- 1 Measuring Color Fastness:
- 1.1 Explanation:
- 1.1.1 1. Crock Meter
- 1.1.2 2. Contact heat transfer
- 1.1.3 3.Weather o meter
- 1.1.4 4. Laundrometer
- 1.1.5 5. Gray scale
- 1.1.6 6. Gas fading chamber
- 1.2 Related
- 1.1 Explanation:
Definition : The ability of a material or dye to maintain its color without fading or washing away.
Color fastness is a term—used in the dyeing of textile materials—that characterizes a material’s color’s resistance to fading or running. The term is usually used in the context of clothes. The first known use of the word colorfast
was in 1916.
- Color Fastness to Wash.
- Color Fastness Test to Light.
- Color Fastness To Rubbing.
- Color Fastness to Laundering.
- Color fastness to Perspiration.
- Color fastness to pressing.
- Color fastness to gases in the atmosphere.
Measuring Color Fastness:
- Crock meter.
- Contact heat tester.
- Weather o meter.
- Gray scale.
- Gas fading chamber.
1. Crock Meter
Color fastness to Crocking
The rubbing off of colors is called as crocking.
Fabrics with a lot of surface dyes like dark color cotton fabric tend to have poor colorfastness to crocking, pigment dyed or printed fabrics also face the same problem.
Some time in order to increase the depth of the colors the surface dyes are not washed off which also results in crocking.
Crockmeter performs scuffing, wet/dry abrasion, flexing, powdering, dry cleaning, ink abrasiveness, and other tests.
The crock meter is used to find the color fastness to crocking.
This instrument has a finger covered by a white cotton fabric which would rub against the specimen.
This test should be performed both as wet and dry test.
The wet test is a severe test since moisture helps in removal of dyes.
AATCC Method 8 specifies the cloth should meet the following specifications:
Fiber: 100% 10.3 – 16.8mm combed cotton staple, desized, bleached, with no optical brightener or finishing material present.
Yarn: 15 tex (40/1 cotton count), 5.09 turns/cm “z
Thread Count: 32 +/-3 warp ends/cm: 33 +/-3 picks filling/cm
Weave: 1/1 plain
pH: 7 +/-0.5
Mass/sq. meter: 113 +/-5g greige: 100 +/-3 g finished)
Whiteness: W = 80 +/-2
2. Contact heat transfer
The heat contact tester consist of 3 pairs of individual controlled heaters.
Allows simultaneous testing of 3 differing temperatures in the range 100 degrees C to 230 degrees C.
After the allocated time the specimens are taken out and is compared to the gray scale from which the color fastness is found out.
3.Weather o meter
It a new and versatile.
It enables the specimen to be sprayed with water if needed.
It also manipulates the light and dark period of continuous exposure is not
These make it most suitable for testing fabrics for end use like outdoor furniture,
tenting or rainwear.
This machine uses carbon-arc-lamp or a xenon-arc lamp as the light source.
Ex: A coating material should have more color fastness than a colored dress shirt. Similarly, clothes not intended to the worn outside should also have certain color fastness to enable drying in sunlight.
Water purity indicator with alarm.
6500 W water cooled xenon arc lamp system.
Calibrated xenon reference lamp.
Chamber viewing window in a door.
Streaming data output via ethernet or USB port. USB thumb drive included.
Universal electrical configurations to meet local frequency, voltage, and electrical requirements.
Direct setting and control of relative humidity.
Direct setting and control of specimen chamber air temperature.
Specimen placed in a metal cylinder containing water, detergent, steel balls and chlorine.
Rotating action of these cylinders produces the same effect as textile products being laundered.
- Temperature controller.
- Bath has the double hinged wall.
- Pre heating bath.
- Electric motor.
- Worm reduction gear box.
- Capacity : 20 m pots of 550 ml or 1200 ml.
- AATCC specified instrument for more than fifty years.
- Large 20 container capacity.
- All stainless steel.
- Handles 550 ml and 1200 ml containers.
- Easy open door.
- Quick-lock retention bars.
- Door safety switch stops rotor if opened.
5. Gray scale
Grayscale is a range of shades of gray without apparent color.
The darkest possible shade is black, which is the total absence of transmitted or reflected light.
The lightest possible shade is white, the total transmission or reflection of light at all visible wavelength s.
- The arrangement of achromatic gray chips in a scale from light to dark.
- Nine pairs of nonglossy neutral gray colored chips, which illustrate the perceived color differences.
- Give a corresponding fastness rating of 5, 4-5,4,3-4,3,2-3,2,1-2, and 1.
Gray Scale for staining:
- Used to evaluate a fabric’s resistance to staining.
- Normally a multi-fiber strip of 6 fiber components used for staining test: Acetate, cotton, acrylic, polyamide, polyester, and wool.
- Same as the gray scale, except for the chip in each pair that remains the same is a standard white.
- A various contrasting pair of chips is given numerical color fastness ratings, from class 5 to class 1.
- Utilizes samples of un dyed fabric to determine if a colored fabric will stain an adjacent fabric.
- Rating 1 shows a white and a gray sample.
- A rating of 5 means that there is no difference between the treated and untreated material.
- .If the result is in between any two of the contrasts on the scale, a rating of, for example, 3-4 is given.
6. Gas fading chamber
Color fastness to gases in the atmosphere:
The major causes for this is due to the reaction of disperse dye with ozone and
oxides of nitrogen.
The disperse dyed with acetate fabric has the maximum effect while nylon,
Polyester, acrylic has the low effect.
Inhibitors are used for this purpose but are not permanent.
Darker, brighter change more dramatically.
Typical changes: Blues turning pinkish, browns turning reddish, green turning brownish.
Gas fading chamber: tests the effects of oxides of nitrogen.
Ozoniter: tests the effect of ozone.
The specimen is placed in the gas filled chamber for a particular time along with the control fabric.
The tests are conducted at 140 degrees F for approximately 2-3 hours.
The relative humidity.