Water loop and bleaching process design to recycle waste paper into printing and writing grades

The production of high grade printing and writing papers from low grade or mixed office waste (MOW) requires an elaborate recycling process system High brightness, excellent pulp cleanliness and extreme low stickies counts have to be achieved matching virgin hardwood pulp qualities. These pulp specifications require a recycling process in which each process module must be individually fine-tuned and its performance depends heavily on the performance of other process modules. Special attention must be given to water management and bleaching as two key process steps within the recycling process. The following paper will describe process parameters and technological data from a fiber recycling system that is producing 300 TPD high grade DIP from MOW.