This article deals with study of minimum ignition temperature (MIT) of thermally modified spruce dust. Dust of several species of spruce was mixed, sieved, dried and subjected to Thermo-S temperature programme. Samples of dust (200 250 μm) were tested in Goldbert-Greenwald furnace apparatus for determination of the MIT of dust clouds. The influence of air pressure and sample weight to the MIT was studied. The results show that the MIT of thermally modified spruce dust gradually decreases as the sample weight and air pressure rise. The lowest value of MIT (470 °C) was measured, when the air pressure was 50 kPa and the sample weight 0,5 g. To reach even lower values of MIT (˂468 °C), the air pressure should gradually rise to approx. 42 46 kPa and the weight of dust sample should be approx. 0,46 0,53 g.

This article deals with thermal degradation of cellulose insulation. The sample of commercially available loose-fill cellulose insulation was tested in electrically heated hot air furnace modified for thermogravimetric analysis. Weight loss, weight loss rate and CO/CO2 ratio was measured, while the sample was heated from room temperature to 530°C. Particular phases of the thermal degradation process of cellulose insulation were identified and explained. The most rapid changes caused by thermal decomposition of loose-fill cellulose insulation were reported in temperature range 270°C – 380°C. The weight loss rate reached its maximum in 308°C, which was equal to 0,198g.min-1. Two temperature ranges in which the yield of CO was higher than the yield of CO2 were detected.