What is the effect of surface sizing on the performance […]
What is the effect of surface sizing on the performance of printing paper?
1 Increase the water resistance and surface strength of the paper, which can reduce the hair loss of the paper in the offset printing; 2 Improve the printability. If the surface rubber is too small, the paper will absorb too much binder in the ink during printing. The print is dull. On the contrary, if there are too many surface rubbers, it will slow down the drying rate of the ink, resulting in smudging and bright stains; 3 increasing the erasability of the paper, surface sizing can reduce the penetration of the ink, so it is easy to wipe off the ink, increasing The anti-friction ability of the paper; 4 increase the strength of the paper, such as bursting resistance, folding resistance and tensile strength; 5 reduce the two sides of the paper and deformation.
What is the role of the filler?
The filler is used to obtain specific properties of the paper, such as whiteness, opacity, smoothness, etc. At the same time, the addition of the filler makes the internal voids of the paper smaller and thinner, thereby increasing the ink absorption of the paper and making the ink absorption change. uniform. The minerals that are usually insoluble in water or slightly soluble in water, which are usually added to the slurry, are contained in the printing paper at a content of about 10% to 25%. Different papers are added in different amounts and may vary greatly.
What characteristics should the printing paper filler have?
The filler of printing paper should have high whiteness, high refractive index, fine particles, low water solubility, low density and good chemical stability. In addition, it is best to be rich in resources and low in price.
What are the common fillers for printing paper?
The most commonly used inorganic fillers are talc, clay, titanium dioxide and calcium carbonate. Among them, titanium dioxide is an expensive and high-quality filler; organic synthetic filler is some high-molecular material.