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.
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