DuPont Vespel Polyimide Shapes
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Vespel® is a durable high performance polyimide-based polymer (or plastic) manufactured by DuPont.
Characteristics and Applications
The high durability and strength of Vespel has helped advance the fields of aerospace, semiconductor and transportation technology. Vespel combines heat resistance, natural lubricity, dimensional stability, chemical resistance, creep resistence, and other properties to become a useful plastic for use in hostile conditions.
Unlike most plastics, it does not outgas or melt at any temperature, which makes it useful for lightweight heat shields and crucible support. It also performs well in vacuum applications and even in extremely low cryogenic temperatures.
Types
Vespel® is produced in five standard formalations including: SP-1, SP-21, SP-211, SP-22, and SP-3. Vespel SP-1 provides operating temperatures from cryogenic to 300°C (570°F), great plasma resistance, plus a UL rating for minimal electrical and thermal conductivity. Vespel® SP-1 is the unfilled base resin grade. SP-1 provides maximum physical strength, elongation, and toughness as well as the best electrical and thermal insulation values. Vespel® SP-21 has 15% graphite by weight added to the base resin for increased wear resistance and reduced friction in applications such as bearings, thrust washers, bushings, seal rings, slide blocks and other wear applications. Vespel SP-21 has the highest mechanical properties of the graphite filled grades. Vespel® SP-22 has 40% graphite by weight for enhanced wear resistance, lower friction, improved dimensional stability (low coefficient of thermal expansion), and stability against oxidation. Vespel® SP-21 has 10% PTFE and 15% graphite by weight added to the base resin for the lowest coefficient of friction over a wide range of operating conditions. It also has excellent wear resistance up to 300°F (149°C). Typical applications include sliding or linear bearings as well as many wear and friction uses listed above. Vespel® SP-3 is 15% moly-filled (molybdenum disulfide solid lubricant) for wear and friction resistance in vacuum and other moisture-free environments where graphite actually becomes abrasive. Typical applications include seals, bushings, bearings, gears, and other wear surfaces in outer space, ultra-high vacuum or dry gas applications.
