Why do the products produced by the factory still have color differences even though I provided a color card (color number) or sample?

The reasons for the color difference of tarpaulins include the following categories, among which the difference in base material is one of the common factors:

1. Differences in base fabric raw materials

The LDPE base fabrics used in PE tarpaulin base fabrics are divided into virgin and recycled materials.The recycled material particles of average quality have some color, and the base fabric produced will show a deviation in the base color.When this type of base fabric is coated with a colored waterproof membrane, the original color of the base fabric will be superimposed on the color of the coating, resulting in a difference between the final color and the standard sample.

2. Raw material stability issues

The purity and dispersion of masterbatches or color powders vary between batches, resulting in color deviations even when added in the same proportions.

3. Improper production process control

Uneven coating thickness during the coating process can lead to darker colors in thicker coating areas and lighter colors in thinner coating areas, resulting in noticeable color differences.Fluctuations in processing temperature can also affect the stability of pigments.High temperatures can cause some pigments to decompose and fade, while low temperatures can lead to inadequate dispersion, resulting in localized color blocks.Inconsistent calendering or extrusion speeds can lead to variations in coating density, which in turn affects light reflectivity and causes visual color differences.

4. Equipment Precision Issues

Clogged or worn nozzles in coating equipment can cause uneven coating thickness in certain areas. Inadequate mixing equipment can lead to incomplete mixing of the pigment and substrate, resulting in streaks or spots of color difference. Incomplete cleaning of equipment can cause residual old material to mix with new material, resulting in discolored impurities.

5. Reference Deviation between Color Cards and Samples

Color cards or samples can fade due to exposure to light and humidity during storage. Suppliers produce based on these discolored standards, which naturally deviate from the original specifications.Small samples and large-scale tarpaulins have different optical properties. Wrinkles and tension on large surface materials cause light reflection angles to vary, which can easily cause visual color deviation.Color card materials differ from the tarpaulin substrate. For example, the color rendering principles of paper color cards and PE film differ, which can lead to errors in reference judgment.

6. Differences in Testing Environment and Standards

The lighting conditions used by both parties during testing differed.The color of the same tarpaulin displayed noticeably different colors under different light sources, such as natural light, fluorescent lighting, and incandescent lighting (a phenomenon known as "metameric heterochromia").Inspectors have varying visual sensitivities, leading to individual differences in their thresholds for detecting slight color differences. This is particularly true in non-standard lighting environments, which can lead to biased judgments. The lack of a clear, unified standard for assessing color differences (such as the allowable range for ΔE values) led to disagreements between the two parties regarding what constituted an acceptable range, leading to controversial color differences.

7. Other effects

Exposure to chemicals during storage or transportation (such as additives released from packaging materials) may cause minor localized discoloration.

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