To minimize the volume of waste generated, press cleaning can be modified to an organized three-stage cleaning process to reuse wastewater or waste solvent (depending on type of printing ink used). Once the ink is drained out of the ink lines, off rollers, out of the ink pan and back into the ink container, the equipment can be cleaned.
Stage 1: The majority of ink is removed using water/solvent that has been previously used for step 2 cleaning.
Stage 2: Ink, left after the first stage, is removed using partially dirty water/solvent that has been previously used for step 3 cleaning.
Stage 3: Any remaining ink is removed by clean water/solvent.
When the water/solvent used in Stage 1 becomes too dirty to be effective, it may be filtered or mechanically treated on site or appropriately disposed off site. Stage 2 cleaning fluids eventually become Stage 1 cleaning fluids, Stage 3 becomes Stage 2 and fresh water/solvent is used for Stage 3.