Color Fastness: The “color fastness” of a colored textile is defined as its resistance to these changes when subjected to particulars of conditions. It follows that color fastness must be specified in terms of these changes and expressed in terms to the magnitude.
Color fastness to wash is an important test for ensuring the fastness of the colored material. It is done in dying lab. Testing procedure can be varying depending on the measuring procedure. In quality assurance system; a record is maintained for each lot of dyed goods or finished goods. Here, Computer Color Matching System (CCMS) is used for save the record.
Required materials: Following materials are required for wash fastness test. Following materials are standard for wash fastness measurement.
- Sample size 40 x 100 mm
- Multi-fiber at 40 x 100 mm
- ECE detergent (WOB)-4g/L
- Sodium Perborate (Na2BO3.H2O2-1g/L)-1g/L
- Distilled water
- Normal cold water
- Steel balls
Required instruments: Various types of instruments are used for it. Followings are the important one.
- Rota wash
- Stitch machine
Color fastness to washing measurement Procedure: Color fastness to wash is an off line quality assurance system. By the following way, color fastness to wash is carried out.
- Cut sample and Multi-fiber at 40 x 100 mm.
- 50 ml ECE detergent (WOB) & 50 ml Sodium per borate is taken with the sample. For marks & Spencer, the solution is taken by the following formula: (Sample fabric + Multi-fiber weight) x 50 ml.
- The sample is kept in 600C for 30 minutes in Rota Wash Machine.
- Rinse the sample twice with cold water.
- Dry at 600C by hanging or by Flat iron pression but temperature should not be more than 1500C.
- Dry the specimen and the change of shade & degree of staining is measured by Grey Scale & Staining Scale.
So, we should be care full during measurement of wash fastness of textile materials.