Identification of heat transfer parameters for numerical simulation of the cooling step in sintering process of polytetrafluoroethylene (PTFE)

• Grant number: 14/20989-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2014
• End date: November 30, 2015
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Rodrigo Bresciani Canto
• Grantee: Antonio Cappelletti Ferreira
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The research project presents as its main objective the identification of polytetrafluoroethylene's (PTFE) heat transfer parameters of the cooling step of sintering process. The identification will be done through experimental analysis and computer-optimization techniques combined with the finite element method (FEM). Specimens will be obtained by isostatic pressing and sintering of PTFE. The specimens will be machined, drilled for thermocouples insertion and finally submitted to appropriate thermal loadings in order to induce temperature gradients inside. In order to reproduce the thermal assays, it will be developed FEM computer models using the specimen's physical properties and parameters' values found in literature, such as density; specific heat; thermal conductivity and convective heat transfer coefficient. Referring to the temperature history during thermal assays from the chosen position of thermocouples, the comparison between those experimental results and theory will serve as a basis to adjust the parameters from the theoretical model until the proper correspondence is reached. By means of computer routines, it will be achieved the best set of values for the parameters, which may depend on temperature. The found parameters are expected to be in concordance with literature and to contribute in the context of a broader project coordinated by the supervisor. This broader project aims to develop theoretical models for simulation of PTFE's pressing and sintering processes. (AU)