Paints and varnishes — Pendulum damping test
1Key Takeaways
This document specifies two methods of carrying out a pendulum damping test on a coating of paint, varnish or other related products. It is applicable to single coatings and to multicoat systems.
2Expert Interpretation
Comprehensive analysis of the coating pendulum damping test method in the ISO 1522:2022 international standard, covering the test principle, instrument calibration, operation process and accuracy requirements of the two pendulums of König and Persoz, and providing professional technical guidance for coating hardness evaluation.
Analysis of the core content of the standard
ISO 1522:2022 specifies two methods for measuring the hardness of coatings using the König pendulum and the Persoz pendulum. The test principle is based on the physical property that the amplitude decay rate of the pendulum on the coating surface is inversely proportional to the hardness of the material.
Instrument Parameter Comparison
| Parameters | König Pendulum | Persoz Pendulum |
|---|---|---|
| Sphere Diameter | 5±0.005mm | 8±0.005mm |
| Total Mass | 200±0.2g | 500±0.1g |
| Swing Period | 1.40±0.02s | 1±0.01s |
| Standard decay time | 6°→3°:250±10s | 12°→4°:430±10s |
Key technology updates
- Substrate expansion: Remove metal/glass substrate restrictions, and add applicability to new substrates such as plastics
- Calibration enhancement: Add pendulum deformation detection process to ensure instrument accuracy
- Accuracy correction: Update König pendulum repeatability limit based on 2006 inter-laboratory comparison data
Test implementation points
Environmental control
The test should be carried out at 23±2℃ and 50±5%RH to avoid airflow interference. The coating thickness is recommended to be ≥30μm and the substrate must meet the flatness requirements of ISO 1514.
Operational procedures
- Sampling according to ISO 15528
- Substrate pretreatment according to ISO 1514
- Calibration of the pendulum (see Appendix A/B for details)
- Single-point test 3 times to take the average
Application recommendations
In the field of automotive coatings, the König pendulum is more suitable for monitoring the baking hardening process, while the Persoz pendulum is more sensitive to highly elastic coatings. The test report should include:
- Substrate type and treatment process
- Coating application method and drying conditions
- Environmental parameter records
- Abnormal phenomenon description