Humidification in print shops

Even if reading has gone a little out of fashion, paper is still in demand as a raw material. Paper is required not only for newspapers and books, but also for parcels, packaging, insulating material, bank notes, and furniture. To avoid corrugated cardboard beds collapsing, to ensure packaging material provides safe protection, and so documents remain intact, paper and printed products must be stored and processed correctly.

Maximum precision and perfect humidity are required if newspapers are to be rattled off the rotary offset press at 55 km/h.

Paper is hygroscopic

Hygroscopic materials are substances that can trap moisture in their cell structure. At low humidity, the air extracts moisture from the materials, often damaging the cell structure and causing cracks to form.

Static charges

Static charge can occur on unearthed production equipment, or on the textiles themselves.

At a relative humidity of 50–55%, damp air increasingly settles on ions, making them heavier and less mobile in the electric field. The conductivity of the air and the material surfaces then increases, so that electrical charges are dissipated, which prevents the formation of potential differences.
Dry air below 40% RH can cause
electrical potential differences
At 50–55% RH, electrical charges can dissipate
due to the increased conductivity
Storage of coated paper
Storage of uncoated paper
Storage of books
Photo printing
Screen printing