Delamination Analysis of Polymeric Materials During the Drilling Process

Currently, the study of the drilling of polymeric materials is increasing. Some of these materials are PA66 (Poly-Amide), PEEK (Poly-Ether-Ether-Ketone) and PTFE (Poly-Tetra-Fluoro-Ethylene) or Teflon. Former studies are shown as PEEK and PA66 have a good machinability, but they are materials that suffer delamination. Moreover, the effect of the tool is decisive in the surface final quality. These considerations can be extended to PTFE. Therefore, the objective is to analyze the delamination during the drilling process of these materials, and to determine adequate cutting conditions. The experiments have been carried out in a machining center in dry. Different cutting conditions have been selected. The selected drill is designed specifically to drill polymers. Its material is WC and its point is of diamond. The geometry responds to a point angle of 90°, a helix angle of 35° and diameter of 6.3 mm. The plates of the three materials have a thickness of 6.5 mm. The results of the tests were treated in an analysis of variance to relate the influence of each factor and in a Student-Newman-Keuls test to identify the homogeneous groups. The analyzed bit provides good results under the cutting conditions studied, but there are not significant factors.