Textiles are an integral part of our daily lives, from the clothes we wear to…
What does Color Fastness to Rubbing Mean?
There was once a joke on friction color fastness where a guy was wearing his blue jeans and driving around in the white leather seats of his new Rolls Royce, and when he was done driving around, he noticed that the white leather seats of his luxury car had turned blue. This was because his pants had lost their color under the action of friction.
This joke contains a phenomenon called color fastness to rubbing, which is an indicator to assess the color loss of fabric when rubbed. Fastness to rubbing is divided into dry fastness to rubbing and wet fastness to rubbing, which corresponds to the ability of garments to resist rubbing fastness in dry conditions and in wet conditions, respectively. The color fastness to rubbing test principle is, under the specified conditions, a white rubbing cloth on a test sample with color rubbing back and forth. After rubbing a certain number of times, by evaluating the color transfer to the white rubbing cloth (can be compared by staining the color gray card or 9 levels of color staining gray depending on a level.) So the color fastness is expressed by the evaluation grade from the degree of color-staining of white cloth.
Clothes with bad color fastness to rubbing not only affect the taste of the people, but also easy to make a “color kiss” with related items, such as the seat surface or underwear fabric, so this is a serious quality problem, which the textile production enterprises must strictly avoid. We found that most of the rubbing fastness failure is pants, this is because, in the usual wear, pants rubbing will generally be more, especially in the hip and crotch, so you should especially pay attention to the problem of friction fastness when buying pants.
International Common Color Fastness to Rubbing Test
The following 9 standard methods of color fastness to rubbing are currently the most popular internationally
(1) ISO 105- X12:2016 “Color Fastness Test for Textiles Part X12: Color Fastness to Rubbing
(2) CAN/CGSB 4.2 No.22-2004 “Textile Test Method: Color Fastness to Rubbing
(3) GB/T 3920-2008 “Textile Color Fastness Test Rubbing Fastness
(4) AS 2001.4.3-1995 (R2016) “Textile Test Methods Part 4.3: Determination of Color Fastness to Rubbing
(5) AATCC 8-2016 “Rubbing fastness: rubbing tester method
(6) JIS L0849:2013 “Test Method for Color Fastness to Rubbing
(7) ISO 105-X16: 2016 “Textile Color Fastness Test Part X16: Rubbing Color Fastness – Small Area
(8) AATCC 116-2013 “Color Fastness to Rubbing: Rotating Vertical Rubbing Fastness Tester Method
(9) GB/T 29865-2013 “Textile Color Fastness Test: Rubbing Color Fastness Small Area Method
|4 Kinds of Color Fastness to Rubbing Test Standard Comparison|
|Standards||GB/T 3920-2008||AATCC8—2007||AATCC 116-2010||JIS L 0849-2004 |
|Simple Size/mm||50×140||50×130||Square with at least 25mm side length||Crock meter typeⅠ： 50×140 |
Crock meter typeⅡ： 30×220
|Rubbing Header Size /mm||Round(general fabric) diameter: 16±0.1 |
Square (pile type) 19×25.4
|Round diameter: 16±0.3||Round |
|Rubbing Header Vertical Pressure||9±0.2N||9±0.9N||11.1±1.1N||9±0.9N|
|Rubbing Times||Rub 10 times in 10S||Rub 10 times in 10S||40 trajectories in opposite directions |
(number of laps)
|Rub 100 times in 200S|
|Rubbing Cloth Size||Non-pile: 50×50mm |
|Rubbing Cloth Request||100%cotton, whiteness (70±5)%||100%combed cotton, whiteness (80±2)%||100% combed cotton, whiteness (80±2)%||100%cotton,85% whiteness|
|Water Moisture |
Of Rubbing Cloth/%
|Running Direction||The rubbing cloth warp direction is the same as the running direction||The rubbing cloth warp direction is the same as the running direction||Fixed-point rotation||The rubbing cloth warp direction is the same as the running direction|
What is a crock meter? How does a crock meter work?
From the test apparatus, there are three types used to do color fastness to rubbing test: parallel reciprocating type (commonly used in Europe, America, and China), over-bridge type (commonly used in Japan), and rotary rubbing type. These rubbing fastness testers are usually called crock meters, there are electronic crock meters and manual crock meters.
The crock meter is generally constructed as follows (using the TESTEX electronic crock meter as an example).
1. Handle of machine 2.Controller and display 3. Power switch
4. Support rod 5. Rubbing Head 6.Testing fabric
- Rubbing Finger 8. Load weight 9. Testing fabric holder
- Sample Holder
- LOGO of TESTEX
- Start button
- Stop button
- Current Value
- Preset Value
- RESET key
- MODE key， press this key to enter the setting page
- Move the position when setting
- Increasing the key when setting
The differences between the 3 types of color fastness to rubbing test
The test standard chosen by each country is different, plus the choice of crock meter is also different, and the rubbing dynamic range, speed, rubbing head pressure, size, rubbing cloth moisture content, humidification method, etc. will be different. So, what are the differences between the parallel reciprocating type (commonly used in Europe, America, and China), over-bridge type (commonly used in Japan), and rotary rubbing type?
Parallel reciprocating rubbing range is generally (104 ± 3 ) mm or (103 ± 5 ) mm, the usual standards follow the AATCC8-2007 and GB/T 3920-2008.
Over-bridge type for the Japanese fastness to rubbing standard, color fastness meter type II, its reciprocating range of 100mm.
The rotary rubbing type is rotating around the center of the circle while above the sample, the contact surface is only the area of the circular rubbing head.
Rubbing speed and times
Parallel reciprocating rubbing type 60 times/min, 10 times reciprocating, a total of 10 s rubbing.
Rotary rubbing type 1 cycle / s, friction 20 cycles, a total of 20s rubbing.
over-bridge type 30 times/min, reciprocating 100 times, a total of 200s rubbing.
The Japanese standard has the highest number of rubbing, and rubbing takes the longest time, so its longer rubbing course brings a more rigorous test, the same textile test results with this method are poor.
Rubbing head size and pressure
(1) Parallel reciprocating type rubbing head.
In addition to the standard specified rubbing head dimensions in the table above, American Standard A ATCC 8-2016, Australian Standard AS 2001.4.3-1995, Canadian Standard CAN/CGSB-4.2 NO.22-2004 cylindrical rubbing head diameter of (16 ± 0.1) mm, area 203.5 mm2, the pressure of 9N.
International standard ISO 105-X12:2016 and GB/ T 3920-2008, with two types of rubbing head, one is a square rubbing head size 19mm × 25.4mm, area 482.6mm2, the other is a cylindrical rubbing head diameter of (16 ± 0.1) mm, area 203.5 mm2, pressure is 9N.
(2) Over-bridge type rubbing head.
Japanese standard JIS L0849: 2013 rubbing head is more special 20 × 20mm square, surface radius of 45mm curved.
(3) Rotary rubbing type head.
International Standard ISO 105-X16:2016, American Standard AATCC 116-2013, Chinese National Standard GB/T 29865-2013, the rubbing head of these standards is also cylindrical rubbing head diameter (16 ± 0.1) mm, area 203.5mm2, but the pressure is 11.1N.
Parallel reciprocating type standard, Overbridge type standard in addition to the U.S. AATCC standard is 45 ° oblique sampling, are warp and latitude sampling; Rotary rubbing type standard for a small area of fixed origin rubbing can be sampled without cutting.
The American AATCC standard of Parallel reciprocating type and Rotary rubbing type is required to wet rubbing cloth moisture content of 65%.
International ISO standards and China GB standards require moisture content of 95% to 100%, but if the moisture content seriously affects the rating, you can use other moisture content, such as the common moisture content of (65 ± 5) %. Canadian CAN/CGSB standard, Australian AS standard, and Japanese JIS bridging friction standard require a moisture content of 100%.
How do you test the color fastness to rubbing?
We can find the answers through this crock meter test. We take AATCC 8 color fastness to rub test standard as an example. Also, more color-fastness articles(PDFs), are ready for you.
Purpose and scope
1-1 This standard is used to determine the extent to which color on colored textile materials is transferred to rubbed white cloth by rubbing. This standard applies to all textile materials, whether by yarn or fabric, whether it is dyed or printed, or other coloring methods. This standard is recommended not to be used in felt fabrics or when its printing block is very small printed fabrics, such printed fabrics please use the AATCC 116 test.
1-2 Using white square cotton, can be measured by drying or wetting with water.
1-3 Since washing, dry cleaning, shrinkage, ironing or finishing, etc. will affect the degree of color transfer of raw materials, therefore, we can consider what kind of processing before and after the test, and then make the test.
2-1 A white rubbing cloth is rubbed back and forth on a colored test sample under specified conditions.
2-2 The color transfer to the white rubbing cloth can be determined by comparing it with the color-stained gray card or 9 levels of the color-stained gray card.
3-1 Color Fastness: The ability of a material to resist color change, encompassing both its own color change and staining on adjacent cloth, such may occur during production, testing, storage, and use.
3-2 Rubbing: The transfer of colorant from a colored yarn or fabric to the surface of another fabric in contact with it by the act of rubbing.
Note: These safety measures are provided as information only. As an aid to the testing process, it is the responsibility of the operator to perform the experimental procedures safely and correctly. The AATCC crock meter manufacturer must provide guidance on safety details such as safety data sheets and other manufacturers’ recommendations. All OSHA standards and regulations must also be referenced and followed.
4.1 Good laboratory practices should be followed and protective eyewear should be worn in the laboratory.
Instruments and raw materials
5-1 AATCC crock meter.
5-2 Test white cloth: cut into 50mm square samples (requirements as 13-4).
5-3 Grade 9 colored staining ash
5-4 Color staining gray card.
5-4 AATCC white absorbent paper.
5-5 Crock meter specimen holder.
6-1 Calibration confirmation of the crock meter should be performed periodically and the results should be maintained for a long period of time. The following proper handling practices are important and will prevent erroneous test results, in addition to abnormal friction images that can affect and lead to final ratings.
6-2 A fabric with internally known poor rubbing fastness was used as a calibration specimen and 3 dry rubbing tests were done.
6-2-1 The measured rubbing stain image was not very round and the stain was not uniform, which means that the surface of the rubbing head was not flat.
6-2-2 The friction staining image was long and formed an ellipse-like circle indicating that the sample was held by a metal collar.
6-2-3 Rubbing staining image elongated and accompanied by a strip indicates that the rubbing white cloth into diagonal clamping, the longitudinal direction should be parallel to the length of the crock meter clamping.
6-2-4 The edge of the test specimen has scratches, indicating that the position of the metal ring is too low, should be higher to prevent the sample metal ring from clamped on the surface of the specimen.
6-2-5 Rubbing color image in the center of a mark, and along the direction of rubbing, indicating that the metal base below the rubbing instrument specimen is not flat or rolled, a support can be plugged to make the base level.
6-2-6 If a specimen holder is used, place the specimen on the base of the crock meter and then place the holder on the specimen and start the rubbing test head by the rubbing handle and move it back and forth to the very front to see if the rubbing head is touching the edge of the holder.
6-2-7 Confirm the moisture content of the rubbing white cloth (see 9-2).
6-2-8 If the rubbing sandpaper on the rubbing base feels smooth to the hand in the rubbing area for the area next to it or if the specimen slides significantly when placed on it, replace the friction sandpaper promptly.
6-2-9 In the process test, observe whether a strip of color marks appears on the friction image, the specimen is generally placed diagonally (45°) in the longitudinal and latitudinal directions. For diagonal tissue or some raised surface patterns, the rubbing image may show a strip of color marks, then please gently adjust the angle of the specimen.
7-1 Generally two specimens are used, one for dry color fastness to rubbing and the other for wet color fastness to rubbing.
7-1-1 In order to increase the accuracy of the test results, more specimens can be used to take the average.
7-2 Cut the specimen size of 50*130mm, the length direction can also be longer, the length direction of the specimen with the warp direction or the length direction of the cloth into
45-degree angle to the length of the cloth.
7-2-1 When it is necessary to test several times and in the process of finished product testing, larger or whole-width specimens can be used without cutting into pieces.
7-3 Yarn sample: It will be pre-woven into a cloth sample of not less than 50*130mm, or it can be wound into a yarn strip of not less than 50*130mm by an appropriately shaped object, and its yarn is in the length direction along the yarn strip, or in other directions.
8-1 Before the test, the specimen, and the rubbing white cloth are pre-humidified and humidified by referring to ASTM D1776, and the specimen and the rubbing white cloth are humidified for at least 4 hours under horizontal conditions at a standard environment of 21±1°C and 65±2% relative humidity.
9-1 Dry color fastness to rubbing test.
9-1-1 Rubbing direction along the length of the specimen, place the rubbing sandpaper along the length of the base of the crock meter and place the test specimen on the rubbing sandpaper.
9-1-2 Place the specimen holder on the specimen to prevent the specimen from sliding.
9-1-3 Place a small square of rubbing the cloth on top of the rubbing head facing downward, with the longitudinal direction of the cloth parallel to the direction of rubbing, and a special metal ring over the cloth, noting that the metal ring should not be positioned too low, because it will drag the test specimen.
9-1-4 Put down the rubbing test head on the specimen, the starting position is to put the friction head in the forefront of the back and forth position, at a rate of one back and forth per second to shake the handle 10 back and forth, so that the rubbing head in the specimen back and forth a total of 20 times, for electronic crock meter. please set and start instrument 10 back and forth. For other requirements, please refer to the requirements for the number of round trips.
9-1-5 Take out a small square rubbing cloth, wet it according to 8-1, and evaluate it by 10. For stretching, pilling, and brushed specimens, if there are some loose fibers on the rubbing cloth, it will affect the rating. Before rating, use tape paper to stain the extraneous short fibers by gently pressing on the rubbing cloth.
9-2 Wet color fastness to rubbing
9-2-1 Prepare a square of wet rubbing cloth according to known techniques by first weighing the wet rubbing cloth and then wetting it completely in deionized water. Each time another square of small white cloth can be prepared.
9-2-2 Squeeze the wetted small white cloth through a hand wringer or a convenient device on absorbent paper in order to make the small white cloth have a moisture content of 65±5%.
9-2-3 The moisture of the small white cloth should be prevented from evaporating before the actual rubbing start test.
9-2-4 Next, test the wet color fastness to rubbing according to the 9-1 procedure.
9-2-5 Cool dry the square small white cloth in the air and adjust the moisture by referring to 8-1 before rating. For stretched, piled, and brushed specimens, once there are some loose fibers on the rubbing white cloth that will affect the rating, use tape paper to stain the extraneous short fibers by gently pressing on the rubbing white cloth before rating.
10-1 The degree of staining of the square white cloth with the color of the specimen is evaluated by using a grade 9 colored staining card or a staining gray card.
10-2 When evaluating, place three layers of unstained white test cloth on the back of the rubbing cloth.
10-3 Use 9 levels of AATCC color staining card or color staining gray card to evaluate the dry and wet colour fastness to rubbing, respectively.
Level 5: Negligible or no color staining.
Level 4.5: Color staining is equal to levels 4-5 of the staining gray card or level 4.5 of the level 9 AATCC color gray card.
Level 4.0: The color staining is equal to levels 4-5 of the staining gray card or level 4.0 of the level 9 AATCC color gray card.
Level 3.5: The color staining condition is equal to levels 3-4 of the staining gray card or level 3.5 of the level 9 AATCC color gray card.
Level 3.0: The color staining condition is equal to level 3 of the staining gray card or level 3.0 of the level 9 AATCC color gray card.
Level 2.5: The color staining condition is equal to level 2-3 of the staining gray card or level 2.5 of the level 9 AATCC color gray card.
Level 2.0: The color staining condition is equal to level 2 of the staining gray card or level 2.0 of the level 9 AATCC color gray card.
Level 1.5: The color staining condition is equal to levels 1-2 of the staining gray card or level 1.5 of the level 9 AATCC color gray card.
Level 1.0: The color staining condition is equal to level 1 of the staining gray card or level 1.0 of the level 9 AATCC color gray card.
10-4 For the same sample when testing multiple specimens, the results will be averaged and accurate to 0.1 level, for the same specimen a group of people to assess can also be averaged and accurate to 0.1 level.
11-1 Indicate whether the color fastness is dry or wet rubbing.
11-2 Refer to 10-3 to indicate the number of grades.
11-3 Indicate the closest 0.1 grade with reference to 10-4.
11-4 Indicate whether the rating is based on a stained gray card or a grade 9 color stained card.
11-5 If any pre-treatment or post-treatment was applied to the specimen, indicate the specific method.
- Accuracy and deviation
13-2 Simulating finger and arm movements, the AATCC rubbing fastness tester provides a reciprocal rubbing action.
13-4 The AATCC Rubbing Fastness Tester is set up to move a 16 mm diameter rubbing head reciprocally by a single handle rotation over a distance of 104 ± 3 mm on the specimen with a rubbing head down force of 9 N ± 10% (2 lbs ± 10%).
13-4-1 Square rubbing small white cloth shall meet the following requirements.
Fiber composition: made of 100% combed cotton fiber of length 10.3~16.8mm by desizing and bleaching, but must not contain fluorescent whitening agents or other finishing aids.
Yarn: 15 texes (40/1 count), 5.9 twists per cm, twist direction “Z”.
Density: Warp and weft density is 33±3 roots/cm.
Weaving method: top and bottom plain.
Cloth weight: Blank cloth: 113±5g/m2, finished cloth: 100±3g/m2.
Whiteness: W: 80±2 (Method 110).
13-6 When accidentally damaging the rubbing head, ring, or rubbing sandpaper, please repair it as follows: replace the new rubbing sandpaper, put the ring on a rod with a smaller diameter than the rubbing head, and bend the ring more loosely or tightly, reinstall the rubbing head, put a piece of extra-fine emery cloth, and test the rubbing head by rubbing it back and forth in the same way as the usual test.
How to improve the color fastness of fabrics to rubbing?
First, we should know what factors affect the fabric’s color fastness to rubbing.
Some water-soluble dyestuff, such as reactive dyestuff, contains excellent water-soluble groups, which is conducive to the dissolution of dyestuff and dyeing in the dyeing process.
However, during the wet color fastness to rubbing test, the presence of water will cause the reactive dye molecules to have the tendency to dissolve in water away from the fiber, thus reducing the bonding between the reactive dye and the fiber.
Some poorly water-soluble dyes, such as reduction dyes, in the continuous rolling and dyeing process, generally in suspension state mechanically rolled and dyed on the fiber, by reduction vapor, into water-soluble dyes cryptic body dyed in the fiber, and then oxidation, soap cooking, fixed on the fiber, to this, the reduction dye molecules and return to the non-water-soluble state.
Therefore, the reduction of dyes dyed fabric because of its dyed dye’s non-water-soluble quality make its wet color fastness to rubbing is better than the dyed fabric dyed with reactive dyes.
Color depth (dye concentration)
In the fabric, pre-treatment and dyeing process are the same conditions, the deeper the color, the higher the concentration of dyestuff, the greater the concentration gradient of dyestuff molecules between the test fabric and friction white cloth, the greater the possibility of dye transfer to white cloth by rubbing, the poorer the fastness to wet rubbing.
The influence of floating color
The floating color includes the dyestuff that has been hydrolyzed and the dyestuff that has not been hydrolyzed but has reacted with the fiber.
These dyes rely on hydrogen bonding, van der Waals force, and fiber attraction together, and the affinity between the fiber is very low, by a small external force can be easily detached from the fabric.
So the floating color is an important factor affecting the wet color fastness to rubbing of the fabric.
The influence of water quality
If you use harder water for chemical materials, especially solid color liquids, because of the CO32-, OH- and other anions, they react with Ca2+, and Mg2+ to generate Ca2CO3, MgCO3, and other insoluble substances.
These insoluble substances and dyes combined together to form a color precipitate and deposited on the surface of the fabric, so that the friction when rubbing greatly increased, resulting in a reduction in wet rubbing fastness.
In addition, Ca2+, and Mg2+ can also react with some anions on the dyestuff molecules, transforming into insoluble substances, thus weakening the hydrophilicity of the dyestuff, so that the dyestuff is not easy to dissolve and diffuse, the floating color is not easy to wash off when washing.
Fabric structure and surface finish
Fabric structure affects the smoothness of the fabric surface, and the smoothness of the friction test determines the size of the friction force, affecting the color fastness to rubbing.
Another important factor affecting the fabric’s wet color fastness to rubbing is the surface finish of the fabric.
Fiber ends are exposed on the surface of the yarn, thus forming a layer of fuzz on the surface of the fabric.
This layer of fuzz in the dyeing and finishing process, constantly subject to friction, washing, and fabric adhesion has been very poor, and then by external forces, some short fuzz from the fabric and stained to the white cloth.
In actual production, the color fastness to rubbing of brushed cloth than mercerized cloth is 0.5 ~ 1 level.
After reading these, we can improve the rubbing fastness through which aspects?
Choice of blank cloth
The same variety of specifications of the dyeing blank, due to the quality of the yarn, weaving, and other factors, will cause the same process conditions of the dyeing fabric with the same difference in friction fastness.
Therefore, it is better to choose a blank fabric with good yarn quality, uniform yarn count, and a smooth surface.
The smoother the surface of the fabric, the higher the wet color’s fastness to rubbing, so the burnishing should be net and the colored fiber micro-particles should be reduced.
Boiling, bleaching process air pressure, temperature, etc. should be uniform so that the fabric has a uniform wool effect and whiteness, conducive to the diffusion and penetration of dyestuff.
Dye selection and dyeing process
Choose the dyestuff with higher lifting power and then less floating color. When it is necessary to color-match, try to choose the same category and the same manufacturer’s dyestuff, and at the same time, the matching value of the color-matching dyestuff should be similar.
In the process of dyeing solution configuration, soft water should be used as much as possible, and water softeners can be added when appropriate, while some penetrating agents can be added to improve the penetration performance of dyes.
In the dyeing process, the pH value of the fabric should be controlled between 4.0-7.5 to prevent the strong alkali from destroying the bonding force between the dye and the fiber, which will reduce the friction fastness of the fabric.
The soaping process should wash away the floating color as much as possible, which can increase the washing times and water flow.
At this time, neutral detergent should be used to prevent alkaline detergent caused by the dye hydrolysis again.
In order to improve the rubbing fastness after dyeing, after dyeing, we should carry out solid color post-treatment. There are two types of post-treatment: one is a cationic color-fixing agent.
The use of the relatively large molecular weight of quaternary ammonium salt cations and dye anions combined, closed its water-soluble groups, thereby reducing the water solubility of dyestuff, and improving friction fastness, but this often causes sun fastness to reduce.
Another type of wet color fastness to rubbing enhancer, is mostly polyethylene emulsion and special amino silicone softener, these substances in the fabric surface cross-linked into a film, thereby reducing the rubbing on the surface of the fabric, to improve the fastness to rubbing.
Rubbing fastness in textiles is a very important indicator to evaluate the quality of textiles, so related tests should be taken seriously.