HIGH SPEED TYRE

Unpublished Data Corporate R D, Allied Corporation. Prevorsek, D. C. Kwon, Y. D. "Fuel Economy Combined with Safe High Speed Driving A Challenge for Future Tire Design", The Fifth Annual National Conference of the Plastics and Rubber Institute -TYRES-, 14 - 16 November 1979 at the Hilton Hotel, Stratford-upon-Avon. 

Rubbers have also become indispensable in automobiles due to their unique elasticity in tyres and shock absorbers. The tyre has itself undergone evolution over the years to give it durabihty against the environmental stresses experienced in high speed transport and improvements in rolhng resistance have reduced the energy used in cars and trucks. 

These are now manufactured in Europe (Polyair Machineban GmbH, Austria) from castable polyurethane and although inferior in performance, especially at high speeds, to conventional textile and wire-reinforced rubber tyres, have sufficient applications for limited production to be established. 

The rate of loss of additives from polymers is determined by migration and volatilisation. Physical loss of additives from polymers is increasingly important in food applications and medical uses of polymers, but also other situations lead to a rapid decrease in antioxidants, such as mechanical extraction of tyres (at temperatures up to 100°C at high speed conditions) or simple solvent extraction of seals and hoses, etc. 

So, a top quality tyre, as required for high speed litxury vehicles, is constructed of three different kinds of rubber in the sidewall (often polybutadiene blends), carcase (natural rubber) and tread (often butyl rubber blends). For a less expensive tyre, constructed totally of natural rubber, a similar (though lesser) effect can be achieved by using more flexible, lightly vulcanised, rubber in the sidewall and higher modulus, more extensively vulcanised, and so more tightly cross-linked, rubber in the tread. 

STUDY ON IMPROVING PERFORMANCE OF NYLON TRUCK TYRE AT HIGH SPEED... 

The causes of tyre damage and wear, such as underinflation, overloading, high speeds, driver behaviour, road conditions, climate and mechanical conditions are examined. The necessity for a tyre to be properly fitted, balanced and serviced throughout its original life if it is to provide a sound foundation for retreading is emphasised. 

An example of research where sulfur, an accelerator (TMTD) and other ingredients (some of an undisclosed nature) have been used to prepare rubber blocks from sintered waste tyre crumb, for end-uses that could include ballast mats for high-speed trains, is that carried... 

Other factors that directly affect the skid resistance are tyre pattern and tyre resilience (high or low percentage of plastic/elastic material). The smoother the tyre surface, the greater the reduction of skid resistance as vehicle speed increases. The higher the percentage of plastic incorporated in the tyre, the lesser the skid resistance on rough surfaces (Sabey 1966). 

These are shown in Table 13.12. All these areas are currently growing at the extent of 2-3% per annum and this trend is expected to continue especially relevant is the growing use of electrically powered vehicles for which PU is often superior as a tyre material at the low speeds and relatively high loads involved. Future advances of PU elastomers in this field will depend upon the development of tyres with improved dynamic performance through lower hysteresis and better traction. 

---