Two new coatings are claimed to provide performance, installation, environmental and cost benefits for O-rings, together with handling advantages in automated assembly processes.

Recognising the increasing use of common O-rings in automated assembly of products, particularly in the domestic appliance and automotive component sectors, Busak+Shamban material technicians have developed two new coatings - both with advanced characteristics - to address the problems associated with the use of elastomeric O-rings in automated assembly.
MF coating, developed for use with traditional elastomer O-rings in static sealing applications, is a transparent PTFE-based coating which greatly reduces the friction so often encountered with dry sealing surfaces and therefore helps to avoid the problem of seal-stick during automated assembly. A further benefit, gained through the application of this high-tech micro coating, is the significant reduction in seal damage during the assembly process - a critical factor in a one-time installation of the seal, within a closed design envelope.
LF coating offers further reductions in friction making these coated O-rings suitable for use in dynamic applications, where increased friction forces are encountered. Although LF coating offers the same benefits as MF coating in automated assembly, tests indicate that the resilience of the LF coating makes possible repeated re-installation of LF coated seals, with no resultant damage.
Furthermore, LF coating will continue to function long after installation, preventing premature failure of the seal in case dry running occurs
Both MF and LF coatings negate the use of costly friction-reducing lubricants and the associated environmental contamination. This, combined with the elimination of 'assembly damaged seals' and consequential costs, makes the use of Busak+Shamban MF and LF coated O-rings a viable design and production proposition.
The coatings, which do not exhibit cracking when the O-ring is stretched, can be applied to almost any elastomer and, being solvent-free, are environmentally friendly and compliant with requirements relating to VDA232-101. In particular, the coatings offer an expanded field of application for inexpensive elastomer seals and, additional to the characteristics previously described, provide quality assurance benefits.

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