On the face of it digital printing is less detrimental to the environment that litho printing. However, there are many instances when litho printing is the only viable method of production – so how does that stack up in terms of the environment? Read on for a consideration of how digital and litho printing can both influence our environment.
Digital Printing Prevents Waste
Whilst digital printing still requires paper it typically uses considerably less material than litho printing, which requires material for the initial set-up and also an element of running waste (i.e. you can’t just stop a press when it reaches the number of sheets you need). Digital printing is the master at print on demand, enabling the exact number of copies to be printed when required and eliminating any excess material waste.
Digital Printing is Clean
Digital printing does not require the use of printing plates but works by sending the image to be printed directly to the press – saving time and money on the process costs involved in litho printing. Without printing plates the process is quick and clean without any need for chemicals or plate materials.
Digital Toners are Eco-friendly
A grey area in digital printing has always been the eco-credentials of the toners or ink employed. But the next generation of toner from industry-leader Xerox has changed that. Produced by Emulsion Aggregation, a chemical process used to 'grow' very small, uniform particles, these toners do not use the conventional kneading or pulverising method. 'Growing' the toner particles uses 25 -35% less energy per 450g of toner, combined with 40-50% less toner required during printing.
A 60-70% energy reduction per printed page
Elimination of fuser oil
Image fixing at lower temperatures
A similar technology is also used by Konica Minolta and their Simitri HD polymerised toners, both of which are used by Kall Kwik Welwyn Garden City in our production printers.
Litho Printing Cleans up its Act
The UK print industry is the fifth largest in the world and has the potential to consume large amounts of energy, chemicals, water, paper, aluminium and plastics.
But things are improving, particularly with regards to litho printing. Today, all hazardous waste (including chemicals and ink) is collected for careful disposal and computer-to-plate technology has eradicated the use of film. And finally, whatever is left over at the end of the printing process is either fully recycled or re-used.
Reduce or Avoid the use of Chemicals
There is a major shift towards waterless printing which delivers four key environmental benefits:
Water sustainability—an increasingly pressing need everywhere
No tainted water discharge—no fountain solution, no waste water management
Reduced solution and chemical in plate processing—minimized VOCs
Sound ecology benefits
Adopting waterless printing also allows presses to run IPA (isopropyl alcohol) free which eliminates the emissions of VOC’s (volatile organic compounds) in to the atmosphere. VOC = bad, no VOC = good!Waterless printing also reduces the time spent in make-ready and the actual press run. As a result, a smaller amount of waste paper is generated in the preparation process.
There is little compelling reason for litho printing inks to contain mineral oil and the new age of printing ink is heavily focussed on using vegetable oil based inks such as soy or linseed. Vegetable oils are derived from renewable resources and the inks made from them are more easily removed from waste paper during de-inking. Vegetable oil based inks do not release VOC’s as they are drying, which is a good thing!
Printing plates can now be produced ‘chemistry free’, eliminating the disposal of exhausted developer in to the hazardous waste chain.
The introduction of the Hazardous Waste Regulations in 2005 has forced all printers to look more carefully at how they can reduce and recycle waste. There are now avenues readily available to recycle all of the paper waste produced in the course of printing and aluminium printing plates are fully recyclable.
Adopting alcohol free printing, or more specifically waterless printing, and chemistry free plate making will reduce the amount of chemical that are generated and require disposal under the Hazardous Waste Act.
Finally, the new generation of printing presses are designed to run leaner and cleaner than than their older counterparts and can consume 50% less electricity. New equipment is more efficient with faster setup and running speeds and ensure more output per Kw of electricity used.