Lube-free chains are now in the mainstream of industrial manufacturing and can replace pre-lubricated chains in many applications, in many cases with enhanced load and life expectancy.

In today's demanding industrial and process environments, lubrication is increasingly becoming a luxury that can no longer be afforded. For years' conventional oil based lubricants have not been used in food environments because of the likelihood that they may contaminate the product. But now the same demands for cleanliness are spreading, or have spread, into other industry sectors.

Paper, packaging, electronics, white and brown goods manufacture are all areas where this is so.

Contamination of the final product from oil spillage or oil mist is a major reason for the lube free demand in these sectors.

But not exclusively so, there are other important considerations, including the observance of Health and Safety regulations, the cost of the lubricants themselves - and the down- line costs of their disposal.

In addition, if lubrication can be avoided altogether then planned lubrication intervals are unnecessary and maintenance costs are reduced accordingly.

One product in particular where removing the requirement for lubrication and maintenance is particularly important is chain.

Normally all chains must be thoroughly lubricated to extend their life.

Most chain manufacturers' issue lubrication recommendations, and most maintenance personnel understand the importance of lubrication.

However, there is often a gap between what is understood and what is done.

Regular observation of chains, it is true, provides assurance that automated lubrication systems are effective, or that manual lubrication schedules are being carried out.

But, the thoroughness with which this is executed is often open to question: especially so if the chain is inaccessible, on an overhead conveyor for example.

The demand for chains, which operate without lubrication and are essentially maintenance free, has resulted in technological innovation of a basic product, which in outward appearance has changed relatively little since its invention by Leonardo Da Vinci in the 15th century.

The result of this innovation is that lube-free chains are now in the mainstream of industrial manufacturing and can replace conventionally pre-lubricated chains in the majority of applications, in many cases with enhanced load and life expectancy advantages.

There are a number of ways of achieving non-lube performance of drive chains.

These vary with the load capacity and life requirements of the transmission medium.

Today engineering plastics, especially self-lubricating acetyl types, play a part but, in the main, these type of chains suit applications where corrosion resistance and weight saving are more important than load capacity.

The first generation of what we will call mainstream lube-free chains (i.e to replace standard chains) were units with oil sealed in via O-rings.

These were only moderately successful for industrial applications and so self-lubricating bush chain became available.

Using a sintered bush, however early technology meant that in order to maintain the strength of the sintered bush it had to be thicker material than normal steel bushing, meaning that a roller could not be used.

Resulting in increased friction between the bush and contact surface.

These designs were quickly supplanted by a new design from Tsubaki back In 1988.

Importantly, the Lambda self-lube design is able to lubricate not only between chain and bushing but also between bushing and roller.

This means that Lambda chain is uniquely suitable for both drive and conveyor applications where roller inner wear is a problem.

The performance of Lambda is the result of a construction that comprises specially sintered, oil impregnated bushings, coated pins and extra durable rollers.

The durable rollers facilitate super smooth engagement on the sprocket for longer periods of time.

This reduces sprocket wear significantly.

Moreover, the smooth articulation of chain and sprocket reduces power transmission losses by a high order.

In addition, the Lambda series can withstand up to 25% higher kW ratings when compared to the previous series: this as a result of an improvement in the maximum allowable load of the connecting links and 2-pitch offset links.

Lambda is especially suitable for 'clean' operations where machines and conveyed materials must be free of lubricants, or where lubrication is difficult or impossible due to limited access.

Such conditions are routinely encountered in food processing, printing, packaging and textile applications.

Engineering plastics come into their own in chain designs where non- lube performance is essential, but the maximum loads and the maximum chain tension required are less than those for standard roller chain.

The resistance that plastics naturally possess to corrosion is also an important factor in their use.

Tsubaki uses engineered plastic sleeves between the pins and bushings of its Plastic Sleeve chain.

The self-lubricating properties of the engineering plastic sleeves increase the wear life of Tsubaki Attachment Chains, RS roller chains and Stainless Chains, while removing any risk to products and the working environment of contamination from lubrication oils.

The design of the chains, with plastic rollers, also eliminates any contamination from metal dust.

In applications where stainless steel plastic sleeve chain is applied, rust preventative and lubrication are unnecessary, so these working environments also stay clean and sanitary.

In addition to cleaner, non-lube working, Plastic Sleeve stainless steel chain offers considerable weight saving advantages over all stainless steel chains.

With standard S type plastic rollers a 15% weight saving is realised and with R type an even more substantial 40%.

Engineering plastics is also the material used for the inner links on Tsubaki's Poly Steel chain.

Poly Steel chains are lube free chains used in power transmission and conveying applications in the production of food or medicines.

They have no rollers.

Instead they rely upon the self- lubricating properties of the plastic from which their inner links are made.

The wear resistance of these chains is higher than that of stainless steel roller chains without lubrication.

Poly Steel chain has the advantage of being 50% lighter than all-stainless steel chain, which gives easier handling and installation, In addition, corrosion resistance is also greater than that of all-metal chain.