The Influence of Tool Path Strategies on Surface Roughness and Machining Time in the CNC Milling of UHMWPE

摘要

The right choice of tool path strategies in the CNC milling of UHMWPE can lead to significant reduction in machining time, improvement of workpiece surface quality and tool life, thereby, leading to overall cost reduction and higher productivity. In the study, the effects of toolpath strategies on the surface roughness and machining time during CNC milling of UHMWPE materials as acetabular liners of artificial hip joints were examined. The machining experiments were performed using 3-axis CNC milling and three toolpath strategies such as raster, step and shallow and optimize constant Z machining were investigated. The cutting parameters for machining UHMWPE was set-up using the toolpath strategy with step and shallow machining, at a spindle speed of 7000 rpm, step over 0.01 mm and feed rate of 1500 mm/rev. The surface Roughness (Ra) of the outer and inner acetabular liner generated by this CNC machine is 1.195 μm. The results meet the ASTM standard for the Ra value of the acetabular liner for the artificial hip joint which requires a maximum Ra value of 2.0 μm.