Keep Oven Chains Protected, Even at Extreme Temperatures

• Bakery ovens used in the production of tortillas, pita bread, pizza dough and other baked goods can expose conveyor chains to extreme temperatures upward of 1000°F (537°C), which can significantly challenge typical food-grade lubricants.

• Klüberfood NH1 CH 6-120 SUPREME is a major development for bakeries looking to provide optimum protection for chains at extreme temperatures, while continuing on the path toward food safety.

At high temperatures, common food-grade chain oils can evaporate and break down, leaving behind high levels of residue and/or requiring constant relubrication. A common alternative is to use a chain lubricant containing suspended industrial solids that will provide emergency lubrication even when the carrying fluid evaporates. Although these formulations can provide high temperature lubrication, it is often accomplished at the sacrifice of the lubricant no longer being registered by the National Sanitation Foundation (NSF) as food grade H1.

New Klüberfood NH1 CH 6-120 SUPREME provides optimum protection of chains at extreme temperatures. The formulation utilizes a solid white lubricant and is NSF H1 registered for incidental contact, providing a long-lasting solution to the challenge of using food-grade lubricants at extreme temperatures.

In all industries, but particularly in the food industry, it is valuable to understand the makeup of the lubricant that is applied to equipment operating at elevated temperatures.

In addition to other areas, the various base oils used in lubricants are affected by extreme temperatures in the levels of evaporation loss and in the formation of residues—factors that influence chain life.

Each type of base oil has a different temperature limit—and even going slightly past this limit can have a dramatic effect. For instance, at temperatures above 500-600°F (260-315°C), even synthetic esters, which are excellent performers in many bread ovens, can evaporate. As a result, frequent relubrication is needed to keep the chain lubricated and protected. However, even with constant relubrication, the continuous break down of certain types of base oils can thin the lubrication barrier, which reduces component protection. Also, residue levels become higher, which impairs fresh lubricant from reaching the intended surface(s).

A common method used to lubricate chains operating at extreme temperatures is to use a solid lubricant. The solid lubricant is in suspension within a fluid carrier when the lubricant is applied. As the fluid carries the complete formulation into the components and begins to evaporate, the solid stays behind inside the friction points as a type of emergency protectant to decrease wear of the surfaces.

Understanding the importance of the types of carrier fluid and solid being used is critical. As with any formulation, they should be selected based on the complete tribological environment. Other important factors include how the lubricant will be stored, the method in which it will be applied to the chain and when it will be applied.

A lubricating formulation using solids held in suspension is likely to require mixing either when being stored or prior to application. Stirring can be done with various methods, such as using an agitator pump inside the lube reservoir. Agitation maintains the proper ratio of the fluid carrier and the solid lubricant(s) during application, which can then be done using an automatic lubrication system.

Because the carrier will eventually evaporate, the application should be performed at a temperature allowing the carrier to first deliver the additives into the friction points. Otherwise, if applied while the oven is at full or too high a temperature, heavy smoking and flashing off of the oil will occur when it contacts the chain. It is best to apply the lubricant at a lower temperature within the operating range of the carrier to allow penetration of the solid additives.