Page 269 - Engineering Plastics Handbook

Thermoplastic Polyimide (TPI) 231

TABLE 10.3 Retention of Tensile Strength after Exposure at High Temperatures
100 h 500 h 1000 h 2000 h
Retention of tensile strength 90% 85% 90% 100%

The value before the testing is 100%.

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change of tensile strength of Aurum after it is exposed to 392°F
(200°C).
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Wear and friction properties. Aurum grades, where Mitsui’s unique
compounded materials are based on the proper selection of matrix,
fillers, and additives, have excellent wear and friction properties.
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Aurum has both outstanding wear resistance and low friction even at
302°F (150°C) in dry conditions. The PV limit, which can show the max-
imum capability of high load and high speed, is the highest of all ther-
moplastics in dry environments (100 kpsifpm) (Table 10.4).
Moreover, its tribological properties are exceptional under oil condi-
tions since the coefficient of friction is surprisingly low and stable in oil.
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This is why Aurum can withstand high-duty loads.
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Chemical resistance. Aurum is widely regarded as a material with
outstanding chemical resistance, and it has a remarkable resistivity
against oil, even at elevated temperatures. The properties and appear-
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ance of Aurum do not change even under harsh conditions such as
392°F (200°C). Therefore, the stable properties are guaranteed under
ordinary usage conditions, such as below 302°F (150°C).
However, there are some limitations on usage against alkali, concen-
trated sulfuric acid, concentrated nitric acid, dichloromethane, and chlo-
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roform since Aurum is a polyimide and is amorphous after injection
molding.

Other. There are other interesting properties of the polyimide that
most people are unaware of:

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■ Metal impurity and outgassing. Aurum is polymerized without cat-
alysts and has no residual solvent after being polymerized. Therefore,
it has outstanding cleanliness and can be used for semiconductor
equipment parts requiring tighter specifications of cleanliness.

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TABLE 10.4 Aurum High-PV Capability in Applications
Grades Applications Typical operating PV Recommended PV range
JCL3030 Thrust washers 810 kpsifpm 480–1400 kpsifpm
JCF3030 Seal rings 1100 kpsiftpm 480–1400 kpsifpm