Investigating the complex problems of waste paper at Larsson Offsettryck

Sammanfattning: Waste paper is a big problem in the graphic arts business, both from an environmental point of view and from a financial one. Since focus is often put on obtaining low costs and high production speed, the work of reducing the amount of waste paper becomes a secondary issue for many companies. In this master thesis we have looked for reasons for waste paper generation in the beginning of the printing process, the adjustment phase, by studying the printing press Heidelberg Speedmaster CD 102-5 at the printing house Larsson Offsettryck AB in Linkoping. We have found suggestions on how to reduce the amount of waste paper by observing and interviewing the staff members at Larsson Offsettryck AB, measuring print quality and perform analyses based on the theoretical knowledge we have obtained through our studies at Linkoping University. For our test printings we used one coated paper quality, Tom&Otto Silk 150 g, and one uncoated paper quality, Maxi Offset 170 g. To analyse the printing result we used both objective and subjective evaluations. The result from our study is that the adjustments made in the beginning of the printing process, to achieve correct colour level, can be finished earlier than the printing press indicates. A total of 40-60 sheets can be saved for each adjustment. According to our research the number of sheets per adjustment at Larsson Offsettryck AB today is approximately 140, which means that the number of adjustment sheets for Larsson Offsettryck AB can be decreased by roughly 35 % through this simple alteration of the printing process. We have also examined the ICC profiles used at the printing house and concluded that the grey balance for uncoated paper is not satisfactory and should be improved.