As in many industries, food manufacturers push the limits of machine performance to increase productivity and reduce downtime for greater customer satisfaction. Interestingly, one of the most effective ways to achieve these performance levels is also one of the simplest and most frequently overlooked: proper lubrication. For food manufacturers, choosing the right lubricant is an especially tricky task. Not only do industrial lubricants come in many varieties and formulations, but food-grade lubricants must also meet a whole set of FDA and NSF requirements that other lubricants are not required to meet. As a result, choosing the proper lubricant for a food manufacturing application is critical. Before making a selection, it is advisable to consult a supplier who can help you answer key questions about your application. Armed with the right information, you and your supplier can determine which lubricant will offer the best performance for your operating conditions. For decades, lubricant suppliers have been developing and manufacturing special lubricants tailored to the requirements of the food-processing industry. Specifically, food-grade lubricants must comply with food regulations and be physiologically inert, without taste or smell, and internationally approved. Furthermore, food-grade lubricants have to meet general technical requirements that all lubricants must meet, such as reducing friction and wear, protecting against corrosion, dissipating heat and providing a sealing effect. Depending on the operating conditions and manufacturing processes in your individual food-processing plant, food-grade lubricants may also provide a host of additional properties. For example, a food-grade lubricant may be expected to provide resistance to food products, chemicals, water and steam. It may also be required to be compatible with rubber and sealing materials or have sugar-dissolving properties. With so many variables, choosing the right lubricant supplier is just as important as choosing the right lubricant. It is essential to choose a supplier who understands the special needs of the food-processing industry. An experienced supplier can help you identify all of the relevant food and operating factors that will affect your lubricant choice. One of the first questions your supplier should ask is if your equipment’s lubrication will be maintained at regular intervals or if it must be “lubricated for life,” as this will help determine the use of a general purpose lubricant or a synthetic specialty lubricant. Oils, greases, pastes and waxes represent the most common categories of industrial lubricants. Typically, an oil lubricant contains 95 percent base oil (most often mineral oils) and 5 percent additives. Greases consist of lubricating base oils that are mixed with a soap to form a solid structure. Pastes contain base oils, additives and solid lubricant particles. Finally, lubricating waxes are comprised of synthetic hydrocarbons, water and an emulsifying agent, which becomes fluid when a certain temperature level is exceeded. The majority of oil lubricants, including many motor oils, are mineral oil distillates of crude oil (petroleum), while synthetic oil lubricants are also used. Synthetic oils, such as polyalphaolefins or PAOs or synthetic esters are produced artificially from other compounds. Because of this, the composition is quite different from petroleum oil. Their higher purity and uniformity provide for several enhanced properties, such as viscosity index, oxidation stability and color. There are also semi-synthetic oils (also called synthetic blends), which are a blend of mineral and synthetic oil. This class of lubricants provides many of the benefits of synthetic oil at a fraction of the cost. When synthetic oil is selected, it is generally to provide mechanical and chemical properties superior to those found in traditional mineral oils. When a manufacturer does not stock an appropriate synthetic lubricant with the performance features needed for the task, a customized “specialty” or “optimized” lubricant may be called for. If the equipment will be regularly lubricated, it is typically not necessary to use a synthetic or specialty lubricant that is designed to last for an extensive period of time. In this case, the lubricant needs only to meet basic performance standards and would be replenished regularly. If the equipment is lubricated for life, synthetic base oils are often recommended for their many benefits, including:

Low temperature viscosity performance High temperature viscosity performance Decreased evaporative loss

Reduced friction Reduced wear Improved efficiency Chemical stability Resistance tooil sludge problems Extended drain intervals

Despite their many benefits, synthetic lubricants are also known for one distinct disadvantage: cost. But, the cost may be mitigated by extended change intervals, as synthetic and specialty lubricants can last five times longer or more than non-synthetic lubricants when a high-quality base oil is used. Other concerns may include potential oil-seal problems. However, an experienced professional can select a lubricant that will prevent these conditions. The key requirement for selecting the proper lubricant is the base oil viscosity. In order to select the appropriate viscosity, your supplier will need to gather information about your application, including the operating speed (variable or fixed), the specific type of friction (e.g., sliding or rolling), the load and the environmental conditions to which the lubricant will be subjected. For example, some lubricants, like PAG (polyalkylene glycol) oils, are good for sliding friction, but are not well suited for rolling friction. Likewise, PAO oils are used for rolling friction and can handle some sliding friction, whereas silicon and PFPE lubricants are typically used for extremely high temperatures. Industry standards may also be an important factor in lubricant selection. During the information gathering stage, equipment owners often make the mistake of overlooking some basic application details, which can have a significant impact on the resulting lubricant’s performance. For example, a supplier might ask detailed questions about the type of gears being used or about the cavity next to a bearing. These may seem like insignificant bits of information, but the answers to these questions are just as important as specifying the load or operating speed. When responding to these types of questions, don’t generalize. It’s important to provide as much information as possible and to be specific, as this will help you and your supplier identify the lubricant best suited to the task. Another common mistake equipment owners make is choosing a lubricant based solely on price. Never assume that a grease is a grease is a grease. Admittedly, there is a vast difference in the price of a synthetic or specialty lubricant and a general purpose lubricant. Some synthetic or specialty lubricants are 50 percent more expensive than general purpose lubricants; some are 500 percent more expensive, but the price per kilogram should not be the only determining factor in selection. Additional factors to take into consideration are the reduced operating costs resulting from less downtime, improved labor utilization (less time required for relubrication and maintenance), measurable energy savings and increased output, which all work to increase plant efficiency. Choosing the right, seemingly expensive, lubricant for your application may result in bottom-line savings for your company. Lastly, when a supplier makes a lubricant recommendation for a particular application, and that application is successful, often the customer wants to use the same lubricant in another application. Unfortunately, this is typically not an option. Remember, every application is different, and while one lubricant may work well for a ball bearing application, it likely will not provide the same performance for a different bearing application. Ultimately, the first step in choosing the right lubricant is choosing the right lubricant supplier. Look for your supplier to provide quality documentation and detailed test data that demonstrate the consistency and quality of the product being recommended. A reputable supplier will spend time educating you, so you can make qualified decisions about lubricating your equipment.