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Parylene C and it’s Value as a Coating for Neodymium Magnets

Parylene C is an ultra-thin, pinhole-free polymer coating for Neodymium magnets that is mostly used in in automotive, military and medical applications but is gaining popularity in the consumer world as its benefits are becoming understood.

Parylene’s common generic name is Poly-para-xylylenes. It forms a plastic film when applied in a vacuum as a gas to target surfaces. It is self-initiated, un-terminated and requires no solvent nor catalyst. The two most commercially used Parylene coatings are Parylene C and Parylene N.

Parylene C is produced from a step by step process that does not include a liquid phase, thus coating will not pool in low areas, bridge across substrates, or exhibit liquid properties such as meniscus or capillary action.  Parylene is a polymer that produces a very thin layer, so is therefore economical and at the same time durable.  In addition, it’s FDA approved.

The useful combination of both electrical and physical properties gives Parylene C a low permeability to moisture and corrosive gases. Parylene C has better electric insulation, bio-stability and provides a moisture barrier.  It has thermal and UV light stability and has complete surface conformity. It’s maximum operating temperature is 680 degrees, much higher than where a magnet loses its magnetic strength. This characteristic makes it useful across the magnetic heat tolerance range.

Parylene coating can be done in room temperature as it does not affect the magnet. It is the best for coating and is medically proven. It’s the most bio-accepted coating for stents, defibrillators, pacemakers and other devices which are permanently implanted into the body. This therefore means it is FDA approved. It is used in various fields such as machinery and electronics, consumer electronics. Holiday and décor, apparel, consumer goods and toys.

For magnetic applications, the Parylene C coating can be an ideal choice when the applications may require an inert coating, weather resistance, and provides a durable alternative to more common coatings such as nickel and zinc.

Published in Physics of Magnets