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Bältarbo tegelbruk och Sveriges tegelindustri under 1900-talet


This thesis is divided into two parts. Part one contains a general description of the flexographic printingtechnique. Part two contains a more detailed investigation in the areas substrate, inktransfer and trends, which are only briefly commented in part one, and conclusions and comments.The major problem concerning substrate is washboard. This phenomena can be limited if one can control and minimize the amount of glue applied in the single- and double facer, use high surface weight on liner, use low surfaceweight on fluting and control the humidity during the conditioning of the corrugated board. Corrugated board with a smooth surface radically increases the quality in print. A certain amount washboardphenomena can be compensated in the printingprocess with soft printingplates.A common trend in the inktransferarea is to decrease and control the amount of transferred ink to the substrate. This can be done by using chamberdoctorblades, aniloxrolls with more cells per inch, cells with less deapth and custom made printingplates. The more cells per inch the bigger is the problem to keep the rolls dean. Hence the washout process have to be more sophisticated and a system for controlling the rolls is needed.The trend among the inkmanufacturers are deliverances of ink with a higher content of pigments. lnks with a high content of pigments are able to cover a fulltone print in spite of the less amount ink transferred to the substrate. The price is higher than conventional inks but since the amount of ink needed for printing is less, the price is not as big disadvantage as one could expect, The most important advantage though, is that the printer at the printingmachine can vary the properties of the ink much more for inks with a high content of pigments than with conventional inks.Stochastic screening seems to be very interesting for the flexo printing business. The major advantages with stochastic screening are the possibility to print a number of colours without risking any moiré, greater tolerance for registerproblems and possibility to print very fine details. The critical area for stochastic screening in the flexo printing business will probably be to keep very small dots on the photopolymer printingplates during exposure of UV-light and to minimize the dot gain during printing,

Författare

Bengt Wittgren

Lärosäte och institution

Uppsala universitet/Ekonomisk-historiska institutionen

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