Tire materials steel cord

The tires account for two-thirds by mass of the elastomer used in an automobile [1]. However, the usage of lightweight steel cord and technical improvements in elastomeric materials have reduced their weight by -20% and this in turn has led to an overall reduction in vehicle weight, concomitant fuel savings, and better road holding property. 

Plies Textile or steel cords extending from bead to bead and thereby serving as the primary reinforcing material in the tire casing. 

Fibers and steel cord are the primary reinforcement and load-carrying materials in the tire. It is thus appropriate to review the properties of such materials for application in tires. 

ASTM 1070 characterizes steel tire cord and tire bead wire. These materials are considered high carbon steei. Steei beits have carbon content between 0.67 and 0.73% whiie bead wire has a minimum of 0.60% carbon. Also, tire steel belts and tire bead wire possess between 0.40 to 0.70% manganese. 

Materials and Process. The steel chosen for tire cord is a eutectoid carbon steel containing 0.7% carbon, 0.5% manganese, 0.2% siUcon, and a very low amount of sulfur and phosphoms (9,48). The steel rod is cleaned with acid, rinsed, drawn through tungsten carbide dies to reduce its diameter from 5.5 to - 3.0 mm, heat treated (patented) to increase ductihty for further drawing to - 1 mm, then patented again. 

Cord materials such as nylon, polyester, and steel wire conventionally used in tires are twisted and therefore exhibit a nonlinear stress—strain relationship. The cord is twisted to provide reduced bending stiffness and achieve high fatigue performance for cord—mbber composite stmcture. The detrimental effect of cord twist is reduced tensile strength. Analytical studies on the deformation of twisted cords and steel wire cables are available (22,56—59). The tensile modulus E of the twisted cord having diameter D and pitchp is expressed as follows (60) ... 

Pyrolysis produces three principal products - pyrolytic gas, oil, and char. Char is a fine particulate composed of carbon black, ash, and other inorganic materials, such as zinc oxide, carbonates, and silicates. Other by-products of pyrolysis may include steel (from steel-belted radial tires), rayon, cotton, or nylon fibers from tire cords, depending on the type of tire used. 

Diazoaminobenzene (DAAB) is used as a chemical intermediate, a complexing agent, and as a polymer additive. DAAB has been used to promote adhesion of natural rubber to steel tire cords. It has also been used as a blowing agent in the production of a foamed polymeric material. In addition, DAAB is used in the manufacture of dyes and insecticides. DAAB is present in cosmetics, pharmaceuticals, and food products, as a dye contaminant in D C Red No. 33, FD C Yellow No. 5, and FD C Yellow No. 6. 

High modulus fibers as strong as steel but have one-fihh the weight, ideally suited as tire cord materials and for ballistic vests, e.g., Kevlar yXwaron. 

Hydraulic structures using scrap tires for bank protection include tire mats, revetment (retaining walls, seawalls, revet mattresses), and tire-concrete imits. In search for economical bank-protection structures, the use of scarp tires as a less-expensive alternative is desirable, considering the costs of the metal and concrete used in reinforced-concrete construction, especially in developing countries. Whole scrap tires can be utilized for surface erosion control, beach and slope protection, and stream bank stabilization. In these applications, scrap tires are banded together and partially or completely buried on imstable slopes. Tires can be used with other stabilization materials to reinforce an unstable highway shoulder or protect a channel slope remained stable and can provide economical and immediate solutions. In bank protection structures, tires are laced together by steel cables and used as a protective layer or mat over stream banks or soil embankments. The top, toe, upstream and downstream ends of the mattress are tied into the banks. Used tires with metal cords were shown to bean excellent construction material that can partially replace reinforced concrete for protection of river banks and canal walls [19]. 

A tire is a textile-steel-rubber composite the steel and textile cords reinforce the rubber and are the primary load-carrying structures within the tire. Because of the performance demands of fatigue resistance, tensile strength, durability, and resilience, seven principal materials have been found suitable for tire application cotton, rayon, nylon, polyester, steel, fiberglass, and aramid the latter three materials find primary usage in the tire crown or belt region. 

Tire cord n. A textile material used to impart the flex resistance necessary for tire reinforcement. Tire yarns of polyester, rayon, nylon, aramid, glass, or steel are twisted to 5-12 turns/in. Two or more of these twisted yarns are twisted together in the opposite direction to obtain a cabled tire cord. The twist level required depends on the material, the yarn linear density, and the particular application of the cord. Normally, tire cords are twisted to about the same degree in the S and Z directions, which mean that the net effect is almost zero twist in the finished cord. 

Recycl Blacks. The pyrolysis of carbon black containing rubber goods has been promoted as a solution to the accumulation of waste tires. In the processes in question, tires are pyrolyzed in the absence of oxygen, usually in indirect fired rotary kiln-type units. The mbber and extender oils are cracked to hydrocarbons which are collected and sold as fuels or petrochemical feedstocks. The gaseous pyrolysis products are burned as fuel for the process. Steel tire cord is removed magnetically and the remainder of the residue is milled into a pyrolysis black. This contains the carbon black, silica, and other metal oxides from the rubber and some newly created char. Typically these materials have 8-10% ash, and contain... 

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