TRUCK TYRE

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. 

Urethane rubbers have found steadily increasing use for oil seals, shoe soles and heels, fork-lift truck tyres, diaphragms, chute linings and a variety of mechanical applications. Fabric coatings resistant to dry cleaning are a recent development. In many of these applications high elasticity is not an important prerequisite so that the polyurethane rubbers must be compared not only with other rubbers but also with a variety of thermoplastics. 

Typical car tyre tread Typical car tyre wall Typical truck tyre tread Typical truck lyre wall Bulk car tyre TDF TDF (de-wired) TDF (de-wired) Car lyre TDF (not de-wired) ... 

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

E. Dommershuijzen, "Super Single Truck Tyre Carcasses A Challenge For P-Aramid Fibers," Conference Proceedings ACS, Rubber Division, Odando, Fla., Paper 53, Oct. 1993, p. 7.012. 

Rubber tyres are by far the most visible of rubber products. Identification is trivial and collection is well organized. Recycling and disposal, however, are less evident. A major route for tyres is their use as a supplemental fuel in cement kilns. Major compounds in tyres are styrene-butadiene rubber (SBR), synthetic and natural polyisoprene rubber, steel cord, carbon black, zinc oxide, sulphur and vulcanization-controlling chemicals. Tyres can be retreaded, which is economic for large sizes (truck tyres), or ground to crumb or powder (cryogenic grinding). Such materials have some limited market potential as an additive in asphalt, and in surfaces for tennis courts or athletics. 

The synthetic rubbers most frequently used for car tyres are emulsion and solution styreen/butadiene random copolymers (ESBR and SSBR) and butadiene rubber (BR). Truck tyres, however, often contain a certain amount of natural rubber (NR) or its synthetic version isoprene rubber (IR). The Tg-value of BR rubber as such can vary, depending on its chemical structure between -100°C and -20°C the Tg-value of SBR can, in principle, vary between -100°C and 100°C. 

Clamping pads Soling materials Mechanical Hano truck tyres... 

Fork lift truck tyres Conveyor rollers Pressure pads... 

NR usage in modern radial tyres has substantially increased. The amount of NR used is about 21 kg per tyre for a radial construction compared with about 9 kg in a bias truck tyre. Bernard and coworkers have compared the NR levels of heavy-duty radial truck tyres to those of the equivalent bias tyre and noted the following increase " ... 

Steel cord has been the main reinforcing material for tyres, hoses and conveyor belts for many decades, indeed the first steel reinforced tyres appeared over ninety years ago. However, it was not until the emergence of radial tyres that steel cord became a common form of reinforcement and understandably the adhesion between brass-coated steel cord and rubber compound became a significant factor governing the performance and durability of car and truck tyres. Therefore, it is necessary to achieve a high level of adhesion and sustain this level throughout the service history of the tyre. 

Brominated butyl rubbers are of interest for truck tyre inner tubes because of their heat resistance, in giant type inner tubes because they may be blended with natural rubber to give a useful combination of properties, and for a variety of other uses. 

To illustrate the effect of a number of commercial oils on the properties of both unvulcanized and vulcanized natural rubber compounds, two levels of oil were applied to a standard truck-tyre type formulation. The oils in the evaluation are listed in Table 2 and the compound used in Table 3. The range of oils examined covers much of the range of viscosities normally used in industry. For ease of reference in subsequent tables the oils are referred to by the reference number indicated in Table 2. 

Laser desorption MS has been used for direct analysis of rubber additives, in situ at the surface of elastomeric vulcanisates [201,202]. For example, the technique was used to analyse a sample of truck tyre that displayed premature sidewall cracking. By using a single laser pulse, the molecular ions of several intact molecular species (AOs, antiozonants and a production impurity of an additive) were observed on the rubber surface. Also McClennen et al. [203] have used controlled laser energy to desorb organic additives from a rubber vulcanisate. 

Truck tyre durability is discussed with reference to the importance of identifying the mode, initiation point, propagation and cause of failure. The process is illustrated for two possible types of failure mode, i.e. tread separation and breaker/ply ending separation. In the development of new compounds, it is important to consider the operating conditions (strain/stress/temp. levels) of the component in the running tyre. The use of compound fracture mechanical behaviour measurements in the development of sidewall compound with improved cut initiation/propagation resistance is described. The retreadability of the truck tyres is also considered with... 

CAUSES OF BLISTERS ON INNER SIDE OF TRUCK TYRE AND THEIR PRECAUTIONS... 

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

The Bayer Tear Analyser is described, and examples are presented of its use in predicting the cut growth performance of rubber compounds for high performance car tyre treads, car and truck tyre breakers, radial truck tyre treads and truck tyre inner liners. Good correlation between the test results and the service performance of various tyre components is demonstrated. The application of the machine in optimising tyre inner liner formulations based on bromobutyl robber and blends of bromobutyl and butyl rubber is also described. 6 refs. 

A study has been carried out to discover where the scrap rubber on the roads comes from. It is claimed that a good portion of the rubber comes from new tyres and not retreads, and that practically all the rubber comes from truck tyres. The main reasons for this are overloading, incorrect tyre pressure and mismatching of dual tyres. USA... 

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