In the production of color masterbatch, many manufacturers will also add fluorescent whitening agent OB to improve the quality of products. Compared with others, the amount of fluorescent whitening agent OB added in the production of color masterbatch is much larger, adding a few kilograms or even more than ten kilograms at a time, which also depends on the concentration to match. Normally, adding fluorescent whitening agent to color masterbatch is to directly add the corresponding amount of fluorescent whitening agent OB into masterbatch, and then stir. This must be stirred evenly, otherwise the color masterbatch produced will have some problems in the next step, for example, some places are white, and some places are dark and yellow. Therefore, the normal stirring is carried out with a stirrer, and the time can be slightly longer to achieve sufficient stirring.

But not all manufacturers have blenders, so how do they add fluorescent whitening agents? Without a blender, it is suggested that the fluorescent whitening agent OB can be dissolved first. Of course, this dissolution is not with water, but with some organic solvents. Such as plasticizers, lubricants, etc., which can dissolve fluorescent whitening agent OB. So what's the ratio? How to add it? Take granulation as an example. Our dissolved fluorescent whitening agent OB is usually 2 kilograms of plasticizer dissolved with 200 grams of fluorescent whitening agent, which is added by drip at the feeding port. I believe that everyone has had intravenous drip, which is the case. Adjust the flow rate according to the production volume to ensure even addition. For example, if we pelletize 500 kg in one hour and 1,000 kg in two hours, then at the end of these two hours, the solution of our dissolved fluorescent whitening agent OB just drops out, and then the 1000 kg of pelleting will be very uniform with the addition of whitening agent OB.

Reference dosage of fluorescent whitening agent OB

As a high-grade additive, the amount of fluorescent whitening agent OB is very small. Normally, the amount of fluorescent whitening agent OB per 100kg of polymer is:

PVC：

1-5% of white (10g-50g);

0.01-0.1 (0.1g-1g) of transparent material (which can improve the brightness of PVC);

PS：

0.1(1g) of white;

0.01-0.1 (0.1g-1g) of transparency;

ABS：

1-5 ten thousandths of its true color (10g-50g) (it can effectively eliminate the inherent yellow color in ABS)

1-5% of white (10g-50g);

PE、PP:

0.05-0.1 (0.5g-1g) of colorless and 0.5-5 (5g-50g) of white;

Other plastics: please refer to the above examples for dosage. Although the amount of fluorescent whitening agent OB is small, it has great whitening effect.