Impact testing

Impact tests are used to determine the behavior of a material at high deformation speeds.

They measure a material’s resistance to the ingress of solid bodies.

 

 

Penetration test

The instrumented test in accordance with this standard describes a test method that is used to determine the penetration behaviour of solid plastics.

An impactor is moved towards the test specimen at right angles at a constant speed and penetrates it. The test can be conducted within a temperature range from –40°C to +80°C.

 

Visual inspection of the plastic specimen after performing the penetration test Visual inspection of the plastic specimen after performing the penetration test

Results of the test method
  • Force and deflection values such as:
    - Maximum force FM [N]
    - Deformation at maximum force IM [mm]
    - Energy to maximum force EM [J]
    - Puncture deflection lP [mm]
    - Puncture energy EP [J]
  • Stress-strain curve
Automatic penetration test apparatus at UL Automatic penetration test apparatus at UL
Plastic specimen after testingPlastic specimen after testing

 

 

 

 

 

 

Charpy Impact test

The Charpy impact test is a quick and simple test to facilitate a comparative material assessment.

Amongst other things, it is used to investigate the effects of changed formulation, compounding or injection molding conditions on the test specimen.

In the Charpy test, the test specimens are subjected to stress in a set-up similar to the three-point loading test and broken as soon as they are sufficiently brittle. Notched test specimens must be used in order to produce a break in ductile materials. The test is possible within a temperature range from –60°C to +80°C.

 

Results of the test method:
  • Charpy impact strength of an unnotched specimen aiU [KJ/m²]
  • Charpy impact strength of a notched specimen aiN [KJ/m²]
  • Incl. break assessment at the corresponding temperature and, where applicable, a rubber-glass transition
Key to method

Example: ISO 179/1 e A

Type of test specimenDirection of impactNotch depth
flat test specimen with dimensions l x b x h = edgewise
= flatwise
unnotched
notch with 0.25 mm radius
notch with 1.00 mm radius
notch with 0.10 mm radius

 

Type of test specimenLength lWidth bThickness h
1 80 10 4
2 25 x h 10 or 15 3
3 11 x h or 13 x h 10 or 15 3

All dimensions in mm.