|
PTFE
| |
Autai
>>
【】 PTFE Properties 【】
|
|
|
♦ PTFE and Teflon History
Polytetrafluoroethylene (PTFE)
resin is in a class of paraffinic polymers that have
some or all of the hydrogen replaced by fluoride. The
original PTFE resin was first discovered on April 6,
1938 by Dr Roy J. Plunkett. While working at DuPont's
Jackson Laboratory in New Jersey on another project,
Dr. Plunkett found that a frozen, compressed amount
of tetrafluoroethylene gas had polymerized into a
waxy white solid substance, forming
polytetrafluoroethylene (PTFE). DuPont registered the
original PTFE resin under the trademark Teflon® in
1945, and the first commercial products were sold
under this trademark in 1946. Interestingly, PTFE was
produced on a limited scale in the early 1940s, and
was used shortly thereafter by the Manhattan Project
in containers for highly corrosive elements during
uranium separation experiments.
|
♦ PTFE Characteristics & Benefits
The extraordinary characteristics of PTFE make it the
ideal choice in a wide range of products and
applications. PTFE has a coefficient of friction that
is one of the lowest of any material. PTFE is
extremely abrasion resistant, making it adaptable to
the harshest environments. In addition, PTFE can
withstand a wide range of temperatures, from 260
Degrees Centigrade down to -270 Degrees Centigrade,
and can even handle brief exposures at higher
temperatures. PTFE also has excellent flame
resistance due to its extremely high melting point,
along with a very low rate of smoke generation and
heat release. Another advantage of PTFE is that it is
chemically inert and pure, and has no additional
stabilizers, lubricants or plasticizers that would
taint process fluids.
PTFE products have an extremely long service life,
primarily due to PTFE retaining its original
properties over a long period of time, even at
extreme temperatures, in ultraviolet (UV) light, and
when exposed to oils, oxidizing agents and solvents.
PTFE also is extremely corrosion resistant,
especially to acids, and harsh inorganic and organic
chemicals. Additionally, the original properties PTFE
remain the same even after extended time periods in
water. Furthermore, PTFE is resistant to atmospheric
aging in the form of discoloration, oxidation, and,
as previously noted, is not affected by ultraviolet
light
|
|
♦ PTFE Properties
|
PTFE Properties
|
ATM
Method
|
Units
|
Virgin PTFE
|
Reprocessed
PTFE
|
25% Glass
PTFE
|
|
Specific Gravity
|
D792
|
|
2.14-2.20
|
2.15-2.20
|
220-230
|
|
Tensile Strength
|
D638
|
PSI
|
1500-3500
|
1500-2400
|
2000-3000
|
|
Tensile Strength
|
D638
|
PSI
|
1500-3500
|
1500-2400
|
2000-3000
|
|
Elongation
|
D638
|
%
|
250-350
|
75-200
|
100-260
|
|
Hardness
|
D1700
|
Durometer "D"
|
50-60
|
N/A
|
55-65
|
|
Deformation %
73 0 F, 1500 psi, 24 hours
|
D621
|
N/A
|
4-8
|
N/A
|
1.73
|
|
Deformation %
100 0 F, 1500 psi, 24 hours
|
D621
|
N/A
|
10-18
|
N/A
|
1.91
|
|
Deformation %
200 0 F, 1500 psi, 24 hours
|
D621
|
N/A
|
20-25
|
N/A
|
4.57
|
|
Impact Strength,
Izod
730 0 F Average
170 0 F Average
|
D256
|
Ft./Lb./In.
|
3.00
6.00
|
N/A
|
2.54
3.69
|
|
Water Absorption
|
D570
|
%
|
0.001
|
N/A
|
0.013
|
|
Coefficient of Friction
(Static) 73 0 F
|
*3
|
N/A
|
0.04
|
N/A
|
0.085
|
|
Dielectric Constant
(100 CPS)
|
D150
|
N/A
|
2.00
|
2.26
|
2.4
|
|
Dielectric Strength (4) (air)
|
D257
|
Volts
|
1000
|
450
|
235
|
|
Coefficient of Thermal Expansion 73 0 F
|
D696
|
In./In./Ft.
|
5.5 x 10.3
|
N/A
|
2.75 x 10.3
|
|
Coefficient of Thermal Conductivity
|
*5
|
Btu/hr/ftz
|
1.7
|
N/A
|
3.12
|
|
PV at 900 ft./min
|
N/A
|
N/A
|
2500
|
N/A
|
15,000
|
|
Color
|
*6
|
N/A
|
white
|
off white
|
brownish white
|
|
|
♦ PTFE and Teflon Applications
The uses and applications of PTFE
have grown enormously over the past 68 years.
Probably one of the most famous uses for PTFE is as a
non-stick coating found on cookware (again, under the
Dupont Teflon® trademark). However, PTFE is used in
the semiconductor, medical, chemical, automotive,
electrical, aerospace, filtration, wire & cable
as well as petrochemical industries.
Chemical processing and petrochemical sectors: used
for vessel linings, seals, spacers, gaskets,
well-drilling parts and washers, since PTFE is
chemically inert and resistant to corrosion
Laboratory applications: Tubing, piping, containers
and vessels due to resistance to chemicals and the
absence of contaminants attaching to the surface of
PTFE products
Electrical industry: used as an insulator in the form
of spacers, tubing and the like
Virgin PTFE had been approved by the FDA for use in
the pharmaceutical, beverage, food and cosmetics
industries in the form of conveyor components,
slides, guide rails, along with other parts used in
ovens and other heated systems.
Semiconductor sector: used as an
insulator in the production of discrete components
such as capacitors and in the chip manufacturing
process.
In many instances PTFE in it
purest form is a perfect solution. However, when an
application demands a modification to the basic PTFE
chemistry, Plastomer Technologies can help satisfy a
broader range of physical, thermal, or practical
demands. Examples include glass or bronze fillers for
added stiffness and strength, carbon fillers for
conductivity, and moly blends for added
lubricity.
|
|
|
|
