PEEK™
Polyether-ether-keytone,
better known as PEEK™ (PEEK is a trade mark of Victrex, PLC.), is
a high-temperature thermoplastic. This aromatic ketone material offers
outstanding thermal and combustion characteristics and resistance to
a wide range of solvents and proprietary fluids. PEEK™ can also be reinforced
with glass, carbon or special additives for applications such as bearings.
CHEMISTRY AND
PROPERTIES
|
MECHANICAL
|
Unfilled
|
30%
Glass Filled
|
30%Carbon
Filled
|
Tensile
Strength:
@73°F (Break/Yield)
@250°C (Break/Yield) |
14,100(y)
1740 (y) |
22,620(b)
4930(b)
|
33,785(b)
6235(b) |
Flexural
Modulus:
@73°F
@250°F
@482°F |
594,500
580,000
43,500 |
1,450,000
1,334,000
435,000 |
2,929,000
2,697,000
739,500 |
Ixod
Impact Strength:
73°F Notched 0.25mm radius
3.5mm depth |
1.57 |
1.8 |
1.59 |
Thermal:
Glass transition temperature.
Tg (onset value) Unit °F |
289 |
289 |
289 |
PEEK™'s structure
contributes to its high-temperature performance and very low water absorption.
Its crystalline character gives it important advantages including resistance
to organic solvents, dynamic fatigue and retention of ductility.
MECHANICAL
At room temperature, PEEK™ functions as a typical engineering thermoplastic.
It is tough, strong, rigid, has good loadbearing properties over long
periods, and it is resistance to both abrasion and dynamic fatigue.
THERMAL
PEEK™'S continuous service UV rating is 482°F (250°C) for unfilled and
500°F (260°C) for glass filled grades. PEEK™ also offers high temperature
mechanical properties making it suitable for some application up to
600°F. (315.).
FLAMMABILITY
PEEK™ has a high "Oxygen Index" and meets UL 94 -VO requirements, and
demonstrates extremely low smoke emission. It contains no flame-retardant
additives or halogens.
CHEMICAL RESISTANCE
PEEK™ has good resistance to aqueous reagents and long-term performance
in superheated water at 500°F. (260°C.). Its resistance to attack is
good over a wide pH range from 60% sulfuric acid to 40% sodium hydroxide
at elevated temperatures. Attack can occur with some concentrated acids.
HYDROLYSIS RESISTANCE
PEEK™ can be used for thousands of hours at temperatures in excess of
480°F. (250°C.) in steam or high-pressure water environments without
significant degradation in properties.
RADIATION RESISTANCE
Preliminary tests suggest that radiation resistance is extremely good.
PROCESSING
PEEK™ is easily processed using a wide range of conventional thermoplastic
processing equipment. Injection molded items do not require post-treatment.
The tensile properties
of PEEK™ exceed those of most engineering plastics and can be reinforced
with carbon fiber resulting in a tensile strength of over 29,000 psi
(200 MPa) with excellent properties being retained up to 570°F. (300°C.).
The exceptional
stiffness of PEEK™ is reflected in its flexural modulus which is among
the best of any thermoplastic. Glass or carbon fiber reinforcement gives
further improvement up to very high temperatures.
PEEK™ combines excellent
tribological properties with moldability and outstanding performance
at high temperatures. Carbon fiber-reinforced PEEK™ is probably the only
injection moldable bearing material that has a measurable wear factor
at over 500°F. (260°C.); all the thermoplastics fail at or below this
temperature.
Parkway
Products, Inc. is one of the leading molders of PEEK™ in Northern
America. Parkway provides complete design, engineering, mold making
and secondary machining in house.
