Tyre, tyres

The main applications of butyl rubber are in wire and cable applications, inner tubes, inner liners in tubeless tyres, tyre curing bladders, and pharmaceutical closures, the latter utilising the low... 

Although tyres can be used as an alternate fuel, they are most often utilized as a supplemental fuel. Tyre fuel exists either in shredded form (known as TDF, or tyre-derived fuel) or as whole tyres. Tyre-derived fuel consists of tyre chips, usually no larger than 5 cm on a side (Blumenthal 1993). The size reduction procedure is itself an energy-intensive process, and costs increase as the particle size decreases (Atal Levendis 1995 Amari et aL 1999). The cost of cryogenic grinding of tyres can be as much as five times higher than that of pulverizing coal (Atal Levendis 1995). Whole tyres or TDF... 

For values expressed in range, the permitted axle weight depends on distance between axles, single/dual tyres, tyre width, load-sharing suspension and so on. 

Other factors that affect the tyre behaviour and have a direct effect on both distribution and magnitude of applied pressure are the following type of tyre (radial or x-ply, high- or low-pressure tyre, etc.), surface and tyre condition (smooth or treaded, worn or new), temperature developed in the tyre, tyre resilience, type and condition of vehicle suspension and pavement surface irregularities. A detailed description of the effect of the above factors is beyond the scope of this book. 

Some criteria are presented for evaluating the various tyre design theories that are based on the equilibrium shape of the sidewall and on the rolling contour of a tyre. Tyre failure types and the mathematical models by which they can be predicted by modem theories of mbber/cord fatigue are also described. A tyre design theory based on stress-strain optimisation of its elements is proposed as is a hierarchic system of complicated tyre models for calculation of stress-strain cycles. Influence of the cross-section geometry and of the iimer stmcture of the tyre on stress-strain cycles in the belt and bead of radial tyres is investigated. 21 refs. 

The type of ground rubber (e.g., whole tyre, tyre tread or other type, e.g., ethylene-propylene-diene monomer, EPDM). 

Our company is dedicated solely to metal-ceramic X-ray tubes since 25 years over this time, we have made lots of different tube models especially for tyre inspection systems. The major reasons for the use of metal-ceramic tubes in this inspection technology are robustness, their small and individual shapes, and the frequent need for modifications of their design due to custom designed systems. 

Emulsion polymerisation of a mixture of butadiene and styrene gives a synthetic rubber (Buna S GBS rubber), which is used either alone or blended with natural rubber for automobile tyres and a variety of other articles. 

Development of Natural Rubber-Based Tmck Tyre Retreading Compounds," in M. E. Cain and Sifi Zubaidah bte Mohd Rashid, eds.. Proceedings of a UNIDO-sponsored Workshop, Kuala Eumpur, Malaysia, Malaysian Rubber Pioduceis Research Association, Heitfoid, U.K, 1992. 

G. CoraHo, "Historical Review of Light-Duty Tyre Carcass Reinforcement and the State of Current and Next Generation Technology," Conference Preprints ACS, PuhherTdivision, Philadelphia, Pa., May 1995, p. 13. 

A. G. Causa, D. K. Kim, and R. S. Bhakuni, "Advances In MetaUic and Polymeric Fibre Reinforcement For Tyres," International Rubber... 

C. D. Tyree, Emission Eevel in Catalyst Temperature as a Function of Ignition-Induced Misfire, SAE 920298, Society of Automotive Engineers, Warrendale, Pa., 1992. 

So far we have talked of ways of reducing friction. But for many applications - brake pads, clutch linings, climbing boots, and above all, car tyres - we want as much friction as we can get. 

Fig. 26.7. Skidding on a rough road surface deforms the tyre material elastically.

Fig. 26.9. Anti-skid tyres, with a high-loss tread (for maximum grip) and a low-loss wall (for minimum heating up).

There is one obvious drawback of high-hysteresis rubber. In normal rolling operation, considerable elastic deformations still take place in the tyre wall, and high-loss tyres will consume fuel and generate considerable heat. The way out is to use a low-loss tyre covered with a high-loss tread - another example of design using composite materials (Fig. 26.9). 

Slides Microstructures of GFRP, glass-filled polymer, cermet, wood sectioned piece of cord-reinforced automobile tyre. 

Slides Split-shell bearings hard particles embedded in soft bearing alloys micrograph of section through layered bearing shell skiers automobile tyres. 

This equation does, of course, assume that all the potential energy is converted into useful work. This is impossible in practice because some work will be done against friction - in wheel bearings, tyres and air resistance - and the free work must really be written as... 

The bulk properties of a polymer ean often be altered considerably by the incorporation of additives. Probably the most well-known examples of this occur in rubber technology where variations in the choice of additives can produce such widely differing products as tyres, battery boxes, latex foam upholstery, elastic bands and erasers. It is also possible to achieve variations as extensive as this amongst plastics materials, in particular with PVC from which rigid rainwater piping, baby pants, conveyor belting, footballs and domestic insulating flex may all be prepared. 

The diene rubbers, including polychloroprene, comprise some 90% of the total rubber market. This is due to their generally low cost, the suitability of many of them as tyre rubbers and their good mechanical properties. 

This lower has a number of ramifications on the properties of polybutadiene. For example, at room temperature polybutadiene compounds generally have a higher resilience than similar natural rubber compounds. In turn this means that the polybutadiene rubbers have a lower heat build-up and this is important in tyre applications. On the other hand, these rubbers have poor tear resistance, poor tack and poor tensile strength. For this reason, the polybutadiene rubbers are seldom used on their own but more commonly in conjunction with other materials. For example, they are blended with natural rubber in the manufacture of truck tyres and, widely, with SBR in the manufacture of passenger car tyres. The rubbers are also widely used in the manufacture of high-impact polystyrene. 

Perhaps the main reason for the widespread acceptance of polybutadiene rubbers arose when it was found that they gave a vastly reduced tendency for the circumferential cracking at the base of tyre tread grooves with crossply tyres when used in blends with SBR. With crossply tyres now replaced by radial tyres, this factor is no longer of great importance but the rubbers continue to be used because of the improved tread wear and good low-temperatue behaviour imparted by their use. 

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