Impacto izod

Laboratory > Mechanicals

Izod

Notch Izod Impact is a single-point test that measures the impact resistance of an oscillating pendulum. The Izod impact is defined as the kinetic energy needed to initiate the fracture and continue the fracture until the sample breaks. The Izod samples have notches to avoid deformation of the sample in case of impact. This test can be used as a quick and easy quality control check to determine if the material is normal.

Test procedure:

The sample is subject to the pendulum. The pendulum is released and allowed to strike through the sample. If it does not break, a heavier hammer is used until a failure occurs. Since many materials (especially thermoplastics) show lower impact strength at reduced temperatures, it is sometimes appropriate to test the materials at temperatures that simulate the intended end-use environment.

Sample size:

The standard sample for ASTM is 64 x 12.7 x 3.2 mm (2½ x ½ x 1/8 of an inch). The thickness of the most common sample is 3.2 mm (0.125 inches), but the preferred thickness is 6.4 mm (0.25 inches) because it is not as likely to bend or crush. The depth below the notch of the sample is 10.2 mm (0.4 inches).

The standard sample for ISO is a multipurpose sample of Type 1A with the final tabs cut off. The resulting test sample measures 80 x 10 x 4 mm. The depth below the notch of the sample is 8 mm.

Values:

The impact energy of ASTM is expressed in J / m or ft-lb / in. The impact resistance is calculated by dividing the impact energy in J (or ft-lb) by the thickness of the sample. The result of the test is typically the average of 5 specimens.

The impact resistance ISO is expressed in kJ / m2. The impact resistance is calculated by dividing the impact energy in the area below the notch. The result of the test is typically the average of 10 specimens.