The quality of the printed product is inextricably linked to the nature of the printed material. The smoothness of the paper, the pores of the paper fibers, the structure, the acidity and alkalinity, the absorptivity of the paper, the viscoelasticity, the whiteness of the paper, etc. The quality of the copy has a direct effect. Due to the different uses of the printed products, the difference in the type of paper at the time of printing has different requirements for its appearance and internal quality. Therefore, when selecting printed materials, the performance must be adapted to the quality of the printed products.
The quality of printed paper includes two aspects
Appearance quality: dust, spots, fiber clusters, sand, light points, holes, creases, wrinkles, cracks, color and other aspects.
Intrinsic quality: physical properties, chemical properties, absorption properties, optical properties, surface properties, printability, etc.
Absorption performance of paper on print product quality
Offset paper requires that the paper absorbability is not too strong. Offset printing mainly depends on the dry form of the ink's oxidized conjunctiva. The pigment particles in the ink are much larger than the linker molecules. If the printing paper absorbs strongly, Then, the binder in the ink will be quickly penetrated into the pores of the paper fibers, and the particles of the pigment will precipitate on the surface of the paper, which will make the product lack luster, dim colors, and affect the product quality.
The size of the paper's absorbency also affects the effect of copying. Usually when printing loose textures, if the ink has high fluidity and low viscosity, the paper will absorb more ink binder. If the diameter of the pores is larger than the diameter of the pigment particles, then the binder will be absorbed. This reduces the saturation of the print and requires a corresponding increase in the thickness of the ink layer. However, increasing the thickness of the ink layer at the instant of imprinting will cause the ink to spread, causing dots to enlarge, which will affect the quality of imprinting.
The low absorbency paper can make most of the ink film appear on the surface of the paper, so that the ink layer has better saturation. In order to improve the quality of printed products, some papers are subjected to high-pressure rolling or rolling into various patterns, patterns, and other shapes after they are made. This is the texture paper and pattern paper. Its purpose is to make the structure of the paper more compact and absorbent. Reducing, improving the effect of copying the printed ink, making the picture, especially oil painting, more faithful. In short, different qualities of paper have obvious differences in quality and effect. It is difficult to reproduce high-quality products on the surface with rough surface, loose structure, and high absorbency. It is imperative to improve the printability of paper. Printing companies must choose the right paper according to the requirements of product quality.
Absorption performance of coated paper is generally strictly controlled between 30 and 60 seconds. If the absorptivity of coated paper is too strong, it often causes ink to be printed on the paper. The ink in the ink is quickly absorbed and the pigment floats. On paper, this will not only reduce the glossiness of the printed matter, but also make the ink unable to adhere firmly to the surface of the paper and wipe it with a little force. The image imprint will be wiped off or the flower will be produced, which will seriously affect the quality of the product.
Coated paper is suitable for printing thin cable products due to its high smoothness. Due to the poor flexibility of the paper surface, if the smoothness of the paper is not high, it will be difficult to obtain a completely clean and smooth dot, which will affect the product's level of sharpness and shape. At the same time, the rough surface will dim the imprint, so high-quality coated paper should have With a high smooth finish, fine and clear fine mesh patterns can be obtained, making prints pleasing and pleasing to the eye. The smoothness is high, the paper absorption is weak, the surface of the relief paper is rough, the paper is loose, the smoothness is poor, and the ink absorption performance of the paper is strong.