بررسي كيفيت سطح لبه MDF طي فرآيند فرزكاري

Investigation on surface quality of MDF edge in peripheral milling process

This research was done in order to investigate the surface quality of MDF edge in peripheral milling process. Non-veneered MDF sheet with 16 mm thickness was cut info 50x50 cm boards. Samples were sawed by CNC milling machine according to ASTM D-1666-87 standard. The machining parameters were: spindle speed of machine in two levels of 12000 and 20000 rpm, feed rate in two levels of 6 and 12 m/min, depth of cut in two levels of 1 and 5 mm. Cutting technique included down and up-milling and cutting directions were in two ways including parallel and perpendicular to MDF axial direction. The edge surface roughness of cut samples in two layers of surface and core (2 and 8 mm from each sample surface), using profilemetry. In order to analyze the surface quality, three roughness parameters including medium roughness (Ra), maximum height on mean line (Rp), maximum depth below the mean line (Rv) and also medium waviness (Wa) were measured. The results showed that the studied factors had no significant effect on surface layer quality in determined levels and the MDF surface layer, due to its high density, showed good resistance to cutting condition and all roughness parameters in this layer were lower than those of core layer. Due to the lower density, core layer reacted to cutting factors variations and had different surface quality in different cutting condition. Except the depth of the cut, other parameters including spindle speed, feed rate, cutting pattern and cutting direction had significant effect on surface quality of core layer. Finally, in order to obtain the best surface quality, spindle speed of 20000 rpm, feed rate of 6 m/min, cutting depth of 1 mm and up-milling pattern for both parallel and perpendicular directions of board is suggested.