PTFE Coated O-Rings
Coated o-rings typically have a thin film of PTFE (a generic compound of Teflon™, a trademark of the Chemours Company), commonly termed a “coating” which is adhered to the o-ring. The PTFE external treatments can be dry or wet coatings or dips.
Another possible coating is poly(p-xylylene) polymers (trademark name: Parylene). These polymers are chemically vapor deposited. These coatings take place through a vacuum deposition where the polymer or Parylene condenses on the o-rings surface in a polycrystalline fashion.
Reasons For Coated O-Rings
The most common reasons for using a specific coating to enhance the performance characteristics of an o-ring or a seal include friction reduction, ease of installation and contrasting color for ease of identification, and increased wear life for less downtime. A coated o-ring or seal is free from dirt and debris because you don’t need to use oil-based lubricants and it can reduce and/or prevent damage from automated equipment.
PTFE Coated O-Ring Color Options
The most common color for PTFE coated o-rings is blue.Coatings are available in a wide variety of colors that can include light, medium and dark blue, black, purple, pink, red, orange, yellow, brown, light, medium and dark green and clear.
O-rings made from Buna (Nitrile°) and Viton® are the most common elastomers that are coated with PTFE to meet application requirements.