Plastic composite springs have been molded from SABIC Innovative Plastics’ Ultem* resin. Among the first springs ever made with high-performance, engineered plastic, LeeP™ compression springs provide critical advantages over traditional metal alloy springs. SABIC Innovative Plastics provided a range of specialized services for this project, including predictive analysis, material characterization and mold optimization.
Ultem resin gives the new springs a broad range of high performance properties including high strength-to-weight ratio, no magnetic interference, high corrosion resistance, and dielectric insulation for non-conductive applications.
Al Mangels, Lee Spring president said “The resin exceeded our expectations at every step. It’s a truly exceptional product that, due to its tougher-than-tough balance of high-performance properties, performs better than any other thermoplastic. “ According to Steve Kempf, CEO of Lee Spring, “Our customers’ wish list includes strength, heat stability, corrosion resistance, non-magnetic properties, insulation, inertness, low flame toxicity and recyclability. What led us to Ultem resin was its excellent all-around performance combined with great strength. Ultem resin satisfies the full gamut of customer requirements in a single offering.”
In marine applications, LeeP springs made with Ultem resin offer longer life due to resistance to salt water. For the medical device industry, LeeP springs avoid the cost of shielding, which is necessary for metal springs that can interfere with diagnostic imaging. Other market sectors that may benefit from the new springs are: medical products and processing equipment, pharmaceutical delivery devices, food processing and packaging equipment, aerospace products, electronics and electrical equipment, water purification systems and automotive interiors.
Spring rate (a function of shear modulus), cycle life (resistance to fatigue) and creep resistance are key performance measures for these compression springs. Ultem resin not only provides excellent results for these criteria, but also delivers other key properties:
• Mechanical stability up to 170C, allowing for use in a wide range of environments.
• High strength-to-weight ratio: Ultem resin is the highest strength amorphous resin in the market.
• High corrosion resistance and generally compatible with many chemicals including strong acids, weak bases, aromatics, and ketones.
• Non-magnetic to avoid interference with imaging and other Ferro-sensitive technologies.
• Dielectric insulating material suitable for non-conductive applications.
• Inert non-contaminating plastic composite protects product purity.
• Low flammability and toxicity ensure environmental safety.
• Recyclable and compliant with most global regulations including RoHS and REACH.