The performance test of coating is one of the key steps to evaluate the quality and applicability of coating. In the coating performance test, hardness is an important index, it reflects the mechanical strength of the coating and the ability to resist deformation. Coating hardness on the scratch resistance and abrasion loss light has a direct impact on performance. This article introduces common methods of coating hardness testing, including the swinging rod damping hardness testing method, walt, Christopher mann hardness, hardness pencil hardness and buchholz hardness method, and discusses its principle and application.

1. The rocker hardness measurement

Swing bar hardness measurement is a commonly used method to test the hardness of coated films. Its principle is to evaluate the hardness of coated films by contacting a swing bar with the film and measuring the attenuation of the swing of the swing bar. Pendulum bar hardness testing methods include Koenig pendulum and Persatz pendulum two kinds.

In the Koenig pendulum test, the pendulum rod oscillates within a certain period, and the softer the film is, the faster the swing of the pendulum rod decays. Przed testem, it is necessary to adjust the damping time of the swing bar according to the standard to ensure the accuracy of the test. In the Persaz pendulum test, it is also necessary to correct the damping time of the pendulum to ensure the reliability of the test results. The advantage of swing bar hardness test method is that the operation is relatively simple, the results are stable and reliable, so it is widely used in the evaluation of coating quality.

Metoda badania twardości powłok: twardość wahacza, twardość ołówka, itp

2. The pencil hardness measurement

Pencil hardness tester is another kind of commonly used coating hardness test method, the principle of which is to use a set of known hardness pencil lead end face of sharp edges, across coating under a certain Angle, through the observation to assess whether the scratch film coating hardness. W teście, pencil hardness said is not scratch the hardest pencil hardness of the coating.

In manual operation, the difference in force may lead to a large deviation of the test results. In order to reduce the error, a special pencil tester can be used for testing. Unlike the swing bar hardness test method, pencil hardness test involves pressure and shear force, and is different from the damping effect of swing, so there is no direct conversion relationship between the two.

Metoda badania twardości powłok: twardość wahacza, twardość ołówka, itp

3. Other hardness measurement methods

In addition to swing bar hardness and pencil hardness, there are several other hardness measurements such as the Swath hardness, Kliman hardness, and Buckholz hardness.

Swart hardness: Swart hardness is measured by the number of times the metal ring swings back and forth on the film. Although the sensitivity is low, the test speed is fast, and it is usually used for rough hardness determination of coated films.

Kliman hardness: Kliman hardness is a scratch test method that evaluates the hardness of the coating by crossing it under a certain load and observing whether it is scratched. This method is applicable to determine scratch resistance of coating.

Buchholz hardness: buchholz hardness is a kind of jade mark test, mainly is suitable for the degree of hardness measurement of the hard coating.

Metoda badania twardości powłok: twardość wahacza, twardość ołówka, itp

The importance of coating hardness

The hardness of the coating is one of the important indexes to evaluate the quality and applicability of the coating. The coating needs to have a certain hardness to protect the substrate from scratches and wear. If the hardness of the coating is insufficient, it is easy to appear scratches and wear in the process of use, reducing the life and appearance quality of the coating. Ponadto, the hardness of the film is also closely related to other properties, such as chemical corrosion resistance, weather resistance and so on.

Metoda badania twardości powłok: twardość wahacza, twardość ołówka, itp

Streszczenie

Coating hardness testing is one of the most important aspects of the coating performance evaluation, the common testing methods including rocker hardness, twardość ołówka, walt hardness, Cleveland, hardness and buchholz hardness. Each test method has its unique principle and scope of application, according to the specific needs to choose the appropriate test methods for coating hardness evaluation, help to ensure that the quality of the coating and performance meet the expected requirement.