Standard Test Methods for Hardness of Organic Coatings by Pendulum Damping Tests

Importancia y uso:

5.1 The pendulum damping test has been found to have good sensitivity in detecting differences in coating hardness, where hardness is defined as resistance to deformation.

5.2 The two procedures given in these test methods embody the principle that the amplitude of oscillation of a pendulum touching a surface decreases more rapidly the softer the surface. However, these test methods differ in respect to pendulum dimensions, and period and amplitude of oscillation.

5.3 In general, the damping time of the König pendulum is approximately half that of the Persoz pendulum.

5.4 The Persoz pendulum has a greater degree of discrimination than the König for measuring the hardness of soft coatings, but it may not be as suitable for testing hard, slippery films because of its tendency to skid on surfaces with a low coefficient of friction.

5.5 The interaction between the pendulum and the paint film is complex, depending on both elastic and viscoelastic properties, and it may not be possible to establish a precise relationship between the two types of pendulum tests.

Subcomité:

D01.23

Referida por:

D0016-24

Volúmen:

06.01

Número ICS:

87.040 (Paints and varnishes)

Palabras clave:

damping hardness tests; König pendulum hardness tester; organic coatings; pendulum hardness tests; Persoz pendulum hardness tester;