As a professional lab person in a textile lab, color fastness to perspiration should be routine terminology for you. This article will discuss the procedure for conducting the color fastness to perspiration test AATCC 15 in a textile lab.
What is the Color Fastness to Perspiration
Perspiration or sweat is a saline fluid generated by the sweat ducts on mammals’ skin. The human body’s perspiration is a complicated mixture containing many salts. It can be either acidic or alkaline, depending on the metabolism of humans. In the fabric testing laboratory, a solution created by replicating acid and alkaline sweat tests color fastness to perspiration. Color fastness means a material’s ability to maintain its color, including transferring its colorants to nearby materials. Multiple testing stages are involved in the conventional process for determining color fastness to perspiration.
Purpose of AATCC 15
The Color Fastness to Perspiration test method, commonly called AATCC 15, measures how well textile colors withstand fading or modification when subjected to artificial perspiration. Due to the advancements in dyeing technology, modern clothing features bright colors and vibrant combinations. Maintaining the brightness of clothing colors is a challenge for manufacturers. Additionally, when it comes to high-visibility safety clothing, colorfastness is essential for preserving brilliant color over time, guaranteeing maximum visibility and safety under safety-related circumstances. Perspiration’s pH can affect a textile product’s color, the main functional element of high-visibility safety clothing and accessories.
Artificial perspiration solutions come in two varieties: acidic and alkaline. These are used in cloth testing laboratories to replicate the effects of human sweat on textiles. Their main differences are in pH, which affects how they react with colors and fabrics. The alkaline test is eliminated due to limited field studies. However, if someone wants to perform the alkaline test, he should consult AATCC 15-1973.
Perspiration Tester can also be used in other methods, including AATCC 107 (Color Fastness to Water), AATCC 106 (Color Fastness to Water: Sea), and ISO-105 E-04.
Other Test Methods for Color Fastness
Color fastness to perspiration is among the many methods used to examine the color fastness of textiles. Similar tests like color fastness to washing, light, and crocking (color fastness to rubbing) clearly understand the fabric’s color stability. The crocking/rubbing test is the color transfer by rubbing the fabric with other materials. In Color fastness to light, the fabric is placed under artificial light D-65 or natural light, and its color fading is measured after exposure. In Color fastness to washing, the fabric is washed with steel balls, and then its color change is measured.
AATCC 15 – Test Method Overview
Apparatus
- Lab Drying Oven
- Weight Scale
- Wringer
- Perspiration Solution
- Multi-Fiber Test Fabric
- pH meter
- Grey scale for Colorfastness rating
- Perspiration Tester (with Acrylic, Plastic, or Glass plates)
| Features of Perspirometer: | |
| Frame Material | Stainless steel |
| Load on the Test Specimen | 8 lbs |
| Separator Plate material | Acrylic |
| Size of Acrylic Separator Plates | 115 mm x 60 mm |
| Number of Separator Plates | 21 |
| Test Method that can be performed | AATCC 15, AATCC 107, AATCC 106, AATCC 135 |
Preparation of Reagent:
- Prepare the acid perspiration solution by filling a 1 L volumetric flask half full of distilled water.
Add the following chemicals and mix them with a stirrer thoroughly.
Sodium Chloride = 10 ± 0.01 g
- Lactic Acid = 1 ± 0.01 g
- Sodium Phosphate = 1 ± 0.01 g
- l-histidine monohydrochloride = 0.25 ± 0.001 g
Now fill the flask to 1 L mark.
- Check the pH of the solution with a pH meter. Avoid checking it with pH test paper because it has less accuracy than a pH meter. If it is between 4.1 and 4.5, keep the test solution; otherwise, waste it and prepare the solution again with accuracy.
- Don’t use pH solution older than three days.
Preparation of Test Specimen:
- Take a specimen with dimension 6 X 6 ± 0.2 cm and attach a multi-fiber size 5 X 5 ± 0.2 cm. Both should be sewn with shorter sides.
- If there are loose fibers or yarns as specimens, place them in between multi-fiber and non-dyeable fabric and sew along 4 sides.
Testing Procedure:
- Record the weight of the test specimen.
- Take a petri dish with a 9 cm diameter and 2 cm depth. Place test specimen in it.
- Add perspiration solution to a depth of 1.5 cm.
- Leave the specimen for about 30 ± 2 min. Meanwhile, occasionally agitate and squeeze the specimen for better solution penetration. Use a wringer if the fabric is difficult to wet to ensure wetting.
- After 30 ± 2 min, pass the specimen through the wringer until each test specimen weighs 2.25 ± 0.05 times than its original weight.
- Sometimes, certain fabrics do not get enough wet pickup. Use the blotting method with AATCC blotting paper. To gain consistent results, every specimen should have a homogenous solution pick-up. Because the amount of retained solution is directly proportional to solution pick up.
- Place the specimen on a glass plate such that multi-fiber stripes run perpendicular to the length of the plate.
- For the Horizontal perspirometer tester, put the glass plate with the specimen along with 21 other plates regardless of the number of specimens.
- Place 8 lbs weight on the tester and lock the pressure plate. Remove the weight after locking.
- For the Vertical perspirometer tester, arrange the specimen between 21 tester plates. Put all plates as described above, regardless of the number of specimens. By using an adjustable screw, exert the 10 lbs force. Lock the tester with a screw and remove the pressure against the plates.
- Put the perspirometer in the lab drying oven for heating.
- Heat the laboratory oven with specimens for about 6h ± 5 min at 38 ± 1 °C (100 ± 2 °F).
- Make sure the temperature remains constant throughout the test.
- Take the test specimens out of the oven after heating. Separate the multi-fiber and test fabric and place them overnight under a conditioned environment as per ASTM D1776, i.e., 21 ± 1°C (70 ± 20°F) and 65% relative humidity.
Report Formation
- Use the Gray Scale for Color change evaluation by visually comparing the difference in color between treated and untreated specimens.
- Use the following grades to evaluate test specimens and multi-fiber.
- Grade 5 = negligible or no change
- Grade 4.5 = change equivalent to step 4-5
- Grade 4 = change equivalent to step 4
- Grade 3.5 = change equivalent to step 3-4
- Grade 3 = change equivalent to step 3-0
- Grade 2.5 = change equivalent to step 2-3
- Grade 2 = change equivalent to step 2-0
- Grade 1.5 = change equivalent to step 1-2
- Grade 1 = change equivalent to step 1-0
- State details about the specimen’s material. (e.g., knit or woven, yarn type, etc.)
- Also, mention the type of color fastness scale used for staining and color change.
- Report the color change grade of each specimen and multi-fiber with it.
- State that the test was performed according to AATCC 15.
Things to keep in mind while performing AATCC 15
- If you find an uneven color transfer, it will be due to a poor wet-out procedure or uneven pressure while arranging specimens between plates. To solve this problem, keenly observe the wetting procedure and all plates if they are in good condition.
- As described in the procedure, try to use a freshly prepared solution for testing. This is due to the reason that fungus began to grow over solution after some time. Even if the solution is kept in a stoppered bottle, its pH gradually rises at room temperature.
- Always use multi-fiber without fused edges due to thickness changes at edges, which lead to irregular compression while testing.
Conclusion
The AATCC 15 test is essential to determine fabric colorfastness to perspiration. Higher color fastness to perspiration value shows that fabric is less likely to fade and is long-lasting. To make sure that clothing and other textile goods maintain their color and appearance after frequent wear and exposure to sweat, we need AATCC 15. Maintaining high standards of quality and improving customer happiness by minimizing color fading depends on this test. Producing durable fabric and, eventually, garments helps to optimize the fabric and dyeing processes, lower the possibility of color bleeding, and enhance brand reputation. In short, AATCC 15 assists producers in providing reliable, high-performing textiles that satisfy consumer requirements.
FAQs
- What are color Fastness and color bleeding?
Although they are related ideas in textile quality and care, color fastness and color bleeding are different. The ability of a material to maintain its color or resist having its colorants transfer to nearby materials is known as colorfastness, while the transfer of color to a secondary fabric is known as bleeding.
- Why is the AATCC 15 test important?
This test is crucial because it guarantees that fabrics will not lose color under the influence of sweat, which is a regular occurrence during wear.
- What materials can be tested using AATCC 15?
Many textile materials, including blended fabrics and natural and man-made fibers, including polyester, nylon, and acrylic, can be tested using AATCC 15.
- How can I improve color fastness to perspiration?
Choosing dyes wisely is the key to improving colorfastness to perspiration. If the dyes have strong stability and a high rate of color fixing, it improves color fastness.
- What is the color fastness to perspiration machine?
The color fastness to perspiration machine, also known as a perspirometer, is a specialized piece of equipment used to evaluate the colorfastness of textiles when exposed to artificial perspiration. Other tests, such as color fastness to water and storage, may also be performed on it.
Related Resource
AATCC 15/AATCC 107 Perspirometer YG(B)631
Mastering Color Fastness: Test Methods and Techniques for Exceptional Results
What is perspiration colorfastness, and how to test