Requirements of the hottest digital printer for pa

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The requirements of digital printing machine for paper

digital printing may have become the hottest topic in the printing industry. At the same time, it also caused lively discussions in the paper industry, "what should the paper industry do for digital printing? What are the requirements for paper quality for this new printing?" According to Pira's prediction for 2001, digital commercial printing will have a large growth, especially brochures and direct mail orders. However, we can only have a rough estimate of the size or growth of the digital printing paper market. We only know that the number of digital printing machines on the market is increasing, their production efficiency is expanding, and therefore the amount of paper used is also increasing. As for the calculation of the amount of paper used for digital printing, it is difficult, because many digital printers still use traditional printing paper on their digital printing machines. Although most digital printing machines have some special performance requirements for paper, familiar offset printing paper is still widely used. No matter how printed, the basic requirements of printed matter on paper are nothing more than weight, thickness, brightness, opacity and smoothness. In these aspects, digital printing is no exception. However, sometimes special digital printers also put forward some specific requirements for paper. For example, digital printers, copiers or desktop printers using the principle of electrostatic printing are the most common. For this kind of printing equipment, it is required that the paper has good dimensional stability, low flexibility and low wrinkling under the environment of temperature and humidity changes. At the same time, it is also required to have appropriate wear resistance, surface conductivity, sufficient stiffness, and less paper wool or dust in the printing process

in addition, attention should also be paid to the printing quality of paper. Due to the application of electrostatic printing principle for printing, and the replacement of ink with pigment, the electrical properties of the paper, such as resistivity, dielectric constant, etc., should be controlled at an appropriate level. We must also keep in mind that the moisture content of paper has a great impact on the performance of paper and its printing performance

the consistency of the quality of the printed matter printed by the electrostatic printing principle depends on mastering the correct machine parameters, but the uniformity of the paper is also very important: the distribution of fibers or fillers in the paper must be uniform, and the smoothness of the surface is also crucial to the quality of the color transfer, especially for those models whose paper surface is in close contact with the color. After the pigment reaches the paper, it is usually fixed by hot pressing. Therefore, the smoothness and surface chemistry of the paper surface. The qp1 liquid silica gel (LSR) performance and heat treatment performance of Dow Corning company must also be mastered at an appropriate level. The stiffness of low gram weight coated paper shall be required to prevent it from being twisted on the hot pressing roller

the change of environmental humidity during the transportation, handling and storage of paper has a great impact on the digital printing quality of electrostatic printing principle. Therefore, air conditioning control is applied to relevant warehouses and printing workshops

digital printing using inkjet technology after exceeding the yield load is very different from digital printing using electrostatic principle. Because 50%~90% of the inkjet is solvent-based, and the vast majority of the pigments are solid polymer with pigments, which is a kind of compound particles that supplement the motor indirect speed change device. The liquid performance of ink used in inkjet technology requires the surface absorption and absorption amount of paper, including: after the ink drops are sprayed on the paper, the pigment should remain on the paper without diffusion, which requires to control the speed and amount of solvent absorption, and let the controlled solvent finally volatilize from the paper to form a uniform impression. Therefore, the ink-jet digital printing machine has high requirements for the surface performance, pore structure, chemical and mechanical properties of the paper, which has brought confidence to the extruder enterprise, and it is not the same for all ink-jet printing machines or inkjet materials

the paper suitable for inkjet digital printing machine must also be wrinkle free, inflexible and stable in size as far as possible, and its surface wear resistance and electrostatic effect must be controlled within the ideal range in order to ensure good printing performance

in a word, although most of the paper used in many digital printing machines is ordinary offset printing paper, there are still certain requirements for some digital printing machines with special structures or technologies under certain specific conditions. It can be said that so far, no paper can adapt to all digital printing machines, which should be noted

reprinted from: Printing Art

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