Comparative Tests of Various Incendiary Mixtures. Part 4 - Improvement in the Test Procedure Evaluation of Different Types of Rubber

Studies were made on improvements in wood burning test procedure, evaluation of different types of rubber, and comparison on the incendiary effect on three different kinds of wood. The standard for comparison was changed from a weight to a volume basis, and the results are now refered directly to a standard volume 97.3 cc of the test sample equivalent to that of 85 g of a 7 solution of smoked sheet rubber in benzene. The investigation of gums of varying concentration of rubber of three types, with both benzene and naphtha as the solvent, has indicated that solutions of very low rubber content and low viscosity have inferior incendiary characteristics. Miscellaneous mixtures studied include solutions of polybutene in naphtha, mixtures of rubber-benzene with sodium nitrate and with nitrocellulose, and celluloid.