Ceramics are used to solve wear related problems during
the paper making process. The most critical is in the “wet” end of the paper making
when water is removed from the pulp slurry by moving over ceramic “dewatering” foils
at high rates of speed, often in excess of 100km/min. 
This represents a very demanding
application since paper pulp is abrasive and the chemical environment severe.
Initially, aluminum oxide was used for dewatering foils.
As the environments have become more demanding, it has been replaced with silicon nitride and silicon carbide “black” non-oxide ceramics. The high
hardness, fracture toughness, wear resistance and thermal shock resistance of these
materials are the key reasons for using non-oxide ceramics.
Ceradyne is a Tier 2 supplier of silicon nitride segments for use in paper processing.