This feature originally ran in the October 2010 issue of Food Manufacturing.
The Food Manufacturing Brainstorm features industry experts sharing their perspectives on issues critical to the overall food industry marketplace. In this issue, we ask: What factors should food manufacturers consider when choosing between mineral-oil-based lubricants and synthetic food grade lubricants for use in their facilities?
Richard "Max" Maksimoski, President, Maximum C/Q, LLC, (An independent consultant to LiQuifix, LLC)
We believe that there are three primary considerations when selecting a lubricant for use in a food facility:
The first and most essential gate in certification is an understanding of the situation where the lubricant is being used, its potential for food contact, and the necessary rating of the lubricant. Whether the item is mineral or synthetic oil-based, this is a key regulatory requirement. Most situations will require the highest level rating, H-1, as the potential for food contact is high. Other ratings such as H-2 or H-3 may be allowable, but an effective analysis must be done to validate that lower ratings are acceptable.
Once certification is determined, the next analysis is an understanding of the shears, stresses, temperatures, materials, and conditions that this lubricant will encounter. By analyzing the operating conditions where the lubricant will be needed, a determination can be made of the specifications that will be required of the lubricant. Analysis of wear patterns on existing equipment, knowledge of the types of materials (type of steel, aluminum, plastics, etc.) that are involved, potential for corrosion, potential for contamination by the food or environment, run temperatures and other operating parameter data needs to be gathered. With this, lubricants can be screened for their capability in these conditions. Reputable lubricant firms will cite specific ASTM tests that correspond with simulations of these conditions. These tests will help to narrow the scope of potential lubricants to utilize in actual plant test trials.
Once the field of potential lubricants has been narrowed, the next consideration is value. Notice that we did not say cost, but value. A lubricant that costs almost half as much but requires twice as much to be used is a comparable value. Durability of the lubricant, use rates, change-out frequency, effect on PM rates and ability to extent machine life are just some of the value effect considerations. Cost is part of the value equation, but is only part. Benefits/effects are just as essential.
Colleen Flanagan, Category Portfolio Manager, Petro-Canada Lubricants
Just like with all lubricant decisions, food manufacturers should carefully do their research to find the right food-grade lubricant for their specific applications. They should take into consideration the lubricant’s performance features and key advantages, such as fluid life, wear protection, temperature ranges and antimicrobial protection.
They must also ensure that the lubricant is NSF registered and complies with local registration requirements for the country of origin and any countries where it will be exported, for use in and around food processing areas. At a minimum, all areas with any potential for incidental contact between the lubricant and the food manufacturing process must use food grade lubricants. Many modern plants use food grade lubricants throughout their plants to prevent any potential for incidental contact.
When assessing a supplier, look for a company that provides a comprehensive portfolio of lubricants designed for specific applications. A partner with a broad base of experience and product knowledge is another must.
Paul Llewellyn, General Sales Manager, Lubrication Engineers, Inc.
There are many factors that come into play when choosing between a mineral-oil-based food grade lubricant and a synthetic food grade lubricant.
First, we must look at what the OEM has specified as the lubricant of choice for the equipment. Often, the lubricant specified will be a synthetic lubricant meeting the designed viscosity needs for the proper operation of the machine. A new piece of equipment will typically be under some type of warranty and using a lubricant other than what meets the OEM’s design specification could void the warranty.
Second, we must look at the equipment’s operating temperature. If the temperatures are high (170°F and above), such as in many oven applications, or low (32°F or below), such as a cooler or blast freezer application, then a synthetic lubricant will be the only lubricant that will perform under these severe conditions. This is due to its designed viscosity stability, as indicated by the lubricant’s high viscosity index (VI). Additionally, equipment speeds, loads and operating environment will play a role when considering mineral-oil-based versus synthetic.
Finally, we must consider what performance goals we are trying to accomplish with the lubricant. If we are going to change the lubricant on a time-based change such as hours of operation or months of operation, and we have met OEM requirements with a mineral-oil-based lubricant, then almost any mineral-oil-based lubricant will work just fine.
If, however, we are basing our lubricant changes on oil condition (determined with regular oil analysis), rather than time-based changes in an attempt to extend drain intervals and be more environmentally conscious, then perhaps the extra cost and stability of a synthetic lubricant or enhanced mineral-oil-based lubricant blend is warranted.
Whether you choose a mineral-oil-based or synthetic food grade lubricant to protect your equipment assets, be sure to take the necessary steps to store, transfer and use the lubricant in the equipment with contamination control in mind. Remember, any lubricant (mineral-oil-based or synthetic) will perform better when kept clean and dry.
Jim Girard, Vice President and Chief Marketing Officer, LUBRIPLATE Lubricants Company
Operating temperature is the key factor in deciding between mineral-oil-based food lubricants and synthetic food grade lubricants. Freezer applications and high temperature baking oven equipment are ideal for using synthetic food grade lubricants. Synthetic food grade lubricants have much lower cold temperature operating capability because they are more viscosity stable.
Oven chain applications are ideal for synthetic products because they are much more thermally stable than mineral-oil-based food grade lubricants. When considering a synthetic fluid for an oven chain application it is very important to choose the correct synthetic base stock. Synthetic H-1 base stock choices include polyalphaolefins (PAOs), polyalkyleneglycols (PAGs) and polyolesters (POEs.) POEs offer the maximum thermal stability, however they are higher priced than the other synthetics.
Also synthetic food grade lubricants are the number one choice for air compressor which require H-1/food grade fluids. Their oxidation and thermal stability are the key selection factors.
Finally, because synthetic lubricants last longer, they are better choices for “greening” the production facility. Mineral-oil-based lubricants are still very popular for food grade re-circulating oil and hydraulic applications.
Doug Kirsch, Technical Service Manager, Natoli Engineering Company
Lubricants are made up of approximately 90 percent base oil and 10 percent additive package. These percentages may vary but one constant is that the base oil makes up the largest percentage of the lubricant. The better the base stock, the more predictable the serviceability of the lubricant. Synthetics can be easily cost justified and offer the greatest versatility and performance. Here are a few factors to consider when choosing between mineral-oil-based and synthetic food grade lubricants:
1. Temperature: both ambient and operating (synthetics operate over a much wider temperature range)
2. Lubricant cycle: hard to lubricate areas and/or production schedules may dictate the use of a lubricant that has a longer service life.
3. Energy savings: synthetics have less internal friction, thus saving energy.
4. Viscosity Index: synthetics have a naturally high viscosity index (more resistance to change in viscosity due to temperature).
5. Greater oxidation and thermal stability: synthetics won’t thicken or breakdown as readily as mineral-oil-based lubricants over longer periods of time.
6. Lowering maintenance costs/increased productivity: less heat and less friction equals extended component life and less downtime.
Perhaps as important as the base fluid is the resulting wear protection when incorporating a performance based additive package into the lubricant. Combining synthetic base stocks along with a superior multi-functional additive package designed to reduce wear will result in a food grade lubricant that exhibits load carrying ability and wear protection that rivals industrial grade lubricants. Lubricants formulated in this manner can have a dramatic impact on maintenance costs. Combining energy reduction, component life and lubricant service interval extensions by utilizing high quality synthetic base lubricants will lower costs and increase profits. It will prove to be more economical to use than the lower cost of mineral-oil-based lubricants.
Ian Davidson, Global Industrial Marketing Manager, Mobil Industrial Lubricants
We have all seen in the past few years the number of food safety incidents that have affected consumers around the world.
We believe that these incidents will lead to increased governmental stewardship and oversight of existing food safety regulations, and possibly even more stringent legislation. One of the results of this will be an increased demand for synthetic oils and greases that are NSF H1 registered.
In addition to helping to promote food processing safety, synthetic lubricants and greases can also help food and beverage processors optimize equipment performance in extremely cold or hot temperatures.
When compared to conventional, mineral-based oils, synthetics offer more effective protection over a wider range of operating temperatures, protecting critical equipment components and helping maximize productivity.
At high temperatures, synthetics typically deliver thicker oil film to reduce wear. During low temperature startups, they offer excellent flow characteristics to reduce the risk of oil starvation. By comparison, conventional, mineral-based lubricants can degrade rapidly when exposed to high temperatures, increasing the tendency for deposit formation to occur and reducing oil life. When subjected to low temperatures, they may not flow as easily to critical parts, limiting the overall protection benefits they can offer.
Fully-synthetic, NSF H1 lubricants and greases offer performance benefits that help enable their use both above and below the processing line as well as delivering NSF H1 registration for incidental food contact to fit into the companies’ risk management systems.
Bob Whiting, President, Ultrachem, Inc.
When it comes to selecting synthetic food grade oils versus white oils, the major task has traditionally been justifying the additional cost of the lubricant itself. This has been especially difficult in the past as white oils have offered reliable, efficient performance for years, and additive packages have further increased efficiencies in white oil technology.
But white-oil food grade lubricants do tend to have limited capabilities compared to non-food grade products. As such, OEMS typically suggest limited operational hours or service time to compensate, often recommending that white oils (gear and hydraulic) be changed yearly. Here’s where the manufacturer would justify a low service time of a process to keep service intervals reasonable and lubrication / maintenance costs low. This compromise has become a generally accepted practice when using white oils.
By comparison, synthetics do offer significant performance advantages over white oil lubricants over a longer term of operation. Synthetics, in general, are based on Polyalphaolefins (PAOs), which are synthetic hydrocarbons that offer manufacturers the benefits of improved energy efficiencies, reduced varnishing, and greater ability to hold contaminants in suspension during the change interval.
But, these benefits do come with a higher up-front cost that must be weighed based on a particular application. Gear oils are normally specified to reduce energy consumption and increase protection from excessive wear, whereas hydraulic oils protect against elevated temperatures. White oil exposed to 120°F to 140°F has a life cycle of 6-12 months based on continuous or intermittent temperature exposure, while synthetics can see well above 140°F and successfully run for 24 months. Further, synthetics today have the ability to be exposed to heavier loads and higher temperatures, allowing the manufacturer to run at higher speeds with heavier loads.
The synthetics vs. white-oil decision comes down to a choice between up-front lubricant costs and long term operational costs. Equipment designers and manufactures today run faster and hotter with smaller sump capacities, allowing synthetics to have their place in food grade manufacturing and further reducing prices with less oil used per application. And another factor that has recently come into play is the increasing cost of white oils, forcing many food processors to examine synthetics as a viable option in their lines.
Today, food grade manufacturers are looking to reduce costs at every corner, and they need to compare lubricant cost with the life cycle of the equipment, the time required to maintain the equipment and reduced down-time and labor for oil changes and maintenance.
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