Bead wire

Tire Cord. Melamine resins are also used to improve the adhesion of mbber to reinforcing cord in tires. Textile cord is normally coated with a latex dip solution composed of a vinylpyridine—styrene—butadiene latex mbber containing resorcinol—formaldehyde resin.. The dip coat is cured prior to use. The dip coat improves the adhesion of the textile cord to mbber. Further improvement in adhesion is provided by adding resorcinol and hexa(methoxymethyl) melamine [3089-11 -0] (HMMM) to the mbber compound which is in contact with the textile cord. The HMMM resin and resorcinol cross-link during mbber vulcanization and cure to form an interpenetrating polymer within the mbber matrix which strengthens or reinforces the mbber and increases adhesion to the textile cord. Brass-coated steel cord is also widely used in tires for reinforcement. Steel belts and bead wire are common apphcations. Again, HMMM resins and resorcinol [108-46-3] are used in the mbber compound which is in contact with the steel cord to reinforce the mbber and increase the adhesion of the mbber to the steel cord. This use of melamine resins is described in the patent Hterature (49). 

Whole tires have been pyrolyzed in an experimental semifluidized-bed reactor (27). The tires are pyrolyzed on a grate that tilts to discharge the steel belt and bead wire. The pyrolysis of whole tires eliminates shredding and grinding costs. 

The pneumatic tire has the geometry of a thin-wallcd toroidal shell. It consists of as many as fifty different materials, including natural rubber and a variety ot synthetic elastomers, plus carbon black of various types, tire cord, bead wire, and many chemical compounding ingredients, such as sulfur and zinc oxide. These constituent materials are combined in different proportions to form the key components of the composite tire structure. The compliant tread of a passenger car tire, for example, provides road grip the sidewall protects the internal cords from curb abrasion in turn, the cords, prestressed by inflation pressure, reinforce the rubber matrix and carry the majority of applied loads finally, the two circumferential bundles of bead wire anchor the pressnrized torus securely to the rim of the wheel. 

In all tyres there are three types of components, the reinforcement layer(s), the rubber parts and the steel bead wires which locate a tyre to the wheel, or rim of a vehicle. Rubber is used in packing strips, inner lining, sidewalls and the abrasion-resistant tyre tread. 

Steel bead wires are used at the extremes of the reinforcing plies to ensure a complete seal to the rim. Many turns of small diameter wire are wrapped in a rubber-impregnated tape to form a flexible hoop of high strength. 

A typical automobile tyre consists of several parts (Fig. 5). The tread and sidewall make up the outside of the tyre. The tread is the portion of the tyre that comes into contact with the road, whereas the sidewall, or wall, is the side of the tyre that connects the tread and the bead. The tread is reinforced from underneath by the belt, which comprises a set of fabrics and/or wires. The plies, found in association with the belt, are layers of rubber-coated cords, which are typically made of fabric, polymer, fibreglass, or steel. The set of belts and plies is often collectively referred to as the cord, or cord body, of the tyre. The cords of the tyre wrap around the bead, the part of the tyre that rests on the tyre rim. The bead consists of both mbber bead filler and a series of steel bead wires. The last major part of the tyre, the innerliner, is a low-permeability... 

Radial wire is the mat of steel placed under the tread to enhance tread strength and durability. Bead wire consists of many strands of high tensile strength steel that provide strength and reinforcement to the tire side walls. Radial and bead wires can account for as much as 10 percent of the total weight of a tire.3 The remainder of the weight of the tire is about 60 percent rubber, and 30 percent fiber. 

On the other hand, the size of whole tires requires the ability, to feed large fuel to a burner, and their strength makes them difficult to cut into more manageably sized pieces of fuel. Also, chlorine, ash, and volatiles are present in higher quantities in tires and TDF than in most coals. Further, the metal contained in tires, in the form of the radial wire and bead, wire can be a problem in many fuel applications. For example, loose or molten wire can clog ash exit or grate combustion openings in boilers. 

Table 8-4. Chromatographic Analysis of Pyrolytic Gas from Shredded Automobile Tires with Bead Wire In2...

Extrusion All types Extrusion is the main process for compounding with additives, fillers, pigments, blended polymers, and then forming pellets for subsequent processing. Eurther processing may form various profiles such as pipes, beading, wire, and cable coating... 

There are certain technical limitations in the devulcanization of rubbers, and vulcanization is, in fact, not truly reversible (Pryweller, 1999). The partial devulcanization of scrap rubber will result in a degradation of physical properties. In many cases, this may limit the amount of substitution levels in high-tech applications such as passenger tires. But it can provide the compounder of less stringent products with an excellent low-cost rubber that can be used as the prime rubber or at very high substitution levels. According to Franta (1989), reclaim cannot be used for tread compounds in tires because every addition may decrease their resistance to wear. However, this statement has not been checked in case rubber devulcanized without an addition of chemicals. Considerable amounts of reclaim are consumed for carcasses of bias ply tires for cars if the compounds are of NR for carcasses of radial tires no reclaim is added. On the other hand, reclaim is added to compounds for bead wires and it may also be added to sidewalls. Within the framework of direct recycling options a number of applications for GRT outside the rubber industry have been proposed. Such applications include the use as a tiller in asphalt for the surface treatment of roads and as a rubberized surface for sport facilities. 

A circumferencial crack was detected by beaded wires on a moulded 321 steel tee junction in the Phenix secondary sodium circuit after 90,000h of operation. The crack was located in the heat-affected zone of the weld between the tee and the adjacent piping. It was shown that the crack occurred because of high stresses induced by an important misalignment. 

The brass process makes use of the fact that electrodeposited brass of certain composition and crystal structure is capable of directly bonding rubber mixtures, providing their composition is compatible with the adhesion process [77]. Whereas today the brass process is of only minor significance for the production of rubber-metal composites, it is widely used in tire manufacture for bonding the bead wires and for bonding the carcass mixture of steel cord. 

This equipment includes alternatives to shredding, alonig with wire removal systems. Recently alternative shreddin particle size reduction equipment has been developed. Of particular interest is the development of the hydroblasting system where the rubber is removed from the belting and bead wire with high pressure water. The water not only separates the rubber from the beat wire and otho cwd material, but it also produces tire chips at a particle size of 13 - 25 mm (1/2 - 1 in.). 

The bead wire in tires consists of many strands of high tensile strength steel to reinforce the tire sidewalls. Special equipment is available to cut the sidewalls off the tire and thus increase the life of cutter blades in the shredding equipment. However, the current procedure for removing the tire bead is very labor intensive and expensive. In most applications it is more economical to sharpen/replace cutter blades than to debead a tire. 

Table 6.6 lists some of the major ash constituents in various TDF samples. Of particular note is the very high zinc content of the ash resulting from the vulcanization processes. As mentioned earlier, the emissions of TDF compared to coal can be either the same or lower with the exception of zinc emissions. It is also important to note that the iron content in the ash is high, even for the wireless tires. This iron has the potential to flux slag formation in cyclone boilers, particularly if the iron is finely divided (e.g., not in bead wire). The high iron content is also beneficial when TDF is used in cement kilns, since it reduces the amount of iron additive needed to obtain cement with the proper iron oxide content. 

Since belted radial tires were introduced in 1948 by Michelin, steel as well as polyester and aramid have been used to make the tire cord for the radial belt. Steel has historically also been used to make the bead wire in tire construction. In addition, steel has been used to manufacture the cable that is used in making rubber mining conveyor belts. Lastly, in the automotive industry, many times rubber parts are made that are composites of rubber and steel. Examples of these parts are seen with motor mounts and bushings. 

Steel tire cord is usually brass plated in order to achieve good rubber-to-metal adhesion. Also, tire bead wire is commonly plated with bronze to achieve rubber-to-metal adhesion. The steel cable used in rubber mining belts may also be brass or bronze plated. 

The grade of steel used to manufacture steel tire cord or tire bead wire is considered a high carbon steel with carbon content typically above 0.60%. 

Brass is an alloy of copper and zinc, which is used in plating steel tire cord, while bronze is an alloy of copper and tin used in plating tire bead wire. 

Steel tire cord Bead wire High carbon steel... 

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. 

Tin is used to make the bronze alloy for tire bead wire, which promotes good rubber-to-metal adhesion. 

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