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Properties of Viton
vulcanizates
Viton may be used over a wide temperature range extending from -30
(-22 ) to 250
(482)). The physical
properties of Vition are very similar to those of natural rubber and synthetic
rubbers. However, its real merits are manifeasted unedr severs circumstances,
such as expouser to acuds, alkalines and ozone, conditions which no other
elastomer can withstand.
Physical Propertise
The Effect of temperature on Physical Propertise is shown in Figure 1-4.
Viton is chemically inert under normal use and is usable for a long period
of time at high temperature (200
(392 )) where other rubbers
will degrade and become unusable. However, the effect of temperature on
various physical propertise is relatively large, and careful consideration
of each property is therefore necessary at the time of product design.
Figure
1 Effect of Temperature on Tensil Strength
Figure2
Effect of Temperature on Elongation
Figure
3 Effect if Temeprature on Tear Strength
Figure4
Effect of Temperature on Hardness
Heat Resistance
The highest usable temperature in a normal atmosphereic environment is
almost 230 (446)
for Continous usage, and can be extended up to approximatel;y 300
(572) for a short period
of time. The results of a compareative test of heat resiustance with other
kinds of rubber are shown in Figure 5
Figure
5 Heat Resistance of Viton and Various Rubbers (after
24 hours of aging at various temepratures)
Resistance to Oils
and Solvents
Vition Possesses
superb resistance to oils and solvents, in addition to excellent thermal
resistance. Vition's resistance to Gasoline and toulene is comparable
with that of Silicone rubber and acrylic rubber, both of which are heat
resistant rubbers, and its excellent performance is illusrated in Figure
6. The oil resistance of Viton is compared here with that of ethyelene
propylene dine terpolymer tyrebutadiene rubber, nitrile-butadiene rubber
and Silicone rubber.
Figure
6 Fluid Resistance of Viton and Various Rubbers
Vition has excellent
resistance to petroleum, fuels, lubricateing oils of the synthetic ester
type, aromatics, aliphatics, and solvents containing halogens. However,
it swells notably when in contact with ketones esters and ethers, and
is rather weal in methanol.
Table
1 Resistance to Oils and Solvents
Chemical Resistance
Viton has excellent resistance to inorganic acids, such as sulfuric acid
and Hydrochloric acid and also various alkalines. In particular Viton
801, 901 and similar products exhibit excellent resistance to stream and
mineral acid
Table
2 Chemical Resistance
Compression Set
Each grade of Viton vulcanizate has a different compression set. Polyaminecured
vulcanizates hace a large compression set, while vulcanizates which arew
cured polyol have a much smaller set; peroxide-curred vulcanizates have
a intermediate set figure 7 shows the effect of temperature on compression
set by comparing Viton 501 and Viton 701 with two other heat resistant
rubbers; silicone and acrylic rubber. Viton has an extremewly small compression
set value at elevated temperatures and is therefore ideal as a sealing
material used under high temperatures.
Figure
7 Compression set of Viton Vulcanzate
Application of Viton (flourcarbon Elastomers)
A wide feild of uses, including those under severe circumstances which
no other natural or synthetic rubber can withstands, is possible for vition
because of its outstanding charachteristics such as resistance to heat
oils, solvents, and chemicals, its physical propertiues and weather stability.
Its greatest demand is in the automobile industry, followed by thr chemical,
machine and shipbuilding industries. Vition is popularlu used for various
packings, oil seals and o rings, diaphragms, hose, sheets and rolls have
greatly increased. Vition, in liquedfied form, is also used as a coating
material of metals, glass fibers cloths, asbestos cloths, etc., or as
an anticorrosion lining or seal reinforcing material made by impergnating
the substance with Vition.s
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