The food industry is usually considered the basic market to which Lubrication Engineers addresses itself. Our QUINPLEX® additive makes Lubrication Engineers an automatic choice in many food applications. Our USDA approved greases are important in sealing and waterproofiing machninery. These products include 2700 and 2701 ALMASOL® Oven Chain Lubricants, 2799 ALMASOL® High Temperature Chain Lubricants, 4010, 4020, 4030, 4090, 4140 QUINPLEX® White Oils, 4023, 4024, 4025 and 4025A QUINPLEX® Food Machinery Lubricants, 4046 Synthetic Food Grade Oil, and 4058 and 4059A H1 QUINPLEX® Penetrating Oils and Lubricants.
In spite of electronics, automated equipment, computers and other modern technology, people are still responsible for lubrication and maintenance in the food processing industry. They are constantly beset with plaguing problems of the operating environment, as well as problems inherent in complex equipment. Some of the classical problems are listed below:
- Moisture is an always present destroyer of lubrication and detrimental to good maintenance. The water or steam present is due to the necessity for constant cleanliness of the machinery and surrounding areas. It may also be a part of the process itself .This moisture can wash out lubricants, cause emulsions of both grease and oil, cause rust and corrosion and increase and hasten deterioration of the lubricant.
- Heat very often is one of the more serious problems. High temperatures may come from drying and sterilizing processes, or from steam and hot water used in cleaning. Higher temperatures can cause greases to melt and run out of bearings and will speed up oxidation of both greases and oils, thereby shortening their life.Conversely, in some plants there may be refrigerated areas, coolers, etc., which require low temperature mobility in greases and low pour points in oils. Wear can result from channeling of the lubricant. These areas may also create moisture problems because of excessive condensation.
- Shock loading or impact may be a factor in many areas. The lubricant may be pounded out of an area leaving metal-to-metal contact with consequent damage to surfaces. Grease may lack cohesion or adhesion, oil may be light or won't penetrate to critical areas.
- Long life of both the equipment and the lubricant is another challenge. Some operations run around the clock, twenty-four hours a day. Again, these operations may be hot, wet, cold, subject to contamination, etc., creating doubly severe conditions. Greases may "shear down" or become very soft or liquid, oils oxidize rapidly and both become contaminated. Both greases and oils may harden or thicken in service, creating increased power demands.
- One of the most severe requirements imposed on lubricants is the demand for purity and the necessity for non-toxicity. The U.S. Food and Drug Administration and various other agencies concern themselves with controlling the possible effects of lubricants on beverage and food processing and packaging. There are stringent and very restrictive regulations in effect, which often limit a lubricant's ability to perform well.
An often ignored problem in the built-in environment of a particular plant is the effect of chemicals in the process-mild acids and alkalis in juices, syrups and other components, citric acid, carbonic acid, various salts, sugars, malts and alcohol often have their own peculiar deteriorating effect on lubricants. These are usually recognized as a fact of life and not something that better maintenance and/or lubrication might be able to overcome or at least alleviate. In other words, prospective accounts feel problems associated with these ingredients are "normal" or expected.
Other chemicals are involved in the cleaning process. Again, acids and alkalis, but also some severe materials such as cleaner lubricants (generally, soaps of some type) for conveyors, sodium hypochlorite, polyphosphates, silicates, acid detergents, sanitizing solutions, iodine sanitlzers, spray insecticides, foaming additives and conditioners for algae, slime and bacteria. Often the interactions of these products are unknown or unrecognized, to the severe detriment of lubrication and maintenance.
In spite of the size and appearance of this vast family of equipment, all of the complicated machinery can be broken down into three basic divisions for lubrication purposes. These are bearings, gears and slides. Chains will also be discussed because of differences, but technically they consist of bearings and slides.Plain or friction bearings are basically two surfaces contacting. They can be flat, but typically are a shaft riding in a journal. Lubrication can be either oil or grease. Oil will flush and clean, and sometimes cool better, but a tacky grease will form a collar to keep out contaminants. Lubrication is not complex, but as in all applications, quality lubricants designed for the specific application will prolong life.
Anti-friction bearings are so named because of the considerably reduced friction from plain bearings. They are divided into ball bearings and roller bearings, but they will be discussed together, as their lubrication problems are similar.
Anti-friction bearing lubricants lubricate any contact between the races and rolling elements, and lubricate the retainer and its contacts. The lubricant also protects highly finished surfaces and seals out contaminants. Heavily loaded bearings and low speeds require heavy oils. Lighter loads and higher speeds require lighter oils. Use the lightest oil that will safely carry the load for least power consumption.
You should grease bearings carefully with high pressure guns. High pressure can damage bearings, can easily over-grease and damage seals. It will also waste grease and contribute to overheating. Applications exist where it will be necessary to use either more or less grease. Where low torque is a requirement, the bearings may be lubricated with a very small amount of grease. With low speeds or exposure to dirt or moisture, the bearing may be nearly full. High speed and/or temperatures require more frequent greasing.
Most gears found in the food processing industry are spur and bevels. Normally, these will give excellent results with turbine oils. If they are heavily loaded and/or subject to shock loading. then gear oils with extreme pressure additives should be used.
Typically, helical or herringbone gears will only be seen in a power-off gearbox from steam turbines and are normally lubricated with turbine oils. Many worm gears are found in the Food Processing Industry. They are used to drive many types of equipment They are quiet, efficient. and usually have fairly large speed reductions. An outstanding feature is that, if and when they fail, they do so without destroying the gearbox. The bronze wheel gradually wears away until the worm will no longer drive it. The bronze wheel is replaced. and full performance is restored to the system. In this application. many manufacturers recommend fatty oils for lubrication, but our preference is a mild extreme pressure gear oil.
Slides perhaps could be classified as plain bearings. but many times they do not have matching surfaces, so they are generally considered simpler and rougher than bearings. In the Food Processing Industry , one of the primary considerations might be chains sliding in guide rails. These would require a minimum amount of oil or a light coating of grease to reduce friction between chains and rail, possibly to prevent noise and prevent binding of the chain links. A critical area might be in the positioning of cams and gibs. Careful attention should be given to these areas. using minimal amounts of high quality industrial oils. light. tacky greases or gear lubricants.
In non-critical areas such as the sliding of cases into position for loading. the considerations might be only keeping the surfaces clean and non-sticky. Other non-critical areas may be lubricated by overflow, over-spray or drip from other lubricated areas.
Chains are treated briefly, and separately. only because they are a rather different idea of bearings and slides. One of the most important concepts in chain lubrication is penetration. The lubricant must be forced into, or creep into very restricted areas of pins and bushings and slide plate clearances.
In other instances, the application can be very loose -simply a coating of lubricant to allow various shapes of metal to slide in some kind of a restricted channel.Power drive chains may be critical and the requirements should be carefully analyzed, so as to reduce both friction and power consumption. They need to be carefully installed, maintained and lubricated in order to get the best service and longest life. Power drive roller chains are usually lubricated with high quality light turbine oils; heavier oils as speed decreases. In certain areas. semi-fluid greases are satisfactory. Occasionally, mild extreme pressure gear lubricants should be used because of additional load bearing capacity. and also because some of them have tackiness and additives.
Cleanliness in chain drives is of utmost importance. Fine abrasives entering the fine clearance between pins and bushings will rapidly destroy them. Because of possibly high temperatures and constant water/steam washing, lubricants must possess good rust and oxidation characteristics. Wear-reducing functions are of value in all applications.
Automatic lubrication systems may be manual (a better name would be multiple --does not include automatic timing), air-operated, electric or hydraulic. In anyone system, various types of applications can be handled: Anti-friction bearings, plain bearings, slides, chains, conveyors, etc. The practical aspect, perhaps most important, e.g., (1) the regularity of delivery of the proper amount of lubricant to a critical bearing area, without relying on human memory and (2) alarms to signal non-delivery.
A typical automatic lubrication system consists of lubricant, pump, air and electrical connections, feed lines, timer, injectors, etc. Systems can be as simple as a block of injectors on the side of a machine, to complicated systems lubricating thousands of bearings, using long piping runs, timers, bulk lubricants and all monitored by a computer.