Why doesn 3M make Post-it® Notes with water soluble adhesive?
The only acceptable adhesives to the recycled paper industry are removable adhesives. Although water-soluble adhesives are partially removed in the paper de-inking process, the residual adhesive goes onto the paper machine. Soluble adhesives pass through the paper and build up in the waste water. Since most of the water is recirculated and reused, soluble adhesives accumulate in the water and eventually precipitate out somewhere in the mill.
