AATCC Testing Method

Fibers in Textiles Identification, AATCC Test Method 20-1973, Technical Manual 50 50, American Association of Textile Chemists and Colorists, Research Triangle Park, N.C., 1974. 

Researchers had noted the release of formaldehyde by chemically treated fabric under prolonged hot, humid conditions (85,86). The American Association of Textile Chemists and Colorists (AATCC) Test Method 112 (87), or the sealed-jar test, developed in the United States and used extensively for 25 years, measures the formaldehyde release as a vapor from fabric stored over water in a sealed jar for 20 hours at 49°C. The method can also be carried out for 4 hours at 65°C. Results from this test have been used to eliminate less stable finishes. 

Prior to 1965, it was not unusual for unwashed finished fabrics to release 3—5000 ppm of formaldehyde when tested by an AATCC test method. Formaldehyde release was reduced to the level of 2000 or less by appHcation of DMDHEU or dimethyl olcarhama tes. This level was reduced to approximately 1000 in the mid-1970s. Modification of the DMDHEU system and use of additives demonstrated that release values below 100 ppm were achievable. As of this writing (1997), good commercial finishing ranges between 100 and 200 ppm of formaldehyde release. 

Another test method appHcable to textiles is ASTM E313, Indexes of Whiteness and Yellowness of Near-White, Opaque Materials. The method is based on obtaining G, ie, green reflectance, and B, ie, blue reflectance, from X, Y, and Z tristimulus values. Whiteness and yellowness index are then calculated from the G and B values. This method has particular appHcability to measurement of whiteness of bleached textiles. AATCC test method 110 also addresses measurement of the whiteness of textiles. 

Fastness to Crocking. Crocking is defined as the transfer of color from the surface of a dyed fabric to another surface by mbbing. AATCC test method no. 8 is a method by which a colored test fabric swatch is fastened to the base of a Crockmeter and mbbed against a white crock test cloth under controlled conditions. Color transfer to the white cloth is evaluated by comparison with the AATCC Chromatic Transference Scale. A similar method, AATCC 116, uses a Rotary Vertical Crockmeter, which requires a smaller area of test fabric than the Crockmeter. 

AATCC Test Method no. 66 describes measurement of recovery angle after placing a crease in a specimen. The specimen is creased by subjecting is to a prescribed load for a length of time. The recovery angle is then measured after a controlled recovery period. Recovery angles of greater than 120° are... 

A second wtinMe-recovery test, AATCC test method no. 128, describes the determination of the appearance of textile fabrics after intentional wrinkling followed by evaluation of appearance in comparison to standard repHcas. A visual rating from 1 (wrinkled) to 5 (smooth) is assigned. This method may be used for both woven and knitted fabrics, whereas the recovery angle method is appHcable only to woven fabrics. 

Water-repeUent fabrics resist wetting or repel waterborne stains they pass AATCC Test Method 22 (Spray Test). 

Water-resistant fabrics protect against water penetration during a light or brief shower and pass AATCC Test Methods 22 and 42 (Impact Penetration Test). 

OU-repeUent fabrics resist wetting by oUy Hquids and repel oilhorne stains. The level of performance of such fabrics is judged by AATCC Test Method 118. 

The rain test simulates the effects of rainfaU the hydrostatic head on the spray controls the intensity of spraying. The repeUency is rated by the weight of water that penetrates the fabric and is absorbed by a blotter mounted behind the fabric at a specific intensity of spraying (AATCC Test Methods 35 and 42 INDA Standard Test 80.2-92). 

OU repeUency is measured by observing a fabric s resistance to wetting by a selected series of numbered test Uquid hydrocarbons with a range of surface tensions. The fabric rating is based on the Uquid that does not wet the fabric surface in a specified time (AATCC Test Method 118 and INDA... 

The hydrostatic-pressure test is performed on fabric mounted under the orifice of a conical weU. The fabric is subjected to increasing water pressure at a constant rate until leakage occurs at three poiats on the fabric s undersurface. The rating is the height of the water head ia centimeters above the fabric (AATCC Test Method 127 INDA Standard Test 80.4-92). 

The dynamic absorption test measures the resistance of fabrics to wetting by water, not the repeUency of the total fabric surface. A weighed portion of fiber, yam, or fabric is tumbled ia water for 20 minutes it is then removed and reweighed to determine the percentage of water absorbed (AATCC Test Method 70). 

In the Spray Test (AATCC Test Method 22), water is sprayed on a taut surface and rating is based on comparison with a standard chart (14). 

In OU RepeUency (AATCC Test Method 118), drops of oUs of various surface tensions are placed on the leather and monitored to absorption (14). 

Tests Simulating Use Conditions. Several simulation tests involving wear and use testing have been developed. The first and only one to be adopted as a standard in the United States is AATCC Test Method 134-1975 for measuring the electrostatic propensity of carpets (60). In this test a person wearing standard neoprene and leather sole shoes and carrying a probe connected to an electrometer walks on a carpet for 30 to 60 s until the measured body voltage builds up to a maximum. 

An important QC analysis in the fibre and textile industry is the surface finish determination by Soxhlet extraction (AATCC Test Method 94-1992). Solvent extraction is used on textile materials to determine naturally occurring oily and waxy materials that have not been completely removed from the fibres (ASTM Method D 2257-96). Meanwhile, environmental, safety... 

The standard astm test method (D-1149-64) for rubber damage includes a test chamber (volume, 0.11-0.14 m ) through which ozonized air flows at a rate greater than 0.6 m/s. Because the residence time of the ozonized air in the test chamber is about 1 s, the ozone may be expected to reach the material in about 0.1 s. A somewhat similar test procedure (aatcc test method 109-1972 ansi L14, 174-1973) is used in testing colorfastness. The ozone generator is usually (but not necessarily) a mercury-vapor resonance lamp with emission lines at 184.9 and 253.7 nm. The 184.9-nm line is absorbed, and two ground-state oxygen atoms are produced ... 

American National Standards Institute (ANSI) Test Method for Colorfastness to Ozone in the Atmosphere under Low Humidities. L14, 174-1973. (same as AATCC Test Method 109-1972)... 

Light Exposures. Silk fabric samples, 0.25 m x 0.17 m, were mounted in Atlas Electric Devices aluminum sample holders according to AATCC Test Method 16E-1982 (7). An Atlas Ci-35 Weather-Ometer xenon-arc was used on continuous light cycle. Exposures were conducted at an irradiance of 0.35 W/m2 measured at 340 nm and the irradiance was monitored and controlled automatically. Borosilicate inner and outer filters were used to simulate the solar spectrum. The relative humidity was maintained at 65% and the black panel temperature was 50°C. The actual fabric temperature during the irradiation was measured, using small thermocouples threaded into the fabric, and was found to be 35 C. Control samples for these tests were kept in the dark at 35°C and 65% RH for the same time period as the illuminated samples. 

To further determine the effect of reusing the re-duction/clearing bath on the dyed yarn properties, lightfastness and crockfastness tests were performed on standard-dyed fabrics, dyebath reuse-dyed fabrics, and dyebath reuse plus reduction bath reuse-dyed fabrics. Lightfastness was performed according to AATCC Test Method 16A-1974, which called for forty hours of exposure to a carbon arc. Crockfastness was performed according to AATCC Test Method 8-1972. All fabrics exhibited the same fastness properties, indicating that the semiquantitative replenishment of the caustic/hydrosulfite bath did not affect the yarn quality. 

There are other minor nonequivalencies of ISO test procedures compared to ASTM standards, but for color difference the ISO Test Procedure No. 105 is unique. Those who use Colour Measurement Committee (CMC) procedures—particularly CMC 2 1 Lightness to Color ratio—claim that it facilitates a uniform description for acceptability decisions that is better than any other system in existence. These equations permit the use of a single number tolerance, DEcmc, in a nearly uniform color space. The CMC formula is a modification to the perceptibility CIELAB formula. It is fully described elsewhere in this book, but it deserves some brief notice here because, after all, it is an ISO procedure. The CMC developed the basic British Standard No. 6923, Calculation of Small Color Differences. Soon afterward, in 1989, the American Association of Textile Chemists and Colorists (AATCC) adopted AATCC Test Method 173, CMC Calculation of Small Color Differences for Acceptability. Ford Motor Company indicated a preference for using CMC 2 1 ratio color difference for plastics weathering data for plastics interior trim materials. 

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