Causes and prevention of color difference in paint spraying

In order to reflect the different functional requirements and visual effects, people will use a variety of uses and a variety of colors of paint, sometimes the same product will appear after spraying 2 or more color differences, to the product appearance defects, and to the customer perception of the adverse effects.

Reasons for color difference in spray paint:

• If the color of the paint is not correct, poor quality or over the expiration date, and different batches, different manufacturers paint will lead to color difference problems.

• The color difference caused by the floating color of the paint or by the precipitation of the paint is due to the fact that the paint is not stirred evenly before construction.

• Different paint solvent volatilization rate is different, will also directly affect the color of the product.

• Uneven distribution of pigment blending will also cause color difference.

• With the paint technician's technology is also closely related, such as the modulation of the color ratio, the number of spraying channels, spraying speed, construction techniques, spraying proficiency and other issues.

• Different spraying technicians spraying the same batch of products will also appear color difference problem.

• Paint film thickness and leveling, curing oven temperature, baking and other parameters are different, especially the film thickness is not uniform, but also very easy to color difference.

• Spraying tools that are not cleaned can also cause cross-contamination and color mixing problems.

How to prevent color difference?

• Choose high-quality qualified paints, and topcoats of the same color should be controlled by one manufacturer.

• Paint dilution should be appropriate, not too thin.

• Prevent floating color and bleeding of paint.

• Paint should be stirred well before use.

• Tools should be thoroughly cleaned before painting, especially the paint pipeline must be cleaned when changing colors to avoid mixing colors.

• Before painting, the substrate should be qualified, flat and with the same surface roughness.

• The same object, the same spraying technician, using the same batch of paint, and strive to paint in the fastest possible time.

• Choose the suitable painting process and ensure the stability of process parameters.

• Control the temperature and humidity of the spraying room, grasp the viscosity of the paint, spraying speed, distance and so on.

• Classify the workpiece according to its material, thickness, shape and size, and then set different baking time for baking and curing respectively, and the temperature distribution of the curing oven should be even, so that the color difference of the coating film may be reduced.