GUANGZHOU BAIYUN TECHNOLOGY CO., LTD. zhengjinghui@china-baiyun.com 86-20-3731-2985
With the development of urban modernization, high-rise buildings are everywhere, with different colors, just like wearing colorful new clothes. The color consistency of the "seam" on these clothes - building sealants is very important for designers who pursue perfection. In the production process of building sealants, how to control color difference?
Before answering this question, we must first understand the principle of color difference, so that we can understand the judgment criteria and influencing factors of color difference, and then try to control color difference.
It should be noted that due to the influence of many factors, the color difference will change during the application of sealant. In order to avoid disputes, the national standard GB/T 18922-2008 "Methods for expressing the color of building materials" is often used as the evaluation standard for color difference.
1. What is color difference? How to judge?
Simply put, color difference is the difference between two colors. We use a colorimeter to measure the color difference between the sealant sample and the standard sample, and express it as △E (color difference value). According to the national standard GB/T 18922-2008 "Method for expressing the color of building materials", △E should be ≤3.
2. What are the factors that affect color difference?
The main factors that affect the color difference of building sealants are:
01 Under the same △E, the human eye has different perceptions of dark and light colors. When the color difference value is the same, the lighter the color, the more obvious the difference is. Especially when △E is between 1.5 and 3, the color difference value at this time fully meets the national standard, but the human eye can feel the difference of some lighter colors.
02 The influence of substrate type
① Various color substrates, such as variegated stone, different people have different perceptions of color difference;
② Reflective substrate: The viewing angle has a great influence on the color. The larger the viewing angle, the lighter the color, and the smaller the viewing angle, the darker the color;
③ Fluorescent substrate or flash substrate: It is necessary to add special color powder to transparent glue to imitate the substrate effect. If ordinary sealant is used, it can only be adjusted to a close color, and the observed color will also be different.
03 Impact of environmental factors
① Impact of climate aging: The glossiness of the sealant surface will change. Whether it is glossy sealant or matte sealant, it will become darker than when it was first applied over time; UV-resistant pigments will also fade slightly; the same sealant applied at different time periods will have color differences between new and old sealant;
② Impact of dust: Sealant will absorb dust, which will cover up the color of the sealant surface to a certain extent. In view of this, in the actual application scenarios of outdoor sealants, it is not of great practical significance to be too strict with color requirements.
3. Will color difference affect the beauty of the building?
First of all, we need to make it clear that there are complex physical and chemical reactions in the production process of sealants, and color difference is difficult to avoid completely.
Even if the color difference △E is within the range of ≤3, the human eye may still perceive the difference between colors under certain conditions. For the same building, different people may have different feelings about color difference when observing at different angles, distances, times, and weather conditions. If it is judged only by the human eye, it is easy to cause controversy.
It is easy to see color difference in building sealants of the same color from different batches when they are just used. After a period of application, this color difference will become less obvious due to the influence of various factors and will not affect the appearance of the building.
4. How to control color difference?
Although we cannot completely eliminate color difference, we can control color difference through professional equipment and methods to ensure that △E is within the national standard. Baiyun Technology strictly follows national standards and uses imported color difference detection equipment to control color difference, and can provide professional special color sealant solutions. Whether it is dealing with complex and changeable substrates or harsh outdoor environments, we will do our best to ensure the excellent quality and beautiful color of the sealant.