Application of Color Masterbatches Across Various Color Types

Plastic colorants refer to granular colorants with high pigment (or uniformly loaded dye) content that are incorporated into plastic resins. By adding a certain amount of color masterbatches and processing the diluted resin through injection molding, extrusion, or other technologies, products with a wide range of colors can be produced. These products are applied in fields such as wires and cables, food and cosmetic packaging, automotive and home appliance parts, serving the functions of marking, beautification, and substitution.

As a professional color masterbatch manufacturer, we not only provide the colors required by customers but also ensure that the color reproducibility of every Letu product is consistent, with color differences controlled within a specified tolerance range. This is an extremely important quality control indicator for manufacturers.

The following is an introduction to color difference testing, its causes, and improvement measures. Based on the **CIELAB** color space, samples are taken from the mixed and extruded Letu pellets. After diluting the pellets with resin, test specimens are prepared using injection molding machines, double-layer molding machines, and hot-pressing equipment. If the color difference between the test sample and the standard sample falls within the specified range, the product is deemed qualified; otherwise, the color masterbatch formula must be adjusted.

Routine color difference testing combines computerized spectrophotometry with visual inspection. Instruments and the human eye differ in sensitivity, which can lead to measurement deviations, so a combination of both testing methods is essential. Sometimes, a product that passes instrumental testing may fail visual inspection, and vice versa. Visual inspection lacks clear quantitative boundaries, while instrumental testing can accurately display color differences in a quantitative manner. For some specific colors, instrumental measurement is more reliable than visual inspection. In general, color differences of various hues should be measured and displayed according to the specified test methods, and the color difference tolerance values should be determined based on the intended application of the color masterbatch.