Correlation between the Thermogravimetric Analysis and Some Other Flammability Tests on Covers of Rubber Conveyor Belts

Thermogravimetric and differential thermal analyses were con ducted on each cover sample of nine different “flame-resistant” and one “non-flame resistant” rubber conveyor belts both in the airflow and in nitrogen gas flow. The TG-DTA curves on each sample were measured under the thermal range from room temperature to around 700°C. The minimum temperatures at which the rapid weight loss of each sample in the airflow, i.e., a sign of combus tion, began to appear were determined through comparison of the TG-DTA data in the airflow with those in nitrogen gas flow. These temperature data ob tained from a micro-scale flammability evaluation method, i.e., the thermo gravimetric method, were compared with the results from some other small- scale flammability tests; i.e., the oxygen index, hot plate ignition and drum friction tests. As a result, it was found that even the data from such a micro-scale flammability test were somewhat consistent with the critical oxygen in dex of cover rubber of belting and with some “ignition temperature” in the hot plate ignition test.