Color fastness is an important factor for fabric manufacturers and exporters, here slightly describe about color fastness to rubbing.

1. Study on color fastness to rubbing by
Crockmeter.
Presented by :Presented by :
Hasibul Haque ChowdhuryHasibul Haque Chowdhury
B.Sc. in Textile EngineeringB.Sc. in Textile Engineering
DUETDUET

2. IntroductionIntroduction
Rubbing means friction. Fastness towards friction. It is
measured by an instrument called Crock Meter. The fabric
we use everyday is always gone through rubbing action by
different ways hence the color of the fabric is faded down.

3. Details on Crock Meter
Crocking is a transfer of colorant from the surface of a
colored yarn or fabric to another surface, or to an adjacent
area of the same fabric, principally by rubbing. Crock meter
which is worked by creating an artificial friction. To
measure the rubbing fastness of the fabric, crock meter is
used.
This is done both in dry & wet condition and the corking
cloth is used with the sample in crock meter. The sample is
gone through rubbing action in the crock meter and after
rubbing color change and color staining is assessed with
the help of grey scale.

4. Standard Test Method
METHOD ISO 105X12/
AATCC8
ISO105X16/
AATCC 116
AATCC 165
APPARATUS CROCK METER ROTORY
VERTICAL
CROCK METER
CROCK METER
DIMENSION OF
RUBBING
FINGER
(19x25.4)mm
Block for pile
fabrics
2.5 cm (19x25.4)
Mm block
DOWN WARD
FORCE
(9±0.2) N 11.1N±10% (9±0.2)N
WEFT PICK UP IN
WET RUBBING
95–100%in ISO
/65%+5%in
AATCC
95–100% in I SO
/65%in AATCC
95–100%in
ISO/65%in
AATCC
NO OF
CYCLE/TURN
10 TIMES IN
SECS
ABOUT 40
RECIPROCAL
TURNS
10 TIMES IN 10
SECS

5. Apparatus and Material Used in
ISO 105/AATCC 8
Crock Meter
Cotton Rubbing Fabric
Grey Scale
Stop Watch
Weight (9N)
Color Matching Cabinet

6. Conditioning
1. At first cut the specimen in ( 5*5) cm.
2. The sample has to be tested in the delivered condition.
3. The fabric/sample has to be air conditioned at least 8
hours by standard climate (20°C / 65% relative humidity).
4. The air conditioned specimen has to be rubbed with the
dry and wet cotton rubbing cloth in warp, weft or diagonal
direction on face side. The test direction has to be noted in
the test report.
Use always cotton test material from James Heal
(Cotton Rubbing cloth ISO 105 F09)
For a correct test result the rubbing point on cotton
must show an even staining with an exact circle

7. Sample Preparation
 The size of the plate of the crock meter is 22cm x 8cm;
hence the sample size is 22cm x 8cm.
 Two samples are taken-one for dry state; one for wet
state, rubbing action is done on the both side of the
sample.
 The color change is assessed in the sample with grey
scale & the color staining is assessed in the crocking
cloth with the help of grey scale.
 The same procedure is followed for the wet condition&
the rating for color change& color. staining is assessed.

8. Dry Sample Test
 Use the holding clamp to mount the specimen on the based
board of the crock meter . The long direction of the specimen
is parallel to the track of rubbing .Ensure the specimen lays
flats on the based board.
 Two test are performed .One along the direction of
warp/length and the other of the weft/width.
 Mount a dry rubbing cloth flat over the end of the peg on the
crock meter and hold it taut by means of the spring clip
provided.
 Rest the finger on the specimen, ensuring that the spring clip
is not in contact with the test specimen.
 Rub the specimen back and forth over a straight track
100mm+/- 8mm long for 10 complete cycle at a rate of 1
second for each cycle.
 It may be necessary to stretch some fabric on to the based of
the crock meter ,to prevent the fabric from rubbing up.

9. Wet Sample Test
 Mount test specimen on Crockmeter base.
 Bring wet pick up of square to 65% ±5%
 Mount crock square on peg
 Lower peg onto specimen
 Turn crank handle 10 times
 Air dry and condition crock square
 Remove loose fiber
 Evaluate

10. Evaluation for result
Dry sample : 4/5 and Wet sample : 3
Here numerical value between 1 to 5

11. Thank You