Title: Machinability of Polytetrafluoroethylene (PTFE) under Dry CNC Milling: Statistical Analysis and Optimization of Surface Integrity and Productivity
Authors: Chuku, I. E.; Bani, S. L.; Jinyemiema, T. K.; Nwosu, H. U.
Volume: 10
Issue: 3
Pages: 32-40
Publication Date: 2026/03/28
Abstract:
Polytetrafluoroethylene (PTFE) is widely used in engineering applications due to its low friction coefficient, chemical inertness, and thermal stability. Despite these advantages, PTFE presents notable machining challenges, particularly under dry conditions, including surface smearing, dimensional instability, and poor surface integrity. This study experimentally investigates the dry CNC milling of PTFE with the aim of optimizing machining parameters for improved productivity and surface quality. A full factorial design involving spindle speed, feed rate, and depth of cut at three levels each was employed, resulting in 27 experimental runs with replications. Material removal rate (MRR) and surface roughness (Ra) were measured and analyzed using analysis of variance (ANOVA) and multiple linear regression. Results show that machining parameters and their interactions significantly influence both MRR and Ra (p < 0.05), with interaction effects playing a dominant role in surface roughness formation. Regression models exhibited high predictive accuracy, with coefficients of determination exceeding 98%. Optimal machining conditions were identified that minimized surface roughness while maintaining acceptable productivity. The findings provide practical guidelines for precision dry milling of PTFE components and contribute to improved process planning for thermoplastic polymers.