Thursday, March 5, 2015

Expanded PTFE (ePTFE) Joint Sealant – A miracle product with varied applications

Starting 2015, Poly Fluoro Ltd. will be among the few companies globally, with the capability to manufacture expanded PTFE (ePTFE).
While the uses of ePTFE are numerous, it falls upon a select few manufacturers to produce this material. As we have covered in an earlier article, the production of ePTFE is as diverse as its applications. Some of the variants that exist include:
  1. Mono-axially stretched ePTFE tape
  2. Bi-axially stretched ePTFE tape and sheet
  3. ePTFE membranes
  4. ePTFE tubes and rods
  5. ePTFE gland packing
Each of these products comes with unique production methods and specific nuances. However, the most commonly used variant at this point is the mono-axially stretchedePTFE tape.
ePTFE 1 ePTFE 2
ePTFE tape – also referred to as PTFE joint sealant or PTFE Gasket Tape, is widely used for creating a sealing joint between pipes and other mating metal parts. Specifically, as a chemically inert material, this tape finds application in chemical plants, biotech plants and oil and gas pipelines. In fact, any pipe-lining application, where two pipes are connected using flanges, would benefit from using ePTFE tape, as the pliable nature of the material ensures that no gaps are left unfilled.
The tape has a soft texture and is easily compressed. Typically, the compression set of the tape is one of the parameters that define the material. The tape needs to be soft enough to compress under minimal load and ensure that it decompresses just enough to guarantee a complete sealing. At the same time, the tape needs to have adequate tensile and compressive strengths to allow for heavy loads to work upon it, without fatigue. In addition to its excellent chemical resistance, ePTFE tape also has a high temperature resistance, which allows it to be employed in applications involving high temperature fluid transfer.
ePTFE tape comes in 2 variants: adhesive and non-adhesive. The application of the adhesive is not highly complicated, but for on-site convenience, it is preferred as else the installation of the tape is difficult.
The application of the tape is very simple. As the visual below shows, the tape is laid along the flange and allowed to overlap at the ends. The soft texture of the tape means that at the point of overlap, the tape does not bulge once compressed, by simply compressed further to make a uniform seal.
ePTFE joint sealant tape is among the most sought after materials for all sealing applications.