The Influence of Leather Type on Thermal and Smoke-Generating Properties

The main purpose of this article was to determine the smoke-generating and thermal properties of selected types of natural leather. Differences in the amount of smoke generated from the type of finish used in the technological processing of leather were observed. Research has shown that the burnt nubuck (367) sample with exposure at the heat flux intensity of 25 kW/m² without the presence of a pilot burner flame achieved the highest value of the specific optical density D_s,max. Comparable values, 312 and 297, were recorded for grain bovine leather and velour bovine leather, respectively; on the other hand, the lowest value of the tested parameter amounting to 220 was recorded for lacquered bovine leather. Tests executed with the use of thermogravimetric analysis show that except for nubuck leather, the start of thermal decomposition for all types of samples appears to be fairly similar and was found to be within the range of 275-282 °C. The highest value of thermal decomposition onset, i.e., 302 °C, was recorded for nubuck leather. The highest percentile of residues from thermal decomposition, i.e., 9%, was obtained for grain bovine leather. This implies that the least gaseous phase during its thermal decomposition in test conditions was generated by this type of leather. The highest average D_s,max value was obtained for nubuck (367), and decreased as follows: grain bovine leather (312) > velour bovine leather (297) > lacquered bovine leather (220).