When the Nobel Prize chemist Paul Crutzen popularized ‘Anthropocene” as a geological term that serves to mark the evidence and extent of human activities that have had a significant impact on the Earth’s ecosystem, he certainly associated it with a rather bleak
As a matter of fact, since the time of John Ford’s 1941 movie “How Green was My Valley” (from Richard Llewellyn’s bestseller), we all have seen huge progress for mankind, but too often at the expense of our environment.
Indeed, at this stage, having passed seven billion human beings on earth, after so many ecological disasters and major food-related health catastrophes, most of the people are
Fortunately, science and technologies have been progressing as well, and we may be now at a turning point when a smart use of our natural resources may help moving towards a greener world.
Fighting one’s way through the jungle of concepts and catchwords
Of course, for the public perception, “green” is largely synonymous for a safe and sound product. Unfortunately, such a catchword is
On the other hand, definitions such as “compostable” and/or “degradable” and/or “recyclable” are certainly self-explanatory, but also kind of dry and technocratic for a larger audience.
Also, confusing most of us, a new polemic did raise, whereby “green” might not only be significantly more costly, but worst, may be detrimental to global food reserve because of using similar bio sources.
Sustainability as the concept which
The relatively “global” concept of sustainability, shared by all professionals, is by now largely understood and supported by the public. As often described, this concept is aiming at capturing all relevant parameters to describe a product, i.e. the economic aspects, ecological performances and social
At Siegwerk, we do fully share this approach as to quantify the sustainability level of our products, and we systematically refer to an even more complete understanding of this concept, where “viable.” “equitable” and “bearable” are also part of the equation (Fig. 2).
In the particular case of printing inks, as stated in Siegwerk “sustainability” brochure, a product is only as sustainable as its raw materials.
As a matter of fact, our customers are now asking both for sustainable and bio-based products.
This is therefore quite a challenge for us since this implies to have adequate availability of renewable raw materials for the “bio” part, but also from sustainable resources, or certified as being sustainable, for our raw materials.
The chemical industry as enabler of the move toward sustainability
Contrary to many prejudices it has to suffer
As a matter of fact, expertise in chemical processes and R&D capability is the way forward as to be able to use natural resources in an economically viable way.
Naturally, using water instead of organic solvent in the formulation of an ink does sound good, in particular for the non-expert world, for the rational reason of not emitting solvent in the atmosphere, thus not increasing the “greenhouse” effect, but also for very emotional and subjectiveperceptions.
However, because Siegwerk does believe that waterborne technology might ultimately be for ink as important as it has been in other industries such as automotive paint, the decision has been taken to invest major innovation effort as to take this product line several steps further down the road of sustainability.
The number of newly available “renewable resources” from which a waterborne ink could be formulated so far is huge (Fig 4). The raw materials range from wood derivatives to animal products, including cereals, grass, algae and oleaginous plants.
Siegwerk first major “green” step change achieved using 100% natural resins
The first generation of product made available for the printing industry from Siegwerk Global Innovation Network (GIN),
This has allowed a spectacular jump from the 7%, at best, of bio renewable content in current waterborne inks up to as high as 55%. This bio-renewable content is calculated as the amount (weight by weight) of the bio-sourced material among all components of the ink except water.
Importantly, the main relevant press behaviors, such as color strength, lay and fine dot printing, have been demonstrated as being very close to a well proven current high performance waterborne ink.
However, as the negative counterpart of the “give and take” of moving to higher renewable content, some of the important performances such as wet rub resistances have been shown to be lower than with the reference ink (Fig. 5).
The recent second breakthrough following generation 2: Hybrid technology!
After extensive effort and through partnering with major chemical companies, Siegwerk did conclude that environmental and economic advantages can be achieved through the combination of renewable materials with classical chemical production and/or fossil products.
In close partnership with its suppliers, Siegwerk chose to utilize as a binder a totally new polymer, being the “hybrid” of bio-monomers, and a “standard” oil derivative” acrylic monomers, allowing the formulation of an ink as good if not better than the current standard (Fig. 6).
Indeed, this generation is to the expense of the renewable content of the ink, being already as high as 16% with an identified potential to be increased to 37% medium-term (Fig. 7).
Importantly, through this approach, all the performances ofstandard waterborne inks are kept, be on the press, on print,or during the packaging’s lifetime (Fig. 8).
Further “greener” formulation is already on the bench of Siegwerk Innovation
While the objective is clearly to promote to customers the already existing formulations, be through generation 1 or generation 2 depending on the balance of their priority between renewable content and performances, the Siegwerk Innovation Team is keeping the momentum by assessing ways to further increase the renewable content without losing performances or increasing cost unreasonably, in particular in the “hybrid” technology.
This effort is mostly focusing on additives and retarders first, but is keeping pigments as well on the radar screen (Fig. 9).
Indeed, even if obviously for longer-term application, mostly for performance/cost limitations, there is a lot of research work going on in the field of pigments with some very interesting routes to be further explored.
Again, similar to resins, there are several potential sources for pigments, be they soil pigments, vegetable-based or from animals. However developments in this area are likely to be medium to long term.
Furthermore, taking an even greater challenge, mostly because of complexity in the process needed to extract it efficiently from the plants, lignin is offering a lot of interest. Indeed, lignin, which is, together with starch and cellulose, an important component of most of the green plants, can be also found as a by-product of paper industry. It means that by being able to use it, we would not only move to a 100% natural and renewable source, but also help improve the management of paper industry by-products (Fig. 10).
Conclusion: Waterborne and green rhymes better and better
Contrary to some negative prejudice, it has been demonstrated that waterborne inks can be formulated toward “greener” products while maintaining performance levels satisfactory enough for fully commercial usage. Competitiveness against conventional inks has to be achieved, and although there is a small premium to pay by kilo, the impact on the cost of the printed square meter is negligible.
Even more importantly, Siegwerk has been able to enter a “positive spiral” in formulating after having achieved the first breakthrough, and identified the potential next steps for improvement.
However, as always in such a major move, this is only through partnerships, with the commitment of all parties involved, that the final goal will be reached: a truly “sustainable “ ink, safer for human beings, friendly with our environment, not more costly to produce and use, and not manufactured at the expense of food reserve.
An added benefit of this project has been to already introduce commercially certain products where the renewable content has been increased, i.e. renewable-based press side additives for maintaining printability.
On top of the process and spot inks of generation 1, containing as much as 55% bio products, and tested industrially with success against standard waterborne inks, a white ink being almost 100% “natural” since containing titanium oxide as pigment, is now on the market after very successful launch. Indeed, all performances, including hot resistance, for pre-print application, have been almost identical to standard!
A project in which Siegwerk is happy to put its Heart and Soul!
Dr. Gilles Catherin, engineer in chemistry and PhD in macromolecular chemistry obtained in 1979, is a real “Inky.” His career in printing inks started in 1982 with Sicpa. Within this group, he has been successively technical director in France, operational director in Asia-Pacific region, and general director for South East Asia. With Sicpa first and with Siegwerk as of 2005, he has organized the research activities and became vice president of innovation. His innovative ideas have made him the co-inventor of more than 12 patents covering different ink technologies as well as manufacturing processes. Since 2010, he works as a consultant to transfer his recognized expertise and knowledge.