The term “Bio-based” was defined by the United States Secretary of Agriculture in the Farm Security and Rural Investment Act of 2002, and said that “bio-based products” means a product determined by the Secretary to be a commercial or industrial product (other than food or feed) that is composed, in whole or in significant part, of biological products or renewable domestic agricultural materials (including plant, animal, and marine materials) or forestry materials OR an intermediate feedstock.
Further to this, the Biobased Manufacturer’s Association defines Bio-based materials as:
- Relies on plant or animal materials as the main ingredient.
- The plants or animals utilized are a renewable resource.
- With some exceptions, generally do not contain synthetics, toxins or environmentally damaging substances.
It would be remiss of me to talk about bio-based materials without throwing out the words “sustainability,” “green,” “carbon footprint” and “environmentally friendly” in the same context. One could also argue that low V.O.C. or V.O.C. free formulations might be better for us than “bio-based” anything because we’re eliminating or limiting the amount of volatile organic compounds that escape into the atmosphere. And we all know that less air pollution equates to a healthier ozone layer, which in turn helps protect and sustain our planet.
Smithers Pira (formerly Pira International) defines “environmentally friendly” as a reduction in V.O.Cs, the use of renewable resources in ink formulations, lower energy usage and a decreasing life cycle assessment (LCA) value. The United States’ EPA’s website states that, “LCA is a technique to assess the environmental aspects and potential impacts associated with a product, process, or service, by:
- Compiling an inventory of relevant energy and material inputs and environmental releases
- Evaluating the potential environmental impacts associated with identified inputs and releases
- Interpreting the results to help you make a more informed decision.
Legislation on bio-based material usage
Legislation has been slow and disjointed when it comes to using bio-based materials, but already we’re starting to see localized communities beginning to take action in the fight for cleaner air and a less harmful environment. In the European community, REACH, the Regulation on Registration, Evaluation, Authorization and Restriction of Chemicals, is affecting how companies formulate, and ISO 16759, provides a framework methodology for measuring the carbon footprint of products and services.
When we look at the landscape of ink (and coatings) development over the last few decades, we’ve certainly come across these terms on a frequent basis, usually in our quest to formulate a “better” ink system; “better” meaning – better for the environment, better for the customer, better for the world. But it goes without saying that bio-based raw materials aren’t necessarily going to meet every criteria in the quest for a better ink system. In this article we’re going to look at some sources for bio-based raw materials and touch on how they can be used to formulate ink systems. In part two of my article we will focus more heavily on ink formulation and printing parameters, but to start with we need to ask ourselves, “When it comes to using bio based materials to create bio-based inks, what are we really after?
The Benefits and challenges of Bio-based Products
It could generally be agreed that using bio-based materials means that our environment is healthier, our health is safer and that we reduce our dependence on imported oil. But most ink developers say that they want to use bio-based materials because at the end of the day they want to get more business! How you ask? By packaging their ink systems in a way that is attractive to the buyer (low VOC, environmentally friendly, better for you… etc..).
NAPIM’s Biorenewable Content (BRC) program identifies the use of such bio-derived renewable resources in printing ink formulations and creates a rating program based on the level of BRC used. But this aside, equally as important is how the ink performs on press, because after all it’s of no value if we can meet the bio-based criteria only to have the ink fail on the printing press or later on the finished package.
Let’s be clear: there are a myriad of bio-based raw materials out there to choose from and we’re only just beginning to identify and qualify some of these in ink formulations. Take a look at the table below (for a full list of over 20 raw materials and more download our free
Take a look at the table below (for a full list of over 20 raw materials and more download our free Bio-based Raw Materials Cheat Sheet for Ink Formulation).:
|Table 1 – Bio-based raw materials for ink formulation|
|Cellulosic resins, including CAP, CAB and Nitrocellulose||Plant||Binder|
|Hemicellulose||Trees||Thickening agent, Binder|
|Gum Arabic||Trees||Thickening agent, Binder|
|Tall Oil Rosin||Trees||Binder|
Bio-based raw materials for Solvent and Water Based inks
The number of companies manufacturing bio-based raw materials has certainly increased in recent years, and while it would be difficult to name all of the materials that we can use, it might be better to note where we can replace some of the traditional products with those of a bio-based origin. The table below illustrates this.
|Table 2. Bio-based raw material alternatives|
|Traditional Material||Bio-based Material||Function|
e.g. Soyanol™ 5000X, 5000X-HS, 5000X-TB
|Viscosity modifier improves pigment dispersion characteristics|
|Soy based emulsions
e.g. Soyanol 1000E, 5000E SGE40 Resin System (Soy Technologies LLC)
|Coalescent/Plasticizer improves freeze/thaw stability.
Improves “open” time
|Acrylics and styrene acrylic emulsions||Polysaccaride resins e.g. INKRESTM 33 (Lorama)||Increases ink transfer
Increases gloss PH neutral inks
Improve ink clean up
|Acrylics and styrene acrylic emulsions||Hemicelluloses||Binder for inks
|Petroleum based resins||Bio-based polyester resins
e.g. Envirez (Ashland)
|Binder for inks and coatings|
Bio-based raw materials for UV inks
The market for UV curable materials continues to rise, and we’re seeing a few companies making UV curable oligomers and monomers made from a certain percentage of bio-derived material. This bio-content can include the likes of Soybean, Linseed oil or cashew nutshell oil. Epoxy acrylates of soybean oil are used to impart flow and offer good pigment wetting. These can also be used to increase the flexibility of ink systems. There are also fatty acid- modified epoxy acrylates, which function to improve the pigment wetting ability of a given oligomer and which also serves to limit shrinkage and brittleness of the cured ink film. A typical ink formulation would look something like this:
- Pigment dispersion…………………………50-60%
- Acrylated monomer…………………………2-5%
- Filler (e.g. talc)………………………………3-5%
- Liquid photoinitiator blend…………………10-12%
Looking to the future
There is certainly no shortage of bio-based raw materials for use in ink formulations and each year we see more and more products becoming available. Litho is probably significantly ahead of other print processes when it comes to formulating with these materials, with flexo printing some distance back.
Today, the biggest opportunities are in formulating inks for paper and board (corrugated and folding cartons) because drying and ink adhesion still remain the biggest obstacles to formulating for non-porous substrates. But there’s no doubt that in the coming months and years we’re going to see a whole new landscape forming when it comes to choices for bio-based formulations.
As you can see there are a number of bio-based raw materials that can be used to create ink formulations.
If you are developing a bio-based ink formulation it is important that you work with an expert ink specialist, to source the correct raw materials, and create a formulation that fits with your technology and end business goals.
I’ve shown you important definitions, and a list of raw materials and alternatives that you can use. Now, I would like to know what you are working on. Are you finding it difficult to find the right raw materials? Or is your struggle with adapting your existing ink formulation to a bio-based formulation? If you have any questions or tips that we can share with others, please let us know in the comments below.
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