TRIESKOVÉ A BEZTRIESKOVÉ OBRÁBANIE DREVA 2008 11. - 13. 9. 2008 69 FACTORS INFLUENCING SOUND EMISSION DURING CIRCULAR SAWING OF OAK-WOOD (QUERCUS ROBUR L.) Ružica Beljo Lučić – Ankica Čavlović – Igor Đukić – Matija Jug Abstract This paper presents the results of research on sound emission during conventional sawing of oak-wood (Quercus Robur L.). The machining process was carried out on a circular saw for rip-sawing. The concerned variables in our research were: wood moisture content, cutting depth and feed rate. The cutting speed and tool parameters were constant. Also, directions of cutting with regard to grain directions in the whole experiment were approximately the same for each cutting depth. Sound emission was measured for a specific condition of wood and machine parameters. At the same time the power requirements were measured, too. The results obtained are summarized as follows: (1) Sound level is higher during sawing of dried wood than green wood under the same sawing conditions. (2) Sound level increases with the increase of feed speed for dried and for green wood but decreases for frozen wood. (3) Sound level increases with the increase of cutting depth for dried wood but noise emission decreases with increased cutting depth for green wood. (4) Cutting power reaches higher values during sawing of kiln dried wood and frozen wood than during sawing of green wood. (5) Sound level for dried wood is in good correlation with cutting power, meaning that more work produces more noise; this statement, however, does not apply to sawing green wood. Key words: circular saw, wood moisture content, sound level, cutting power INTRODUCTION For achieving efficient wood machining with circular saws, it is essential to understand thoroughly the interaction between raw materials, end products, machinery and the sawing process itself. Adequate knowledge of correct bite, feed speeds, tooth speeds, side clearances, depths of cut, cutting forces and power requirements is essential for a good saw operation. We have a good understanding of the influence of most wood and machinery parameters on cutting forces and power requirements. Also, the influence of sawing conditions on sawing quality is a frequent object of research (Steward, 1984; Williston, 1989; Goglia, 1994; Aquilera and Martin, 2001). Sound emission is an important parameter of sawing. Exposure of workers to noise is a health risk. There is sufficient scientific evidence that noise exposure can induce hearing