The Basics of aspire® ePTFE sealing

When sealing aspire® membrane products to plastic parts there are a several factors to take into consideration. These include membrane handling, design elements, and properties of the support materials. Consideration also needs to be given to how the seal is created.

  • Will the membrane be in contact with the plastic part?
  • Will the support material be in contact with the plastic part?
  • What are the thermoplastic characteristics of the two materials?
  • Are the materials the same or different?

Handling Parameters:

  • When handling membranes it is recommended to wear latex-free gloves or finger cots. Oils on the skin can adversely affect membrane properties.
  • Parts and work surfaces must be clean and free of particles.
  • Static elimination is advised when handling and placing membrane.
  • Relative humidity of 50% and temperature of 21° C (~70°F) are recommended.

Design Parameters:

  • The design of the seal area is an essential factor in the integrity of the finished seal.
  • It is advantageous to have a radius in all angles in contact with a membrane.
  • It is preferable to have flow in the finished device go in the direction of the seal so that the membrane is supported.

Material Properties:

  • aspire® medias are available with a variety of supporting substrates. The support material influences many of the sealing and handling considerations.
  • Dwell time and melting temperature and pressure are important attributes to factor when sealing either to membrane or support sides of aspire® medias.

Sealing Methods:

  • Adhesive sealing
  • Mechanical sealing – including molding
  • Heat sealing
    • Heated dies
    • Radio frequency
    • Ultrasonic welding