New Nanoparticle Coating for Plasticating
Screws has Greater Wear Resistance Than
Standard Thermal-Spray Tungsten Carbide
Nordson’s Xaloy® MPX™ Technology for Single
and Twin Screws Provides Improved Abrasion
and Corrosion Resistance, with 61% Less Mass
Loss in Abrasion Tests
Compared with standard HVOF tungsten carbide
coatings, the Xaloy MPX technology exhibits
61% less mass loss in ASTM G65 abrasion testing,
18% less mass loss in ASTM G77 sliding wear
testing, and 8.5% greater bond strength in ASTM
C633 bond testing. As an example of corrosion
resistance, the Xaloy MPX coating survived more
than 1,000 hours of salt fog testing, in part because
of its near-zero porosity.
A technology that uses exceedingly tiny tungsten
carbide spheres barely larger than the particles in
cigarette smoke has yielded a coating for single
and twin plasticating screws that resists abrasive
and corrosive wear better than standard coatings
applied by high-velocity oxygen fuel (HVOF)
thermal spray. Nordson Corporation will introduce
the technology at K 2016 (Hall 11, Stand A26).
“Nordson’s Xaloy MPX screw coating provides
best-in-class wear protection compared with
standard HVOF coatings, and its higher bond
strength eliminates potential for chipping,” said
Mark Colella, global product manager for the Xaloy
brand. “This new technology extends the working
life of screws in extrusion and injection molding,
enabling processors to work with some of today’s
most challenging materials.”
The new Xaloy® MPX™ thermal spray coating from
Nordson is made up of particles only 5 microns
in diameter. Consisting primarily of tungsten
carbide, the particles are six to seven times smaller
than those in standard HVOF coatings and more
densely packed owing to a uniform spherical
shape produced in a controlled plasma process.
The combination of ultra-fine particle size, higher
coating density, and a 2.5 times greater application
velocity results in a stronger bond with the parent
metal of the screw and improved resistance to
wear.
TN October 2016
Nordson recommends the Xaloy MPX technology
for resisting abrasion from compounds with
medium (15 to 35%) filler loadings and for resisting
corrosion from halogenated materials, including
flame retardants and PVC. For filler content above
35%, Nordson supplies the high-hardness coating
Xaloy® X-8000™.
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