The adhesion of water-based ink to film materials and the overlapping adhesion with UV ink are adopted。 Firstly, we need to choose the appropriate water-based ink to make it adhere to the surface of the film material; secondly, we should pay attention to whether the links of water-based ink material or any accumulated water can be matched by UV ink overlay。 If there is no overlap or the adhesion of UV ink after overlay is not good, we should consider printing a special coating to ensure the quality of the overlay。 Surface or printing water-based ink, UV ink signature will not withstand 3 M tape test。
Controlling the relationship between ink pressure and printing pressure
If printing with UV ink, the printing pressure is slightly higher, and the quality of the label will not be too large。 However, if water-based ink is used for printing, the printing pressure is high, and the edge of the text is prone to "wild ink", "dirty" and "burr" problems。 If it leads to unnecessary waste, the gains are not worth losing。
Consider the cost of the product process
Note the difference between two-layer printing and one-layer printing
Typically, in field printing, most label printing companies use double-layer ink to avoid dirty spots. In fact, there is another reason for this: under the same color density, using two kinds of thin ink is better than one kind of thick ink.
It should be noted that the printing ink is thicker, the smoothness of the ink is usually not good, easy to flower, false flowers, and looks lighter. Ink penetration will aggravate this phenomenon if printed on copperplate paper, but when two layers of ink are printed, it is not the case. The first printing ink is usually thinner. In addition to removing dirty spots on the matrix, it can also fill the blank matrix or uneven surface, and then the second ink, the printing effect in the field of printing will be smoother. The density value measured by the instrument will be higher.
Determine whether glazing is required
There are two purposes of polishing: one is to increase the gloss of the label, the other is to protect the label from wear and tear. If only to increase gloss, flexographic ink itself has a certain brightness, so there is no need for luminescence. If it is to protect labels, some labels may not wear out during transportation and use, and do not need to be polished. If the actual situation is not considered, blindly selecting the polishing process will lead to unnecessary light oil loss. Although ink is cheaper than ordinary ink, ink is often coated with thick film, so it is wasted a lot in use.
Therefore, in the early stage of process design, we need to consider whether glazing is necessary, or whether full-board glazing is necessary。 If the position attached to the label, transportation and use do not occur friction, then the ultra-transparent label can not be polished。 If it's a different label, because it needs a large die-cutting area, then it doesn't need a full-page polishing, only a partial polishing。 For the parts that need polishing, we also need to consider the thickness of light oil layer to meet customer requirements。 For the wear-resistant requirements of labels, it is necessary to ensure enough light oil thickness, and sometimes even need to add some wear-resistant additives in light oil。 In short, it is enough to meet the needs of customers, without high quality and high cost, unnecessary processes will result in waste of resources。