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Melt Fluidity
AURUM is practically thermoplastic, and there are three basic grades of AURUM neat resin, depending on the melt viscosity.
| Grade | Type | Melt viscosity (Poise at shear rate 100[1/sec]) | Melt Flow Index at 400°C, [g/10min]) |
| 400 | High flow | 3,000~4,000 | 12.0~18.0 |
| 450 | Standard | 6,000 | 4.5~7.5 |
| 500 | Low flow | 10,000 | 2.5~4.5 |
Melt viscosity data of AURUM is shown in Figure 1, 2 and 3.
Spiral Flow
As AURUM is heat resistant resin, it is necessary to set the processing temperatures high enough. AURUM polyimide has similar spiral flow length to PES with processing temperatures about 40°C (72°F) higher than that of PES. Although flow length changes with mold temperature, the degree of such change is relativity small compared with the influence of processing temperature or pressure. A 30°C (54°F) change in mold temperature corresponds to approx. 5°C (9°F) change in processing temperature.
Predrying Conditions Before Molding
- Drying Conditions Required drying time is dependent upon the thickness of resin layer, and normally 10 hours or more at 180°C (356°F), or 5 hours or more at 200°C (392°F) is recommended.
- Dryer Shelf-type dryer with hot air circulation, with a temperature control range of 200°C (392°F) or more is recommended.
- Hopper Dryer It is necessary to seal the top of the hopper to avoid contamination and humidity. A hot air circulation type dryer with a dehumidifier is recomended for higher drying efficiency and lower running cost.
(Click
here to view Fig.8 Moisture Content Change Under Drying and Absorption
Condition Chart) 64.7 kb
Molding Conditions
AURUM can be easily processed by standard type injection machines designed for super engineering plastics.
- Molding Temperature Resin melt temperature is required to be approximately 390~420°C (734~788°F).
- Mold Temperature 170°C (338°F) or preferably 200°C (392°F) is recommended.
- Injection Machine Part volume should be more than 20% of the maximum injection capacity of the injection machine.
- Example of Molding Conditions Typical molding conditions are as follows.
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| (Click here to view Table of Typical Molding Condition) 42.6kb | (Click here to view Table of Electric Wire Coating Condition by Extrusion) 13.3kb |
Crystallization
AURUM is
a crystalline polymer. However, the extruded or injection molded products
are amorphous because the crystallization speed is lower than that of
typical crystalline polymers.
AURUM can be used up to 240°C (464°F) in the amorphous state
as molded, while it can be used over 240°C (464°F) up to 320°C
(608°F) when crystallized after molding.
- Grade
Selection:
- use in amorphous: #3000, #4000 series
- use in crystalline: #6200 series
Crystallizations
Conditions
The typical crystallization diagram of the AURUM#6200 series is shown
in Figure 9.
The conditions of crystallization and stress release of AURUM molded products
are as follows.
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| (Click here to view Fig.9 Crystallization Condition of AURUM#6200 Chart) 9.28kb | (Click here to view Table of Crystallization and Stress Release) 38.7kb |
CAD/CAE/FEM as Engineering Analysis
The mold design and molding conditions are very important to achieve the desirable properties of injection or extrusion molded products. Weld lines, anisotropy, improper orientation of reinforcement fibers, sink or voids must be eliminated. Our customers using AURUM have an access to the computer aided mold flow analysis and structural analysis developed by Mitsui.
- Mold
Flow Analysis
- Filling Analysis
- Distribution of mold temperature
- Warp and Sink Analysis
- Fiber Orientation Analysis
- Structural
Analysis
- Stress Analysis
- Stress/Strain Analysis
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| (Click here to view Injection Molding Speed vs. Pressure Chart) 8.92kb | (Click here to view Image of Mold Flow) 49.6kb |
AURUM® Sections
- AURUM Home
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- AURUM Contacts
