AATCC 79:2000 pdf download.Absorbency of Bleached Textiles
1.1 Absorbency is one of several fac- tors that determines the suitability of a fabric for a particular use, as in the case of gauze or toweling. It is important in fabrics that are to be dyed, since the com- pleteness and uniformity of the dyeing are dependent upon the absorbency. Where fabrics are to be given resin or other specialized finishes, absorbency is a factor to be considered. Wettability or absorbency of textile fabrics or yarns can be determined by this test method.
2. Principle
2.1 A drop of water is allowed to fall from a fixed height onto the taut surface of a test specimen. The time required for the specular reflection of the water drop to disappear is measured and recorded as wetting time.
3. Terminology
3.1 absorbency, n.—the propensity of a material to take in and retain a liquid, usually water, in the pores and interstices of the material.
4. Safety Precautions
NOTE: These safety precautions are for information purposes only. The pre- cautions are ancillary to the testing proce- dures and are not intended to be all inclu- sive. It is the user’s responsibility to use safe and proper techniques in handling materials in this test method. Manufac- turers MUST be consulted for specific details such as material safety data sheets and other manufacturer’s recommenda- tions. All OSHA standards and rules must also be consulted and followed.
4.1 Good laboratory practices should be followed. Wear safety glasses in all laboratory areas.
7.4 Using a stopwatch, measure the time required, up to 60 s maximum, for the surface of the liquid to lose its specular re- flectance. This point is determined by hav- ing the hoop between the observer and a source of light—such as a window or lab- oratory spotlight—at such an angle that the specular reflectance of light from the surface of the flattened drop can be plainly seen. As the drop is gradually absorbed, the area of this tiny mirror diminishes and finally vanishes entirely, leaving only a dull wet spot. At this instant the watch is stopped and the elapsed time is recorded. When the wetting time exceeds 60 s, 60+ s should be recorded.AATCC 79 pdf download.