Eric Pettersen, a retired United States Air Force officer, and his son, Matthew Pettersen, are the president and chief product officer of TALubes. They recognize that biobased, environmentally friendly lubricants provide human health and environmental safety advantages, but commercial success requires performance and cost-effectiveness at least equal to products formulated from petroleum and synthetic base stocks.

At first flummoxed by a suspension problem with larger molybdenum particles they had been using in their formulations, the duo set their sights on long-term suspension that would not reduce the effectiveness of the molybdenum in the final product.

After plenty of practice shots, the Pettersens applied to patent lubricants made by a method for dispersing colloidal metal sulfide particles in base oil, producing what they say are high-performance biobased lubricants.

Colloids

A colloid is a stable mixture of two insoluble materials, typically microscopic particles or droplets dispersed in a continuous material. Common examples of colloids are smoke (solid particles in hot air), milk (globules of butterfat in aqueous solution), and inks and paints (solid particles in fluids).

The chemistry of the particles and fluid affect interactions between particles and between the particles and the fluid. These interactions balance in stable colloids, where individual particles are separated. Imbalance of these interactions can cause particles to agglomerate or settle into a sediment.

In general, a stable colloid contains particles that are between 1 nanometer and 1 micron in size. When colloids are prepared commercially, it is usually necessary to apply milling, high-shear mixing or spraying to break apart particle agglomerates and disperse individual primary particles in the fluid, along with chemical dispersants such as surfactants. But TALubes prepares stable dispersions of metal sulfide particles in oil without resorting to energy-intensive shearing or other mechanical means.

For pilot-scale batch production, base stock is pumped into a reactor vessel such as a 55-gallon drum. An electric or magnetic field, or both, is applied while an overhead mixer stirs the oil as metal sulfide powder is gradually added.

In general, an electric field is produced by any charged particle, and a magnetic field is produced by a magnet or a moving charged particle. These fields affect other particles, atoms, molecules, etc.

The magnetic field is applied using electromagnets attached to the exterior of the reactor, which pass an electric current through a wire coil to generate the magnetic field. The electric field is applied by immersing a cathode (positive electrode) in the batch and attaching an anode (negative electrode) to the outside of the reactor. Both electrodes are attached to a direct current power source.

After mixing, the batch is centrifuged to separate larger particles from the colloidal dispersion of smaller particles in the fluid. The stable colloidal suspension is packaged, while the larger particles are processed with high shear to reduce their size and then used to make another batch of lubricant.

Formulations

TALubes said its process works for dispersing molybdenum disulfide in vegetable oils and methyl, ethyl, propyl and butyl esters of fatty acids.

MoS2 is used commonly as a friction-reducing additive in lubricants. For example, commercially available MoS2 with an average particle size of 6 microns is supplied in powder form. TALubes reports that after dispersing this MoS2 powder in oil, average particle size was smaller, with minimum particle size of approximately 1 micron in some cases and submicron sizes in other cases.

Blending MoS2 in soybean oil using TALubes method produces an opaque mixture that appears nearly black. After centrifuging, the mixture has a translucent, golden appearance. This processed oil is used as the base for greases and anti-seize compounds.

For metalworking applications, TALubes disperses between 0.1 and 2.0 pounds per gallon of MoS2 in a methyl ester derivative of a vegetable base oil. Nano-cellulose is added to adjust the viscosity and make metalworking fluids for use in computer numerical control machining, screw machines and minimum quantity lubrication applications.

In contrast to conventional metalworking techniques that flood tools and work pieces with fluids, MQL techniques atomize the metalworking fluid and apply it directly to the cutting zone. MQL machining processes are applied in particular to titanium and other metals that are relatively difficult to machine.

So far, the company has parlayed its techniques into eight formulations: Enviro brand aerosol oil, high oleic soybean oil, transformer oil and grease; universal joint grease; pneumatic oil; anti-seize compound; and tapping and machining paste. Four ounces of the machining paste sells for $45 from Travers Tool Co., and the anti-seize compound goes for $30 per pound. TALubes considers its products to be cost competitive with other high quality lubricants.

These base formulations can be used for general purposes or adapted for specific applications.

The company also produces what it calls environmentally friendly lubricants for firearms and fishing reels, distributed by Sconix Outdoors as Shooters Gold and Anglers Gold premium greases and oils.

Field Trials

Eric Pettersen and Scott Pearson, business development consultant for TALubes, told LubesnGreases about several field trials of the companys metalworking lubricants.

A soybean oil based machining fluid was formulated for a trial at the Machinist Training Center at Pueblo Community College in Pueblo, Colorado. The trial used a CNC machine and a single 3/8-16 UNC-2B tap tool to tap a piece of 318 stainless steel, with lubricant sprayed onto the drill. The goal was to run the trial until the tool failed, but it was stopped after 179 holes were drilled and the tool was still usable.

The company also formulated metalworking paste from a colloidal dispersion of MoS2 in vegetable oil. A customer suggested that a paste might improve upon fluids by staying in place better on metalworking tools, Pettersen explained.

The tapping paste is applied by hand or brushing instead of spraying. In Pettersens opinion, there is less mess and easier clean-up with a paste versus spraying a fluid. While end users may be unfamiliar with paste lubricants for tapping, they have been impressed with its performance and cost savings due to fewer failed taps and broken parts and less down time, he said.

In a trial, a variety of metal alloys were tapped (see graph on Page 36). The paste outperformed a traditional commercial product in horizontal drilling on superalloys Inconel and Hastelloy, which are high-performance metals with excellent mechanical strength, high temperature stability and corrosion resistance used primarily in turbine engines for aerospace and marine applications.

According to Pearson, significantly more holes per tool were tapped or drilled using TALubes paste versus the traditional lubricant, using identical tools and production methods. Tool life was extended between 192 percent (beryllium copper) and 366 percent (K-Monel 500). Similar results were obtained for cutting operations with these alloys.

Pearson estimated that using 1 kilogram of the paste could save as much as $10,000 in tool costs when processing Inconel 718, in addition to reduced downtime to replace tools and fewer broken or rejected parts.

In another field trial with a different customer, Electro Methods in South Windsor, Connecticut, Tap It All paste was used to tap Inconel 718. Threaded holes are tapped routinely in Inconel 718 for aircraft engine parts such as turbine blades. The trial used an Okuma B8050 machine with horizontal spindle, servo feed and tension and compression tapping. Drill size was 0.217 inches in diameter, speed was 100 revolutions per minute and tap depth was 0.3000 inches. Resulting tool life was 6 parts per tool with the paste. Another commercial product was unable to drill any holes under the test conditions, though TALubes did not share any details about that product.

Aiming Higher

According to Pettersen, shelf stability tests of formulations under warehouse conditions are in progress. Model formulations have shown excellent stability and resistance to microbial growth. Wide variations in ambient temperatures do not affect performance over at least seven years, he said, and extensive laboratory evaluations with standard tests are planned for this year.

Tap It All Lubricants says its goal is to make environmentally friendly lubricants that present minimum risk to users and the environment and have low disposal costs. The company claims that all of its lubes meet U.S. Environmental Protection Agency standards for being nontoxic, as the amount of molybdenum in the finished products hovers below toxicity thresholds or reporting requirements.

The oils and greases contain at least 93 percent biobased material, meeting the EPAs definition for biobased products, and also comply with U.S. Department of Agriculture BioPreferred Program standards. TALubes is working to formulate products that meet requirements for Environmentally Acceptable Lubricants and other environmental regulations.

In the meantime, the companys lubes are earning a reputation for versatility in niche markets such as firearm lubricants.

Rich Reiley of High Tech Custom Rifles in Colorado Springs has used the products for manufacturing rifles as well as for use on the finished guns. The [machining] paste performs with extreme precision, no noxious or offensive odors and consistently outstanding results. The absolute best part is that it can handle extremely small tapping to cutting large flutes on every gun grade metal or alloy Ive used it on. For extremely precise work, it is without peer, he enthused.

TALubes brought me gun oil and grease to try as cleaning, lubricating and protection lubricants. Both products provide extremely crisp trigger, bolt and semiautomatic actions while keeping corrosion at bay, Reiley said. Their CLP lubricants collect far less carbon in heavy use… [and] require less frequent cleaning off.

Mary Moon, Ph.D., is a professional chemist, consultant and technical writer and is technical editor of The NLGI Spokesman. Contact her at mmmoon@ix.netcom.com or (+1) 267-567-7234.