Polyvinyl chloride, abbreviated as PVC, is a common plastic product material now. It has no fixed melting point and generally begins to soften at 80-85 degrees. It will automatically catalyze and decompose above 100 degrees or after long-term sun exposure to cause discoloration. Therefore, certain Optical Brightening agents should be added in the production process of PVC products to prevent yellowing in the later period.
Due to different production methods, PVC products can generally be divided into soft PVC, hard PVC and foamed PVC. Different kinds of Optical Brightening agents should be selected to achieve appropriate effects.
Soft PVC is generally used for floor, ceiling and leather surface. However, because soft PVC contains softener, it is easy to become brittle and difficult to store, so its application scope is limited. It is recommended to use whitening agent FP-127 at a temperature of less than 220 degrees. This is a special Optical Brightening agents for soft PVC products. In the production process, the addition amount is usually about 2-3/10000, which can achieve good results.
Hard PVC does not contain softener, has good flexibility, is easy to form, is not easy to be brittle, non-toxic and polluting, and has a long storage time, so it has great development and application value. It is generally used on pipes, profiles and gussets. Brightener OB-1 is recommended for this type of products. The application temperature is within 360 degrees, and yellow or green powder is added in an amount of about 2/10000 to 3/10000. The effect is also very good. It can not only whiten, but also prevent yellowing in the later period.