Resistance of spruce wood (Picea abies L.) treated with a flame retardants after the radiant heat exposure / Iveta Čabalová ... [et al.]. -- Fotogr., graf., tab. -- Lit. - The aim of the paper was to determine the resistance of spruce wood (Picea abies L.) treated with a flame retardant after exposure to radiant heating. The treatment was performed with a typical flame retardant HR prof and an aluminium coating used to protect metal objects at high temperatures – Striebrenka, an atypical retardant not commonly used in wood protection. The samples treated with retardants as well as untreated (control) ones were heat- loaded by radiant heating using a radiation panel for 30 min. Changes in the basic chemical composition, especially the content of extractive substances, holocellulose, cellulose, hemicelluloses and lignin in two layers removed below the charred layer (layer 1 - thickness up to 20 mm. and layer 2 - thickness from 20 to 40 mm) and thickness of the charred layer were evaluated. During the thermal loading of the control sample, we observed the temperature of 300°C in time of 860 seconds on thermocouples (M 1.0). The average thickness of the charred layer was 15.41 mm. The limit temperature of 300°C was not reached on any thermocouple (M 2.0 – M 5.0) in all samples. The average thickness of the charred layer of the sample treated with HR prof was 14.9 mm and with Striebrenka 15.18 mm. Following the results, it can be stated that the chemical composition of the timber was changed as a result of the chemical treatment of wood by radiant heating. However, the largest changes were recorded in the sample not coated with any retardants at all. A decrease in the saccharides component of wood, especially hemicelluloses (from 13.57 to 20.25%) was observed in the case of this sample. When comparing the chemical changes of samples treated with flame retardants, it can be seen that the HR prof retarder was more effective in terms of saccharides and the Striebrenka retardant in terms of lignin protection. In contrast, during the thermal degradation of treated samples, a decrease in lignin (from 7.66 to 8.10%, HR prof retardant) and holocellulose (from 5.83 to 8.3%, Striebrenka retardant) content compared to the original sample was observed.

In Acta Facultatis Xylologiae Zvolen : vedecký časopis Drevárskej fakulty. -- Zvolen : Technická univerzita vo Zvolene, 2021. -- ISSN 1336-3824. -- Vol. 63, no. 2 (2021), s. 103-116

I. Čabalová, Iveta, 1979-
II. Zachar, Martin, 1981-
III. Bélik, Michal, 1997-
IV. Balážová, Žaneta, 1971-
V. Acta Facultatis Xylologiae Zvolen : vedecký časopis Drevárskej fakulty. -- Vol. 63, no. 2 (2021), s. 103-116

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