P R O D U C T S , I N C
Ultem® / Polyether-imide
| Polyetherimide (marketed by GE Plastics under the trade name Ultem®) is a high-performance thermoplastic. This material is characterized by high strength and rigidity at elevated temperatures, long-term heat resistance, highly dimensional stability, good electrical properties, broad chemical resistance and is injection moldable. Also, it exhibits an inherent flame resistance and a low smoke generation without the need for incorporating additives. Unmodified polyetherimide material is amber transparent in color. |
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CHEMICAL RESISTANCE
Polyetherimide resists a wide range of chemicals including most hydrocarbons,
alcohol's, and fully halogenated solvents. It resists mineral acids
and tolerates short-term exposure to mild bases. Partially halogenated
solvents are acceptable to polyetherimide.
HYDOLYTIC STABILITY
Hydrolytic stability is good with greater than 85% tensile strength
retention after 10,000-hr. boiling water immersion and 100% tensile
strength retention after 2000 steam autoclaving cycles at 270°F.
RADIATION RESISTANCE Polyetherimide has good resistance to UV and gamma radiation, the latter shown by a 94% retention of tensile strength after treatment of 400 megarads of cobalt irradiation.
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HEAT RESISTANCE Polyetherimide resins are rated for 338°F and 356°F continuous-use temperatures by Underwriters Laboratories, and are UL 94-VO listed down to 10 mils thickness depending on grade. Oxygen index is 47%. Polyetherimide complies with FAA flammability and heat release requirements for aircraft interior applications. Glass transition temperatures of 419°F and greater allow intermittent use at 392°F. and short-term excursions to higher temperatures. At 356°F., the tensile strength and flexural modulus are more than 6,000 and 300,000 psi, respectively. Higher strength and stiffness at elevated temperatures to the material's glass transition (Tg) are obtained with glass or carbon fiber reinforcement. Long-term resistance to creep at high temperatures and stress levels allows polyetherimide to replace metal and other materials in many structural applications. |
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ELECTRICAL
Electrical properties show very good stability under variable temperature,
humidity, and frequency conditions.
OTHER PROPERTIES
Low dissipation factor at GHz frequencies makes polyetherimide highly
transparent to microwaves.
The material also has low levels of ionic contaminants with conductivity of the water extract staying above 20 megaohms after 120 hr. extraction at 250°F., 100% RH, and 30 p.s.i.g., making it suitable for use as an insulation material for sensitive electrical components.
GRADES
Resins are offered in the following grades: unreinforced; glass fiber-reinforced;
easy-flow and release grades; wear resistant grades; carbon fiber-reinforced
grades for high strength and static dissipation; and a family of high-heat
grades offering 25°F.-plus higher heat defection temperatures and 392°F.
service. Other grades and blends for structural foam molding are offered.
New materials for EMI shielding, new resin systems for advanced composites
and spun polyetherimide are now available.
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PROPERTY
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ULTEM
1000
(Unreinforced) |
ULTEM
2300
(30% Glass Reinforced) |
ULTEM
7801
(25% Carbon Fiber) |
| Mechanical: Tensile Strenght, yield, Type 1, 0.125" (3.2mm) Flexural Modulus, 0.125" (3.2mm) |
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|
31,000 psi 2,200,000 psi |
| Impact: Izod Impact, notched, 73°F (23°C) |
1.0 ft-lb/in |
1.6 ft-lb/in |
7.6 ft-lb/in |
| Physical: Specific Gravity, solid Water Absorption, 24 hours @ 73°F (23°C) |
1.27 0.250 |
1.51 0.160 |
1.37 ----- |
| Electrical: Dielectric Strength, in air, 62 mils (1.6mm) |
831 V/mil |
770 V/mil |
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PROCESSING
Polyetherimide materials can be machined using conventional, laser,
and water jet techniques. Typical assembly methods include ultrasonic,
vibrational, and hot platen welding plus mechanical fastening, adhesive,
and solvent bonding.
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APPLICATIONS Transportation |
 Sample Application of Aircraft Interior Ultem Parts |
Parkway Products, Inc. is the acknowledged leader in carbon filled Ultem molding and ranks among the top technical molders in North America.