Measuring Color Difference in Paint Industry Using Paint Colorimeter

Time:2020/12/04 17:00:00 Browse:453

Paint color difference has always been a problem in the paint spraying process. If there is a color difference when the paint is toned, the paint color we sprayed on will be less than ideal. Linshang paint colorimeter provide color measurement and color comparisons for painters, printers, quality controller staff. Portable color difference meter ensure accurate color difference comparison, which can measure colors in difference spaces such as CIE Lab、Luv、LCh、Yxy、CMYK、s-RGB、Hex ,etc. How can Linshang paint color difference meters help painters with the paint color difference? Let's see.

1. How does the painter paint the object?

First of all, let's take a look at how the paint workers mix the color. They will color the paint color paste based on their own experience. After the color is adjusted, they will spray according to the use ratio of the paint. When spraying, ensure that the paint substrate is in good condition. Spray the paint to an appropriate thickness according to the relative properties of the paint to avoid unevenness. After that, we use the heating method to dry the paint. When heating the paint, we recommend using a temperature of about 50°C to ensure normal humidity. In such an environment, the performance of the paint will not change. It can also ensure that the paint is not easily discolored during the heating process. 

2. Measure color difference of paint using paint colorimeter

To demonstrate how does a color meter help the painters. We made a small experiment. 

  1. Step 1: Paint each of the three wooden boards with blue paint. 

  2. Step 2: Add a scoop of white paint to blue paint and brush the paint on the No.2 wooden board. 

  3. Step 3: Add the second scoop of white paint to the paint and brush the paint on the No.3 wooden board.

  4. Now, we got 3 pcs of wooden boards. No.1 is painted with blue paint. No.2 is painted with the mixed blue and white paint. No. 3 has more white paint then No.2. 

  5. Step 5: Use the paint color difference meter measure the No.1 wooden board, take this color as the standard color

  6. Step 6: Measure the color of No.2 and No.3 wooden boards as the sample color.

The painter can adjust the color according to the color cast direction prompted by the portable paint colorimeter. As we can see from the color quality control App,  the No.2 wooden board is more white than No.1. The ΔE between them is 3.51. The No.3 wooden board is also more white than No.1. The ΔE between them is 11.19.

No.1 wooden board

Color quality control App
portable colorimeter

No.2 wooden board

color meter App interface
color difference meter

No.3 wooden board

color meter interface
color meter

Linshang paint colorimeter is powerful with QC testing function. After setting the tolerance value, we can determine whether the color of the object is qualified or unqualified. When we make color comparisons between the sample color and standard color, if the color difference value of paint is less than 0.5, it basically meets people's visual perception requirements. If the tolerance value is set within 0.2, people can hardly see the paint color difference with naked eye. 

3. What does L * a * b * stand for?

Colorimeter use the principle of three primary colors. Most companies now use paint colorimeters to assess color difference. The paint color difference meter can quantitatively indicate the color difference with high accuracy. The lab color space is the hue space for measuring the color of the object. In the color space, "L" is the lightness, "+L" is the white direction and "-L" is the black direction. "A", "b" are chromaticity coordinates, +a* is the red direction, -a* is the green direction, +b* is the yellow direction, -b* is the blue direction and the center is colorless. L*, a*, b* can be calculated from the tristimulus values x, y, z, △eab* means that the smaller the ΔE value, the smaller the color difference.

Linshang Technology Co., Ltd. has produced two portable color difference testers, Linshang LS170 and LS171. The measuring principles of these two color difference meters adopt the 45°/0 principle and the integrating sphere principle respectively and support Chinese and English. Linshang colorimeter price is very low. Linshang cheap colorimeter has the same performance compared with other expensive colorimeters. The measuring aperture of these two paint colorimeters is 8mm, which is compact and cost-effective. 



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