TE cooling units have the following results in this field:
- No electrostatic charge
- Protection against drying, shrinkage and deformation of paper and paperboard
- Uniform printing quality, less waste (scrap)
- Employees are more comfortable, especially during the winter months
Wood fibers are the main raw material for making paper. This is a hygroscopic material, which is therefore directly related to the moisture content in the surrounding air. Paper absorbs or releases moisture until a balance between paper and air is achieved.
For example, the air extracts moisture from the paper if it is less moist in comparison to the surrounding air. This is a simple drying mechanism. If the paper drying has to be avoided, it is enough to ensure that the balance of moisture content in the air and the desired moisture content of the stored paper is maintained.
The moisture content of the paper also depends on the raw materials used. Mechanical wood pulp absorbs more moisture than chemical pulp, but raw materials of the highest quality, such as cotton and flax, have the lowest absorption range..
Ideal air humidity ensures uniform print quality, and less waste (scrap). The unpleasant consequences of too low or too high humidity in the air include paper distortion, cracking of paper during rotation, reduced number of machine cycles, poor print and, therefore, additional costs.
Every investment in quality air humidifiers will pay off quickly in terms of business savings.
Recommended values of relative humidity in the paper and printing industry:
od - do °C
od - do %
% r. v.
|Storage of natural paper||18 – 20°C||45 – 50%|
|Storage of coated paper||20 – 22°C||50 - 55%|
|Storage of paperboards||20 – 22°C||55 – 60%|
|Book Engraving||20 – 22°C||60%|
|Paper bags production||20 – 25°C||60 – 65%|
|Printing of photos||22 – 24°C||50 – 60%|
|Rotation||22 – 24°C||60%|
|Silk Screen||22 – 24°C||50 – 60%|
|Book trafficking||15 – 20°C||60 – 65%|