IMPROVEMENTS IN OR RELATING TO DEINKING OF PAPER

摘要

The invention discloses various methods for separation of laser and xerographic printed paper waste containing ink having a magnetic component from other paper waste products containing ink which does not contain any magnetic material, by the use of at least one magnet. The invention also provides a method for removal of magnetic ink from pulp stock formed from such xerographic and laser printed paper waste comprising feeding such pulped paper waste past at least one magnet for removal of all or substantially all of such magnetic ink. The magnetic ink can be removed by capture or deflection techniques. The preferred magnetic force to be applied in order to achieve the required results, utilises background magnetic fields in excess of 4000 Gauss and a field gradient in excess of 1000 Gauss/cm. The invention also provides a method for improving the recyclability of paper waste having ink thereon which does not normally contain a magnetic component, by utilising one or more magnetic carriers in the formulations of the printing ink utilised. Also disclosed is a method of enabling adhesive material to be removed from paper pulp containing same comprising incorporating a magnetic filler or carrier in said adhesive and removing such adhesive by magnetic means.