Problems caused by ink
1. The excessive viscosity of the ink causes the stencil
the excessive viscosity of the ink will not only make it difficult to transfer the imprint, but also destroy the condition of fracture in the middle of the ink layer, resulting in insufficient remaining ink layer in the layout, and the stencil is caused by the bare and worn parts of the text and text
treatment method: add an appropriate amount of debonding agent to reduce the viscosity of the ink without increasing the fluidity of the ink too much. For printing fine products, it is better to use anti adhesion agent to reduce the viscosity of ink, because it does not increase the fluidity of ink while reducing the viscosity, and is good for ink drying. However, the dosage should be appropriate. Excessive dosage will affect the gloss of imprinting. Generally, the dosage of yellow ink is 1% ~ 1.5%, and that of other color inks is about 2%
2. The viscosity of the ink is too small, which is easy to paste the version.
the ink with small viscosity is easy to emulsify, causing floating dirt, making the ink unable to transfer normally, and gradually accumulating pigment particles on the ink roller, printing plate and blanket. When pigment particles accumulate to a certain thickness on the printing plate, it will cause a paste. Sometimes, due to insufficient residual ink layer in the layout, the stencil is caused
treatment method: add some concentrated inking oil appropriately, but not too much to avoid affecting other properties
3. Excessive ink fluidity will enlarge and deform the point, and insufficient ink fluidity will produce stencils
excessive ink fluidity will spread the ink layer, expand the geometric size of the imprint, and the imprint cannot be copied correctly. 1. Do not click the "start" experiment button before starting the experiment. Insufficient ink fluidity often leads to uneven ink distribution, resulting in insufficient ink on the printing plate and stencil
treatment method: the ink fluidity is not completely suitable for all printing machines, and the high-speed machine has greater fluidity than the low-speed machine. Other materials that regulate the fluidity of ink generally use No. 6 inking oil and high boiling point kerosene. But be careful not to add engine oil or other non drying mineral oil to the ink
4. The ink particles are thick and produce a stencil.
the ink particles are thick and act as an abrasive on the printing surface. In thousands of rolling, the graphic and text foundation is damaged and the stencil is caused
treatment method: when printing, try to use ink made of pigment with small specific gravity. For dilute ink, transparent dilute ink or gloss paste should be used as diluent instead of white ink
5. There is too much dry oil in the ink and the plate is pasted
in printing, some operators add desiccant to the ink with drying performance to promote the aging degree of the ink roller, thicken and emulsify the ink, so that the ink layer on the printing plate cannot be broken from the middle, and most of them remain on the printing plate, resulting in plate stacking. Under the action of printing pressure, the ink layer on the dot gradually expands, resulting in a paste
treatment method: for the paste caused by too much dry oil, we can't solve it by increasing the moisture content of the plate, although the probability of electromechanical appearance is not very high. We should clean the old ink on many rolls of the ink assay machine and replace it with new ink. It is necessary to add an appropriate amount of dry oil ink to the printed parts. When the downtime is short, you can apply some anti drying agent on the ink roller. When the downtime is long, you should clean the ink on the ink roller
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