In daily operation of laundry shops, fading of clothes is a common reason for customer complaints. It is not caused by a single factor, but is the result of the combined effects of dye quality, fiber properties, washing conditions, and wearing environment. Only when people systematically understand the causes of fading can they effectively avoid laundry risks and improve service satisfaction.
Quality and Stability of Dyes
- Types of dyes and fastness level (most fundamental)
Different types of dyes (reactive dyes, disperse dyes, direct dyes, and acid dyes) show significant differences in affinity for different fibers and color fastness (including wash fastness). Cheap, low-quality dyes usually have poor color-fixing ability and are more likely to peel off during washing.
- Dyeing process
Whether the dye is fully fixed during the dyeing process is key. Inadequate processes (insufficient use of color fixatives or incomplete water washing) will lead to excessive surface dye (unfixed dye). This excess dye tends to peel off during the first wash or the first few washes.
Characteristics of Fibers
– Fiber types are important.
- Cotton, linen, viscose (regenerated cellulose fibers)
Natural fibers and their regenerated counterparts usually need more robust dyes (reactive dyes) and more complex processes to get good color fastness. Their structure is less smooth than that of synthetic fibers, so dyes easily leach out.
- Silk, wool
Protein-based fibers mainly use acid dyes or mordant dyes. These fibers are sensitive to friction and alkaline detergents. Improper handling easily causes fading.
- Polyester, nylon, acrylic (synthetic fibers)
They typically use disperse dyes or acid dyes. With a relatively dense molecular structure and strong hydrophobicity, these fibers are inherently more resistant to fading.
– The fiber surface also matters. The smoother the surface of the fiber is, the less likely the dye is to be washed off. If the surface is rough or damaged, it can easily accumulate dirt and grime. The friction during washing will accelerate the shedding of dyes.
Washing
Washing factors are external triggers that accelerate dye release.
- Excessively high water temperature
High temperature is also a key. It increases the activity of water molecules and causes fibers to swell and dye molecules to loosen, which makes them more likely to be washed away by detergent and water. Dark-colored, bright-colored, and new garments should be especially avoided in high-temperature washing.
- Excessively long washing duration
Long-time soaking and stirring friction will continuously wear down the fibers and cause the dye to detach.
- Chemical friction/force
Vigorous machine washing and stirring (especially in agitator washing machines), strong rubbing, and scrubbing will accelerate the physical peeling of dyes.
- Components of a detergent
Regular laundry detergent/liquid is usually alkaline. Strong alkalinity damages the structure of certain dyes (especially acid dyes used for protein fibers and some direct dyes) and harms fibers (silk and wool), leading to severe fading and fiber damage. Laundry soap powder has a stronger alkalinity and has the greatest impact on color fastness.
- Chemical reactions of the detergent
Bleaches (chlorine/oxygen bleach), optical brighteners, and strong enzyme preparations are oxidizing or chemically active substances that may damage dye molecules.
- Excessively long soaking time
Long-time soaking in a wet state causes fabric fibers to swell continuously. The unfixed dye dissolves in water, which leads to fading.
Drying
Ultraviolet (UV) rays are the killers of dye molecules. With strong energy, they directly decompose many dye molecules, especially those of bright colors (red, blue, and purple). This causes colors to fade or turn pale (known as sunlight fading).
Wear and Contamination
- Sweat stains
The salt, oil, and weakly acidic/alkaline components in sweat can corrode some dyes. Some areas’ colors (underarms/necklines) easily fade due to sweat stains.
- Cosmetics, sunscreen, and daily chemical products
Some chemical substances in these products may react with dyes.
- Friction
During daily wear, friction with other surfaces or the clothes themselves (cuffs/pant hems) can cause fading.
Clothes’ Own Condition
- New clothes
They usually have more unfixed dye, so fading will be more noticeable during the first few washes.
- Color fastness grade
The color fastness grades (wash fastness, rub fastness, light fastness) evaluated through standard testing directly reflect the garment’s fade resistance. The higher the grade (grade 4-5), the less likely the garment is to fade.
Colors Susceptible to Oxidative Fading and Causes
– In textiles, dyes of specific colors are more prone to fading (especially under sunlight) or chemical oxidation due to their molecular structure characteristics:
- Bright warm tones (especially reds, oranges, bright pinks)
Azo dyes are mostly used for these colors. Their chromophoric groups (-N=N-) are extremely sensitive to ultraviolet (UV) rays (from sunlight). UV rays with high energy can break this chemical bond and cause the color to decompose and fade (lighten/turn pale). Red is the most common color that suffers from severe fading.
- Dark denim blue (indigo-dyed)
Traditional indigo dyes adhere to the surface of cotton fibers rather than penetrating them. Physical friction during washing easily causes the surface dye to peel off (manifested as “dye bleeding” rather than chemical fading). Although indigo dyes have moderate light fastness, consumers often pursue a vintage look, leading to repeated friction during wear and washing, which makes fading noticeably apparent.
- Some dark purples and blue-violets
Purple is a mixed hue of red and blue. If purple dye has a high proportion of red components (especially those with an azo structure), its light fastness will decrease greatly. Also, some blue components in blue-violets may be sensitive to oxidizing agents.
- High-saturation neon colors
To achieve an ultra-vibrant effect, special fluorescent dyes or brightening additives are often used. These components tend to have unstable structures. They are also susceptible to fading or dulling when exposed to ultraviolet rays, sweat stains, or detergents.
– Chemical oxidative fading is mainly caused by bleaches (Chlorine-based bleaches: sodium hypochlorite solution. Oxygen-based bleaches: sodium percarbonate), strong alkaline detergents, and sweat stains.
The following colors are particularly sensitive:
- Dark colors: black, navy blue
Many black clothes are dyed multiple times using mixed dyes (blue + red + yellow). When bleach oxidizes and decomposes one of these components (often red or yellow), the overall color becomes distorted. This results in part of whitening, reddening, or yellowing.
- Cool tones: blue shades (non-denim)
Some blue dyes (those with an anthraquinone structure) have good light fastness but are sensitive to chlorine-based bleaches. After oxidation, they fade and may leave a yellowish tint.
- High-purity greens (e.g., Emerald Green, Grass Green)
Green is mostly a mixture of yellow and blue dyes. Oxidizing bleaches may preferentially break down the more fragile yellow component, causing the green to turn bluer or even grayish.
The summary table is as follows:
| Fading Type | Color-Sensitive Hues | Main External Triggers | Chemical Nature |
| Sunlight Fading | True red, orange, bright pink, some dark purples | UV radiation, especially intense sunlight exposure | Azo bond breakage, dye decomposition |
| Friction Fading | Indigo denim | Physical friction, washing intensity | Surface dye peeling-off (physical) |
| Chemical Oxidation Fading | Black, navy blue, blue shades, green shades | Chlorine/oxygen-based bleaches, strong alkalis, sweat stains | Oxidative degradation of dye molecules (local damage) |
| Complex Fading Distortion | High-saturation neon colors | Combined effect of light, oxidizing agents, and friction | Unstable dye structure, combined impact of multiple factors |
Conclusion
Fading of clothes is a result of many factors together. From the selection of dyes, characteristics of fibers, the washing process, and daily wearing and care, every link should be controlled professionally. It is suggested that laundry industry practitioners actively identify the fabrics and colors that easily fade, choose neutralized detergents, strictly control the water temperature and mechanical forces, and avoid direct sunlight after washing. This can provide a more professional care service for customers.
