The liners prevent packaged chemical products from releasing or consuming gases, which cause plastic containers to collapse, swell, leak, or even burst. The cap liners let containers breathe without leaking and maintain maximum airflow. Venting is through a hole in the cap (3FL-363) or through the threads of a cap without a hole (3FL-373).
The 3FL cap liners have multilayer construction with an ePTFE (polytetrafluoroethylene) membrane bonded across the face of the liner. This lets gases be released inside and outside the container, while preventing liquids from leaking out and contaminants from entering. The liners are only 1 mm thick and repeatedly reseal in use.
W. L. Gore & Associates Inc. –Portable Electronic Vents, 401 Airport Rd., Elkton, MD 21922, (800) 523-4673