Polyphthalamide

Mechanical Properties

PPA plastics are high-performance polymers characterized by a range of outstanding mechanical properties, making them a preferred material for demanding applications, particularly as a metal replacement. PPA plastics exhibit exceptionally high mechanical strength and rigidity. This applies to both tensile and flexural strength, making them ideal for components that must withstand high loads. Glass-fiber-reinforced PPA grades, in particular, achieve very high tensile strengths and elastic moduli.

Thermal Properties

Arguably the most important thermal property of polyphthalamide is its exceptionally high heat deflection temperature (HDT). Depending on the specific PPA grade and filler content, especially for glass-fiber-reinforced variants, HDT values ​​typically range between 250°C and 300°C. This means that PPA components retain their shape and mechanical properties even at very high temperatures, making them indispensable for applications subject to thermal stress. PPA plastics can be used over a wide temperature range. The typical long-term temperatures at which polyphthalamide retains its mechanical properties are around 170°C.

Chemical Resistance

PPA grades exhibit very good resistance to a wide range of chemicals. This includes most fuels (gasoline and diesel), oils (engine and transmission oils), brake fluids, and coolants. PPA plastics also exhibit good to excellent resistance to many solvents, acids, and alkalis. Polyphthalamide is resistant to most commercially available oils and greases, making it an ideal material for transmission, engine, and hydraulic components. Low swelling and strength retention are crucial factors. Glycol-water mixtures are often used in cooling systems. PPA also exhibits high resistance and is insensitive to the corrosion inhibitors and other additives added to these mixtures.

Other Specific Properties

Although PPAs are high-performance polymers and require higher processing temperatures than conventional polyamides, they can still be efficiently processed by injection molding. The good flowability of PPA melts enables the production of complex and thin-walled components. Some PPA grades are flame-retardant and achieve high UL 94 classifications. This property is particularly important for applications in electronics and electrical engineering, where fire safety regulations must be met. The halogen-free flame retardants often used in PPA contribute to improved environmental compatibility.

Automotive industry: The automotive industry is one of the primary applications for PPA materials, as they can optimally utilize their superior mechanical, thermal, and chemical properties. Given the constant demand for weight reduction, increased efficiency, and the need to withstand demanding operating conditions, PPA has established itself as an ideal metal replacement. PPA offers excellent resistance to gasoline (including ethanol blends), diesel, engine oils, coolants (glycol-water mixtures), and brake fluids. Low fuel and moisture permeation, as well as high temperature resistance, are crucial. PPA materials are used for water pumps, coolant pumps, and other fluid-handling components due to their rigidity, wear resistance, and resistance to hot media.

Electrical engineering: PPA's high dimensional stability, low shrinkage, and flowability enable the production of precise, thin-walled connectors with tight tolerances. This is particularly important for miniaturized connectors in smartphones, tablets, computers, and other electronic devices. In environments with high temperatures or aggressive media, such as industrial automation or medical technology, PPA housings protect sensitive electronics. PPA provides the necessary electrical insulation, high temperature resistance, and dimensional stability to securely hold the windings in coil formers and withstand the demands of operation, even under thermal stress caused by current flow. In appliances such as coffee machines, irons, or cooktops, where electrical components are exposed to high temperatures, PPA can be used for switches, connectors, or housing elements.

Industry: PPA plastics are widely used in mechanical and plant engineering, where components are often exposed to high loads, temperatures, and aggressive media. Due to their high wear resistance, rigidity, and the ability to improve tribological properties, PPA materials are used for highly stressed gears, plain bearings, and guides, especially where high operating temperatures occur. For pump housings, impellers, valve bodies, and seals in systems that handle aggressive chemicals, hot liquids, or gases, PPA offers excellent chemical and thermal resistance. High-strength PPA bolts, nuts, or clamps can replace metal fasteners to save weight and prevent corrosion.