In life, whether it is packaging bags, document bags, envelope bags or some food packaging, kraft paper can be seen. Many products are packaged on kraft paper for printing, so how does the moisture factor of kraft paper affect printing? The following is the introduction of the editor of China Paper Industry Network:
When kraft paper is used as a packaging, it is impossible to design and print this process. During the printing process, if the moisture content of kraft paper is too high, it will affect the final printing effect. Since the raw materials for making kraft paper are plant fibers and other fillers, in the process of printing, the longitudinal expansion rate is small, but the lateral expansion will be larger, even up to 0.3mm or more, which directly affects the final printing effect.
During the storage process of kraft paper, the four sides are in contact with the air more, which will lead to the phenomenon that the moisture content of the four sides is less and the moisture content of the middle paper is larger. The moisture content of the kraft paper in this storage time is uneven, which will lead to the appearance of “lotus leaf”, and once the word problem occurs, the graphic imprint obtained during the printing process will not be consistent with the printing plate. This results in inaccurate overprinting.
Therefore, everyone needs to pre-treat the kraft paper before printing. First of all, the tattered and uneven paper must be removed and cannot be used. The temperature and humidity of the kraft paper storage space should be consistent with the printing workshop, so as to prevent the phenomenon of uneven water flow and upturning during printing. In addition, when kraft paper is produced, it can also be wrapped in packaging for storage, and can be removed one or two days in advance when it needs to be printed, so as to avoid moisture loss due to long exposure time.
The above is the specific content introduced by the editor of China Paper Industry Network, and I hope it will be helpful to you.
