All about Colorfastness to Ozone

Ozone is a strong oxidizing agent that can change the dyed fabric shade. It causes a change of shade in fabric which is a serious concern for textile manufacturers. Colorfastness to ozone is tested using an ozone color fastness tester in the presence of 1 – 4 ppm ozone concentration.

How does Ozone affect the Fabric Colour?

The concentration of Ozone in Earth’s atmosphere is 0.3 ppm. It is a strong oxidizing agent that can break the bond of dyes and pigments. It affects the fabric’s brilliance and fades the colors.

There are different types of dyes and pigments. Some of them take more impact from the zone, like natural dyes, which fade faster in the presence of O₃. Synthetic dyes are developed to be ozone-resistant, but somehow, they are also affected by prolonged contact.

It is observed by experimentation that bright colors are more affected by O₃ than dull colors. For example, lemon yellow, golden yellow, orange, and red are more vibrant colors that fade faster than navy blue, dark brown, and black shades.

Which Factors Enhance the Ozone Impact On Textile?

Several factors enhance the O₃ impact on the color brilliance.

1. If a fabric is dried in sunlight for a longer time, the heat and UV rays will boost the impact of ozone, breaking down the dye’s chemical bond and causing the color to fade.
2. Some areas have a comparatively higher concentration of O3 than others, which decreases a fabric’s colorfastness to ozone.
3. A higher humidity supports the reaction between O3 and dyes, reducing the shade strength.
4. The presence of NOx in polluted areas reduces the ozone resistance in textiles.
5. The fabrics treated with ozone-resistant finishes have the appeal of colors compared to untreated finish textiles.

Why were anti-Ozone Finishes Developed?

The colorfastness parameter is considered a major concern in the textile sector. To improve fabric longevity and reduce environmental impact on textiles, anti-ozone testing methods and ozone-resistant finishes were developed.

This testing method helps to study the effect of ozone concentration on the fabric color in the presence of humidity and temperature for different periods.

Textile colorfastness depends on various environmental factors, including ozone. The colorfastness of ozone is also called a fabric’s anti-oxidizing ability.

Textile colors fade in the presence of oxidizing agents, which break down dyes’ chemical bonds, leading to color dullness and fading. So, anti-ozone finishes prevent the fabric from dullness of color through oxidizing agents.

Anti-Ozone Testing Standards & Parameters

The International Organization of Standardization (ISO) and the American Association of Textile Chemists and Colorists (AATCC) formulated the testing methods for colorfastness to ozone.

ISO 105-G03 and AATCC TM109-2011 are testing standards for evaluating the effects of Ozone exposure on fabrics. China also developed the testing method GB/T/T 11039-2005 in accordance with the ISO standard.

Different types of dyes react differently in the presence of ozone and humidity. That is why these tests include two types of testing method

1. For room temperature, colorfastness to ozone is measured at a relative humidity of not more than 65%.
2. The second method used at higher temperatures, colorfastness to ozone, is evaluated at more than 80% relative humidity.

Ozon Colour Fastness Tester   

Ozon colorfastness tester contains a test chamber in which a fabric specimen is placed to evaluate the color resistance of the textile against ozone. The O₃ is a common contamination in the atmosphere and presents up to 0.3 ppm.

Ozone is considered a strong oxidizing agent, which breaks down the chemical bond of dyes and causes fabric to change shade. That’s why an ozone color fastness tester is used to evaluate the change of shade concerning the ozone color fastness scale.

Types of Ozon Colour Fastness Tester                  

Two types of testers are normally available, which are used to measure the impact of O3 on a fabric specimen.

1. Automatic Ozone Maker Tester
2. Manual Ozone maker Tester

Automatic Ozone Maker Tester   

An automatic ozone maker tester is a self-contained unit that produces ozone inside the machine automatically. It also decomposes the ozone inside the machine.

It is used in a room-temperature environment and you can put it in your lab directly without the need of any ventilation cabinet or something like that.

The latest models have English and Chinese versions on the touch screen you can change the target ozone concentration and then the test time.

Usually in most standards we set the target ozone concentration to 5 ppm and these types of machines can go from 0 ppm to 8 ppm maximum, so there is a range of values that you can choose from also for the test.

Usually, we will do a four-and-a-half-hour test and you can see here that we also monitor the relative humidity and the temperature of the environment.

The machine starts when you press the run button and then it will control the concentration of the ozone inside automatically to plus or minus 0.1 ppm.

At the back of the machine, there is a box of car ozone catalysts which can decompose the ozone before it is exhausted in the lab.

It also has a door sensor if you open the door during the test they will sound an alarm. Because ozone is harmful to humans if you open the door before the test you will not be able to do the test.

If you open the door during the test the machine will sound. All the values inside can be calculated like the ozone concentration the relative humidity and the temperature.

All the values can be calibrated and provide good traceability this tester conforms to testing standard AATCC109 ISO 105-G03 and GBT11039-3.

As for consumables for this machine, the only consumable is the ozone catalyst once you change the ozone catalyst you can use it for about five to six months if you use it every day for eight hours.

Manual Ozone maker Tester   

In manual ozone maker testers, you have to produce ozone according to your requirements. Manual ozone testers are operated by following the below guidelines.

First of all, get the accessories and test sample ready, and open the security door of the instrument. Place the prepared sample into the rotating sample holder (accommodating 24 samples)

Release the sample and close the instrument safety door. Turn on the instrument and enter the LCD interface. Set parameters such as operating time and number of revolutions. Add purified water at the water filling point of the machine.

The water level should be increased to about 60 – 70. Turn on the power air switch at the back of the machine. Set parameters such as temperature, humidity, and ozone concentration. The sample holder begins to rotate while the separator system injects ozone into the test chamber.

Press the power button on the panel to turn on the power, lightning is the button to turn on the light in the test chamber. Fix the test to enter the fix test page. Set the temperature and humidity according to the standard.

Run the test, after the displayed temperature and humidity reach the set value and become stable. Start to set the concentration value of the ozone meter

Click up and down arrow button to set the ozone concentration value.

Warm tips: please set the ozone concentration according to the standard. Click ozone to turn on the ozone, ozone value will start to increase. When the test time specified in the standard is reached, it means the test is completed. Press the ozone switch to turn off the ozone and press clear the ozone clearing switch.

When the ozone in the test chamber is cleared, the light of the [clear] button will go out. When the [clear] button is dark, it shows the current ozone value in the test chamber is low and the sample cab was taken out.

The test is over and the instrument. Close the instrument at the end of the test, and remove the samples for comparison and observation, to evaluate the ozone resistance of a material.

How to Improve Color Fastness to Ozon?     

Applying ozone-resistant finishes and using the best ozone-resistant dyes can improve a fabric’s colorfastness to ozone. Use synthetic dyes specially designed for ozone retardant.

Natural dyes are not good for O3, so avoid them in textiles where the demand for O3 resistance is high.

Protecting clothes from prolonged sunlight exposure and UV rays, avoiding putting fabrics in high temperatures & humidity places, and using sunscreen can also help to Improve Color Fastness in Ozon.

Conclusion 

The colorfastness parameter is considered a major concern in the textile sector. To improve fabric longevity and reduce environmental impact on textiles, anti-ozone testing methods and ozone-resistant finishes are developed.

ISO 105-G03 and AATCC TM109-2011 are testing standards for evaluating the effects of Ozone exposure on fabrics. China also developed the testing method GB/T/T 11039-2005 by the ISO standard. 

FAQs

How does ozone affect the colorfastness of a fabric?

Ozone is a strong oxidizing agent that breaks down the chemical bonds of dyes. It causes a change of shade in fabric, which is a serious concern for textile manufacturers.

How much concentration of O₃ is used in the ozone colorfastness tester?

Colorfastness to O₃ is tested using an ozone colorfastness tester in the presence of a 1 – 4 ppm ozon concentration.

Which types of dyes are affected more by exposure to ozone?

There are different types of dyes and pigments. Some of them take more impact from the zone, like natural dyes, which fade faster in the presence of O3. Synthetic dyes are developed to be ozone-resistant, but somehow, they are also affected by prolonged contact.

Does ozone affect the brilliant shades?

It is observed by experimentation that bright colors are more affected by O3 than dull colors. For example, lemon yellow, golden yellow, orange, and red are more vibrant colors that fade faster than navy blue, dark brown, and black shades.

Which Factors Enhance the Ozone Impact On Textile?    

Prolonged exposure to sunlight, UV rays, higher temperature & humidity, a higher concentration of O3, and the presence of NOx in polluted areas enhance the one impact on textiles. Fabrics without ozone-resistant finishes are affected more than treated textiles.

Why were anti-Ozone Finishes Developed?  

The colorfastness parameter is considered a significant concern in the textile sector. To improve fabric longevity and reduce environmental impact on textiles, anti-ozone testing methods and ozone-resistant finishes were developed.

What are the Anti-Ozone Testing Standards & Parameters?

ISO 105-G03 and AATCC TM109-2011 are testing standards for evaluating the effects of Ozone exposure on fabrics. China also developed the testing method GB/T/T 11039-2005 by the ISO standard.

Which methods are focused on ISO & AATCC standards for ozone colorfastness?

Two types of testing methods are focused on the O3 colorfastness test.

For room temperature, colorfastness to ozone is measured at a relative humidity of not more than 65%. The second method used at higher temperatures, colorfastness to ozone, is evaluated at more than 80% relative humidity.

What is the purpose of an ozone colorfastness tester?

Ozone is considered a strong oxidizing agent, which breaks down the chemical bond of dyes and causes fabric to change shade. That’s why an ozone color fastness tester is used to evaluate the change of shade with reference to the ozone color fastness scale.

How many types of ozone colorfastness testers are used?

Two types of testers are generally available, which are used to measure the impact of O3 on a fabric specimen.

1. Automatic Ozone Maker Tester
2. Manual Ozone maker Tester

What is the difference between Automatic and Manual ozone colorfastness tester?

With an automatic tester, you do not need to worry about managing the ozone concentration. The machine will automatically adjust the concentration according to your demand from 0 to 4 ppm.

In a manual tester, you have to add water and adjust the level of water according to your requirement of ozone concentration, and then manage it manually through the machine.

Related Resources

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AATCC 107 Colorfastness to Water Test Method

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