When cutting plastics, workpieces are deformed after machining. This is due to the poor thermal conductivity of plastics, which results in a much faster cooling of the surface after processing than the internal parts of the workpiece. Consequently, there are residual stresses that cause bending of workpieces after processing. With the Design of Experiments method, the milling parameters were optimized in order to minimize bending of workpieces after processing, while at the same time minimizing the processing time. It has been found that the greatest impact on bending has feed rate and depth of the cut, while a slightly lower impact has spindle speed. If cutting is done less intensively (small feed rate and a small depth of the cut), the deformation of the pieces after processing will be reduced.
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