Polymer coating:

We are working with a Canadian company in 2015, back then, we try to find a solution for magnet underwater application in acid environment, sampling state takes around half a year, since we used standard thickness NICUNI with three layers, epoxy grey(not black) and tefelon,

but none of them fit it perfectly, so our R&D started with electroplating of magnet testing since that time, and this case solved from now on through our new coating solution:polymer coating.

We call it “high density polymer resin coating” sometime, which is similar with Japanese traditional URUSHI coating, polymer coating coats and drys with super multi-layer and high density without a pin-hole. In another word, this structure gives the advantage in electric insulation, rust resistance and adhesion. Additionally speaking, polymer coating is halogen-free and environmental friendly with colorful options for specific application.

  • Anti-rust: Polymer coating helps prevent iron such us rare earth permanent magnet from being oxidized. Generally speaking, surface treatment such as nickel plating or other traditional way can not avoid small gap between the coatings(we call pinhole), leading to some oxygen from the pinhole into the sprayed materials, therefore oxidized materials. It adopts super multi-layer process to prevent oxygen from sliding effectively, so the product will not rust inside the coating, which is great for magnet motor rpm remaining;
  • Wear-resistant: Adhesion of polymer coating coefficient is 3 to 5 times stronger than electroplating. Therefore, polymer coating is difficult to fall off and wear very tightly with magnet motor, HAST or other high rotation test can not broken it as well;
  • Insulation: Polymer coating is also used to magnetic ring for insulation, especially for radially oriented ring magnet, mainly used to prevent radiation and leaking electromagnetic waves in electronic equipment.The radiation and electromagnetic waves will interfere with normal operation of other equipment, resulting in equipment dysfunction, signal transmission errors, some of them are also harmful to health of people. The wire is usually wrapped around the magnetic rings after coated with resin. Since the edges of skin on the surface of it are apt to destroy the wire, resulting in leakage of electricity. 3M gave a thermal stability of slot insulation materials coefficient within 0.36, if higher than it, marginal decrease will cause expensive financial burden for a baby project. On the one hand, that coating?helps temperature rise in magnet motor or magnet generator decayed, so it is not necessary to use AH or EH grade of neodymium to cut down the cost. On the other hand, heave rare earth element in only found in China, which is really rare, so we need to save them for?sustainable development for next generation!
  • High value: Polymer coating can be used for decoration, assigned any color according to specific application. In addition, special ingredients can be added.
  • Safety: with RoHS certificated, our coating does not contain halogen, conforms to the ROHS international standard, passed Japanese company’s allergy test as well. And eco-friendly is the value of our company.

Coating of magnet:

Many customers ask us why magnet need electroplating, apparently, we can not just tell people the characteristics of rare earth element is vivacious, you may check more in magnet F&Q.

CHEMICAL NI 15-30μm 亮银色 ≤200℃ ≥96h ≥200h ≥72h excellent
EPOXY 12-35μm 黑色、灰色 ≤120℃ ≥96h ≥200h ≥72h excellent
NI+GOLD 10-20μm 金色 ≤160℃ ≥96h ≥200h ≥72h excellent
NICUNI 15-30μm 亮银色 ≤200℃ ≥72h ≥200h ≥48h excellent
NI+TIN 20-30μm 半亮银色 ≤160℃ ≥72h ≥200h ≥48h excellent
SINGLE NI 10-30μm 亮银色 ≤200℃ ≥72h ≥96h ≥48h excellent
ZINK 6-15μm 彩虹色 ≤160℃ ≥48h good
KM ZINK 6-15μm 蓝白色 ≤160℃ ≥24h good
PARKERISING 1-3μm 黑灰色 ≤80℃ normal

Notification: salt spray testing depends on many elements effect, barrel plating is usually better than rack electroplating

1) Nickel is the most common choice for plating neodymium magnets. It is actually a triple plating of nickel-copper-nickel. It has a shiny silver finish and has good resistance to corrosion in many applications. It is not waterproof.

2) Black nickel has a shiny appearance in a charcoal or gunmetal color. A black dye is added to the final nickel plating process of the triple plating of nickel-copper-black nickel. NOTE: It does not appear completely black like epoxy coatings. It is also still shiny, much like plain nickel plated magnets.

3) Zinc has a dull gray/bluish finish, that is more susceptible to corrosion than nickel. Zinc can leave a black residue on hands and other items.

4) Epoxy is basically a plastic coating that is more corrosion resistant as long as the coating is intact. It is easily scratched. From our experience, it is the least durable of the available coatings.

5) Gold plating is applied over the top of standard nickel plating. Gold plated magnets have the same characteristics as nickel plated ones, but with a gold finish.

6)Nano-deposit is new type of anti-corrupted coating for long time salt spray test in magnetic materials, however, Kyle Magnetics R&D realized?Ni-based nano coating does not perform very well in wear resistant for specific customer’s application, so our team find this new method after working on this project over 1 year.


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