Removal Of Residual Leukoplakia From Samples By Color Fastness Test

Daily life Spin Products need to be washed and reused after they are taken. Whether the sample is washed or not is an evaluation product. quality Important indicators. The soaping color fastness test is a classical test method for simulating the color fastness of household textiles after soaping. However, according to the test method of GB / T3921-2008 "color fastness test for soaping fastness", it is easy to produce white spots on some samples, which makes it difficult to evaluate the color fastness of samples. In view of this situation, this paper discusses the method of removing white spots by using a certain concentration of acetic acid, and does not affect the evaluation results. It proves that this is a simple and effective way to solve such problems in the laboratory.

　　 1 Experiment

1.1 experiment Material Science

Samples: the samples of 4 kinds of leukoplakia after soaping were selected in the daily test, numbering 1~6.

Soap tablets: meet the requirements of GB/T3921 - 2008.

Grade three water: meet the requirements of GB/T6682-2008.

Acetic acid: analytically pure.

　　 1.2 test equipment

Color fastness tester: can maintain stable washing temperature and washing speed, meet the requirements of GB/T3921 - 2008.

Balance: accuracy is 0.01g.

Constant temperature water bath pot: preheating test solution, the temperature control accuracy is + 2 degrees Celsius.

1.3 soaping test procedures and results

According to the standard of the method, the corresponding concentration of soap solution is set up and preheated to the temperature stipulated in the product standard. The sample and the multi fiber bonding seam are combined to form a combined sample, and the washing soap liquid with a prescribed bath ratio is injected into the container, and the sample is placed in the machine and washed. After washing, remove the combined sample, wash it in three level water for 2 times, then rinse with flowing water.

　　 1.4 acid washing test steps and results

A certain concentration of acetic acid solution was allocated. Each sample was soaked for about 1 minutes in a solution of about 100mL. Then the sample was removed and washed at 30 C three level water and hung dry. Figures 1 to 6 are the original sample and the effect after treatment.

　　 2 Analysis

As the main ingredient in soap tablets is sodium fatty acid, it is easy to agglomerate. During the washing process, the detergent hydrophilic group and the hydrophobic substances in the fabric are firmly combined, and are not easily washed away by water. Therefore, a large amount of fatty acid sodium salt is gathered together to form the white spot. As a detergents, soap tablets are more suitable for the actual household washing. However, the white spots washed by soap flakes do bring difficulties to ratings. If the white spot samples and acid washed samples are rated separately, the results will be very different. Table 1 shows the grading results of the sample after soaping and the sample after pickling.

　 3 conclusion

After washing the fabric color fastness test, some samples may appear leukoplakia. The white spot is the result of the aggregation of fatty acid sodium, which is the effective ingredient of detergent. This residual white spot has changed the overall color of the sample. It has greatly affected the evaluation of the color change of the sample. In the actual detection operation, a certain concentration of acetic acid solution can be used to soak the sample. Fatty acids and acetic acid react to form water-soluble substances. The white spot can be removed. After the test, the real "face" under the cover of the white spot can be displayed, thus solving the difficulties of evaluating the color change of the sample, and also without affecting the real test results of the sample.