Search

Cleaning performance is the most important index to evaluate the detergency performance of washing machines and detergents. With the continuous development of the washing industry, the corresponding evaluation methods are also evolving. The stained cloth is adopted as the test object for the detergency performance of washing machines and detergents. At present, China’s washing industry mainly adopts three kinds of standard stained cloths (carbon black, sebum and protein) specified in GB/ T 4288 - 2018 for the testing of detergency performance. In the corresponding international standard EN 60456, the combined stained cloth is used to test the detergency performance. Swissatest Testmaterialien AG and wfk, Testgewebe GmbH have developed dozens of stained cloths, including starch stained cloth, lipstick stained cloth, and cosmetic stained cloth. However, the stain components of these stained cloths greatly differ from the real life. Firstly, in order to ensure the stability and fouling absorption effect of stained cloth, it is a common practice to add a certain amount of stabilizers and adhesives. Secondly, the standard stained cloth is made by immersing the whole base cloth in the stained solution with a large amount of stains, leading to the maximization of washing time, detergent dosage and other indicators in optimizing the washing performance. However, as the stain amount is relatively small in domestic life, the testing and optimization of washing performance with standard stained cloth would easily lead to excessive washing of clothes, damage to clothes, and waste of energy. In order to address the above problems, this paper intends to develop a new type of stained cloth in domestic life. 15 common household stains are selected, including soy sauce, red wine, coffee, grass stains, blood stains, carbon black, ketchup, cocoa milk, mud stains, peanut butter, peanut oil, chili oil, mechanical lubricant, lard, and lipstick. Taking knitted 100% cotton cloth and knitted 100% polyester cloth as the base cloth, the stained cloth is made using spot dyeing method, scraping method, and filling method. The quality of the stained cloth is tested through the evaluation experiment of the detergency performance by the washing machine. First, the standard deviation of the pre-washing Y value for 25 stained cloths of the same stain is tested. Secondly, the stained cloths are washed under the procedures of 7A, 5A and 2A specified in GB/ T 8629 - 2017, respectively to investigate whether the difference in cleaning rate under different washing conditions is significant. Thirdly, the stained cloths are washed three times under the same washing procedure, and the standard deviation and relative standard deviation of the cleaning rate of the 15 fabrics are investigated. Finally, the stained cloths are washed after being stored for one month to investigate the difference in the cleaning rate with the non,storage stained cloths. The stained cloth is made by locally staining, which is closer to the way and the amount of stains for the base cloth in real life. In terms of stain components, no additional ingredients are added, aiming to be close to real life. In terms of types of stains, 15 practical stains that are common in life are selected, covering most of the common types of stains in life. The results show that the best aging conditions for the prepared stained cloth through this method are: at the temperature of 60, and time of 2 hours. The pre-washing reflectance difference of the stained cloth is small, meeting the requirements of dyeing uniformity. The difference in the cleaning rate of the stained cloth under the washing procedures with different strengths is significant, meeting the requirements of washing sensitivity. The cleaning rate of stained cloth under the same washing procedure is stable, meeting the requirements of washing stability. The cleaning rate of stained cloth changes slightly after being stored for 30 days under low temperature and sealing conditions, exhibiting good storage stability. The actual household,use stained cloth prepared in this paper supplements the existing standard cloth and enriches the existing kinds of stained cloth used in the washing evaluation experiments. The research results can provide experimental samples and theoretical basis for household electrical appliance enterprises to design washing machine parameter and develop new products. [ABSTRACT FROM AUTHOR]