What do manufacturers really mean by lubrication-free chain, and what are the latest options available to suit the very specific requirements of the food industry? David Compton of Renold Chain untangles the lubrication-free roller chain story.
Precision roller chain is the technology of choice in a wide range of applications. It combines high efficiency with dependable durability, for a long-lasting, cost-effective mechanical power transmission solution. A correctly specified chain, appropriately lubricated, will almost certainly be the best all-round performer with the longest working life.
Eliminating the risk of oil contamination
Dimensionally interchangeable with standard chain
All-round performance – longer working life
The most significant element of chain wear occurs at the load-bearing surfaces in-between the pin and bush components. Wear causes elongation of the chain, which is accelerated by high or highly dynamic loads, or if lubrication is inadequate. Chain tensioners or regular adjustments will work for a while, but sooner or later the chain needs to be replaced. And the more basic the chain’s design and manufacture, and the poorer the lubrication regime, it’s sooner rather than later.
The problem is that in some applications, keeping the chain adequately lubricated may be difficult or undesirable. It could be because access for maintenance is difficult, or it could be the lubricant itself that’s the problem, because of the risk of contamination.
In these circumstances – as OEM s and end users are discovering – a lubrication-free chain could be the answer.
Lubricant – not lubrication
It’s important to be clear that lubrication-free chain isn’t chain without a lubricant. It’s just chain that doesn’t need a lubrication regime, because it’s lubricated for life.
The most common type, suitable for the widest range of applications, is of carbon alloy steel construction, with an oil-impregnated sintered bush. Lubricant is released from the bush onto the bearing surfaces during operation, but always remains inside the chain.
This type of chain normally needs little or no maintenance during normal service life. It’s also interchangeable with the same size of standard chain – with no need to change the existing sprockets.
In any application, these precision roller chains reduce the maintenance required, eliminate the need for – and cost of – drip guards and automatic lubrication systems, and also save on the cost of lubricant itself. In food industry applications in particular, there’s the additional important benefit of eliminating the risk of oil contamination of the end product or other parts of the process. And with the higher cost of food grade lubricant, the savings on lubricant are even more impressive.
Say “yes” to Syno
The latest generation of lubrication-free chains benefits from advances in materials technology, surface treatment expertise and manufacturing processes.
Even lubricants have developed and improved, and now have the exact properties required to maximise the benefits of the advanced chain design.
Renold first introduced lubrication-free chains in the 1950s. The latest version – known as Syno – is the most advanced so far, designed specifically to meet the requirements of applications often found in food manufacture (and occasionally elsewhere).
Syno NP is made using a custom-developed nickel plating process, with excellent anti-corrosion properties. The chain incorporates a food grade lubricant in the sintered bush, and a unique food industry-approved treatment process is applied to the roller surfaces. Dimensionally interchangeable with standard chain, and featuring ISO standard pin diameters, it can be supplied with standard attachments on the outer links.
Syno PC is a lightweight, corrosion resistant polysteel chain, designed with polymer inner links and high-grade stainless steel pins and outer plates. Eliminating metal from the bush and roller components means no lubrication is required, so it can be used for a much wider range of lower power applications – and can even be run underwater. The outer plates accept all standard attachments.
Lastly, for heavier-duty applications, Syno PB polymer bush chain provides greater wear- and fatigue resistance. Its specially developed polymer sleeve is located between the pin and the bush – eliminating metal-on-metal contact in this critical area. Available with a corrosion- resistant surface treatment, it brings lubrication-free operation to more – and more arduous – applications than previously possible.
With such a choice of chain options, lubrication-free precision roller chain is an increasingly realistic and achievable upgrade from standard chain, for an ever-expanding list of applications. So now you can can the can, for the chain that can.