Are you navigating the complex world of heat tunnel testing for textiles and feeling overwhelmed…
Your favorite shirt, dress, or pair of pants’ color retention over time is determined by the fabric’s colorfastness. When you wear and wash your clothes frequently, you may have noticed that their colors become dull instead of vibrant. This is because colorfastness is an important factor in maintaining the fresh and vibrant appearance of your clothing.
If your clothing were superheroes, colorfastness would be their anti-fading shield. We’ll delve into colorfastness in this blog post, look at the reasons why clothing fades over time, and learn how to stop it.
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Why Does Your Favorite Shirt Lose Its Color Over Time?
Your bright blue jeans start to take on the appearance of faded, grayish denim, and your once-bold red shirt becomes a soft pink. But don’t worry, there are a few culprits that are responsible:
1. Light Exposure:
Consider your clothing as a small-scale superhero team up against UV rays, the villainous force. These rays, which originate from artificial and solar light sources, are the worst enemies of the colors in your clothing. The colors bleed because UV rays damage the fabric’s molecules and the dyes. Using garment bags to protect your clothing from direct sunlight or storing them in a dark location can help avoid this.
Sweat is a byproduct of playing and running around, and salt can be a cunning villain when it comes to your clothes. Your clothes bleed because of a reaction between the salt in your sweat and the dyes. This explains why, wearing colored shirts, you might notice white streaks under your armpits. You can avoid using too much deodorant and wash your clothes right away after perspiring to prevent this.
Although washing your clothes is necessary to keep them looking new, it may also cause issues with their colorfastness. The bonds between the dye and the fabric can be weakened by the friction created by your clothes in the washing machine and the detergents. You can reduce this by washing your clothes on a gentle cycle, turning them inside out, and using detergents made especially for colored fabrics.
4. Air Pollutants:
Tiny particles and chemicals found in the air we breathe have the potential to change the color of our clothing. The colors in your clothing may become less vibrant as a result of air pollution changing the way the dyes are arranged. Regretfully, you have no control over the air, but you can lessen the effects by keeping your clothes tidy and stored correctly.
Effect of Types of Fiber and Dye:
Let’s look at how your clothing’s colorfastness can be affected by the kind of fabric and dyes used in it.
1. Nature versus. Artificial Dyes:
Natural dyes are less colorfast; picture them as paint made from berries and leaves. Conversely, synthetic dyes are designed to remain vibrant, much like superhero paints. Therefore, choose clothing made with synthetic dyes if you want your clothes to retain their color for a long time.
2. Reactive vs. Acid Dyes:
Reactive dyes adhere firmly to the fibers of your clothing, similar to Velcro, but acid dyes are more akin to sticky notes that could come off. The dye selection can significantly impact the durability of your clothing after washing and wearing. If you want colors that last, use reactive dyes.
3. Dark Colors and Patterns:
Dark hues and patterns can conceal fading more effectively than light ones, much like a superhero’s disguise. If you have a strong affinity for vivid hues, you may opt for garments with striking designs or deep tones to minimize the fading over time.
Colorfastness to Washing
Colorfastness to washing, often referred to as wash fastness, is the resistance of dyed or printed materials to the loss of color when exposed to washing. In other words, a fabric can withstand the rigors of laundering without experiencing significant color degradation.
Several factors influence colorfastness to wash, including the penetration of dye molecules into the interpolymer chain spaces of the fibers and the strength of the bond between the dye and the fabric.
To assess colorfastness to washing, standardized tests are conducted. These tests are essential in the textile industry to determine how well a fabric will retain its color after multiple wash cycles, helping manufacturers ensure the quality of their products.
Colorfastness to washing is evaluated through various procedures. The International Organization for Standardization has recommended several tests for wash fastness:
- ISO Test No. 1: Formerly known as the handwashing test.
- ISO Test No. 2: Formerly known as S.D.C Test No. 2.
- ISO Test No. 3: Formerly mechanical washing.
- ISO Test No. 4: Known formerly as mechanical washing test
- ISO Test No. 5: Formerly known as S.D.C Test No. 4.
Colorfastness to Washing Rating
To determine the colorfastness of fabric to washing, a standardized procedure is followed. Here’s a brief overview of the process:
Instruments and Materials Needed for Washing Test:
- SDC recommended multi-fiber fabric
- Water shaking bath
- Color matching cabinet
- Sewing machine
- Reagents Required for Washing Fastness Test
- ISO reference detergent
- Sodium carbonate
- Distilled water (Grade – 3), and more
Preparation of Test Specimen:
A sample of dyed fabric, measuring 10cm X 4cm, is cut and placed between two undyed, unfinished samples of size (5 X 4) cm². Both sides of the fabric are sewn together, creating a composite test sample.
The Test Procedure for Washing Fastness:
- A composite sample is shaken in a water-shaking bath for 30 minutes at 50 or 52°C with a solution and water in the required amounts.
- After the 30-minute testing period, the sample is removed from the washing solution.
- The sample is then washed for 10 minutes in running cold water after being rinsed twice with cold distilled water.
- The sample is carefully squeezed to remove excess water.
- Stitching is removed on two long sides and one short side.
- The sample is dried at 60°C in a tumble dryer.
- The contrast between the treated and untreated sample is compared with the color change greyscale, and the staining of adjacent fabric is compared with the staining scale in the color matching cabinet.
- Color change in shade – Grade 4 (indicating a good result).
- Color staining in cotton – Grade 4/5 (indicating a good result).
AATCC Gray Scale Rating – Compares Washed Samples to Standards
After conducting colorfastness tests, the results are often compared to established standards to assess the degree of color change. One of the widely used tools for this purpose is the AATCC Gray Scale, developed by the American Association of Textile Chemists and Colorists. The Gray Scale consists of a set of color standards that can be used to compare the color change of tested samples visually.
The AATCC Gray Scale ranges from Grade 5 (no color change) to Grade 1 (severe color change). By comparing the tested fabric’s color change with the standards on the Gray Scale, you can easily determine the level of colorfastness and the impact of washing or perspiration on your garments.
|TESTING METHOD||TEST NO.||SAMPLE SPECIMEN SIZE (CM)||WATER RATIO (ML)||TEMPERATURE (°C)|
|SO 105 C06||A1S||4×10||150||40|
Colorfastness to Perspiration
When it comes to sportswear or clothing designed for active lifestyles, color fastness to perspiration is of paramount importance. Our bodies naturally produce sweat, which, when in contact with fabric, can affect its color fastness. This is where ISO 105 E04 and AATCC 15, the most common standards for assessing colorfastness to perspiration, come into play.
AATCC 15 focuses on testing color fastness in the presence of acidic perspiration. This is particularly relevant because human sweat is typically acidic. However, the composition of sweat can change in different conditions, becoming alkaline at higher temperatures or when bacteria are present.
The textile or leather sample must be submerged in a solution of synthetic perspiration in order to undergo the fastness to perspiration test. In order to replicate the composition of human sweat, this artificial perspiration solution has distinct concentrations of various salts and acids. Next, for a predetermined amount of time—typically four to twenty-four hours—the sample is baked at a regulated temperature and humidity.
The sample is rinsed and dried after the sweat exposure period, and then its color and staining are assessed. The assessment is frequently carried out with a colorimeter or a grayscale. Both the fading or discoloration of the fabric itself and the material’s ability to transfer color to other surfaces are evaluated in this test.
An arbitrary scale, usually between 1 and 8, is used to report the perspiration fastness test results. Greater color fastness in response to sweat is indicated by higher numbers. These tests are commonly employed in the leather and textile industries to guarantee that goods retain their quality and appearance while being used, particularly in scenarios where they might come into contact with liquids such as sweat or water.
Color Fastness to Light
Perhaps you’re not aware of it, but your clothes are subtly changing when you walk outside in the sunlight. Sunlight exposure can fade the colors in your fabric over time, giving your clothes a lifeless, faded appearance. This is known as a lack of color fastness to light.
Standardized tests are commonly used to measure color fastness to light. ISO 105 B02 and AATCC 16 are the most widely used standards. Finding out how a fabric responds to sunlight exposure requires conducting these tests.
An Xenon Arc Lamp, which emits light very similar to the sun’s rays, is used to simulate the effects of natural sunlight on a piece of fabric. The AATCC 16 test involves placing a fabric strip in a fadometer and exposing it to accelerated fading units (AFUs) for a predetermined period.
Testing for colorfastness to light is particularly crucial for outerwear and clothing that will be exposed to prolonged sunlight, such as items that are regularly hung out to dry on a washing line. The outcomes of these tests aid in the understanding of how well a fabric maintains color under such circumstances by both manufacturers and consumers.
Color Fastness to Crocking (Rubbing):
The reason behind the blue stains from denim jeans on your white t-shirt can be attributed to the material’s color fastness when it comes to rubbing or crocking. This test assesses a fabric’s ability to resist color transfer when repeatedly rubbed against a dry or wet surface.
When evaluating a fabric’s colorfastness under rubbing conditions, the most widely used standards are AATCC 8 and ISO 105 X12. Using a specially made device known as a crockmeter, the tested fabric is rubbed against both wet and dry, non-dyed fabric for a predetermined amount of time.
A rating of four for dry rubbing and three to three points five for wet rubbing is usually given to high-quality materials. These ratings indicate how much rubbing the cloth can withstand without significantly transferring color or staining it. You can avoid those unsightly dye stains by selecting fabrics that are less likely to transfer color between your garments by knowing the outcomes of these tests.
Tips to Extend Color Vibrancy
Now that we’ve discussed why clothes fade easily let’s look at some practical tips that will help you maintain the vibrancy of your clothes for a longer period:
Use Certified Colorfast Dyes and Finishes During Manufacturing:
When shopping for clothing, look for items made with certified colorfast dyes and finishes. Manufacturers who prioritize color fastness often indicate this on the label. High-quality dyes and finishes can significantly improve the color longevity of your clothing, including through perspiration, washing, and exposure to sunlight.
Line Dry or Dry Clean Delicate Shades:
Keep delicate or brightly colored clothing away from harsh drying techniques, like using a dryer. A kinder option that can keep the color of your clothing is line drying. Dry cleaning might be an option for particularly delicate items since it can preserve the fabric’s integrity and prevent color loss.
Wash in Cold Water with Mild Detergent:
Use a mild detergent along with cold water when washing clothes. The likelihood of the dye bleeding is lower with cold water than with hot.
Additionally, mild detergents are designed to be kind to colored fabrics. For the best advice on preserving color fastness, pay close attention to the care instructions on the label of your clothing.
Consider Clothing Materials Suited to Longevity:
Invest in clothing made from materials that are known for being colorfast. A blend of natural and synthetic fibers can also offer good color fastness, so keep that in mind.
Various factors, such as washing and exposure to perspiration, can cause the beauty of vibrant and colorful clothing to fade over time. To maintain the vibrancy of your wardrobe, you must comprehend colorfastness and the methods used to evaluate it.
You can significantly increase the lifespan of your clothing and keep it looking brand new by observing the advice mentioned above and caring for it properly. Keep in mind that prevention is essential for maintaining colorfastness and preventing color fading, ensuring your clothes continue to bring you joy and confidence for years to come.