In all plastic products, white accounts for a large proportion of plastics, such as white crisper boxes, PVC drain pipes, white food bags and so on. In the process of processing, many manufacturers increase their whiteness by adding fluorescent whitening agents. However, many manufacturers will encounter such a problem, which is also adding fluorescent whitening agents. Why does “my” product whiteness Does it always improve little?
Today, Xiaobian analyzes the reason why the whiteness has not improved even though the fluorescent whitening agent is added to the plastic…
1. Is the correct type of fluorescent whitening agent selected?
There are many varieties of plastic products, and their characteristics and production processes are also different. Therefore, the types and properties of fluorescent whitening agents required are different. For example, the transparent plastic packaging bags we have seen have better light transmittance and weather resistance requirements for whitening agents, so it is recommended to use fluorescent whitening agent OB for transparent plastic products; for engineering plastics, it is recommended to use fluorescent whitening agent OB. White agent OB-1.
2. Dosage of fluorescent whitening agent
Although the fluorescent whitening agent brightens, it is not that the more the amount added, the better. Research shows that when the amount of fluorescent whitening agent added in each plastic matrix exceeds a certain value, it will precipitate agglomeration, reduce the whitening effect, and even cause hair loss. The phenomenon of yellowing, in severe cases, will show the color of the whitening agent itself, resulting in more losses than gains.
3. Influence of pigments in plastic processing formula on whitening effect
The principle of action of fluorescent whitening agents is to convert ultraviolet light into visible blue light or violet light. The components that have the greatest impact on fluorescent whitening agents are the components that can absorb ultraviolet light, namely white pigments and ultraviolet light stabilizers. For example: titanium dioxide in white pigments can absorb 380nm light waves in ultraviolet light, and if it exists in plastic products, it will reduce the whitening effect of fluorescent whitening agents. If titanium dioxide is used together with fluorescent whitening agent, it is recommended to use anatase type titanium dioxide and appropriately increase the amount of fluorescent whitening agent.
Have the above points solved your problem when using brighteners in plastic production? Today, the editor will share the above three common situations that may occur when adding whitening agents. At present, we have various types of fluorescent whitening preparations for Subang plastic products, and provide technical services for your whitening needs.
For more plastic whitening issues, you are welcome to call Shandong Subang Fluorescent Technology for communication.
Post time: Apr-14-2022