Recycle treatment of wash water contg. acrylate and/or protein - by addn. of hydroxide in alkaline medium, esp. for water from flexoprinting

摘要

In the recycling treatment of wash and rinsing waters contg. acrylates and/or proteins, esp. water from flexo-printing, the acrylate and/or protein present as binder is flocculated by addn. of a hydroxide in an alkaline medium, with bonding of any filler and/or pigment suspended in the water. ADVANTAGE - The process can be controlled, and suspended solids are agglomerated. Fillers in the water, esp. chalk, are not attacked, and there is no evolution of CO2 and foaming. The flocculated material remains stable during later neutralisation with acid, can easily be filtered off, and can be used as recycle dye (claimed), avoiding the need for its disposal. The treated water can be used to clean dye-coated surfaces, or as consumption water.