POREX® Microporous PTFE 7751 is part of a line of porous filter materials for use in medical device manufacturing. POREX Microporous PTFE 7751 consists of a 1.3mm thick expanded, porous PTFE (polytetrafluoroethylene) sheet. POREX Microporous PTFE 7751 offers excellent temperature, environmental, and chemical resistance making it ideal for applications requiring hydrophobic molecular filtering. A diagram depicting POREX Microporous PTFE 7751 is shown in Figure 1.
With the properties of temperature, environmental, and chemical resistance, POREX Microporous PTFE 7751 is suitable for laser cutting. The non-contact nature of laser processing allows applications to be processed with small features and fine geometry which might be difficult to achieve with traditional mechanical methods. Processes other than laser cutting are not indicated as they are not conducive to the intended use of POREX. Universal Laser Systems (ULS) makes it possible to consistently and repeatedly process this material to a high degree of dimensional accuracy, with virtually no material deformation during processing.
Laser Processing Notes
POREX Microporous PTFE 7751 was tested to assess laser processing compatibility and determine the best configuration of laser peak power and wavelength. There was found to be no substantial difference between 9.3µm and 10.6µm laser energy when used to process POREX Microporous PTFE 7751. A microscopy image taken at 100x magnification of the edge of POREX Microporous PTFE 7751 after laser cutting is shown in Figure 2.
Figure 2. Microscopy image (100x) of the edge of POREX Microporous PTFE 7751 after laser cutting. The heat-affected zone measures 75µm.
Processing Example
POREX Microporous PTFE 7751 applications requiring fine geometry and intricate detail with no degradation of the material’s physical properties can be achieved with ULS technology. An example demonstrating the results of laser cutting POREX Microporous PTFE 7751 using the recommended system configuration is shown in Figure 3.
Figure 3. Example of the geometry possible when laser cutting POREX Microporous PTFE 7751.
Conclusion
POREX Microporous PTFE 7751 is suitable for laser processing and was extensively tested to determine the optimal processing configuration. Through this testing it was determined that laser cutting is viable with this material and that a single 75 watt 9.3µm or 10.6µm wavelength CO2 laser source is the best system configuration. POREX Microporous PTFE 7751 efficiently absorbs both the 9.3µm and 10.6µm wavelength laser energy to produce a processed edge that has a minimal heat-affected zone and no discoloration.
