ADVANCED FORMULATION - PART 2

TECHNOLOGY FOCUS

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ADVANCED FORMULATION - PART 2

ALTERNATIVES?

by Dom Ruggeri

May 2003:

I recently returned from the STLE National Meeting in New York. As I expected, many vendors were touting their own replacements for Petroleum Sulfonate. Other Sulfonate suppliers were saying they will supply anyone who has need without interruption. I have but one question, if Shell did in fact have 85% of the market, and these other suppliers had 15% of the market, how can these other suppliers ramp up their production to fill the void created by Shell in only 7 months?

Back when the first Sulfonate crises hit (at least the first one I remember) I was working for a major formulating house. We measured our Sulfonate usage in the millions of pounds per year. So a shortage of a key raw material would do us quite a bit of damage as well as the entire metalworking industry. However, in every crisis there is opportunity. The opportunity here was to develop new fluids and reduce our dependence on this one material. I suggested we work toward this goal. While I was able to gain support among my peers, managers were too busy wringing their collective hands to listen.

Eventually I did get a green light to proceed. My assignment was to develop an emulsifier package that would reduce our dependence on Sulfonate. I began looking at various emulsifiers and emulsifier blends. Nothing would emulsify oil as easily as sulfonate. Eventually I came up with a versatile emulsifier package. Although not a Sulfonate replacement, it worked in about 65% of the products. Right about then the price of petroleum rose to the level our supplier wanted and like magic, we had all we needed.

Those of you who remember the formulation series remember we formulated a soluble oil using some rather simple raw materials. These raw materials were both inexpensive and functional we will revisit this formulation in this article.

Formulation:
Nap Oil – 69.8%
Petroleum Sulfonate – 4.0%
Phosphate Ester – 5%
Boric Acid – 3.4
MEA – 6.6%
2:1 Amine Fatty Acid Amide – 3.8
ButylCarbitol – 2.5%
Nony; Phenol EO-4 – 2.0%
Grotan – 2.3 %
Na Omadine – 0.3%
Antifoam – 0.3%

The above represents a simple soluble oil formulation, balanced so that all components work together to make a stable emulsion that will hold together for quite some time. Formulations such as this, and variations there of, are currently being used throughout the metalworking industry. Suppose we opted to use a synthetic sulfonate in place of the natural sulfonate?

The entire dynamic of the formulation is changed. We know that natural medium sulfonates are a blend of high and low molecular weight sulfonates to an average molecular weight of around 450 amu. This blend yields not only good emulsions, but also imparts a certain amount of corrosion protection due to the blend of high and low molecular weight sulfonates.

Substitute a synthetic sulfonate and you could have to reformulate this product. For example:

Synthetic sulfonates are used at a level of about 20% less the natural sulfonates.
They are amine based rather then sodium based.
They tend to be foamier then the natural sulfonates.

Therefore our formulation would look something like this:
Formulation:
Nap Oil – 70.6%
Synthetic Sulfonate – 3.2%
Phosphate Ester – 5%
Boric Acid – 3.4
MEA – 6.6%
2:1 Amine Fatty Acid Amide – 3.8
ButylCarbitol – 2.5%
Nony; Phenol EO-4 – 2.0%
Grotan – 2.3 %
Na Omadine – 0.3%
Antifoam – 0.3%

This formulation assumes that the sulfonate is the only change you will have to make. -- I doubt it will be the only change. The synthetic sulfonate molecule is very different then the natural sulfonate molecule. This difference will cause changes in your fluid from something as minor as a spec change to as major as emulsion particle size. What will change and how it will change will depend on the formulation and the other additive packages. At the very least, your product may be foamier as synthetic sulfonates do tend to foam more then natural sulfonates. My advice is that if you are going to change to a synthetic sulfonates, work closely with your supplier and question them till you feel comfortable making the change.

A broad brush approach, yes, but with the millions of formulations out there it is impossible to take to discuss all the possible scenarios. As always though, should you have any questions, please feel free to e-mail me in care of the magazine. (Feedback Page) Till then,

Good Luck,
Dom