There are three main paper properties that are of most concern to the paper properties printer:
The first is printability. In short, it is the performance of paper, ink, printing press pressure and printing plate to obtain the best quality print under certain suitable conditions. This comprehensive performance has no precise definition. At present, there are no theoretical indicators and practical data. However, there are two points that will directly affect the printing effect.
(1) Printing glossiness: An ideal paper, when the ink is printed, the luster of the printing surface is 5-10% higher than that of the original paper. If it is increased by 35%, the image of the printed product seems to be "out of the blue". However, the glossiness of general paper after printing tends to decrease. This may be due to the paper's air permeability, smoothness, and ink drying time.
(2) Paper flatness and flatness: The so-called flatness is that there are no depressions between the paper's parts, and the flatness is the difference between the “population†of the paper (that is, multiple sheets overlapped) (such as unevenness in the periphery, etc.) . An ideal paper, that is, a small amount of ink can also produce the desired ideal color and printing density, and can reduce the markings caused by uneven ink absorption. If a simple and slender straight line cannot be represented completely on the paper surface, it means that its flatness is too poor. The reason may be related to the formation of paper, looseness and resistance to surface peeling.
The second is operationality. In addition to the good print quality performance of paper, another manifestation is that it can make the printing production process smooth, that is, it works well on the printing press (stably transfers the ink) and responds well to the "acceptance" of the ink. Here are two things to note:
(1) Dryness and ink-holding performance of ink: When the paper is printed on both sides, when the first side is printed, when the second side can be printed, it is a matter that the printing worker is very concerned about. If the second side is printed prematurely, ink film peeling may occur due to the ink on the first side not completely dried. If it is too late to print on the second side, it will undoubtedly reduce the production efficiency. Therefore, it is necessary to make the paper have an appropriate ink drying time, and there is resistance to fast absorption of the ink, so that the ink on the surface of the paper rich ink support, resulting in the best gloss effect. The paper's absorbency and its acid-base value should be fully considered.
(2) Rub resistance of ink: When the paper has a firm structure and a flat surface, the rubbing resistance of the ink is increased. Therefore, the paper's tightness and surface strength (calendered or not) will affect the printing performance.
The third is appearance. When customers purchase paper, they generally assess the quality of the paper from the appearance, such as whiteness, evenness and luster. Brightness refers to the degree of light reflection with the wavelength of 457 nm, the brightness of a good paper surface is more elegant, so people love it more, finger to play paper, relying on the sound of about the level of its strength can be discerned, this is a common method.
Source: Zhiqiao Paper Net