Pilot Mill and Laboratory Deinking Studies Using Office Paper Furnishes Containing Photocopied and Laser-Printed Papers, 1994 Recycling Symposium Proceedings

John K. Borchardt, Drew W. Matalamaki, Vevolyn G. Lott, James H. Rask

The results of pilot scale deinking studies are described. The furnish used was a PS-40 grade mixed office paper containing about 80-90% laser-printed and photocopier-printed paper. Two deinking processes were studied. In the first, the sequence of operations was pulping - deflaking - screening - flotation - washing - reverse cleaning - forward cleaning.

The second deinking process had the

following steps: pulping - deflaking -screening - reverse cleaning - forward

cleaning. Image analysis results indicated certain proprietary deinking

surfactants were highly effective in removing ink particles. The effect of

process temperature was studied in both

the laboratory and the pilot mill. Particle size distribution studies indicated the relative effectiveness of ink removal as a function of particle size for each unit operation. Results

reported focus on the flotation and forward cleaning steps.