Industrial baking equipment operates under intense conditions. Inside a proving chamber, temperatures of around 38°C combined with humidity of between 85% and 100% create conditions that can cause an ordinary lubricant to fail within days. Lubrication Engineers (LE) South Africa recently worked with a bakery to more effectively lubricate its rack prover chains.
The bakery’s rack prover is fitted with four different chain configurations, which run continuously for 24 hours a day, six days a week, with only one day set aside for maintenance. The chains hold the bread dough under controlled temperature and humidity so the yeast can work and dough can rise before baking.
“The combination of heat, moisture and continuous movement makes it particularly challenging,” says Bongani Zondo, Sales and Technical Engineer at LE. “A chain lubricant must do more than coat the outside of the chain. It needs to reach the chain pins, links and bushings where movement and wear occur. At the same time, it must remain in place despite the hot and humid environment.”
A costly, drip-prone lubricant
The bakery had been using a relatively expensive speciality-grade black aerosol grease, and had also tried several other lubricant brands. “The maintenance team could not find a product that performed satisfactorily under the hot and humid conditions,” says Zondo. The lubricant would drip off the chains both during application and operation, wasting product, leaving the chains without dependable protection and creating cleaning problems on the factory floor.
Weekly chain lubrication had become a regular and labour-intensive maintenance task, but was not giving the equipment the protection it needed. “Frequent lubrication does not necessarily mean effective lubrication,” Zondo adds.
Finding the right lubricant
LE recommended its Wirelife® Almasol® Coating Grease 452 for the prover chains. It is a soft, semifluid and highly adhesive lubricant designed to coat chain links, pins and bushings and which does not get flung
off during operation. Because it is applied by brush, it gave the bakery’s maintenance team more control over how much lubricant was used and exactly where it went.
The results were significant. “The most important improvement was the extension of the lubrication interval,” says Zondo. Where the previous product required weekly application, the interval on Wirelife 452 was extended to once every two to three weeks, depending on the chain. Lubricant consumption also dropped because the product was applied directly by brush and stayed on the chain far more effectively. A representative from the equipment manufacturer, who watched the maintenance team applying the product, was impressed by how well it penetrated the chain and continued to adhere under the hot, moist conditions.
Zondo says this case study is a great example of how maintenance teams should think about lubrication costs. “A product should not be judged only according to its price per kilogram,” he says. Fewer lubrication applications, less wasted product and better protected chains all mean a lower total cost, even where the lubricant itself is not the cheapest upfront option.
Getting food-grade lubrication right
Food safety adds another layer of complexity to lubricating bakery equipment, and Zondo says a single product cannot simply be used everywhere. “The lubrication point must first be assessed and correctly classified.”
In this case, the prover chain position did not need an NSF H1-registered lubricant, since there was no possibility of incidental contact between the lubricant and the food. In other places, where incidental food contact was possible, LE’s H1 Quinplex® Food Machinery Lubricant 4025 was used instead. “The correct approach is to separate the plant into food-contact-risk and non-food-contact-risk lubrication zones,” says Zondo. He worked with the bakery’s engineering, quality and food-safety teams to choose the right lubricant for their needs.
LE also supplied two other products for other applications on site: Multilec® Industrial Oil 6803 for the plant’s air compressor, and Monolec® Gear Lubricant 703 in the maintenance workshop.
For bakeries facing similar issues, Zondo recommends a properly controlled and documented trial, starting with a baseline of current lubricant consumption, maintenance labour and chain condition, so that any improvement can be measured in concrete performance and cost terms.
