In the course of this work a basic characterisation method for the content of lubricant in polytetrafluoroethylene (PTFE) during the paste extrusion process should be determined. The content of lubricant in PTFE powder during the paste extrusion was called „lubricant-restraining-capability“. Different material types and lots are restraining the lubricant differently. This aspect has not been studied in literature yet. The characterisation methods thermogravimetric analysis (TGA), differential scanning calorimetrie (DSC) and Raman spectroscopy were used to investigate different production stages, namely PTFE powder after the lubricant migration („Pulver“), pressed billet („Puppe“), extruded line („Strang“) and lubricant-wet film („Folie“). Raman spectroscopy was selected, because PTFE is a very good Raman emittor as well as the used lubricant shows a pronounced Raman vibration near the PTFE waveband. In addition, the tensile strength of the dry film was measured. In total, seven different formulations that are based on distinct types and lots were tested. Raman spectroscopy was found to be the best method for the determination of lubricant content in PTFE. Moreover, the results of the Raman-measurements are in good correlation with the tensile strength values, which means that with an increasing content of lubricant the tensile strength of the film becomes lower. Generally, the most reliable results can be reached by corresponding measurement of the billets („Puppe“) and extruded lines („Strang“).