Web Cleaning

Paper dust and flaws in the print image are easily avoided

By Sergej Schwigon M.A., technical editor, Wandres GmbH micro-cleaning

Even microscopic particles can become a huge problem during the processing of paper and cartonboard webs. The build-up of paper dust results in flaws in the print image which disrupts the production process and can pose a risk to occupational health. A leading supplier of packaging was able to radically mitigate these problems through the use of the aptly named sword brushes. How is dust generated? High-end paper and cartonboard webs should ideally feature a perfectly smooth and clean surface. To achieve this, a solution of starch is applied to the surface in the size press. All the same, abrasive contact with deflection rollers in the nip of a web transport system may still cause weakly bonded paper fibres or filler particles to detach from the surface during downstream processing. This effect is referred to in the industry as «dusting». During slitting and cross-cutting of the web, large quantities of contaminating particles frequently occur. Avoiding the presence of dust on unbound edges and surfaces is simply impossible. Sharp, well-set knives are crucial in minimising the risk of debris generation and preventing even larger fibres from being deposited at the edges in addition to fine dust.

Wandres GmbH micro-cleaning, D-79252 Stegen, www.wandres.com