Causes of ink blocking and its influencing factors
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
Dry ink is basically caused by the following: The old printing is not cleaned. The solvent is drying too fast (the printing speed does not match the solvent evaporation rate). Dry hot air blows onto the board. When the contact point between the scraper and the plate is mixed with dust, moisture, bubbles, etc. in the imprinted ink, the transfer rate of the ink may decrease due to the decrease of the actual amount of ink in the cell, and some coarse particles may even be embedded in the cell. . The accuracy and angle of the electric engraving of the cells during the plate making process will also be affected. The transfer to the ink causes the outlet to be insufficient or lost. The quality of the ink and solvent is also one of the causes of blocking. If the ink has poor fluidity, the printing viscosity is too high, the ink has deteriorated or mixed into different series of inks, improper solvent or solvent ratio is used, or even added. Improper operation of the solvent in the ink will affect the transferability of the ink and cause blockage.
Effect of the active particles: After printing for a certain period of time, the ink produces a lot of reactive groups, which will combine with the chromium ions of the plate roll. When these combinations are in the shallow mesh part of some gradient versions, their binding forces hinder The transfer of ink to the substrate causes blockage, and the basic performance is: shallow screen printing. To solve these problems, an activity slowing agent (such as CHY-1 type printing aid) can be added to the ink for treatment. Leakage is mainly caused by pressure roller, film, improper operation, etc.: uneven roller or air bubbles can cause serious leakage. The film is corona or contaminated during use, resulting in insufficient local corona. The amount of ink in the ink tank is insufficient, and the plate roller has a partial lack of ink. A hard object is stuck under the printing blade, and the ink is scraped off to cause an ink-printed blade mark. Missing marks due to adhesion or ink shedding. There are many reasons for the adhesion and peeling of ink. Everyone generally considers ink, film and solvent residue, ignoring the mismatch between temperature and air volume during drying, surface dry-drying caused by low temperature and high air volume, and insufficient cooling of printed film after drying. These two points.
European and American countries have higher requirements for solvent residues, and the benzene content is generally not more than 0.5 mg/m2. At the current printing level in China, it is very difficult to have a benzene content of less than 2 mg/m2. Solvent residues are mainly present in the printing and drying process, while benzene solvents are mainly caused by printing residues (if the drying machine has a long drying tunnel and sufficient drying capacity, sometimes the residual solvent of the printing will be volatilized. Therefore, we now mainly discuss printing solvent residue problems.