Evaluation of the Milling Performance on Wood-Plastic Composite

Abstract

This research aims to study the milling factors that affect the quality of milled surfaces, including surface roughness and burr formation. A composite material composed of recycled polypropylene plastic and rubber wood powder was selected. The side milling parameters evaluated comprise spindle speeds of 330, 610, and 850 rpm; feed rates of 43, 120, and 200 mm/min; and cutting depths of 1, 3, and 5 mm. Surface roughness decreased with increased spindle speeds, but reduced feed rates and depths of cut. Burr formation diminished with increased spindle speed and feed rate, but required a lower depth of cut. Regression models for surface roughness and burr development were established, demonstrating prediction errors of approximately 1.54% and 2.29%. The optimal milling parameters to minimize surface roughness were determined to be a spindle speed of 850 rpm, a feed rate of 43 mm/min, and a depth of cut of 1 mm, resulting in a surface roughness of 5.184 µm. The suggested conditions to reduce burr formation were a spindle speed of 610 rpm, a feed rate of 200 mm/min, and a depth of 1 mm, which resulted in a burr height of 0.251 mm. The optimal parameters for minimizing both burrs and roughness were a spindle speed of 610 rpm, a feed rate of 43 mm/min, and a depth of cut of 1 mm. This yielded 6.958 µm of roughness and 0.255 mm of burr creation. These conditions eliminate the necessity for post-milling finishing and correspond to ISO 21920 surface texture standards.