Since January 1, 2023, French law n° 2020-105 (AGEC) of February 10, 2020 for the elimination of inks containing MOH and decree n° 2020-1725 of December 29, 2020 (articles D. 543-45- 1 and D. 543-213 of the Environmental Code) applies to mineral oils containing substances that interfere with the recycling of waste or limit the use of recycled materials because of the risks they present to human health with MOAH and MOSH rate steps at 1% and 0.1% respectively for 2024 and 2025.
In France, there is almost no more mineral oil which is replaced by new inks based on vegetable oils, inks based on biosourced oils, inks based on so-called "white" oils and new technologies coming.
- Vegetable-based inks are widely used in sheetfed offset, but they are not yet applicable to rotary offset.
- Bio-sourced inks that have been tested so far require a lot of adaptations and compromises. They are therefore not the expected simple alternative either, while presenting a significant additional cost.
- Inks « white », compatible with the requirements of the "Blue Angel" standard, are composed of purified and refined mineral oils that do not contain controversial aromatic compounds. Their slight additional cost and their relatively simple implementation, position them, at present, as the only alternative ink applicable to the rotary offset printing sector.
The problem comes mainly from large rotary offset printing companies for newsprint, magazines and cardboard packaging. The risk is at the time of collection and sorting of used paper, because packaging and graphic paper recycling loops are common. Paper from rotary offset printing can then end up in the packaging paper recycling circuit and expose consumers to the aromatic compounds present in conventional inks, by migration into food.
No ! we print in Heidelberg offset with UV curing. UV offsets do not use inks with oil (see difference between inks below). This is another ink technology that is used to enable the use of UV which will dry liquid ink to solid ink at high speed to adhere to polypropylene which is inherently impermeable to oil. Oil cannot be used on this technology to print on polypropylene. Inks with mineral oil are for printing on paper and cardboard.
Ordinary offset printing ink is mainly composed of rosin resin, mineral oil, vegetable oil, pigments, filler, oxidation desiccant and additives. Fillers, pigments and driers remain mineral in nature. This is why no ink is 100% vegetable.
These inks have many advantages for the printer :
- better transfer providing more intense, more brilliant colors and allowing a reduction in consumption
- better water/ink stability allowing printing at high speed (up to 18,000 sheets/hour) and reducing waste
- better environmental management: reduction of VOCs. (Volatile Organic Compounds), easier recyclability of printed matter…
However, they have a strong odor and cannot be used for printing food packaging because they can degrade the organoleptic properties of packaged food.
Its drying process depends on the combination of oxidation of the conjunctiva surface, internal penetration of the ink layer binder and solvent volatilization. This drying process is not temperature sensitive and can adapt to a wide temperature range. At the same time, the daily lighting source has little effect on the drying process of ordinary offset printing ink, but when transporting and using ordinary offset printing ink, it is necessary to avoid prolonged contact with oxygen.
UV offset printing ink provides significant technical advantages for a printer regardless of the type of printing used.
- A gain in productivity thanks to its instantaneous drying under ultraviolet radiation, allowing any reworking or shaping immediately after printing.
- High quality prints (high gloss, high resistance to physical and chemical attack).
- A clean technology without Volatile Organic Compounds (VOC) thus preserving the environment.
UV offset ink is mainly composed of unsaturated resin, prepolymer, photoinitiator, thinner, pigment, filler and additives. Its curing process is that under the irradiation of ultraviolet light, the photoinitiator absorbs the radiation energy of ultraviolet light and splits into free radicals, which initiates the reaction of polymerization, crosslinking and grafting of the prepolymer, and solidifies into three-dimensional network polymer in a short time to form a cured film. In this process, the UV intensity determines the degree of curing of the UV offset ink. 100% of the ink deposited on the support ends up in the dry film, unlike traditional inks.
UV technology is clean energy because it is free of Volatile Organic Compounds (VOCs). This technique preserves the environment. In addition, UV dryers consume 10 to 50 times less energy than hot air ovens used for printing with solvent ink. Finally, the UV process does not require the installation of air control or pollution control systems within the printing plant.
The sector of printing on paper and cardboard support is obliged to follow the law concerning the prohibition of mineral oil, however one can wonder about the ecological aspect of this law which was adopted by policies that are influenced by a short-term ideology and a limited vision of medium- and long-term consequences. (We have very instructive precedents such as the decision to phase out nuclear power which caused an explosion in the production of energy from gas and coal). Indeed, the use of vegetable oils (linseed, tung, soybean, sunflower, rapeseed, palm, etc.) promotes intensive and industrial agriculture by using more chemical fertilizers, herbicides, fungicides, insecticides, growth regulators , GMOs which will also impact not only humans but also all ecosystems. We can add the problem of intensive irrigation, deforestation, the rise in food prices, the transport of these oils from all over the world... We find this same problem with agro-fuels: an attractive idea whose disadvantages may to be superior to the advantages!
We can nevertheless underline an evolution and a recent effort for new inks without vegetable oil with a Heidelberg partnership and the inks of the company Pure. It is hoped that the entire ink production industry will find similar solutions.