Reprocessing printer ink in inkjet printing poses technical and business challenges to environmentally sound printing. Epson’s “Closed Loop Recycling program,” according to its 2023 Sustainability Report, recycles approximately 120 tons of used ink per year (1.2 percent of overall sales), disassembling dye-based inks such as Cyan Dye with chemical depolymerization technology into initial monomers and manufacturing new cartridges. Reduced carbon footprint by 45% (energy consumption per litre of ink manufacturing from 18kWh to 9.8kWh). But this technology could only be utilized in certain models (such as the EcoTank series), and the recycling fee is a maximum of 50 yuan per kilogram (it costs 30 yuan per kilogram to manufacture new ink), and the requirement of relying on government subsidies in order to remain operational (the EU REACH regulation requires companies to bear 30% of the recycling fee).
Third party recyclers such as TerraCycle offer cartridge shredding and sorting facility by which the plastic casing (60%), residual ink (25%) and metal chip (15%), are separated from which the plastic is recyclable to stationery (80% reuse). But the ink can be deteriorated only for industrial paint due to mixed pollution (error in compatibility >40% due to diversity in different brand formulations) (value reduced from 200 yuan/liter to 50 yuan). Reports say that 23,000 tons of inkjet printer waste ink are produced every year, and just 12% of them go through proper recycling channels (U.S. EPA figures), and the remainder has the possibility of seeping into groundwater via landfills (0.5 grams of chromium and cobalt heavy metals per liter of ink).
As far as technical bottlenecks are concerned, pigment ink nanoparticles (80-120 nm) such as HP Vivera are difficult to completely isolate using centrifugal technique (only 55% recovery percentage), while dye inks are biodegradable (breakdown rate of 90% after 6 months). However, it needs treatment under specified conditions of pH 5-6 and temperature 25°C (degradation in the natural environment for over 5 years). In 2022, the Japanese Toray Company developed an “ion exchange resin filtration system” to isolate 95% pure water from waste ink (cleaning the nozzle) and deconcentrate pigments into ink by-products (30% saving on processing costs per ton), but the investment in equipment is up to 2 million yuan, which limits its application in small and medium-sized printing plants.
Environmental certification requires change, like recycled inks bearing the Nordic Swan Mark being required to meet the ISO 14001 standard (heavy metal content <0.01%), having their printable performance (e.g., color gamut area coverage sRGB 92%) 8% lower than original inks (ΔE color difference >3), and having their printing performance 8% lower than original inks. But the price is 40% less (0.15 yuan vs. 0.25 yuan per milliliter). According to consumer research, 65% of consumers will pay a 10% premium for recycled ink, but only 28% will accept a color difference of more than 15% (Pantone certified sample test).
Policy and innovation are mutually complementary, and one good example is the California’s Print Consumables Recycling Act of 2024 that mandates the makers of inkjet printers to provide free recycling packages (comprising 90% of models sold), which will increase recycling rates from 12% to 35%. Meanwhile, the “photocatalytic decomposition technology” invented by Harvard University Materials Laboratory can break down organic ink materials within 30 minutes under ultraviolet irradiation (300% more efficient than the conventional technology), yet it will take three to five years to go commercial. Gartner expects the global recycled ink market to reach $4.7 billion (11% CAGR) by 2027, with significant improvement in reducing the separation accuracy error (from ±15% to ±5%) and improving the printhead compatibility of recycled ink (the current failure rate is 25% above the original factory).