Greasing the Gears
May 1, 2007
Greasing the Gears
By Tom Wray, Associate Editor
Food-grade lubricants, especially synthetics, are an advancing part of processing.
Processors rely on machines to produce the products they make. And the materials to keep those machines working are as important as the materials they process.
One of the most basic things to keep equipment running is lubricant. Additionally, on food-processing equipment the lubricant used must be non-toxic and safe for use around food products. That said, there are plenty of options for companies looking for solutions to keeping their machines running.
“Food-grade” lubricants are harmless if accidentally consumed at less than 10 parts per million. That compares to the Food and Drug Administration’s zero-tolerance for nonfood-grade lubricants.. The FDA also says that is illegal to sell “adulterated food” or food contaminated with a foreign substance. A list of food-grade compounds can be found at www.nsf.org.
To be rated H1, or food-grade, by the National Sanitation Foundation, it must meet several requirements, says Colleen Flanagan, specialty fluids and food-grade lubricants category manager at Petro-Canada. In the United States, the chemical composition must conform to FDA regulations that restrict both the type and quantity of the additives and fluids that can be used. Both the formulation and the label for the product must be reviewed by NSF to receive the registration. Protocols for the manufacturing process must ensure the cleanliness of the product and that no cross-contamination occurs.
Flanagan adds that customer requirements also play a large role as well, including the need for approval for use in producing kosher or halal foods, among others.
The type of lubricants used is governed by Hazard Analysis and Critical Control Points, or HACCP. Jim Girard, vice president and chief marketing officer at Lubriplate Lubricants, says that every food processor is required to have a HACCP program on file for all materials in their facility. Commodities are divided in to physical, chemical and biological risk categories.
“Lubricants are considered a potential chemical risk,” he explains. Switching to food-grade will remove lubricant as a risk. “It’s rooted in the [U.S. Department of Agriculture] and FDA. … It helps their customers cine if the lubricant [should happen to leak], it can’t contaminate the food.”
Eddy Stempfel, product application specialist for food-grade lubricants and team leader local R&D services at Shell Lubricants, explains the main difference that modern food-grade lubricants have over previous iterations.
“They are formulated with FDA-approved chemicals only and fulfill the criteria formerly set by the USDA in the H1 category and today controlled by NSF.”
The lubricants can be synthetic or “white oil.” White oil, explains Bill Kersey, are mineral oils from which food-grade lubricants traditionally have been made. Kersey is the product manager for food-grade lubricants and greases at Fuchs Lubricants.
There are three types of white oil, Kersey adds: United States Pharmacopeia (USP), Technical Fine and White Oil. Each one has a different purity level, with USP having the most stringent requirements. Synthetics are made with polyalpha olefin (PAO), a synthetic hydrocarbon.
Many newer lubricants have moved toward the use of synthetics, Kersey says. While more expensive, they are better-suited for longer use. “Equipment demands are higher,” he states. “And there is an increase in the base product pricing for white oil.”
As those natural products get closer to the price of synthetics, the cost benefit of using the new lubricants grows.
Typically, advances in raw materials, additives and new technology lead to new developments in food-grade lubricants, says Beth Kloos, president of Haynes Manufacturing Company. “Because this is a much smaller market than the industrial lubricant market, new developments trickle down to the food-grade market much slower than they do for other markets.”
Since lubricants have to be compatible with food applications and machinery, materials that can be used for this purpose are limited.
Some of the new products and processes are developed with the NSF, Kersey says. Since 1998, ISO procedures and audits require that every product be registered to qualify for use as a food-grade lubricant. A new procedure, ISO 29469, is currently being developed for certification of food-grade lubricant manufacturing facilities. Kersey’s own company, Fuchs Lubricants, sits on the certification-development board as a consultant.
The biggest benefit of the synthetic H1 lubricants is the life expectancy. Kersey says that, depending on the temperature, a synthetic typically lasts two to three times longer than natural lubricants, with the potential to last as much as five times longer.. He uses a compressor as an example.
“With white oil, you can get 500 to 700 hours out of it,” he says. “After that, the lubricant oxidizes and breaks down.”
A synthetic oil, on the other hand, will last 1,000 to 1,200 hours. Moisture would shorten the life expectancy for both, so proper maintenance is necessary for both. There are some drawbacks to the synthetics, other than a higher price.
“PAOs do tend to shrink elastics,” warns Kersey. “You can get some leaking, so you want to know if you have those issues.”
Some ether-based synthetics may also strip the paint off machines. Thus, processors must pay careful attention when selecting a lubricant.
Any lubricant can potentially affect the performance of a machine if it is not the proper lubricant for the application, says Kloos. Properly used food-grade lubricants for the correct application should not affect the performance of the machine. Lubricants should enhance the performance when used correctly.
Flanagan adds that food-grade lubricants can show effective performance in machinery. Just as with regular lubricants, there are differences in performance depending on composition of the material. Also, it is important to assess the application and to put the right type of lubricant in the equipment.
Stempfel explains that synthetic food-grade lubricants act the same way as regular synthetic lubricants and can provide extended oil life as well as food-safety benefits.
“In our research, we have compared food-grade and non-food-grade lubricants, and we have seen oil life extended between two to four times in some applications.”
Making the switch
Key to making the switch to food-grade lubricants for any company is verification.
When investing in food-grade lubricants, a company should verify that the lubricant is acceptable for use through a third party, such as NSF, according to Kloos. State or local agencies and plant inspectors may also be a source for what is acceptable.
When a company does make the switch, it is always good to flush the gearbox, hydraulic system, oil recirculation or bearing housing, advises Girard. “When you flush those, you are getting rid of the general purpose industrial lubricant that was in there,” he says. A flushing or purge is needed to ensure the efficacy of the new lubricants in the machine. It becomes even more important in air compressors.
Flanagan adds that part of the maintenance should include oil monitoring and analysis. Food-grade lubricants work very well with all types of machinery, says Girard, adding that he would put food-grade lubricants up against industrial strength fluids. His company encourages customers to go to complete food-grade lubricant programs.
Stempfel says that detailed switchover guidelines are available from every lubricants supplier. They are normally not very different from standard switch over processes for regular lubricants.
“However, to get the full advantage of food-grade lubricants and to follow hygienic guidelines in order to conform with food-safety requirements, the switch over to food-grade lubricants should be done during a major overhaul/maintenance break,” he adds. “Existing machinery should be dismantled and cleaned properly; seals should be checked and replaced if necessary.”
Several manufacturers are coming out with new H1 lubricants that take advantage of new processes and materials.
Haynes recently unveiled its Haynes Silicone Grease. The food-grade product designed to prevent the sticking of valves and o-rings during high and low temperature (freezing) applications and EPDM seals.
Petro-Canada announced the launch of its new Purity FG with Microl line in March. According to Flanagan, the lubricant is industrial-strength and uses an antimicrobial preservative rated for use in food-grade lubricants by the Environmental Protection Agency.
At presstime, Fuchs Lubricants was preparing a global rollout of a full line of products.
“Food-grade lubricants undergo the same development as regular lubricants,” says Stempfel. “Industry and OEM specifications are constantly changing, and food-grade lubricants have to be respectively updated.”