Color fastness to wash is very important for Lab-dip. There are varieties of testing procedure, because:
1.Washing conditions may vary from one country to another.
2.The methods on the use of dyed goods.
3.To evaluate repeated washing accelerated test methods are used.
The degree of fading and staining of dyed goods for washing depends upon the following factors:
1.Temperature range may be from 40 Degree centigrade to 95 Degree centigrade.
2.The type and amount of detergent added to the washing bath. In many testing procedures a standard detergent is used.
3.The extent of mechanical action which can be varied by changing the agitation speed in a washing machine or by adding steel ball to revolving the bath.
4.The washing liquor to goods ratio is 50:01.
5.The hardness of water.
6.The rinsing, drying, or pressing methods used to restore the sample after the washing test.
So, how to measure color fastness of a Textile Material?
Procedures of Fastness Measurement
A Specimen (Lab-dip) in contact with specified adjacent fabric or fabric is laundered, rinsed and dried. The specimen/composite sample is treated under appropriate condition in a chemical bath for short time. The abrasive action is accomplished by the use of a liquor ration and an appropriate number of steel balls. The change in color of the specimen (Dyed Sample) and the staining of the adjacent fabric is assessed by recommend Grey Scales (1-5).
Apparatus & Materials used for measuring Color Fastness of Textiles Materials:
1.Wash-wheel with a thermostatically controlled water bath and rating speed of 40+-2 rpm.
2.Stainless steel container.
3.Stainless steel ball.
4.SDC, Multifiber Fabric (Acetate/Cotton/Nylon/Polyester/Acrylic Fiber/Wool).
5.Thermometer,
6.Sewing Machine.
7.Dryer.
8.Color Matching Cabinet and
9.ISO Scales.
