Monsanto oscillating disc

Laboratory measur ent of curing characteristics have been somewhat revolutionized by the introduction of the cure meters. There were two types of cure meter the reciprocating paddle type as in the Wallace-Shawbury curometer, and the oscillating disc type such as the Monsanto rheometer. In the oscillating disc type (ODR) a biconical disc is embedded in the rubber in a closed cavity. The disc is oscillating through constant angular displacement, and the torque required monitored. 

Both the rate of vulcanization after the scorch period and the final extent of vulcanization are now measured by using devices called cure meters. Many researchers have contributed to this development (Decker et al., 1963 Juve et al., 1964). Widely used cure meters are oscillating disc rheometers of the type introduced by the Monsanto Company around 1965. The development of the oscillating disc rheometer, largely through the efforts of Wise, was the beginning of modern vulcometry, which has become standard practice in the industry. Before the development of the cure meter, it was necessary to measure... 

Rubber mixes were prepared in the Banbury mixer according to the recipes in Table 1-2. The rheological properties of all compounds were determined by using an oscillating disc Monsanto Rheometer MDR 2000 and Mosanto Viscometer VM2000. 

Figure 9.5 Oscillating disc rheometer (Monsanto). The force required to shear the rubber is monitored leading to a complete cure curve of the compound.

The oscillating die rheometer (ODR) and the moving die rheometer (MDR) have been developed and maiketed by Monsanto, the MDR being introduced in 1985 [16]. In the MDR, a thin sheet of rubber, around 2 mm thick, is placed between the two dies kept at the desired temperature the lower disc oscillates and a reaction torque/ pressure transducer is positioned above the upper disc. It has been found that the MDR gives shorter times of cure than the ODR because of better heat transfer and higher torque values, owing to the die design. 

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