TRACTOR TYRE

The main reason for this is that the polymer molecules are extremely large compared with those of the solvent. To take an extreme example, consider 78 g of benzene injected into a perfectly crosslinked tractor tyre. On a molar basis, this is an extremely dilute solution one molecule of solute in one mole of solvent. Yet, because of the extreme difference in size between the two types of molecule involved, the behaviour of such a system is nothing like that of a dilute solution. 

The degree of damage caused to the soil by a tractor depends on the weight, which is distributed over the area covered by the tyres. It should be borne in mind that in spite of an equal specific load on the soil (contact area pressure) a heavier tractor (even if it has bigger tyres) will exert greater pressure on the soil. 

The basic rule is drive into the orchard as little as possible, and with as light a tractor as possible. Only a light tractor weighing less than 2000 kg, and with broad tyres (at least 35 cm), conserves the larger pores of the soil. 

The following types of tyres are suitable for orchard tractors. 

The tyre pressure is also critical for conservation of the soil. With a lower tyre pressure, the area covered hy the tyre increases while at the same time the specific pressure exerted on the soil (kg/cm ) is reduced. As a general rule, tyres with as large a volume as possible should be chosen, so as to be able to keep the tyre pressure as low as possible (<1 bar), taking into account the minimum load-bearing capacity. The front wheel tyres of compact tractors, in particular, are usually too small, with the result that the area covered by the tyre is too small and excessive damage is done to the soil. 

Tyres and related products Pneumatic tyre manufacturing dominates the rubber industry in terms of the quantity of raw rubber consumption. About 50-60% of the rubber produced in the world is used for manufacturing tyres and related items. Tyre products include pneumatic tyres and tubes, sohd tyres, t)n e flaps, retread material, and puncture repair Wts (PRKs). NR is the ideal base material for tyres for aircraft, racing cars, heavy duty vehicles such as trucks and buses, off the road vehicles, and tractors. An oil extended form of natural rubber could be used as base material for the manufacture of winter tyres [61]. 

The main use of NR is in automobiles. In developed countries nearly 60% of all rubber consumed is for automobile tyres and tubes. The superior heat build-up and tensile strength of NR makes it indispensable in the manufacture of aviation tyres. In heavy-duty tyres such as those for tractors and trucks, the major portion of the rubber used is NR. In addition to tyres, a modern automobile has more than 300 components made out of rubber. Many of these are processed from NR. NR is also widely used in the manufacture of hoses, footwear, battery boxes, foam mattresses, balloons, toys, etc. In addition to this, NR now finds extensive use in soil stabilization, in vibration absorption and in road construction. A variety of NR-based engineering products have been developed for use in these fields. Seismic isolators, bridge bearings and dock fenders are niche products relying on the superior properties of NR. 

---