The First Step to Quantifying 'Green'

By Al Berna, Inksolutions LLC | June 9, 2009

There has been a growing trend in the ink industry for “green” inks.

There has been a growing trend in the ink industry for “green” inks. Currently this is such a hot topic that nobody will mistake this for phthalo green ink; I am referring to inks that are better for the environment.

While this trend has been going on for quite a long time, the interest in producing a “green” ink is as keen now (maybe keener) as it was during the soybean sticker inks of the mid ’90s.

According to NAPIM’s Executive Summary currently on its website,www.napim.org, “Printing with inks formulated with soybean oils as a replacement for petroleum-based oils is one of a number of approaches aimed at reducing the environmental impact of printed products. Generally, this objective can be accomplished by reducing air pollutant emissions (volatile organic compounds or VOCs), using raw materials based on renewable resources and minimizing the impact of the entire life cycle of the ink from the production of the raw materials through the disposal or recycling of the finished printed product…….”

The NAPIM report then explains ways to increase the environmental friendliness of ink and explains why some popular ideas aren’t actually making ink more “green.” The NAPIM report also explains that soybean oil is not applicable to all types of ink but is partially limited to oil-based offset ink. This article will focus on the vehicle portion of these types of ink.

Let’s listen in on a conversation between an ink maker and a varnish maker:

Ink Maker: “I need to make a green ink so I need to buy a green varnish.”
Varnish Maker: “How green does it have to be.”
Ink Maker: “Green is green, isn’t it?”
Varnish Maker: “Some raw materials are greener than others.”
Ink Maker: “You’re the varnish maker, if you say it’s green then my ink is green.”
Varnish Maker: “OK, I’ll make it as green as I can and shoot you a sample.”

Now, as a varnish maker, I go off and make the varnish “greener” by reducing petroleum solvents and increasing soybean oil. I than have a varnish that is “greener” than…..what?

Quantifying ‘Greenness’

What we need, as an industry, are definitions that will allow us to gauge the “greenness” of a resin, wax, oil, varnish, flush or ink. Inksolutions has begun to quantify how green the varnishes are we produce.

Before I explain the system we are developing, I would like to pull one more quote from the NAPIM statement:

“Soybean, linseed, tung, safflower and other vegetable oils are all clearly renewable resources while petroleum oils are not. Therefore, the use of vegetable oils of any type will reduce the demand for petroleum oils in the printing ink industry.”

I point this out because our system considers all of the seed/vegetable oils renewable non-volatile ingredients and, as such, “green.”

Table 1: Inksolutions Green Score.
The system is simple and based on the concept that VOCs are not green and seed oil is green. Using simple formulation percentages, the system simply subtracts the percentage of VOCs from a base number (100%) and adds the percentage of seed oil. This results in a “green” score. The higher the number, the “greener” a product is for the environment. As an added benefit, the VOC content and the percent of seed oil is kept separate for more refined choices.

In this scale the lowest score, 0, means that the product uses all volatile solvent and no seed oil. The highest score, 200, means that the product uses all seed oil.

This is all done by subtractingpercentage of VOCs and adding percentage of SOCs:

GS = Green Score
VOC = % Volatile Organic Content
SOC = % Seed Oil Content
Therefore:GS = 100 + SOC – VOC

A formula consisting of 100% volatile ink oil would be:

VOC = 100
SOC =0
GS = 100 + 0 – 100 = 0

A formula consisting of 100% vegetable oil would be:

VOC = 0
SOC = 100
GS = 100 + 100 – 0 = 200

A formula consisting of:

Modified Phenolic Resin40
Alkyd Resin10
Ink Oil20
Soybean Oil20
Linseed Oil10

would result in:
VOC = 20
SOC = 37 (70% seed oil in Alkyd Resin)
GS = 100 + 37 – 20 = 117

Inksolutions has applied this system to all of the varnishes it produces to obtain this information. Here is a partial list of products (Table 1):

This information can be useful for a number of reasons: besides allowing an ink formulator to pick greener vehicles, this information can be carried through to an inkformula or a blend of vehicles.

A vehicle’s green score can be used to calculate the green score for any blend of vehicles, or an ink, without knowing the vehicle’s formula. Algebra tells us that the calculation for the green score (GS) requires two variables (see above).

Using a known green score, the VOC content of a vehicle and the percent of seed oil (which may be calculated if unavailable) the green score formula can be applied to any blend of vehicles or an ink.

Table 2: Comparison of formulas to determine Green Score.
For example, the following two ink formulas have been slabbed and compared to each other (Table 2).

Now, using the Green Score information, a formulator can easily see that formula B is a greener ink than formula A.

This information can then be balanced with the results of printing tests to determine the best performance at the highest green level.

Developing a Clearer Picture of ‘Greenness’

This method, which is in its infancy, has plenty of room for enhancement. With the cooperation of suppliers and ink makers, the more producers who report VOCs and SOCs of materials that go into finished inks, the more refined the results will be. In the above example, every unfilled box in the VOC and SOC column that can be filled in will give a better picture of the greenness of the finished ink.

In addition, you can see that additional variables can be used. This would allow for ideas like raw materials which are not 100% renewable or any other green considerations. The idea of a “scoring system” is to be able to make improvements and to communicate to all involved people what is going on.

Armed with this data, we can clearly make progress that satisfies our customers and helps our supplier focus on the right issues.

Inksolutions is dedicated to helping the environment, not unlike any other responsible manufacturer. We feel this system will help advance our industry’s ability to demonstrate our continued efforts to help the environmental demands of the ink manufacturing and printing industries.

Al Berna is technical supervisor at Inksolutions LLC. He has been in the varnish industry for 22 years, including 18 years at Lawter. He has a bachelor of science degree from Roosevelt University, Chicago, IL.

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