What characteristics should digital printing paper for custom printed books have?
What characteristics should digital printing paper for custom printed books have?
As an important material in printing work, how should digital printing paper be used, and what are its properties and characteristics? Please see the paper analysis below:
The printing paper must have the correct moisture content, good electrical properties to ensure good pigment adhesion, and not curl to ensure good printing performance on digital presses.
(1) Moisture. For non-coated paper, it should be controlled at 4.5% to 5.5%, and the moisture content of coated paper should be less. High moisture levels can lead to uneven surfaces and speckled defects.
(2) Electrical. The electrical conductivity, which can be balanced and controlled within a certain range, can avoid defects such as spots, maintain color stability and good adhesion of pigments.
(3) Roughness. Ideally below 300 Bendsten units. High-textured paper does not retain pigment in the raised areas, which can affect image and quality.
(4) Consistency. The format and size of the paper should be uniform.
Since it is now recognized that digitally printed paper is very sensitive to the environment, the moisture content of digitally printed paper needs to be taken into account when packaging. Printing paper manufacturers need to pay special attention to the constant control of the moisture and conductivity of the paper.
Cellophane packaging keeps the paper intact from the manufacturer to the printing house, but once the cellophane is opened, the properties of the paper are difficult to maintain. So it is not good to use half the first day and print the other half without sealing the next day. Paper is usually transferred from temperature-controlled warehouses to cooling trucks and then into a warm press room. Ideally, printers should follow the paper manufacturer's recommendations and allow sufficient time for the paper to acclimate to the press room environment before printing on the machine. But because of the tight printing time, nine out of ten sheets are printed directly from the delivery truck to the press.
High pressure glossy papers have their own unique set of problems. Calendering with a calender increases the high density of the fiber aggregate, which changes the electrical and moisture properties of the local paper and affects how the pigments are distributed.
The paper should have a smooth coated surface to bond well with the pigments. Uncoated (or some coated) papers are first surface treated to ensure image adhesion. Paper should also have certain oil absorption and high surface strength.
