PTFE is quite simply an amazing material. Comprised of a series of repeating Carbon and Fluorine bonds, the C-F bond is one of the strongest and most stable chemical bonds. As a result, the base polymer that makes up PTFE offers excellent properties that included: robust chemical resistivity, a high melt point, a low coefficient of friction, UV resistivity, biocompatibility, and superior dielectric properties. Stretch or expand a paste extruded form of this PTFE, however, and the formerly "solid" PTFE will be transformed into PTFE with higher tensile strengths as compared to its non-expanded precursor. Even more important, however, is the fact that the stretched or expanded PTFE becomes micro-porous.
Nodes, Fibrils, and Aspect Ratios
Characterized by a spider-web like appearance, expanded PTFE (ePTFE) has a matrix that is very unique. As shown in the SEM images, there are repeating sets of PTFE nodes and PTFE fibrils. By expanding one ePTFE more than another, the distance between adjacent nodes is increased. Conversely, a reduction in the ePTFE expansion enables nodes to be located within closer proximity of one another. Since fibrils serve as connectors between adjacent nodes, nodal separation dictates fibril length and fibril diameter.
While perhaps not immediately apparent, the ePTFE’s nodal separation distance and the fibrils aspect ratio (its fibril length to diameter ratio) have a profound impact on the material’s functional properties. These include air permeability, water intrusion pressure, air filtration efficiency, and reflectivity just to name a few and it is here that ThermoPore’s expertise shines brightest.
ePTFE Development Projects
ThermoPore understand the balancing act required by most development projects, especially those that involve seemingly competing functional specifications. We also understand the need to arrive at a part specification that has your application and your functional specifications in mind. Let ThermoPore's associates tailor an ePTFE solution for your needs to ensure a solution that can be consistently manufactured with a high level of repeatability. We'll bring the project in one time, on budget, and within specification. Contact us today and put our expertise to work for your next development challenge to ensure your project’s and your company’s success.