The filler is used to make the paper obtain specific properties, such as whiteness, opacity, smoothness, etc. At the same time, the addition of the filler makes the internal voids of the paper smaller and finer, thereby increasing the ink absorption of the paper and making the ink absorption uniform. Usually added to the water-insoluble or slightly water-soluble minerals in the slurry, the content of the printing paper is about 10%-25%, and the amount of addition of different papers is different, and may vary greatly.
Bulk packing has Raschig ring, Pall ring, step ring
Structured packing has corrugated plate and corrugated mesh
There are many forms of bulk packing. The ones listed above are commonly used in industrial installations.