Glazing and film covering process II of the hottes

2022-10-14
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Glazing and film covering process of paper products (II)

how to ensure the stability of the glazing quality of water-based varnish

of course, it is also necessary to conduct incoming inspection to ensure the stability of batch quality. The inspection items of incoming materials are the same as those of solvent varnish, namely viscosity, solid content and pH value. Generally, water-based polish can be used directly on the machine, and the volatility of water is much weaker than that of Tianna water, so the quality of water-based polish is relatively stable. However, if it is circulated for a long time, especially in the high-temperature and dry season, a large amount of water in the water and oil will also evaporate, so the supplement can also be determined by measuring the viscosity, while the matching clearance of ordinary rib is difficult to adjust the amount of water. In addition, the operator should adjust the speed, roll distance and drying channel temperature according to different conditions, which is also an important part to ensure the stability of water-based glazing quality

how to ensure the stability of polishing quality? The following points should be paid attention to when polishing:

1 The polishing temperature is moderate. If the temperature is too high, it is difficult to take off the plate and damage the oil film. If it is too low, the print cannot adhere to the steel strip, and the polishing effect is not good

2. The polishing pressure should be appropriate, and the pressure should be adjusted according to the thickness of the cardboard and the polishing effect. Generally, the pressure should be maintained at about kg/cm2

3. To obtain a good mirror effect, the oil layer cannot be too thin when glazing. It has 224000 employees and the best effect is to polish it after glazing for about half an hour

4. To ensure the stability of the polishing quality, there are two other things that must be done: one is to avoid stopping halfway, and the other is to maintain the stability of the polishing speed. Table 1. Cause analysis and improvement countermeasures for common problems of solvent based and water-based glazing common problem cause analysis and Improvement Countermeasures after glazing, the surface adhesion gloss concentration is too high, add an appropriate amount of Tianna water for dilution, and the water-based gloss should be added with alcohol or water for dilution. The oil layer is too thick. It is learned that when the coating roller is reduced, the machinery manufacturers in Asia and the Pacific can obtain the advantage of rapid delivery and the gap between the pressure roller, Or add a small amount of solvent to dilute the glazing equipment. The hot air drying device is aging. Replace the drying equipment. The drying property of the varnish itself is poor. Replace it with a faster drying varnish. If the glazing speed is too fast, it should slow down the machine speed. After glazing, the wear resistance is poor The surface is easy to lose color. The abrasion resistance of varnish is poor. Change to a more wear-resistant varnish. The concentration of varnish is too low. When the varnish is diluted, appropriately reduce the proportion of solvent. The varnish oil layer is too thin. Appropriately increase the gap between the coating roll and the pressure roll. The ink is not dry. Polish after the ink is dry. The adhesion of the oil film is poor after polishing, The ink that is easy to scratch is not dry. Polish it after the ink is dry. The ink absorption of the printing paper is too poor. Replace it with paper with better ink absorption. The varnish quality is poor. Replace it with a new varnish. The drying temperature is too high. Reduce the drying temperature appropriately. The gloss is poor. If the oil layer is too thin, increase the coating thickness, or apply a layer of base oil first, and then polish it, Or increase the concentration of varnish. If the varnish is too thin, reduce the proportion of Tianna water. The calendering temperature is low, and ensure that the temperature is ℃. The oil tank is thoroughly cleaned by mixing other kinds of varnish in the oil tank. If the printing ink does not match the varnish, replace it with a new ink or a varnish grinder. The steel belt is atomized to replace the steel belt. The printing paper has strong absorption, If the absorption of varnish is too large, change to paper with poor absorption. The smoothness of paper surface is not good. Change to paper with better surface smoothness. The gloss of varnish itself is poor. Replace the varnish. There are pockmarks on the surface after polishing. If the varnish is too thin, the thickness of oil layer should be appropriately increased, or the concentration of varnish should be adjusted. The paper drying time is not enough. Generally, it should be dried for about half an hour after oiling. The proportion of wear-resistant additives in the varnish is too high. When using new Polish, it is difficult to take off the plate, and the polishing temperature is too high to reduce the polishing temperature. Generally, it is not more than 105 ℃. The polishing pressure is too high. Reduce the pressure properly, and the oil is not dry, and then polish it after a period of time (secondary title). Vu glazing process UV glazing process is a process in which a layer of UV varnish is coated on the surface of a print, and the varnish is crosslinked, conjunctived and cured by ultraviolet (UV light) radiation. UV varnish is polymerized by photosensitive resin, diluting monomer, photoinitiator and additives. It has the advantages of fast drying (drying time is only 0.s), good corrosion resistance, solvent resistance, high gloss, wear resistance, environmental protection and so on. (level III title) UV light (UV) UV light is a radiation line outside the purple visible light, with high energy (see Figure 4 for details)

uv light oil curing machine the photoinitiator is excited to produce free radicals under the action of UV light, and the energy is transferred to the copolymers rich in double bonds and diluted monomers to produce chain reaction, and cross-linking is produced instantly and cured into a film. (Level 3 title) how to ensure the stability of UV glazing quality

1 Carry out incoming inspection on UV oil to ensure that each batch of incoming materials is qualified. The inspection items include viscosity and solid content

2. Do not use slow drying inks. Using gold and silver inks may cause quality problems. When using these inks, gloss and adhesion should be tested after polishing

3. Do not use leveling aids with high surface activity, and try not to use anti scratch AIDS, and do not use too much powder

4. The paper/sheet used for glazing should have low permeability. After printing ink, the printed matter should be left in the air for more than 12 hours before UV glazing

5. Avoid mixing water with UV oil when washing the machine

6. In the process of UV glazing, pay attention to that the machine speed should not be too fast, and the UV lamp should have sufficient light intensity to ensure that the varnish is completely cured

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