Coatings Information -
Overview

Fluoropolymer coatings can be applied to many
different materials to improve their surface
properties. Fluoropolymer coatings are unique
non-stick, low friction, dry lubricant materials that
impart a new and improved working surface to
many industrial articles such as industrial rolls,
shafts, valves, mandrels and articulating
mechanical devices.


Types of Fluoropolymer
Coatings

PTFE  -  PTFE (polytetrafluoroethylene)
non-stick coatings have the lowest coefficient of
friction and highest temperature resistance of any
of the fluoropolymer coating systems. PTFE based
products can typically withstand temperatures of
500°F on a continuous basis and up to 550°F for
brief periods. PTFE coatings are very good
electrical insulators and are extremely
non-wetting. Unlike FEP and PFA based coatings,
PTFE does not melt-flow during the curing
process. Instead, the surfaces of the sub-micron
sized PTFE particles soften (sinter) and form a
film through interparticulate contact at
temperatures above 680 F. PTFE is inert to
almost all chemicals, but is somewhat porous, and
thus permeable to water vapor and other gases.
The substrate must be able to withstand a cure
temperature of at least 700°F to consider PTFE
based coatings. In summary, PTFE has an
extremely low coefficient of friction (feels waxy),
high temperature resistance, fair to good
abrasion resistance, very good chemical
resistance and has excellent non-stick properties.


FEP  -  FEP (fluorinated ethylene propylene)
based coatings have superb release qualities and
are frequently used as mold release coatings. FEP
coatings, which are thermoplastic, melt-flow
during curing to form smooth, non-porous films,
and are thus more chemically resistant than PTFE
coatings. FEP coatings have lower heat resistance
than PTFE coatings, 400°F, but also cure at lower
temperatures for heat sensitive substrates. In
addition to having excellent non-stick properties,
FEP coatings have a very low coefficient of friction.


PFA  -  PFA (perfluoroalkoxy) exhibits high
viscosity melt-flow during the curing process
similar to FEP and forms non-porous barrier films.
Has excellent chemical resistance properties and is
tougher and more abrasion resistant than PTFE &
FEP. Non-stick release properties are not as good
as FEP though. Temperature resistance rating is
500 degrees Fahrenheit.


Composite Coatings  -  These coatings are
formulated with special blends of fluoropolymers
and high-performance organic resins like
polyamide-imide, polyphenylene sulfide, and
polyether sulphone. The organic resins (PAI, PPS,
PES) improve the composite's toughness and
abrasion resistance whereas the fluoropolymers
(FEP, PTFE) provide the non-stick, low friction
properties. Composite coatings can sometimes be
applied to smooth, clean metal, eliminating the
need for abrasive blasting.


PTFE/PFA Silverstone - This family of
coatings contains a blend of PTFE and PFA
polymers which are combined with ceramic
particles to form a matrix having long lasting
release properties and advanced abrasion and cut
resistance. It is a more expensive coating to apply
because of its higher material cost and a standard
cure temperature of over 800 degrees Fahrenheit.
This 3-coat system is designed for applications
requiring durability and abrasion resistance with
excellent release properties.
FEP/PAI Coated Guide Bar
A product metering bar which has been
coated with FEP and Polyamide-imide to
prevent corrosive attack around the inlet
ports. All other areas were selectively
masked.
Abrasive Blasting Cabinet
This abrasive blasting cabinet is used to
clean metal surfaces prior to applying
organic finishes. By manipulating this
units operating parameters we can vary
the surface profile (roughness) the
substrate receives.
FEP Coating on Engraved Roll
Industrial engraved roll coated with
green pigmented FEP. Although clear
unpigmented FEP coatings have better
release properties, users often prefer
colored (pigmented) coatings as an aid
in evaluating wear rate and wear
patterns.
Precision Spraying Equipment
Composite primer being applied to
industrial roll. The spray gun is mounted
in an automatic traversing unit to ensure
a uniform thickness of coating. By
combining the automatic traverser with a
precision dispensing metering pump,
highly reproducible results are obtained.
Worn PTFE Coating for Resurfacing with Silverstone
This worn PTFE coated rail used in the
food service industry is being prepared
for recoating. PTFE/PFA Silverstone will
be applied for increased surface
protection from scratches.
Pioneer Valley Coating
South Hadley, Massachusetts 01075 USA
Tel. (413) 535-1424