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Electroless nickel on extrusion molds

I'm having several problems for the application of electroless nickel on extruders moulds (PVC).

They work not more than a week, and when they took off the mould the electroless was all corroded and waste.They don't have the problem when they applied hard chrome. but I thought that electroless nickel was more corrosion resistant to the "PVC" than hard chrome.

Before the nickel application I mirror polished the base material.

If someone can suggest me what to do I will appreciate very much.

thanks very much.

EMMANUEL SCHONWALD
- BUENOS AIRES ARGENTINA
2000

Hi Emmanuel,

PVC will slightly decompose and release hydrogen chloride at melting point. Hydrogen chloride accounts for the corrosion of nickel. Actually chrome is much more resistant to hydrogen chloride than nickel.

Ling

Ling Hao
- Grand Rapids, Michigan
2000

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You did not say what type of EN you are using. There are three basic types of EN coatings, Low P, Mid P and High P. High P has better corrosion resistance in an acid environment like the PVC extruder.

George Shahin
Atotech - Rock Hill, South Carolina
2000