Water-based ink printing techniques on corrugated paper

Water-based inks have been used in the printing of corrugated paper for a long period of time abroad and have been in the country for more than 20 years. Corrugated paper printing is printed by letterpress (embossing), offset printing (flat printing), rubberized water washable printing, and development of flexible flexographic waterborne inks. Flexopress water-based inks also evolved from rosin-maleic acid modified resin series (low grade) to acrylic resin series (high grade). Printing plates also transition from rubber plates to resin plates. Printing presses have also evolved from single- or dual-color machines with large rollers to three- or four-color FLEXO machines. The mesh wheel is also gradually developed from a 150-200 mesh metal roller to a 180-250 mesh ceramic roller. With the ever-changing printing technology, the use of water-based ink technology is very important. Before discussing the usage techniques of water-based inks, we must first understand the characteristics of water-based inks and the relationship and impact of various factors in printing, such as plate material factors, paper factors, mesh wheel factors, mechanical factors, ink-and-ink factors, and operator factors. Wait.
First, the characteristics of water-based ink printing corrugated paper
1. Water-based inks are roughly divided into two categories:
(a) Rosin-maleic acid modified resin series (low grade);
(b) Acrylic resin series (high grade).
2. Comparison of the characteristics of two types of water-based inks: (slightly)
Second, the performance of water-based ink requirements:
1. After long-term storage of the precipitate, it should be easily redispersible after stirring;
2. Must have good flow properties and viscosity;
3. Have good storage stability;
4. Drying performance is fast and appropriate;
5. Can not have any adverse effects on printing plates and printing presses;
6. Must not have too much pungent odor;
Third, water-based ink technical parameters
1. Color: Approximate to the standard sample Note: The manual color development wheel is used for color contrast comparison between the sample and the standard.
2. Fineness: less than 20 micron instrument: 0-50 micron scratcher fineness meter.
3. Viscosity: 20 seconds ± 5 seconds Instrument: RIGOSHA 4 # cup (25°C).
4. pH: 8.0-9.5 Instrument: Portable pH meter (PHB-2 type).
5. Heavy metal content: in line with the world's packaging green environmental protection standards.
6. The patience: meet the requirements.
Fourth, the correct use of water-based ink requirements:
1. Before use, it should be fully stirred to keep the ink composition uniform;
2. After opening, the ink should be stamped and sealed immediately to prevent dust from falling and crusting.
3. Yu ink, such as containing impurities should be filtered first, and then with the use of new ink;
4. Avoid exposure to high temperatures or burning in the sun during storage. Can be stored for one year without deterioration under normal conditions;
5. If it is found that the viscosity of the applied ink is slightly larger, an appropriate amount of water may be added for adjustment.