Color Fastness to Rubbing Test Method

Last Updated on 12/01/2022

Rubbing Fastness Test:
A fastness is a place, such as a castle, which is considered safe because it is difficult to reach or easy to defend against attack. Color fastness to rubbing test is designed to determine the degree of color which may be transferred from the surface of a colored fabric to a specify test cloth for rubbing (which could be dry and Wet).

Rubbing or crocking fastness is the transfer of dyed textile material’s color from its surface to an adjacent area by the same fabric or other surface (normally bleached cotton fabric) principally by rubbing. It is tested using a crockmeter. It may be either hand-driven or motorized. Depending on the kind of fiber, especially its tensile strength, small abraded colored fiber particles cause the staining effect on the partner textile. Coarse fiber particles are not taken into consideration by the determination of the crocking fastness rating. If the dyestuff involved is water soluble and not sufficiently fixed on the fiber, this can also be the reason for staining. But even dyeings with the best wet properties, for example vat dyeing, have limited/restricted wet crocking fastness because of cellulose fiber abrasion.

Color Fastness to Rubbing Test Method

Purpose and Scope:
This test determines the fastness of a dyestuff to either wet or dry rubbing.

Apparatus and Materials:

Crockmeter or comparable alternate apparatus.
Test Cloth, cut in 50 mm squares.
Chromatic Transference Scale.
Gray Scale for Staining.
White Textile Blotting Paper.
Specimen Holder for Crockmeter.
In-house poor crocking cloth.
Crockmeter Verification Cloth.

Sample Preparation:

Two specimens are used, one each for the dry and the wet tests.
Additional specimens may be used to increase the precision of the average.
Cut specimens at least 50 x 130 mm (2.0 x 5.1 in.) and position for testing preferably with the long dimension oblique to warp and filling or wales and courses.
Larger or full width lab samples may be used without cutting individual specimens, when multiple tests are needed and when using for production testing.
Knit a piece of fabric at least 50 x 130 mm, or wind yarn tightly on a suitable form at least 50 x 130 mm with the yarn running in the long direction; or otherwise stretched.

Color Fastness to Rubbing Procedure:
The procedures for the determination of fastness to rubbing are specified in BS EN ISO 105‐X12:2016. The tests involve rubbing the sample under test with a dry rubbing cloth and a wet rubbing cloth. For this test an instrument called a crockmeter is usually used, which rubs a finger, covered with cotton rubbing cloth, 10 times to and 10 times fro over the sample under test at a fixed pressure. Two fingers of different dimensions are used – for pile fabrics, a rectangular‐shaped finger (19 × 25.4 mm) and a cylindrical‐shaped finger 16 mm in diameter for other fabrics. The rubbing tests are carried out with dry and with wet cotton rubbing cloths. The degree of staining of the two cotton rubbing cloths is assessed using the grey scale for staining.

There are two test methods for rubbing fastness:

ISO-105-X12
AATCC-08

In ISO-105-X12 the wet pickup of the rubbing cloth is 100%. While in AATCC-08 the wet Pickup of the rubbing cloth is 65%. We check rubbing by Dry and Wet methods. In wet rubbing we wet the rubbing cloth according to test method and give rating by comparing the Staining with the gray scale.

Similarly for dry rubbing we check the rubbing with dry rubbing cloth and compare the staining with gray scale for ratings. Color fastness to rubbing is a main test which is always required for every colored fabric either it is Printed or dyed.

If the color fastness to rubbing is good then its other properties like Washing fastness and durability etc improves automatically because the rubbing is a method to check the fixation of the color on the fabric. So if the fixation is good its washing properties will be good.

Rubbing Fastness depends on:

Nature of the Color
Depth of the Shade

Construction of the Fabric Nature of the color Each color either it is pigment, Reactive, Disperse or direct has its own fastness properties to rubbing. There are some colors like black, Red, Burgundy, Navy blue which have poor Color fastness properties because of their chemical structure.

Like Black color is a carbon base color and the particle size of carbon is large than the other colors that’s why its rubbing properties are poor. Similarly red and blue are in the same case. So to improve the color fastness we add more binder to improve the fastness properties of these colors. It doesn’t mean that we can not achieve the best results with these colors. The required results can achieve but production cost will be increase. On the other hand the construction of the fabric also effects the fastness properties.

If the rubbing fastness on 100.80/40.40 is 3 on the gray scale it will be 2-3 on 52.52/22.22 with the same printing parameters. So always keep in mind these effects during finalize the required parameters with your customer.

Always Check:

Quality construction
Color
Depth of the Color
End Use of the product

Results which we can achieve in normal conditions are:

	Dark Shade	Medium shades	Light Shades
Dry	3-4	4	4-5
Wet	2-2.5	3	3.5-4

Rubbing Fastness Rating:
Fastness ratings, according to the grey scales for staining, range from 1 (poor rating) to 5 (best rating). Parameters of influence include:

Kind and concentration of dyestuff
Dyeing or printing procedure, degree of fixation, ring dyeing
After treatment with softeners, silicones, crosslinking agents
Type of fiber (tensile strength, wet abrasion)
Type of textile in contact: shade, surface, kind of fiber and fabric
Intensity of the contact: pressure, time, moisture and temperature.

The influence of the moisture is taken into account in the test methods (dry or wet crocking tests). Wet cellulosic fibers may be partly destroyed by rubbing, leading to additional staining. The rubbing force for the wet testing procedure is about double the rubbing force for dry rubbing. Therefore the wet rubbing ratings of the same sample are always poorer than the dry ones (up to two ratings difference).

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Mazharul Islam Kiron

Founder & Editor of Textile Learner. He is a Textile Consultant, Blogger & Entrepreneur. He is working as a textile consultant in several local and international companies. He is also a contributor of Wikipedia.