2. Precautions for use

The properties are measured on test specimens whose processing is standardized and, in reality, the values can be significantly different for many reasons, for example :

• presence of additives of any kind: impact modifiers, functional plasticizers, fibers or fillers, release agents, antistatic agents, regrind;

• processing conditions resulting in heterogeneous hardening, orientation of macromolecules and reinforcements, physical defects such as weld lines, etc. ;

• finishing: surface treatment, painting, assembly...

Part geometry can create notch effects or stress concentrations.

Test temperatures are 20°C or 23°C, which is not necessarily the operating temperature. For some materials, a relatively small difference in...