Foaming or delamination of paper in cardboard printing can be analyzed from the two processes of printing and papermaking
Reasons for printing:
One: The ink has not gone even when the printer has just turned on, and the temperature has not reached the requirements for uniform ink flow, especially on high-speed machines. The printing pressure increases the peeling tension between the ink and the paper, and the foaming and delamination of the paperboard. In this case, only the ink viscosity reduction agent is added to the ink roller. The surface of the blanket can be cleaned without residual ink or traces of gasoline. In the winter or when the temperature is low, the ink is heated to reduce the cohesion of the ink and increase the fluidity of the ink.
II: The three rollers of the printing press make the blanket lose elastic pressure quickly. The uneven printing surface of the blanket and backing can only increase the printing pressure to fill the low point of the rubber, but when the pressure is increased, the pressure is increased. The pressure is greater than normal. Aging on the surface of the blanket does not transfer the print well, the surface absorbency decreases, and the paper slips on the surface of the blanket. At this time, the pressure is increased to make the paper layered and foamed.
Three: The printing effect in the field and the large amount of ink must be solid and even, and the printing pressure is slightly increased. The paper requires high interlaminar strength. The same is also true for inks: the printing ink has less viscosity but good transferability, and strong coloring power can be achieved with a small amount of ink. This reduces blistering and delamination.
Reasons for Papermaking:
I. Insufficient bond strength between layers. This phenomenon is mainly caused by improper control of the beating process indicators during beating and poor starch quality between layers.
II. Improper control of drying cylinder temperature curve, too quick drying, prolonged escalation of moisture between layers, causing blistering