Deinkability Score Impact on EPR Eco Modulation Fees in Recycled Stock
Deinkability scores under INGEDE Method 11 directly determine EPR eco-modulation fee surcharges or discounts on printed recycled paperboard packaging.
Flexographic Ink Saponification
Chemical Hydrolysis
Alkaline reactions between paperboard packaging contents and acidic ink binders cause printed graphics to degrade and dissolve on the carton surface. Packagers of soaps and detergents must prevent flexographic ink saponification to ensure that spilled product does not smear the printed branding. This degradation happens when basic salts in the product react with the carboxyl groups of water-based inks.
Alkaline Exposure
Industrial cleaning agents and laundry powders contain sodium hydroxide or other alkaline agents that migrate through cardboard fibers to contact the ink layer. The onset of flexographic ink saponification turns the dry, protective resin film into a soft, sticky soap-like substance that easily rubs off. This chemical reaction ruins the aesthetic appeal of the carton.
Print Failure
Protective varnishes can isolate the printed ink from alkaline exposure, but they must be applied flawlessly to prevent localized failures. When flexographic ink saponification occurs, it breaks down the polymer network of the ink, which causes it to run, smudge, or transfer to the hands of the end-user. Correcting this issue requires printers to transition to alkali-resistant pigments and acrylic binders that do not hydrolyze under high pH conditions, ensuring the packaging retains its integrity even in damp environments.