Determination of Color Fastness to Rubbing.

Experiment No.: 04

Experiment Name: Determination of Color Fastness to Rubbing.

Introduction:

In the textile industry, a rub test determines the colorfastness of the color or dye in a fabric. It  is an essential test.

Rubbing: 

This part of ISO 105 specifies a method for determining the resistance of the color of textiles of all kinds of fabrics, to rubbing off and staining other materials.

Principle:

Specimens of the textile are rubbed with a dry rubbing cloth and with a wet rubbing cloth.

Objectives:

1. To know about the color fastness of the given sample fabric.
2. To know the dyeing characteristic of fabric.
3. To know about crock meter.
4. To know the working principle of crock meter.
5. To know the color fastness of given sample.

Apparatus:

1. Suitable Crock Meter
2. Cotton Rubbing Cloth (desized, bleached, without finish)
3. Distilled Water
4. Emery Paper
5. Grey Scale for Staining
6. Filter Paper
7. Sample

Test Specimen:

If the textile to be tested is a fabric, two pieces not less than 14cm X 5cm are required for dry rubbing and two for wet rubbing. One specimen of each pair shall have the long direction parallel to the warp yarns and the other parallel to the weft yarns.

If the textile to be tested is yarn or thread, knit it into fabric to provide specimens at least 14cm X 5cm or from a layer of parallel stands by warping it lengthwise on a cardboard rectangle of similar

dimensions.

Before testing conditioning the specimen and rubbing cloth at least 4 hours.

Figure:

Machine Description:

All the parts of machine is suitable on a base. A standing device is contacted with base. There is an emery paper on the base to support the sample on pinned specimen holder is used on the emery paper to base the sample. At the right side of the standing device. Operating handle is situated at the left side a finger arm is placed a loading unit is situated on the finger arm lower of the finger arm a danger is attracted. There is spring is used to hole the crocking cloth.

Working Principle:

1. At first cut the fabric as required.
2. Set the fabric on the emery paper of crock meter.
3. Then set the crocking cloth in the finger pin with clip.
4. Rotate the handle of crock meter in ten times for rubbing the sample.
5. Remove the crocking cloth from peg.
6. In this way, we have done the rubbing for dry and wet condition of fabric

Dry Rubbing:

Place the conditioned rubbing cloth, flat over the end of the finger with weave parallel to the direction of rubbing finger. At a rate of one cycle per second, rub to and fro in a straight line 20times, 10times to and 10times fro along a track (104 +/- 3) mm long on the dry specimen with downward force of (9 +/- 0.2) N. Remove test specimen and again conditioning as described before.

Wet Rubbing:

Establish  a technique for preparing rubbing cloth by weighting a conditioned piece of cloth, then thoroughly soak in distilled water and re weight to ensure take up 95% to 100%. Then follow the instruction of dry rubbing.

Drying:

Air dry the test cloth.

Evaluation:

1. Back each tested rubbing cloth with three layers of white rubbing cloth when evaluating.
2. Assess the staining of the cotton rubbing cloth with the grey scale for staining under suitable illumination.

Fastness Property Evaluation:

• Grey scale for color change.
• Grey scale for staining

Fastness Grades:

1-5 for all except light fastness

Grade-1: Poor

Grade-5: Excellent

Interpretation of Grade:

1	Very Poor
2	Poor
3	Fair
4	Good
5	Excellent

Range of Limit: 1-5 Grade.

Accuracy(+/-): 0.5

Conclusion:

In this experiment, we get knowledge about color fastness to rubbing and crock meter. We learn about how crock meter works, how determine color fastness. This experiment surely help us to measuring the color fastness of fabric.