REVISTA DYNA ENERGÍA

Key words:

neumático, recauchutado, resistencia a la rodadura, consumo combustible, eficiencia, etiqueta, ensayo, carcasa, banda, histéresis, deceleración, : tyre, retread, rolling resistance, fuel consumption, efficiency, label, test, carcass/casing, tread, hysteresis, deceleration

Article type:

ARTICULO DE INVESTIGACION / RESEARCH ARTICLE

Section:

RESEARCH ARTICLES

ABSTRACT:
The reduction of fuel consumption of vehicles is one of the priority objectives in addressing the reduction of CO2. Current EC regulations stipulate minimum requirements for new tyres in relation to their low rolling resistance coefficient (RRC < 8N/kN, for commercial vehicles) and rolling noise (73÷75 dB(A)). Nevertheless, these requirements do not apply at present to retreaded tyres, very usual in commercial vehicles. The influence of different parameters on the RRC obtained after retreading and there is estimated the influence on vehicle fuel consumption is studied. First, an attempt has been made to eliminate the influence of the condition of the starting casing, studying separately the influence of factors associated with the retread process and the materials used therein. To achieve this goal, RRC tests were carried out on new tyres, on the casings of the same tyres after being scraped, and finally after being retreaded using different formulations and processes. The results show that retreading significantly increases RRC. On the other hand, the dynamic properties of the material added in the new tread are important, but the difference encountered between retreaded tyres using different rubber formulations and retreading processes remains below 5%. To study the influence of the aging of the materials, used tyres were also tested before and after retreading. In view of the results, the aging condition of the casing seems detrimental for the truck samples studied. Those effects are smoothed during retreading, and the casing condition is not presented as a main factor of the RRC of the retreaded tyre. It is worth noting that the study was carried out on a small sample of tyres of a European standard size for long-distance trucks (315/70 R22.5). Although the results and conclusions are very interesting, they should be taken with caution when extrapolated to other types of tyres. The difference found in RRC and in fuel consumption between new and retreaded tires places the latter far from reaching efficiency values equivalent to new original tires. It should be noted that the consumption data have been estimated from other authors and that a more exact value would require a complete evaluation of the complete life cycle of a tire which is the subject of another line of research.

Key Words: tyre; retread; rolling resistance; fuel consumption; efficiency; label; test; carcass/casing; tread; hysteresis; deceleration.