AATCC 165-1999 Colorfastness to Crocking: Textile Floor Coverings— AATCC Crockmeter Method.
7. Verification
7.1 Verification checks on the opera- tion of the test and the apparatus should be made routinely and the results kept in a log. The following observations and corrective actions are extremely impor- tant to avoid incorrect test results where abnormal crock images can result and in- fluence the rating process.
7.2 Use an in-house poor crocking car- pet or rug as a calibration specimen and conduct three dry crock tests.
7.2.1 A double, elongated image may indicate a loose sleeve.
7.2.2 A stretched and streaked crock image may be due to mounting the crock test cloth diagonally.
7.2.3 Arc shaped indentions in the crocked area of the test cloth may indicate the crock block is mounted improperly, most likely perpendicular to the specified placement (see 13.2). 7.3 Replace the abrasive paper on the tester base if it is smooth to the touch in the crocking area compared to the adja- cent area, or if slippage of the specimen is noticed.
8. Conditioning
8.1 Prior to testing, condition the test specimens and the crock test cloth for dry crock testing as directed in ASTM D 1776, Standard Practice for Condition- ing and Testing Textiles. Condition each specimen for at least 4 h in an atmosphere of 21 ± 1°C and 65 ± 2% RH by laying each test specimen or crock test cloth separately on a screen or perforated shelf of conditioning rack.
9. Procedures
9.1 Dry Crocking Test. 9.1.1 Place a test specimen on the base of the crockmeter so that it rests flat on the abrasive cloth with its long dimension in the direction of rubbing (see 13.5). The pile lay should point to the back of the crockmeter if direction of pile is distinguishable.AATCC 165 pdf download.