A number of lubricants were identified as suitable for the paste extrusion of polytetrafluoroethylene (PTFE). They were characterized in terms of both flow and surface properties. It was found that it is possible to alter the flow and surface properties of these lubricants independently and thus it became possible to study their relative effects on preforming and extrusion of PTFE paste. Based on this study, it was concluded that preforming quality increases with increase of lubricant viscosity and with improvement in the wettability characteristics of the lubricant with PTFE. The extrusion pressure also increases with increase of the lubricant viscosity and decrease of the wettability of lubricant with PTFE. These two effects were identified to be due to the increased resistance of fluid in migration under the application of pressure for high viscosity lubricants and due to the even distribution of lubricant around the individual PTFE particles for low surface tension lubricants. (C) 2004 Elsevier B.V. All rights reserved.