Analysis Of Causes Of Yellowing Of The White Cotton Products And Solutions

White knitted garment enterprises in order to meet the export products need bleaching agents (especially fluorescent whitening agent) and done a lot of testing on the bleaching improves whiteness bleaching products, meet the requirements of foreign investors. However, in recent years, especially white yellowing phenomenon attracted the attention of foreign investors, some manufacturers products in the production of whiteness it is good, however in the storage, transportation and sales has changed significantly in the process of yellowing, this paper analyzes the problem.

1 textile fluorescent whitening agent on photo degradation

Especially white products are generally treated with fluorescent whitening agent, some manufacturers in order to improve the whiteness, on the selection of fluorescent whitening agents for a number of tests, but often only with a view to increasing brightness, and ignore the whitening agent-related fastness testing. It is understood currently Japan on the market to sell some brands t-shirt garments apart packed, in the long light of fluorescent brightener will be photo degradation and yellowing phenomenon of white products, in this case, light resistance, heat resistance properties of fluorescent whitening agent is very important.

Fluorescent whitening agent in the presence of ultraviolet light, its molecules are gradually destroyed, so white fabric effect gradually decreases as the exposure time increases. Various different light fastness of fluorescent whitening agent, light fastness depends primarily on the fluorescent brightening agent molecular structure and the nature of the substituents and location, improving light fastness is the development of fluorescent whitening agents. Improve the purity of fluorescent whitening agents can also to some extent prevent yellowing, which is a developing direction of optical brighteners. Reduce yellowing of white products, pay attention to choose good light fastness, high purity of fluorescent whitening agents.