Interpretation of UV aging test of paint and coating
October 22, 2020
Long-term outdoor sunlight, high temperature and humidity are the main causes of coating cracking, loss of gloss, fading, yellowing and chalking.
The ultraviolet accelerated aging test can simulate the damage of the ultraviolet part of the sunlight to the coating, and it takes a few days or weeks to reproduce the hazards that occur outdoors for months or even years.
Light, high temperature and humidity, any one of these three factors will cause the aging damage of automobile paint coatings, but they often act at the same time, and the damage caused will be greater than the single effect of any one of them.
1. Sun exposure
The degree and type of degradation of the coating depend on the spectral sensitivity of the resin. Different wavelengths of light have different destructive effects. The spectral sensitivity of each resin is different, and the spectral sensitivity determines whether a resin is sensitive to short wavelengths, long wavelengths, or both.
2. High temperature
High temperature is also an important factor in the destruction of automotive paint coatings. When the temperature increases, the destructive effect of light will also increase. Although temperature does not affect the main light-induced reactions, it does affect the minor chemical reactions. The laboratory aging test must provide precise temperature control, and the aging process can usually be accelerated by heating up.
Dew, rain, and high humidity are the main causes of moisture hazards in automotive paint coatings. Statistics show that cars placed outdoors will remain wet for a long time every day. Dew formed by moisture is the main factor of outdoor humidity. Dew is more harmful to automobile paint coatings than rain, because it adheres to the paint coating for longer and causes more serious moisture absorption.
LIB INDUSTRY UV accelerated aging test adopts the UV aging test machine produced , which can realize the following simulation functions.