Mitsubishi Chemical Group
Reading, Pennsylvania, USA
Overcoming Industry Challenges with Duratron® Polyimide Shapes and Direct-Formed Parts

n the current business climate, it’s understood that OEMs and engineers are under intense pressure to meet material design demands to support increasing loads, with higher speeds, at elevated temperatures. Customers want materials that will adapt to fit their exact needs, but at a lower cost.

Mitsubishi Chemical Group (MCG) has been working on ways to help overcome these challenges and one answer may be Duratron® PI. Polyimides like Duratron PI are high-end engineering polymers that perform at the highest level in extreme environments and can do their job when other high-performance plastics fail.

Created from a resin formulation, Duratron PI is made from monomers to produce fully imidized polyimide parts and does not require post-curing. Because of its chemical structure, it is a non-meltable pseudo thermoplastic polymer, with a well-defined Tg (glass transition temperature) designed for opportunities in state-of-the-art applications. Duratron PI has higher mechanical properties in tensile, flexural, and compressive strengths while providing lower tolerance capabilities and thermal conductivity. Its components can help keep your systems running through improved performance and efficiency and raise part reliability, therefore limiting the Mean Time Between Repair (MTBR).

wooden shapes of different sized and colors sit organized on a surface
MCG is advancing the manufacturing capability of Duratron PI into Direct Formed (DF) processing capability allowing for individual part processability and providing a finished part to a print design and/or near-net design, essentially eliminating material waste and machining at a lower part cost measure. The DF process can enable smaller components through lighter-weight parts, replacing standard metals and many other engineering plastics, while enhancing the operating performance of the component.

The Duratron Polyimide products are made from highly durable polyimide resins for demanding applications where exceptional thermal resistance, low wear and low friction, strength and impact resistance are required. This product line includes Duratron PI ”STD” and Duratron PI “Ultra” grades.

Duratron PI STD grades offer cost-effective combinations of high strength, low wear and outstanding electrical properties, for lubricated and un-lubricated sealing and wear performance.

Duratron PI Ultra grades offer the highest performance of wear and friction, with the lowest moisture uptake and increased thermal oxidation stability at very high temperatures.

Manufacturing processes
Duratron PI is manufactured through Hot Compression Molding (HCM) or Direct Forming (DF) process.

The HCM process manufactures large semi-finished shapes such as plates, rods and tubes by applying high pressure and temperature for some period of hours. Then the manufacturing of precise components with high mechanical stability is completed by machining these shapes into finished parts. Duratron PI shapes can be an ideal starting point for designs where smaller series are required and where tolerances and geometry of end parts require machining.

Direct forming provides the ability to produce a large quantity of smaller near-net-shapes or finished parts to be produced cost-efficiently and rapidly. This technology includes the production of “green parts” at extremely high pressure and in ambient temperatures, with subsequent sintering in an external furnace to complete the imidization process for the finished parts. The sintered parts can be manufactured with a high degree of precision and require little or no machining before they are used.

Duratron PI performance
High temperatures, speeds and loads often limit the use of ordinary engineering plastics, whereas advanced high-performance polymers have taken their place in these demanding applications. Materials in the Duratron PI family can perform in temperatures ranging from –320°F/–196°C to 662°F/350°C and in short durations up to 842°F/450°C. When extreme temperature resistance is required, Duratron PI “Ultra” grades are designed to operate successfully at elevated temperatures, with excursions as high as 1,022°F/550°C in applications such as hot glass container manufacturing. Duratron PI continues to perform in progressively extreme temperatures with reliable thermal resistance when most plastics begin to lose integrity at 446°F/230°C, Duratron PI is one of the only materials that can offer peace of mind at operating temperatures above that. Even in the case of unexpected equipment failure, Duratron PI will not melt, avoiding sudden shutdowns and consequent safety risks.

Today’s engineers seek to lower energy requirement usage by reducing the friction between moving parts, mainly due to mechanisms and parts getting smaller, lighter and faster. As a result, designers are pushing the limits in the performance capabilities of existing materials. Duratron PI grades offer excellent wear resistance and low coefficients of friction due to the self-lubricating graphite filler. This eliminates the need for any external lubricants, offering immediate and long-term savings, by going the extra step in extreme temperatures.

Duratron PI Ultra offers the same excellent bearing and wear behavior as the standard Duratron PI grades, but with significantly lower moisture uptake for environments where humidity affects dimensional stability. The PI Ultra also has outstanding thermal oxidative stability with five times longer retention of structural capacity and higher strength and stiffness than the standard grade.

Application: Duratron PI for semiconductor test sockets

MCG’s recommendation for Semiconductor test sockets is to use Duratron DFU7000 PI. The PI “ultra” grades provide toughness and cleanliness for internal manifold components used for the thermal cycling and burn-in of semiconductor chips. The key potential benefits are chemical resistance and high mechanical strength and stiffness in both high and low temperatures. Duratron DFU7000 has outstanding thermal oxidative stability with five times longer retention of structural capacity and significantly lower moisture uptake, for environments where humidity affects dimensional stability.

For additional information, contact Mitsubishi Chemical Group at P.O. Box 14235, 2120 Fairmont Avenue, Reading, PA 19612-4235 USA; (800) 366-0310 or (610) 320-6600, fax (800) 366-0301, email or visit