Chemical Dispersion of Wax Coatings at Inland - Maysville, 2000 Recycling Symposium Proceedings

M.J. Coffey, D.H. Slinkman, J. R. Cable--Bales of old corrugated containers (OCC)used in the manufacture of recycled paperboard often contain paraffin wax. These wax coatings tend to break down and soften or melt during pulping to form a slurry of particles which can agglomerate and deposit. Recent work on controlling the contamination problem caused by wax coatings has focused on manipulating the particle size of the wax. A new dispersant blend has been developed which works by shifting the thermal transitions of paraffin waxes with a melting point reduction agent. This allows for the comminution of wax coatings into a stable dispersion with conventional dispersion chemistry at typical process temperatures. The effectiveness of the dispersant blend in controlling wax was tested at the Inland mill in Maysville Kentucky.

The dispersant was first fed on a continuous basis to normal production to improve the appearance of the sheet. The area of the sheet covered by contaminants was reduced by 50 to 70% by using the dispersant blend. The slide angle of the sheet also improved by nearly 50%. A second trial simulated a wax excursion by adding 3000 lbs. of wax coated OCC to the repulper. The dispersant was then added in a slug feed mode to control the negative impact of the wax. Adding the dispersant controlled the negative effect of the wax.