How to Solve the Color Difference Problem of GRC Decorative Panels?

Solving the color difference problem of GRC decorative panels requires a full-process approach covering “raw material control, standardized production processes, and post-adjustment optimization.” The core targets are a surface color difference of ΔE≤1.0 for individual panels and a color difference of ΔE≤1.5 between panels in a batch. Through digital batching and unified curing, Qinglong has achieved a color difference pass rate of 99.5%, and projects such as Shanghai Xinghewan and the Dongguan Women and Children's Activity Center have all achieved uniform and consistent colors.

I. Raw Material Control: Eliminating Color Difference Risks at the Source

Raw material consistency is the core of color difference control. Cement uniformity: use low-alkali cement of the same brand and same batch to avoid color variation caused by differences in cement composition; Qinglong tests cement color before warehousing, and the same batch of cement is used for the same project. Pigment standardization: use inorganic mineral pigments, selecting products from the same manufacturer and same batch for the same color, with precisely controlled dosage (error ≤±0.1%); Qinglong uses electronic scales for precise batching, keeping pigment dosage deviation ≤±0.05%. Aggregate uniformity: use aggregates with uniform color (mud content ≤0.3%), and use aggregates of the same origin and the same specification for the same project; Qinglong aggregates are screened and washed, achieving 99% color consistency. Additive compatibility: admixtures (water reducers, retarders) must be compatible with cement and pigments to avoid discoloration caused by chemical reactions; Qinglong admixtures have all passed compatibility tests with no discoloration risk.

II. Standardized Production Processes: Controlling Color Uniformity During Production

Standardized processes ensure stable and controllable color. Batching and mixing: use an automated batching system with batching error ≤±0.1% and a uniform mixing time of 5-8 minutes to ensure even distribution of pigments and aggregates; Qinglong's automated mixing equipment improves slurry color uniformity by 30%. Casting and molding: GRC panels of the same batch use the same mold and the same casting sequence to avoid color variation caused by differences in molding methods; Qinglong produces products of the same batch in concentrated runs, with uniform and controllable casting speed. Unified curing: use constant temperature and humidity curing (temperature 20-25℃, humidity ≥90%) to avoid color differences caused by variations in the curing environment (such as temperature, humidity, and light); the temperature and humidity precision of Qinglong's curing rooms is ±1℃, and the curing cycle is uniformly 7 days.

III. Post-Adjustment and Optimization: Remedying Minor Color Differences

Post-processing further optimizes color consistency. Factory inspection: each panel is inspected with a spectrophotometer before leaving the factory, and panels with excessive color difference are individually marked; Qinglong's inspection standard is a surface color difference of ΔE≤1.0 for individual panels and ΔE≤1.5 between panels. Color difference repair: minor color differences (ΔE 1.5-2.0) are locally repaired with a repair agent of the same color family, reducing the color difference to ΔE≤1.5 after repair; Qinglong's repair agent is compatible with the GRC material and leaves no visible traces. Sorted stacking and installation: panels are stacked by color shade, and installation follows the sorted sequence to avoid interleaving of different shades; the Qinglong Shanghai Xinghewan project was installed with color-coded numbering, achieving overall uniform and consistent color. Project case: for the GRC curtain wall panels of the Dongguan Women and Children's Activity Center, through unified raw materials + automated batching + constant-temperature curing, the batch color difference between panels was ΔE≤1.2, with uniform appearance color, earning high recognition from the designer.