Color Fastness Due to Rubbing

Introduction

Rubbing fastness is the ability to sustain the original color of the dyed fabric when rubbing. Dry rubbing color fastness is the condition when fading and staining of dyed fabric occurred after rubbing with a standard white cloth. In wet rubbing color fastness, the standard white cloth contains water 95% to 105%. Here it is measured by the degree of staining of white cloth. After the test, the white cloth is compared with the standard sample for measuring staining fastness.

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Objectives

To know about color fastness due to rub.
To know about the importance of the colorfastness test for textile materials.
To know about the function of the crock meter.
To know about the greyscale.

Apparatus

Crock meter
Crocking cloth
Scissor
Greyscale
Stopwatch etc.

Working Principle

Dry rubbing color fastness refers to the situation of fading and staining of dyed fabric when rubbed with a standard white cloth. Wet rubbing color fastness refers to the situation of fading and staining of dyed fabric in which water content is 95% to 105%. The evaluation of rubbing color fastness depends on the degree of staining of the white cloth. It divides the degree into 5 grades and 10 tiles on a greyscale.

Machine Description

Crock Meter

©Textile Pad

The crock meter consists of a metallic base. On one side of the base, an emery surface and pinned specimen holder is placed, on another side of the base a connecting rod is placed and a rod holding the operating handle finger and a spring clip are used over the cloth. The crocking cloth is scoured and bleached white cotton fabric.

Working Procedure

Dry Crocking Test

First, collect and cut the sample to the dimension of (13cm✕5cm).
Then lock the test specimen into the base of the crock meter which is placed on an emery surface and pinned with the specimen holder.
Then the crocking cloth (5✕5) cm is attached with the finger by a spring clip.
Then give ten cycles, the rate in 1 cycle per second.
Then remove the sample and crocking cloth and check with greyscale.

Wet Crocking Test

At first, wetted the crocking cloth with distilled water.
Then it is squeezed to remove excess water.
Then carry out the whole process as a dry test.

Assessment

Greyscale no 1: Change in shade

Greyscale no 2: Staining.

Evaluation

In this stage compare the contrast between the treated and untreated white rubbing cloth and sample with greyscale and rate 1 to 5.

Results

The degree of colorfastness:

Greyscale of staining scale: Dry condition= 5, Wet condition= 5.

Greyscale of changing scale: Dry condition= 4-5, Wet condition= 3-5.

Remarks

From this experiment, we knew about the testing of colorfastness due to rubbing. It indicates some properties of wash fastness too. The fastness property of fabric should be checked must before large production.