous business development, after the launch of the project and upon achieving predictable financial indicators, we plan to introduce recycling of new types of waste: 1. Processing plastic bottles: a) the production of granules for production of preforms (blanks for new plastic bottles); b) chemical products used in the manufacture of clothing, the production of bio-oil and biochar, which are subject to further processing into fuel, relying on the use of ablative pyrolysis.