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Electroless chemical nickel - maximal processing temperatures?

We have problem with polymer melt sticking (polyvinylalcohol) to metal surfaces of our extrusion apparatus. We speculate about chemical nickel plating of die to eliminate melt sticking resulting to thermal degradation of material. Could you advise me what phosphorus content in nickel bath is ideal for this application? What maximal temperatures can we use for the EN plated tools? Are thermal resistance and lubricity of the coating dependent on phosphorus content? The last question is if the heat treatment (for hardness improvement) influences non-sticking properties of the plated surface?

Thank you for your answer

Tomas Kolbl
process engineer - Czech Republic
September 11, 2008

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Tomas,

Talk to a reputable EN plater in your area about the temp/phos content, Probably not a big issue. I would consider a EN/teflon plate for lubricity.

Good Luck

Trent Kaufman
electroplater - Galva, Illinois
September 16, 2008

Dies with too complicated geometries (sharp entrant angles) or too small are always a challenge. Tool steels require special pre-plating procedures which if not carried out properly will cause problems. Look for an experienced plater specialized in tooling for plastics and learn more about similar cases in this forum before you take a decision. Problems may range from a simple bare corner or face with little consequence, to (believe-it-or-not) the destruction of your valuable tool. Good luck,

Guillermo Marrufo
Monterrey, NL, Mexico
September 18, 2008