WOOD RESEARCH Volume 62, Number 3, 2017
Ján Svoreň, Ľubomír Javorek, Mária Krajčovičová, Katarína Klobušiaková, Ivan Kubovský, and Richard Kminiak

The effect of the circular saw blade body structure on the concentric distribution of the temperature along the radius during the wood cutting process

The paper presents the experimental results of a research aimed at the distribution of the temperature on thecircular saw blade body. The temperature was measured at four distances from the centre of the circular saw blade body (60 mm, 70 mm, 80 mm, 90 mm) by means of an infrared thermometer. Three circular saw blades with the diameter of 350 mm and a variable adjustment of the body (without slots and coating, with slots and without the coating, with both slots and coating) were used for the longitudinal sawing of the spruce wood (Picea excelsa) with the thickness of h = 25 mm. Feed speed vf = 12 m•min-1 and cutting revolutions n = 4000 min-1 were constant. The measured temperature was in the range from 22°C to 30°C. The highest measured temperatures were recorded on the circular saw blade with the slots and coating.

WOOD RESEARCH Volume 63, Number 6, 2018
Jozef Kúdela, Ivan Kubovský, and Michal Andrejko

Impact of different radiation forms on beech wood discolouration

This study analyses beech wood surface discolouration induced through UV radiation during an accelerated ageing process and with radiation emitted from a CO2 laser beam operating under specific settings. The results show that the extent of beech wood surface discolouration was dependent on the amount and the type of the energy delivered and on the absorption performance of the main wood components. It was observed that increasing irradiation dose caused decreasing wood surface lightness in both UV radiation and CO2 laser-produced radiation scenarios. In most cases, the values of colour coordinates a* and b* increased, and the wood surface was gradually turning dark brown. At high irradiation doses from the CO2 laser, there were recorded decreasing trends in a* and b*, and the beech surface darkened substantially (up to black). To attain purpose-oriented wood surface discolouration under specific modification modes, there is necessary to carry out thorough chemical analyses of the treated wood surface and to express quantitatively the dependence between the energy supplied, colour, adsorption capacity of the main wood components and the ongoing chemical changes.