Quality Defect
Print run interruptions frequently arise from the release of mineral additives from the surface of uncoated paper sheets. The phenomenon of particulate filler detachment occurs when clay or calcium carbonate particles are pulled from the fiber matrix by high-tack offset inks. This separation leaves microscopic voids in the coating and deposits abrasive dust on the rubber blankets of the printing press.
It directly reduces print quality by causing premature wear on plates and ink contamination.
Sheet Binding
Papermaking chemistry utilizes synthetic polymers and natural starches to anchor fine minerals securely to the cellulose fibers. When particulate filler detachment is observed, it often indicates insufficient starch retrogradation or poor retention aid performance in the wet end of the paper machine. Surface sizing can mitigate this issue by sealing loose particles under a film of starch.
This treatment ensures the paper can withstand the high peel forces encountered during multi-color offset runs.
Press Performance
Continuous build-up of mineral dust forces press operators to stop the run for frequent wash-ups. This unwanted particulate filler detachment causes hickeys on the printed image and reduces productivity. Measuring the surface pick strength using wax sticks or dry tack testers helps mills monitor this risk before shipping the paper.
