Tread compounds speeds

Friction Properties of Tread Compounds at Higher Speeds.698... 

Friction Coefficients and Relative Ratings of Four Tire Tread Compounds at 4.5°C Ice Surface Temperature and a Speed of 0.5 km/h... 

Figure 26.33 shows the side force coefficient as function of log speed for different temperatures at a constant load and slip angle for a tire tread compound based on 3,4 cw-poly-isoprene, a polymer... 

FIGURE 26.36 The side force coefficient of an OESBR black-fiUed tire tread compound on wet blunt Alumina 180 as function of log a v obtained at three speeds and five temperatures (black open squares) with a quadratic equation fitted to the data (black solid line). The red marked points were obtained at one speed for five temperatures with the dotted red line the best fitting quadratic equation, indicating the risk of extrapolation with a limited set of data. 

Experiments carried out at a constant speed over a range of temperatures showed, however, that for tire tread compounds the temperature dependence of abrasion, although smaller reaches in this case, too, a minimum at a particular temperature as shown in Figure 26.51 and rises sharply with a further decrease in temperature. 

FIGURE 26.52 Sliding abrasion of three different tread compounds as function of temperature at a sliding speed of 0.01 m/s (a) styrene-butadiene rubber (SBR), (b) ANR, (c) NR,-tread compound, —gum compound. 

FIGURE 26.61 Log (abrasion) of an OESBR and a natural rubber (NR) tire tread compound as function of load at different slip angles at a speed of 19.2 km/h. left Abrasion loss of the OESBR compound as function of load. Right the relative wear resistance rating of natural rubber (NR) to the OESBR as function of load for different slip angles. 

FIGURE 26.65 Log (abrasion) as function of log (energy dissipation) for a commercial tire tread compound at three different speeds. Surface Alumina 60. 

FIGURE 26.66 Log (abrasion) as function of log speed for three different tire tread compounds. Load 76 N, slip angle 14.6°. Surface Alumina 60. (From Grosch, K.A. and Heinz, M., Proc. IRC 2000, Helsinki, 2000, paper 48.)... 

FIGURE 26.68 Log abrasion as function of log energy and log speed for a tire tread compound. 

Relative Ratings of Four Passenger Commercial Tire Tread Compounds for Which Road Test Ratings Were Available as Function of Log Energy and Log Speed... 

This is not surprising since at a given speed the coarseness of a track (the average spacing of the asperities) influences the friction only on a logarithmic scale. Also the observed dependence of the friction coefficient on load of soft mbber compounds on smooth surfaces disappears for harder black or silica-filled treads compounds on rough surfaces. 

Typically, the compounded rubber stocks need to be further processed for use. The process could be an injection or transfer molding into a hot mold, where it is cured. Extrusion of the rubber stock is used to make hose or tire treads and sidewalls. Another common process is calendaring, in which a fabric is passed through rolls where rubber is squeezed into the fabric to make fabric-reinforced rubber sheets for roofing membranes, belting or body plies for tires. The actual construction of the final product can be quite complex. For example, a tire contains in excess of six different compounded elastomeric stocks. All the components must be prepared and assembled with high precision so that the final cured product can operate smoothly at high speeds and last over 50,000 mi. 

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