Mechanics of polytetrafluoroethylene-based composites densification

In the study an assessment of specific friction forces occurring during the compaction of polytetrafluoroethylene workpieces in a mold was done, based on the analysis of axial and lateral pressures. In addition, an analysis of a compacted workpiece model was performed to predict the pressure distribution over its height. The pressure distributions at the bottom and walls of the mold were determined experimentally. The coincidence of theoretical and experimental values proves the validity of the used calculation formulae. The values of the specific friction forces and coefficients of external friction were determined on the basis of Coulomb’s and Siebel-Prandtl’s laws of friction.