1. Improve control standards
1. For customers who have extremely high requirements for color difference (e.g., ΔE ≤ 0.4) or products with slight color differences but significant visual changes (such as light colors with red or yellow tones), quality control standards must be elevated, and visual inspection must be strengthened. Generally, companies control color differences at ΔE ≤ 1, and some at ΔE ≤ 0.5, mostly under a single light source, which can easily result in noticeable visual color differences. To enhance control, it is necessary to ensure color difference consistency under various light sources (e.g., also ΔE ≤ 0.5) and achieve consistent qualification through inspection, proofreading, and visual checks by auditors.
2. Increase the volume of raw material purchases
Even products from larger raw material manufacturers, especially pigments, generally exhibit color differences between batches. Some powder coating products are particularly sensitive to color, and on-site color technicians cannot always ensure the color matches previous batches despite their best efforts. Raw material suppliers suggest that powder manufacturers increase the purchase quantity per batch to ensure color consistency across multiple batches, which has certain improvement effects. For some important customers and key controlled products, it is also necessary to take such measures.
3. Product Inventory
The orders from coating customers are determined based on the batch size of workpiece processing. Many customers place relatively small orders per batch, which brings difficulties to the production and quality control of powder coatings. For those customers who use the same product throughout the year but cannot place oversized orders per batch, powder coating manufacturers may, after sufficient demonstration, produce larger quantities in smaller batches and maintain a proper product inventory. Coating customers also suggest and welcome this approach.
4. Strengthen technical services
Color discrepancies generally require after-sales technical service, whereas pre-sales technical service can effectively reduce the occurrence of color differences. Minor color variations are generally acceptable to customers, but continuous fluctuations or increasingly large deviations can lead to strong complaints. Regular visits and proactive communication can quickly identify issues and allow for timely correction. For products with excessive color differences that customers refuse to use, a prompt replacement should be provided; when customers experience color fluctuations in associated coatings or molded parts, it is necessary to communicate with them promptly to prevent excessive deviations based on standards (many customers may use coatings or molded products to dictate the color of powder coatings). Timely visits also help to keep track of customer information and actively adjust products to meet their needs.
5. Reasonably Construct a Pigment Repository
The fundamental solution to color difference lies in having a complete range of pigments. However, establishing a comprehensive pigment library requires a significant investment of human, material, and financial resources, making it a long-term and ongoing process. Moreover, it cannot be guaranteed to fully meet a company's operational needs, and a company cannot bear the risk of storing newly packaged pigments for several years just for a small order. Theoretically, there is an infinite number of pigments, but in practice, inventory is limited, which is a significant contradiction. Coordination methods include: first, enriching the variety of pigments, such as having yellowish and bluish hues for green, and orange-red and purplish-red for red; second, ensuring complete specifications, such as high quality at a higher price, cost-effective options, domestic and foreign sources, leaded and lead-free options, etc.; third, special preparation for high-sales, high-profit, or important customer products, by actively selecting and reserving necessary pigments; fourth, technical reserves, for certain special pigments (such as expensive, high-quality, unique, or new varieties), by sampling, storing, or trial use.
Summary
Color matching and quality control are the most basic and important technical tasks in powder coating production. Currently, many enterprises still rely on low-efficiency manual operations, while some have begun to use color difference meters for assistance. In domestic major powder coating companies, color matching technology is often only mastered by a few key technical personnel, and frontline quality inspectors only make minor adjustments to product colors based on visual observation. However, with the continuous development of powder coating, many managers have gradually realized the efficiency and quality assurance that color matching instruments can bring to enterprises. The use of color measurement instruments will gradually become more widespread. Only by fully integrating instrument measurement and matching technology with visual judgment and practical experience can technical personnel truly perform effective color measurement and control in powder coating products.
