Rubbing - Aatcc

8/13/2019 Rubbing - Aatcc

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Color Fastness To Rubbing AATCC 8


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Scope & Applications:

This test method is determination of the amount

of color transferred from the surface of coloredtextile materials to other surface by rubbing.It is applicable to textile made from all fibers in

the form of yarn or fabric whether dyed, printedor otherwise colored.


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Apparatus & Materials: AATCC Crockmeter.Cotton Rubbing Cloth.

Crock meter test cloth should meet the followingspecifications: Fiber 100% combed cotton, desized, bleached withno optical brightener or finishing

Yarn - 15 tex Thread Count - 32 + 3 ends/cm

- 33 + 3 Picks/cm Weave 1/1 PlainPH 7 + 0.5

AATCC Chromatic Transference Scale or GreyScale.

Color Matching Cabinet.


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Preparation Of Test Specimens:Fabric:

Two specimens are used, one each for the dry & the wettests. Cut specimen at least 50X130 mm (2.0X5.1 in) andposition for testing suitable with the long dimensions

to warp & weft or Wales & courses.

Yarns:

Knit or piece of fabric at least 50X130 mm, or wind yarntightly on a suitable form at least 50X130 mm with yarnrunning in the long direction: or otherwise stretched.


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Conditioning:Condition each specimen for at least 4hrs inan atmosphere

Temperature - 21+ 1 0C (70 + 20F) &RH - 65+ 2%

by laying each test specimen or crock squareseparately on a screen or suitable shelf orconditioning rack.


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Dry Crocking:

Place a test specimen on the base of the crock meter with itslong dimensions oblique to warp & weft or wale & course in thedirection of rubbing.Place the specimen holder to prevent slippage.Mount a conditioned white test cloth, the weave parallel with thedirection of rubbing, over the finger and hold by the spiral wireclip with loops upwards.Lower the covered finger onto the test specimen. Beginning withthe finger positioned at the front end, crank the meter handle 10

complete turns at the rate of one turn per second.Remove the white test cloth square, condition & evaluate. The crock square requires 4 hrs conditioning in standardatmosphere before color rating.


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Wet Crocking:

Establish technique for preparing wet crocking clothsquares by weighing a conditioned square, thenthoroughly wet out white testing square in distilled water. Apply water evenly over crocking square and weigh the

wet square.Calculate the wet pickup. When 65+ 5% wet pick up isachieved.Continue in the same way as for dry Crocking.

Remove & Air dry the white test squire, then condition beforeevaluating. The crock square requires 4 hrs conditioning in standardatmosphere before color rating.


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How to get a Wet Pick-Up?

Weigh dry crock square.Using a syringe tube or pipette draw up water in mL to0.65 times, weigh of crocking square.If crocking square weight equals 0.24gm the mL used

would be 0.24x0.65 = 0.16 mlLay crocking square on white plastic dish.

Apply water evenly over crocking square on weight the wet square


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How We Remove The Loose Fiber On The

Crock Cycle Before Color Staining Evaluation?

In the case of napped, brushed or sanded material

when loose fiber might interfere with the rating,remove the extraneous fibrous material by pressinglightly on the crock cycle with the sticky side of

cellophane tape before evaluating.


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What Are The Reasons In Poor Crocking Images?

A poor circular image with uneven dye pick-up may indicate thecrocking finger needs resurfacing.

A double elongated image may indicate a loose clip. A stretched and streaked crock image may be mounting thecrock square diagonally.Scuff marks to the sides of the specimen indicate the loops to

the wire clips are positioned downwards and are not high enoughto prevent rubbing the specimen surface.Replace the abrasive paper on the tester base if it is smooth tothe touch in the crocking area compared to the adjacent area orif slippage of the specimen is noticed.If specimen holders are used, place the holder over the specimenon the tester base. Move the crocking finger on the crocking armto the most forward position and observe whether it hits theinside edge of the holder. If this occurs move the holder slightly

forward for all tests without correction, this problem will cause adark area on one side of the crocking image.


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Test Report:

Test report should contain the following information: State whether dry or wet crocking test.

The numerical rating for staining for each test

specimen.State whether gray scale for staining or chromatictransferences scale was used for evaluating staining.If any pre treatment or after treatment was givento any specimens indicate method of treatment.


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The End.

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Rubbing - Aatcc