Stanyl® polyamide 4,6 (PA46) from DSM Engineering Plastics is finding increasing use as replacement for metal in assemblies that have traditionally been made of metal and rubber. Designers gain new design freedom as well as reduced production costs by using Stanyl as the rigid component in such applications as automotive strut mounts, electromechanical anti-vibration and anti-shock mounts, energy-absorption components and exhaust hangers.

“Replacement of metal with thermoplastics began decades ago,” said Paul Habets, Application Developments Manager Stanyl. “But, there are significant challenges when selecting the right material for applications with rubber components. Manufacturing requires high heat for vulcanisation, and many of the traditionally rubber-to-metal components require very high stiffness and strength. In a rapidly growing number of applications, Stanyl meets or exceeds the mechanical and thermal performance needed for the rigid element in these products.”

Stanyl exhibits properties ideal for applications that marry a strong substrate to a relatively soft or compliant element: excellent creep resistance, high stiffness and strength, combined with heat resistance to withstand both vulcanisation and application environments, including automotive under-bonnet uses. The material can handle continuous use temperatures as high as 200°C with transient peaks of up to 250°C. Stanyl also provides good chemical resistance, particularly to grease, gasoline and oil.

Compared to metal, Stanyl is up to seven times lighter, and it is more easily formed into complex shapes. Compared to other engineering thermoplastics, Stanyl offers excellent weld line strength and fatigue resistance. Stanyl exhibits unmatched toughness and ductility compared to aluminium. Charpy impact values remain at a high level, even at temperatures below 0°C.

Stanyl offers potential cost reduction by eliminating production steps, including the grinding, degreasing, machining and other operations generally required for metal components. Stanyl provides excellent adhesion to rubber using conventional primers and adhesion systems. Finally, Stanyl offers both high wear resistance and compared to metals (even after surface treatment or polishing) a lower coefficient of friction.

Crystallinity is performance key with Stanyl

Many of the engineering properties of Stanyl derive from its molecular structure. Stanyl reflects a 70% crystallinity, far above PA6 and PA66 at ~ 40%. This extraordinarily high crystallinity results in the following:

● high heat resistance
● toughness
● excellent chemical resistance
● little loss of properties from 80° - 250 °C (176° - 509 ° F)