AATCC 8:2007 pdf download.Colorfastness to Crocking: AATCC Crockmeter Method
1. Purpose and Scope
1.1 This test method is designed to determine the amount of color transferred from the surface of colored textile materials to other surfaces by rubbing. It is applicable to textiles made from all fibers in the form of yarn or fabric whether dyed, printed or otherwise colored. It is not recommended for use for carpets or for prints where the singling out of areas may be too small using this method.
1.2 Test procedures employing white test cloth squares, both dry and wet with water, are given.
1.3 As washing, dzycleaning, shrinkage, ironing, finishing, etc., may affect the degree of color transfer from a material, the test may be made before, after, or before and after any such treatment.
2. Principle
2.1 A colored test specimen is rubbed with white crock test cloth under controlled conditions.
2.2 Color transferred to the white test cloth is assessed by a comparison with the Gray Scale for Staining or the Chromatic Transference Scale and a grade is assigned.
3. Terminology
3.1 colorfastness, n—the resistance of a material to change in any of its color characteristics, to transfer of its colorant(s) to adjacent materials, or both, as a result of the exposure of the material to any environment that might be encountered during the processing, testing, storage or use of the material.
3.2 crocklng, n.—e 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.
6.2.1 A poor circular image with uneven dye pick-up may indicate the crocking finger needs resurfacing (sec 13.6).
6.2.2 A double, elongated image may indicate a loose clip (see 13.6).
6.2.3 A stretched and streaked crock image may be due to mounting the crock square diagonally.
6.2.4 Scuff marks to the sides of the specimen indicate the loops to the wire clips are positioned downwards and are not high enough to prevent rubbing the specimen surface.
6.2.5 A streak in the center of the crock cloth image and in the direction of rubbing may mean the top of the metal base is warped and not flat. This will require a brace inseit to square up the tester base.
6.2.6 If specimen holders are used, place the holder over the specimen on the tester base. Move the crocking finger on the crocking arm to the most forward position and observe whether it hits the inside edge of the holder. If this occurs, move the holder slightly forward for all tests. Without correction, this problem will cause a dark area on one side of the crocking image.
62.7 Confirm the wet pick-up techniques (see 9.2).
6.2.8 Replace the abrasive paper on the tester base if it is smooth to the touch in the crocking area compared to the adjacent area, or if slippage of the specimen is noticed (see 13.7).
6.2.9 In routine testing, observe if multiple streaks are on the crocking image. Position specimen normally with the long dimension oblique to the warp and filling. If the direction of rubbing falls along a twill line or surface pattern, etc., then streaks may occur. If they do occur, slightly adjust the angle for testing.AATCC 8 pdf download.