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Reasons Why Plastics Do Not Add Fluorescent Brighteners

Nov. 24, 2019

Before the advent of fluorescent brighteners, magnesium oxide and barium sulfate, which were close to a completely diffuse reflector, were considered ideal whites. However, after the fluorescent whitening agent is used in some materials, the effect far exceeds the whiteness of the full diffuse reflector, so the fluorescent whitening agent is recognized by more and more users. In recent years, the plastics industry has made rapid progress, and white plastic products have also become large households using plastic brighteners. Plastic products fulfill our daily needs. Hard plastics, soft plastics, white plastics, and colored plastics abound. As the saying goes, if you sell a piece of leather, if the appearance of the plastic product is not white enough and the color is not bright enough, it will greatly affect its sales. Fluorescent brighteners for plastics are used as an optical brightener in plastic Plays a vital role in production and development. There are two main aspects of plastic coloring. First, plastic products made by mixing and dispersing dyes or masterbatches with plastic materials; and second, using coating, printing, and dyeing techniques to impart the desired color to the surface of plastic products. For white plastic products, ordinary colored Baidu does not meet the requirements and is not bright enough, and it is prone to yellowing after standing for a period of time. At this time, the fluorescent whitening agent for plastics has played its unique role.

After adding plastic fluorescent whitening agent to plastic products, the appearance is added a lot, making it look white and bright, which directly promotes the sales of white plastic products. However, some manufacturers report that the effect is not obvious after adding a whitening agent, and even yellowing may occur. What is the reason? Optical Brightener Manufacturer combined the following points with books and experiments.

1. Dosage of fluorescent whitening agent

The amount of plastic fluorescent whitening agent is the most intuitive factor that affects the effect of the whitening agent. Although the fluorescent whitening agent whitens, it is not that the more the amount added, the better, but there is a certain concentration limit, which exceeds a certain limit. Value, not only does not have a whitening effect, even the phenomenon of yellowing, and in severe cases, it will show the color of the whitening agent itself.

2. Influence of other additives on whitening effect

Optical Brightener Agent For Plastic's repeated test results are not ideal, not necessarily because of whitening agents, but also may be affected by other additives such as ultraviolet absorbers and plasticizers. The principle of the fluorescent whitening agent is to convert ultraviolet light into visible blue or purple light. The component that can most affect the fluorescent whitening agent is the component that can absorb ultraviolet light, that is, white pigment and ultraviolet light stabilizer. Since the titanium dioxide in the white pigment can absorb the 380nm light wave in the ultraviolet light, if it is present in a plastic product, the whitening effect of the fluorescent whitening agent will be reduced. If titanium dioxide is used with a fluorescent whitening agent, it is recommended to use anatase titanium dioxide and increase the amount of fluorescent whitening agent appropriately.

Optical Brightener Agent For Plastic

Optical Brightener Agent For Plastic

3. The effect of UV absorber

The ultraviolet absorber absorbs ultraviolet light, thereby reducing the whitening effect of the fluorescent whitening agent. The role of optical brighteners depends mainly on the properties of other pigments and UV absorbers in the formulation. Therefore, in products using fluorescent whitening agents, it is best to use histamine light stabilizers that do not change color.

The above is the reason why the Fluorescent Brightener For Detergent supplier introduced the plastic to the fluorescent whitening agent is not effective.