AATCC 27:2004 pdf download.Wetting Agents: Evaluation of Rewetting Agents
3. Terminology 3.1 rewetting agent, n.- in textile preparation, dyeing and finishing, a sur- factant which, after application and dry- ing onto textiles, promotes rapid wetting on subsequent exposure to an aqueous solution.
3.2 wetting agent, n.- a chemical compound which when added to water lowers both the surface tension of the liq- uid and its interfacial tension against the solid 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.
4.2 Observe padder safety. Normal safeguards on pad should not be moved. Ensure adequate guard at the nip point. A foot-operated kickoff is recommended.
7. Evaluation
7.1 Readings of rewetting time are made so easily and quickly that ten are taken for each concentration. The aver- age times of disappearance of a drop for 2.50, 5.0, 10.0 and 20.0 g of rewetting agent per liter of pad liquor are then plot- ted on log-log coordinate paper with con- centration as the abscissa (X-axis). A straight line is drawn to approximate the four points as nearly as possible.
7.2 From this line relating disappear- ance time to concentration, one can find the concentration which would give a dis- appearance time of 10 s. This is called the rewetting concentration for the product. A corresponding value is then determined for the second rewetting agent. By using a simple proportion with these figures it can be calculated how many parts of the second product are equivalent to 100 parts of the first product (or Standard) for rewetting.
8. Precision and Bias
8.1 Precision. Precision for this test method has not been established. Until a precision statement is generated for this test method, use standard statistical tech- niques in making any comparisons of test results for either within-laboratory or between-laboratory averages.
8.2 Bias. Rewetting agents can be de- fined only in terms of a test method. There is no independent method for de- termining the true value. As a means of estimating this property, the method has no known bias.AATCC 27 pdf download.