Air humidification in paper industry and printeries
In the heating period and during warm summers, the exeptionally low humidity level may cause numerous problems in printeries. The humidification system ensures the shape and dimension stability of the processed materials, lowers the ink, lacquer and solvent consumption, lowers the level of the dust in the air (especially the smallest particles that are the most difficult to filter), reduces the losses in materials etc. The tendency of generating dust may be described by the ease of detachment of small paricles of filler and fibre parts from the surface of the paper due to friction, shaking and bending. The effect of dust
gerneration by the paper is a cause of the reduced printing speed. The dust increases the maintenance stops when cleaning is required. The paper may generate dust regardless of the printing technology that is used.
It may be divided into four categories:
- The dust that is generated during cutting the roll into separate sheets
- Edge dust- it is produced when cutting is performed with a dull knife or too thick sheet is processed. This kind of dust is visible on the edges of the paper in form of torn fibres and particles.
- The dust from pigments ftom the covering layers (this form of dust transfer from offset blanket to printing form, causing its erosion)
- The dust from the fibres accumulates on the offset blanket, causing distortions
The dust may be transferred from the printing profm into the ink container causing inconsistent, random transfer of the ink to the feecing supply. The dust may cause wiping of the image from the offset form
It may be said that the paper “lives” because its natural component- wood- despite being processed, preserves some of its properties- one of them is sensivity to humidity level. The bigger the difference between the humidity of the paper and the relative humidity of the room that it is stored in, the bigger the risk of experiencing problems during printing. When the paper is too dry, the static charge that generate during handling he no way of discharging. This may lead to electrostatic “bonding” of two or more sheets, what may lead to phenomena like jams, or insufficient adhesion of the fresh ink. Properly designed air humidification eliminates the abovementioned problems. Our extensive experience allows us to design an installation perfectly suited to the needs of our customer. We provide free design and pricing, moreover, we provide professional advice.