Investigation of computer numerical control wood milling parameters for occupationally safer by the minimization of produced wood dust

Computer numerical control (CNC) wood machining produces wood dust, harming the operator's health. In this research, the effective parameters of the amount of produced wood dust (PM) in CNC milling are investigated. The design of the experiment was done based on the response surface method (RSM) and subsequently, 27 experimental tests were performed. The results of the analysis of variance show that the parameters of the depth of cut (ap), step over (ae), feed rate (vw) and cutting speed (vc) have a great impact on PM, respectively. Changing these machining parameters leads to severe changes in the PM (0.043-11.200 mg/m3). Also in 78% of experimental tests, the amount of PM is higher than the National Institute for Occupational Safety and Health (NIOSH) standard value (1 mg/m3). In the next step, for the reduction and minimization of PM, a quadratic regression equation was derived. After model validation, the model was minimized by the distance-based optimality method at Minitab software. Optimization result shows that by choosing the optimum parameters ap = 3 mm, vw = 50 mm/s, vc = 15,393 rpm and ae = 6.270 mm, PM is reduced to 0.011 mg/m3, which is much lower (about 89%) than the NIOSH standard value. This prediction was tested and validated by the experimental test.