Study on material parameters and processing conditions on porosity, poresize and properties of PTFE sheets made via sintering

This study explores the influence of forming pressure on the fabrication of porouspolytetrafluoroethylene (PTFE) membranes using a conventional powder procedure. Due to PTFE'shigh melt viscosity, sintering is preferred over traditional melt-based processes. The fabricationprocess involved cold-pressing PTFE powder at various pressures within a cylindrical mold (۵ cmdiameter), followed by a designed thermal cycle to achieve sintering. The resulting porous structureswere characterized by permeability tests and scanning electron microscopy (SEM), with an emphasison the influence of forming pressure on porosity and permeability. The results revealed the existanceof an operational compression pressure range (۰.۵ to ۱۲ bar) for creating porous PTFE membranesexhibiting a desired permeability and pore size. In this range, sufficient fluid passage is achievedwhile maintaining the mechanical integrity of the membranes. Furthermore, the results showed adecreasing trend in both permeability and porosity with increasing forming pressure. These findingsdemonstrate that forming pressure can be used to control the porosity and permeability of sinteredPTFE membranes that have been fabricated using conventional methods. This approach holdssignificant potential for the development of porous PTFE membranes with tailored properties,opening doors for applications in loop heat pipes for various fields, including electronics cooling,spacecraft thermal management, and medical devices.

کلیدواژه ها:

Membranes ، Sheets ، Polytetrafluoroethylene (PTFE) ، Sintering ، Permeability