The printing holes of white board
The quality of white board paper generally refers to its printability suitable for printing, including some of its characteristics in transportation and storage. And its printability refers to the necessary physical conditions to reproduce a certain quality of printed matter should have a comprehensive physical and chemical reflection. The quality of white board paper must reflect the best printing quality and color effect. During the operation of the roller, the printing ink on the plate can be smoothly transferred to the surface of the paper, and the full, full and clear layers of ink and ink are obtained.
The printability of white paperboard includes: pore structure and ink absorption; smoothness and compressibility of the paper; surface strength of the paper; acidity and alkalinity of the paper and moisture content and elasticity of the paper.
The white paper is a kind of network structure by a variety of plant fibers are intertwined, in this network structure, fiber between pore filling and packing, some glue and pigments to meet the characteristics of the paper itself should have the. The addition of fillers is to improve the paper whiteness, smoothness and opacity; adding rubber material is to make the paper has a certain degree of water resistance, not easily by the infiltration of water or other liquid; adding pigment, the white paper has higher brightness. The pore structure of white board paper is the basis for paper to absorb ink, and it is also one of the key factors in printing and drying of printing press. Therefore, to understand the ink absorption of paper, we must first understand the pore structure of paper. Because the white board pore structure and ink permeability, penetration speed, printing smoothness, ink penetration, coagulation and drying, as well as the quality of printed matter are closely related.
The pore structure of white board mainly includes the porosity of the paper, the porosity of the paper indicates the volume of the air in the paper and the volume of the paper, and the porosity of the paper can be obtained by the method of calculation and the method of experiment determination. The rate of air voids white paper paper size = (per unit area) / paper volume (per unit area) x100% from the above equation shows that the white paper in the air volume is large, that gap board rate is high, the white paper also verified the pore structure of paper fiber the less, more sparsely interwoven, the gap between fibers is bigger, the white paper pore structure becomes worse. On the contrary, the more fiber, the more closely woven, the smaller the fiber gap, the better the white paper pore structure.
The solidification and drying of ink on paper surface is accelerated with the increase of porosity, and the ink absorption is also increased. But the gloss of ink on paper surface decreases with the increase of porosity.
The white board paper has a pore structure, and the porous structure of the white board determines the permeability, moisture absorption, absorbability and compressibility of the paper, which is the basis for the paper to absorb water, ink and other substances. In order to ensure better printing quality and printing effect, printing paper needs better ink absorbency. The ink absorbency of white paperboard refers to the nature of the ink absorbed into the whiteboard and absorbed by the ink when the paper touches the ink and transfers it to the surface of the paper. The greater the porosity of the paper, the more loose the structure, and the more ink it absorbs, the less it is. This is why we often say that the white paper has poor ink absorption.