How to solve the problem of color difference in powder coatings?

Update:08 Apr,2021

1. Improve control standards

For those customers with extremely high color difference requirements (such as ΔE≤0.4) or products with slight color difference but significant visual changes (such as light colors with red or yellow), quality control standards must be improved and visual inspections must be strengthened. General product companies control the color difference ΔE≤1, some of which are ΔE≤0.5, and most of them are under a single light source, which can easily cause obvious visual chromatic aberration. In order to strengthen the control, the uniformity of the color difference under various light sources (such as ΔE≤0.5) must be required, and the uniformity must be achieved through the visual inspection of the inspection, proofreading and review personnel.

2. Increase the batch of raw material purchases

Even the products of large-scale raw material manufacturers, especially pigments, generally have color differences between batches. The color of some powder coating products is particularly sensitive to them. The on-site colorists can not guarantee the color consistent with the previous efforts. The raw material supplier recommends that the powder manufacturer increase the purchase amount of a single batch to ensure the color consistency of multiple batches of products, which has a certain improvement effect. For some important customers and important control products, it is also necessary to take such measures.

3. Product inventory

Coating customer orders are determined according to the batch size of the workpiece, and many customers have fewer orders in a single batch, which brings difficulties to the production and quality control of powder coatings. For those customers who use the same product all year round but cannot over-order a single batch, powder coating manufacturers may wish to produce small batches in large quantities on the basis of full demonstration, and do a good job of product inventory. Painting customers also recommend and welcome this approach.

4. Strengthen technical services

The appearance of chromatic aberration generally requires after-sale technical service work, while pre-sale technical services can well reduce the occurrence of chromatic aberration problems. Slight fluctuations in color are basically acceptable to customers, but continuous fluctuations or expanding deviations will cause strong complaints from customers. Regular visits and advanced communication can quickly find problems and correct them in a timely manner. For those products whose color difference is too large and customers refuse to use, they must be quickly replaced; when the color fluctuations of the coatings and moldings used by the customers, they must communicate with the customers in a timely manner to avoid excessive deviation of the customers according to the standards (many customers We will use coatings and molded products to request the color of powder coatings); visit in time to learn customer information at any time, and actively adjust products to meet customer needs.

5. Reasonably build a paint library

The fundamental problem of solving the color difference lies in the complete variety of pigments, but the comprehensive establishment of the pigment library requires a lot of manpower, material and financial resources. It is a long-term continuous process, and it cannot be guaranteed to fully meet the business needs of the company, and it is impossible for a company to be one. A small order bears the risk that the entire package of new pigments may be stored for several years. The infinite number of pigments in theory and the limited inventory in practice are indeed a great contradiction. The coordination method is to enrich the variety of pigments, such as green pigments, which should have yellowish and blue shades, and orange-red and purple-red, etc.; the second is complete specifications, such as high-quality, low-cost, high-priced and high-quality, domestic and foreign ones. , Lead-free and lead-free, etc.; third, special goods are specially prepared, for the pigments needed by products with large sales, high profits or important customers, actively select samples for backup; fourth, technical reserves, for some special pigments (such as high prices, Excellent quality, special needs or new varieties), sampling, storage or trial.