Granulometric Characterization of Wood Dust Emission from CNC Machining of Natural Wood and Medium Density Fiberboard

The aim of this paper was to determine the particle size composition of wood dust emission from CNC milling of natural wood and medium-density fiberboard (MDF) and evaluate the associated occupational exposure risks. The paper is focused on some of the most commonly used materials in the woodworking and furniture industry, i.e., solid wood (beech, oak, and spruce) and composite materials (MDF panels). In addition to the influence of the machined material, the effect of the technical-technological parameters, namely, feed speed and depth of cut on the particle size distribution, was also investigated. The selected values of the technical-technological parameters used in this study followed the common work practice in small wood processing companies. The particle size distribution was evaluated by using sieve analysis of samples from the total mass of collected wood dust. The results demonstrated that machining of natural wood is characterized mostly by the formation of coarse dust fractions (2 mm–1 mm sieves), whilst the processing of MDF was associated with generation of fine dust fractions with a size below 100 μm. The results obtained can be used for optimizing the technological programs of CNC milling machines, thus, reducing the occupational exposure to harmful wood dust emissions in the wood-processing industry.