Published On: Mon, Jun 9th, 2014

Nickel-coated graphite fibre particle additive offers EMI shielding

FiberGraf Materials has introduced a new line of nickel-coated GrafMat powder to provide EMI shielding properties in engineered thermoplastic and thermoset resins, as well as elastomeric grades.

FiberGraf Materials says that GrafMat powders have been developed for enhanced thermal and electrical conductivity applications.

The company adds that the nickel coated graphite fibre GrafMat powder offers three key benefits:

  • High EMI/RFI shielding effectiveness at lower cost (in some cases a fraction of alternate materials)
  • Processes faster and with less energy than other shielding additives (lowering cost of production time)
  • Can be compounded to higher loading levels and replace multi-component formulas (65% weight additions have been compounded).

There are two new grades labeled: GrafMat A280N60 and GrafMat A90N60.

Nickel-coated graphite fibre particle additive offers EMI shielding

Nickel-coated graphite fibre particle additive offers EMI shielding

The A280N60 has a 280 micron average particle size while the A90N60 is about one third smaller at 90 microns. Either grade particles are individually coated with 60% weight addition nickel. The very thin nickel coating completely encapsulates each particle individually for a free flowing powder.

FiberGraf Materials adds that a moulding compounder has successfully run a 40% loaded very high density (> 2 grams/cc) TPE resin that showed good electrical conductivity while retaining the same conductivity after being twisted 180 degrees. Nickel coated GrafMat will replace a mixture of four other additives in this TPE resin application. In addition, GrafMat will allow the compounder to minimise waste by over 90% as compared with the current mixture since processing efficiency is dramatically increased and regrind is eliminated.

GrafMat nickel-coated graphite fibre powder is claimed to offer substantial cost savings over other nickel coated carbon and silver coated additives. In one example, nickel coated GrafMat is less that 50% of the cost of a short length nickel coated carbon fibre grade that is not completely encapsulated with nickel.

FiberGraf says that it can tailor particle size distributions; as well, the amount of nickel can be varied. Other metal coatings such as aluminum, silver and silicon carbide, for example, can be also be considered.