The True Cost of a Lubrication Cycle

How PFPEs can reduce downtime and increase intervals between lubrication cycles.

If you ever wanted a pet growing up, you’ll probably recall having a conversation about how taking care of an animal is a big responsibility—you need to feed them, clean up after them and keep them healthy. Depending on how young you were, that may be the sum total of what you remember.

What child can focus on the nuances of obligation when there’s a puppy in the room?

Most of us would like to think we’ve gotten more responsible as adults, but the simple fact is that many people still make commitments without considering the long term consequences.

Take industrial lubrication, for example.

The Price You Pay for Low-Cost Lubricants

We all get tunnel vision from time to time. From adolescents to adults, human beings tend to focus on whatever is most important to them—often to the exclusion of almost everything else. The 8-year-old only cares about how cute the puppy is, not how much of a mess it will make. The purchasing manager only cares about sourcing the lowest cost lubricant, which means thinking strictly in terms of the minimum specifications. The production engineer only cares about keeping things running, which means sticking with whatever lubricant has “worked” thus far.

Though the consequences differ, what all three people share in common is the inevitable regret that comes with failing to consider the long term. For the purchasing manager or production engineer, this can mean higher costs, lower efficiencies and more unplanned downtime.

Machine failures create ripples of increased cost and lost productivity, and they can often be traced back to lubrication issues. “We’ve had people calling in dire straits because their asset keeps breaking down and they don’t know where to turn,” commented Chad Warriner, Technical Services Engineer at The Chemours Company. He pointed to the use of low-quality, hydrocarbon-based lubricants as a common culprit.

“At higher temperatures, conventional hydrocarbon lubricants will start to oxidize,” he explained. “PFPE doesn’t, giving you a longer run time.” In addition to being inert, high-performance perfluoropolyether (PFPE) lubricants are water and oil repellant, solvent resistant, non-flammable and can perform over a wide temperature range (-75C to >400C). Although this higher performance comes with a higher capital cost, as Warriner explained, the upfront cost of a lubricant doesn’t tell the full story.

Reducing Re-Lubrication Intervals

“As a reliability engineer, if you’re sending a lube technician into the field to grease an asset every six months to a year, you need to look at the total cost of doing that, not just the cost of lubrication,” Warriner said. “You’re spending money for the schedulers and supervisors on top of the lube tech, plus you’re locking the asset down. If you can eliminate one or two grease intervals, the potential savings are huge.”

Chemours Technical Service has seen multiple instances of this first-hand.

For example, The Chemours Company worked with a copper rod manufacturer that had been re-lubricating its rollers’ bearings with a synthetic hydrocarbon grease every four hours. Due to the high temperature environment, the copper rod manufacturer believed this to be the optimal re-lubrication interval.

However, by switching to a PFPE lubricant, the manufacturer lowered the number of re-lubrications to a monthly interval. In addition, the switch cut annual bearing failure rates by nearly 98 percent—going from replacing 186 bearings per year to just four. According to The Chemours Company, switching to PFPEs saved the copper rod manufacturer $66,920 USD annually in reduced maintenance costs, parts costs and production downtime.

In another case, a polyethylene manufacturer was having issues with a high-capacity, sealed centrifuge because the mineral oil lithium-thickened grease for its bearings was leaking. The manufacturer turned to PFPEs because it needed an option that was non-reactive, insoluble to hexane and which could provide enough adhesion to avoid leaks while remaining fluid enough to deliver lubrication.

Although the upfront cost of the PFPE lubricant may have been higher than the hydrocarbon option, the manufacturer has seen significant reductions in the number of unplanned shutdowns and re-lubrication cycles since switching to PFPE. This, in turn, decreases maintenance costs, but the benefits of using PFPE lubricants over hydrocarbon ones go beyond simple ROI calculations.

“Every re-lubrication introduces the risk that your assembly will be contaminated,” Warriner commented. “There’s also the risk if you miss a lube cycle that something will fail, and you’ll end up shutting down for days, if not weeks.” In other words, having fewer re-lubrication cycles not only lowers the overall cost, but the overall risk as well. “It gives you a safety net,” Warriner confirmed.

As an added bonus, fewer re-lubrications means less strain on your maintenance team. The skills gap is putting pressure on many manufacturers, as companies struggle to find workers with the necessary skills. “A lot of maintenance teams are shrinking,” said Warriner, “and reducing re-lubrication intervals means you can maintain reliability.”

Switching to PFPE Lubricants

Assuming the ROI makes sense for replacing a hydrocarbon-based lubricant with PFPE, the most important thing to keep in mind is preparation. “When you’re switching to PFPEs, you need to clean out the old hydrocarbon grease entirely,” Warriner said. “Customers leaving old grease in—we find that mistake quite a lot.”

The benefits of a PFPE lubricant—such as high thermal stability—are undermined when traces of your old lubricant mix with a new PFPE grease. For this same reason, you should ensure that any bearing rust-preventative is removed before applying the new lubricant. When it comes to cleaning or preparing bearings prior to adding PFPE lubricants, Warriner recommended Vertrel fluorinated cleaners—especially if you need to remove a fluorinated lubricant—because fluorinated lubricants are resistant to most common organic solvents. You can further increase cleaning efficiency by brushing or wiping your parts with rags or, ideally, immersing them in an ultrasonic cleaner.

The Life of a Bearing

Thinking in the long term isn’t easy, especially if you’re trying to consider all the potential consequences of a decision. The natural response is to narrow our focus to what seems most important in the moment. When that happens, and your focus is the immediate cost, you tend to get what you pay for.

Even for something as simple as re-lubricating a bearing, there’s a big difference between the upfront cost and the total cost over its lifetime, which includes potential opportunity costs and the risk of unplanned downtime. All of these variables need to be considered if you want to find the true cost of re-lubrication.

For more information, visit The Chemours Company website.

The Chemours Company has sponsored this post.  All opinions are mine.  –Ian Wright