Because of its high crystalinity levels, Stanyl retains a high level of stiffness up to temperatures very close to its melting point. This provides wider safety margins for critical applications than standard engineering plastics like PA6, PA66, and polyesters.
Other high heat resins (like PPA and PPS) have a very high modulus at room temperature but show a significant drop in stiffness at elevated temperatures [above 100°C (210°F)].
In practice, Stanyl has a higher stiffness at temperatures >100°C (210°F).
The stiffness advantage offered by Stanyl at elevated temperatures can be exploited by designing components with reduced wall sections, some 10 to 15% thinner than those compared to PPA or PPS but with the same level of glass fiber reinforcement. The weight savings achieved with Stanyl are important for automotive and aviation applications where weight is a vital issue. By adding reinforcements, stiffness levels can be increased further.
For optimum performance and maximum lifetime, engineering plastics, which are subjected to long-term loading, must have a high creep resistance - low plastic deformation under load. Stanyl's high crystallinity results in an excellent retention of stiffness at elevated temperatures [above 100°C (210°F)] and hence a creep resistance superior to that of engineering plastics and other heat-resistant materials.
Creep behavior is one of the factors that limit the maximum application temperature of a material. When Stanyl and PA66 or PPA are compared at the same temperature exposure, customers have several choices: You can either decrease the wall thickness by using Stanyl (with an equivalent level of reinforcement); or reduce material usage and cost by using a lower-reinforced Stanyl grade than possible with PA66 (for equal wall thickness).
Only Stanyl offers a real performance improvement over PA66.
Effect of glass fiber reinforcement on the creep modulus of Stanyl at 140°C (285°F)
Creep behavior of glass fiber reinforced Stanyl versus competitive glass fiber reinforced materials at 160°C and load 20 MPa
Toughness and fatigue
Toughness or ductility is usually measured by impact resistance (related to high speed) and (tensile) elongation (low speed). While tensile and flexural strength decrease with increasing temperature, toughness increases. Therefore, toughness is usually most critical at lower temperatures. For automotive applications the low temperature impact at -30 or -40°C is critical. For many E&E applications, toughness at room temperature or elevated temperatures is important in processes like pin insertion, winding operation and soldering.
Thanks to its fine crystalline structure, Stanyl offers unmatched toughness and ductility in comparison to many other engineering plastics/heat resistant resins.
The effect of different amounts of glass fiber reinforcement is different for both toughness parameters. With increasing reinforcement percentages, the elongation at break decreases while the Izod or Charpy impact resistance increases.
The Izod or Charpy impact resistance of glass fiber reinforced Stanyl is also unmatched. This makes Stanyl the material of choice for demanding applications and enables new assembly steps, for instance using inserts and snap-fits. The very high elongation at break of Stanyl offers the best solution for thin-walled parts, film hinges, and insert molding (eg in gears and pulleys).
Stanyl offers a significant improvement in fatigue resistance compared to PA66, PPA and PPS for high temperature applications. Fatigue resistance is particularly important for gears, charge-air coolers, air ducts, and chain tensioners.