Material Selection Requirements

If your part will be exposed to impact strains, address energy management issues early in the design process. Including

Consider the following rules of thumb to improve impact performance.

If using multiple ribs, space them unevenly or orient them to prevent resonance amplification from the impact energy
Avoid boxy shapes that concentrate impact forces on rigid edges and corners; and
Use rounded shapes to spread impact forces over larger areas.

When selecting a plastic material for impact applications, consider the following design tips:

Select a material with good impact performance throughout the part's working-temperature range;
Address all temperatures and impact loads including those found in the manufacturing process and shipping;
Considering notch sensitivity of the material in applications with unavoidable notches and stress concentrators; and
Check flow orientation—especially in fiber filled materials—and the difference between flow and cross flow mechanical properties.
Some plastic materials are better for impact than others. Polycarbonate and polycarbonate blends are frequently used for impact applications. Materials that contain fillers, although stiffer may exhibit poor impact properties.
Consult with your Bayer MaterialScience representative to see if high strain rate stress/strain curves are available for the material you are considering.