Tsubaki Europe Industry Applications

How Does Lube-Free Chain Really Work - And what are the Real Benefits?

2004-05-01T06:09:48Z

With so many companies claiming expertise in manufacturing roller chain products that do not require any external lubricant throughout their lives, Tsubaki, the original creators of lube-free chain explain how it is done and detail some surprising real world benefits...

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. Where conventional externally lubricated steel roller chain is normally used power transmission capacity and wear life are the main criteria for selection and an all steel lube-free chain is required.

How do they work?

There are two main methods of achieving 'lubrication-free' steel roller chain and both involve internal lubrication between the load bearing surfaces, i.e. between the chain pin, internal bushing and the roller. As chain passes over a sprocket, particularly a driven one, it is these internal bearing surfaces that have to articulate under load. Given inadequate lubrication, these are the main areas of wear and the resulting chain elongation.

The first method for lubrication is to pack the rollers with a high viscosity grease lubricant that maintains internal lubrication, externally the chain is virtually dry to the touch and additional external lubrication is virtually impossible due to the inability to penetrate through the existing lubricant and is therefore generally not recommended. This type of lubrication does limit the temperature range of the chain and has a limited effective life span. Where there are any contaminants such as paper particles or general grit and dust present the lubricant can become contaminated or dry out and the wear rate of the chain is then significantly accelerated.

The second method of achieving internal lubrication of the chain is oil impregnation of the components during their manufacture known as sintering. The steel bushings are forged with lubricant actually included within the material structure of the steel. During operation, the lubricant forms a micro thin layer between the pin and internal roller surfaces. Meanwhile, the exterior of the chain is totally dry to the touch, a condition that stops it acting as a surface receptor for harmful contaminant particles.

An additional benefit of this process is that the motion of the lubricant within the rollers under load is from the centre outwards, the opposite direction to conventionally lubricated chains that draw lubricant in from the exterior. As a result of this, any debris from the atmosphere that does settle on the surface of the chain is mostly excluded from the load bearing surfaces of the rollers and deters the acceleration of wear.

The overall performance of a good lube-free chain is also enhanced by specially hardened pins and 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.

So what are the benefits?

There are some obvious initial benefits to using lube-free or (internally lubricated) chain. Food production environments that have traditionally used expensive food grade lubricants can now operate food production lines without the need for chain lubrication, even in some arduous washdown environments. Although only sintered chain is recommended in these environments. Other areas where the chain is proving extremely effective are the paper, packaging, electronics and white goods industries where any external lubrication of chain can lead to unacceptable product marking or quality failures.

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-the-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.

Surprising

One of the less obvious benefits of 'lube-free' chain is in extending wear life. Most chain manufacturers issue lubrication recommendations for standard chain and most maintenance personnel understand the importance of lubrication. However, there is often a gap between what is understood and what is done. The thoroughness with which external lubrication is carried out is often open to human error and forgetfulness, especially so if the chain is hidden away or inaccessible, on an overhead conveyor for example.

A high proportion of chains in use are lubricated erratically and this can result in them not reaching their predicted life or require more frequent adjustment because of excessive wear. This problem is avoided by using chains that do not require external lubrication, but in the case of sintered lube-free chain, wear life can be extended to over thirty times that of standard chains in some applications, especially where contaminants are present.

It is in this instance that the real world benefits make even more sense when they can contribute towards a company's operating efficiency and profits. The best technology lube-free chain costs on average two and a half times more than good quality standard roller chain. Taking into account the lack of lubricant, maintenance adjustment and initial purchase cost - lube free chain can conservatively contribute over twelve times its initial purchase cost to a company's bottom line.

The demand for chains that operate without lubrication began with the food and IT manufacturing sectors, but has now spread to many more industry sectors where product cleanliness and environmental conditions have become far more important. The result is that lube-free chains are now in the mainstream of industrial manufacturing and can replace conventionally lubricated chains in the majority of applications, including a comprehensive array of attachment and conveyor types for replacement and OEM applications.

Tsubaki Lube-Free Chain Takes the Heat at Horwich Foundry

2004-05-01T03:55:55Z

The maintenance department at Horwich Castings foundry in Bolton, one of the largest and most advanced green sand casting plants in the UK, was used to roller chain lasting a maximum of six months on a conveyor removing hot boxes from the central mould machine. In an attempt to extend chain life in this arduous environment, standard roller was replaced in July 2001 with Lambda Lube free roller chain from Tsubaki. The chain is still running two years later, there has been a considerable cost saving made on replacement chains, plant reliability is now 100% and the level of maintenance work required has been greatly reduced.

Horwich Castings manufacture castings up to 300 Kg in all grades of grey and ductile iron, supplying the rail and general industrial engineering markets. Central to the whole production operation is an automatic Kunkel Wagner 3-stage high-pressure greensand-moulding machine that presses the sand into mould boxes to create a continuous stream of fresh moulds ready for the molten iron to be poured. Once the castings have been poured, they are cooled and removed from the mould boxes; an external conveyor transports the empty boxes from the cooling tunnel back towards the filling station.

Keeping the moulding machine running smoothly is essential to maintaining plant performance; so when previous roller chain showed signs of wear and began to elongate beyond set parameters, it would be replaced. Chain replacement required two six hour maintenance shifts and was frequently carried out during the evening or on weekends when casting was not in progress. In some instances, unexpected breakages could also cause a pause in production, with the resultant increase in running costs. The use of Lambda lube-free chain has so far ensured the smooth running of the conveyor, it has also completely removed the cost of replacement chain and the additional work required for fitting and maintenance.

The working environment is extremely harsh; as castings are removed from the moulds they are often still glowing cherry red with heat, hot casting sand and small drops of scrap metal are also expelled from the mould and both these elements frequently come into contact with the chain. Effective external lubrication under these conditions is not easily achieved, hence the search for a better solution.

Inadequate lubrication and mechanical wear caused by debris retained in external lubricant are the two main factors that cause reduced chain life in this type of application, both are conditions that contributed to the previous chain lasting a maximum of six months. Tsubaki's Lambda chain uses specially sintered rollers to lubricate the chain internally, the heat does not affect the self-lubricating properties significantly and as the chain is dry to the touch, it does not pick up surface debris. Lambda chain is also shot peened throughout to maximise it's tensile strength and resistance to impact damage.

These features have ensured the performance of Lambda chain is outstanding in applications where the use of standard chain can prove a false economy due to harsh operating conditions or restricted lubrication. The Lambda chain fitted on the moulding conveyors at Horwich Castings two years ago is still in operation and not yet due for replacement. The maintenance team at Horwich approached the problem of chain performance 'as part of a plant-wide commitment to continuous improvement where we are always looking to improve process capability and plant operating performance' they are so impressed with the chain's performance that it's use in other areas of the foundry is currently being considered.

Tsubaki Chain Proves To Be a Hero at Cadbury

2004-04-01T07:34:22Z

Tsubaki conveyor chain has enabled Cadbury to significantly increase production on an automated Bindler chocolate moulding plant at the company's Bournville works in Birmingham. The wear characteristics of the chain previously fitted to the machine meant that frequent adjustment was required to maintain accuracy and replacement was required every twelve months. The new Tsubaki chain has been in operation for over six months and has not yet required any adjustment. Maintaining this level of accuracy has also allowed throughput on the machine to be increased, resulting in a production increase of thousands of chocolates per day.

The Bindler machine is a fully integrated chocolate moulding plant, used to produce chocolates with centres such as Roses™, Milk Tray™ and Miniature Heroes™.

The chocolate making process starts with a mould tray being brought to the correct temperature, a chocolate shell is then deposited into the mould, a centre such as cream, noisette or strawberry is then added and passed through an intense cooler that freezes it before the chocolate back is deposited. The back section is cooled and the chocolate is then de-moulded ready to be foil wrapped.

During the process, the moulding trays are transferred from one conveyor section to another within the plant. Any elongation of the conveyor chain caused by wear, results in the conveyors running slightly out of synchronisation and can cause tray collisions if the speed of the machine is increased passed a certain point. Frequent adjustment of the chain was also needed to maintain a high transfer rate.

Having fitted the unusual sized (20mm pitch) Tsubaki conveyor chain, there has been no adjustment required due to wear elongation for a period of over six months. As a result, the transfer operation has remained in-sync and the speed has been increased beyond what was previously possible. An additional few trays per minute does not sound like much, but with over 100 individual chocolates in each tray, the increase in throughput equates to many thousands of chocolates per day.

Tsubaki employs an advanced heat-treating process to carburize the pin surfaces of its roller chain to help achieve the improved chain performance. The link plates and rollers are also shot-peened, and the surface areas between pins and bushings and between bushings and rollers are pre-lubricated. After assembly the chains are also taken through a process of precise pre-loading and running on sprockets before being approved, packed and shipped. The result is great improvements in wear performance over other standard chains.

The first trials at Cadbury have proved so popular that Tsubaki metric pitch attachment chain is now being specified as standard replacement stock for all Bindler machines at the Bournville site.

Tsubaki Supplies BSW Sawmills with Fit and Forget Chains

2002-05-01T05:27:48Z

Tsubaki UK has supplied BSW Timber, the UK's largest specialist sawmill business, with a complete solution to their conveyor system maintenance problems. Shaping the wood from rough-cut logs requires a five stage conveying process, involving loads of up to 10 tonnes of timber and exposure to considerable amounts of airborne debris. From the initial Drive Ramp Conveyor to final Chipper Edging Machines, the non-lube low-elongation properties of Tsubaki's Third generation Lambda chain has significantly cut maintenance costs and downtime.

The operating conditions in any sawmill are tough for moving machinery due to the large amounts of airborne dust from the cutting and shaping processes. At the BSW Sawmill in Caerphilly, the problem is exacerbated by the Mill exclusively cutting Spruce Sitka, a highly resinous variety of tree. Richard Barnet, the maintenance engineer on the site explains, "BSW had problems with dust sticking to the greased chain and sprockets, which often caused clogging and derailment. Machines were constantly having to be adjusted, dismantled and cleaned, taking up valuable production time as well as resources".

Two years ago, a Tsubaki Third generation Lambda chain was fitted to a Chipper Edging Machine, which profiles the sides of 120 meters of board per minute. Previous conveyor chains used on feeding ramp of the machine had an average service life of six months due to the amount of debris produced by the chipping process. Mr Barnet states that: "we chose Tsubaki's Lambda III because the oil impregnated bushings allow the chain to effectively run dry, avoiding the problem of sawdust building up and clogging the links. We now only need to give the system a monthly visual check and have had to adjust the chain just once in two years".

BSW Timber produce 500,000m³ of cut wood a year and have recently invested over £3 million to improve the efficiency of their mills. The use of Tsubaki chains has now significantly contributed towards BSW's program of continuous improvement at the large South Wales site. Due to the success of the first application, Tsubaki's lube-free Lambda chain has been fitted on machines throughout the plant. These further applications highlight the second major benefit of its use, namely virtually zero elongation.

The Aside Transfer system, which handles wood cut by the band saw, requires chains to be automatically tensioned as they operate in forward and reverse motion. Mr Barnet explains that: "a standard chain would last three to six months during which time the automatic tensioners would often fail or have to be padded out until the chain stretched enough to insert an extra link. The thick pin, narrow side plate design of the Lambda chain enabled us to avoid rubbing against components such as gearboxes and its very low-elongation properties have allowed us to fit smaller automatic tensioners and resulted in twelve months of trouble free operation to date".

Specialist Tsubaki sprockets have also provided additional benefits on the largest Chipping Machine at BSW. Used for squaring the edges of the rough-cut logs, it produces so much dust that the conveyor chains and sprockets often have to work through the build ups, making normal lubrication impossible. BSW used a combination of 1inch Lambda chain and Tsubaki Duplex Sprockets with extruder grooves to successfully prevent sawdust getting trapped in the teeth and causing derailment. According to Mr Barnet "the self lubricating properties of the Lambda chain increased the effectiveness of the 'Sparge Line', used for blowing chips away from the conveyor and similarly has enabled the whole system to run problem free for over twelve months".

Lambda WP Chain Survives Daily 70°C Salt Wash Downs Without Corroding

2001-04-01T05:49:14Z

Specialist packaging machine manufacturer BWI Dawson have designed and installed a new depalletising machine for New Zealand Milk using 'Lube-free Water Protected' drive chain from Tsubaki UK. The lambda WP chain has enabled BWI Dawson to design a completely corrosion resistant machine for the first time, one that has to survive a daily washdown using hot brine in a food safe environment.

New Zealand Milk, manufacturers of the Anchor butter brand import over 26,000 tonnes of butter into the UK every year. The butter is wrapped in 25 kilo blocks, stacked five layers deep and frozen for transportation. The butter arrives on pallets holding 50 blocks each, it is then thawed, salted and processed for retail packaging on-site at their Swindon depot. The throughput at Swindon amounts to 120 tonnes per eight hour shift and previously involved six lines of labour intensive unpacking.

This process is now carried out by four compact depalletising machines from BWI Dawson. The machines receive 1250kilo pallets from forklifts in a lift well and raise them using stainless steel lift bars attached to two continuous loops of 1" pitch Tsubaki Lambda WP chain, the chain then indexes up as each layer of butter blocks is swept off the top pallet. At any one time the chains can be lifting up to three tonnes of butter. The mechanism that sweeps each layer of ten 25kilo butter blocks from the top pallet onto a conveyor is also driven by more Lambda WP chain.

Because of the food grade nature of the plant, each machine is washed down using high pressure salt water at 70^oC after each shift. The Lambda WP chain requires no external lubrication due to specially sintered oil impregnated rollers and is coated with a water protective finish. It is able to work cleanly in a food processing environment and withstand extremely arduous conditions without corroding. With a high load and exposure to fat and salt, plus high pressure hot washdown the Tsubaki chain is still operating perfectly after 12months.

Andy Temple, Project Manager at BWI Dawson commented, "The Tsubaki chain was essential to the success of this project. Our previous supplier could only offer us standard chain with external food grade lubrication, which would have been impossible bearing in mind the wash down conditions. The combination of lubrication free operation and an extreme resistance to corrosion featured in this chain has allowed the project to go ahead, without it we would have been looking at a complete re-design. The Lambda chain is also very strong and so we have been able to use a sensible 1" pitch for a high load, this has helped keep the machine compact and control the costs of peripheral equipment such as motors and sprockets".

The new machinery has increased efficiency and aided the maintenance of strict hygiene levels at New Zealand Milk, the need for manual lifting and transfer with it's inherent risk has also been removed. Empty pallets are also neatly stacked by the machine ready for removal adding to the new system's convenience.

Lube-free Lambda WP chain from Tsubaki is a unique product in the market place and is available through local distribution outlets and direct from the company at their Nottingham Head Quarters. The Lambda series of chains is the only lube-free drive chain on the market that is available in attachment, conveyor and corrosion resistant variants.

Lambda Lube-Free "Frog" Chain Keeps Daily Mirror Production Flowing

2000-10-01T05:37:58Z

Tsubaki's lube-free Lambda chain is now in its third year of operation at Mirror Group printing (MCP Watford), where the unique operating conditions meant that previous generations of roller chains were lasting only three months. Since installation Lambda has also saved critical down time in an operation where there are only a few hours available for maintenance between print runs.

Lambda chains are utilised in two areas of a continuous printing process at MCP Watford. The first is on forwarding stations where the printed papers are moved from the press to assembly machines. The second area of usage is in transfer stations; these are effectively crossroads in the finishing and assembly process where three pairs of chains run in parallel, each pair with plastic 'frog' attachments, set at different intervals to carry papers as they change format with folding and inserts.

The newspaper printing industry represents one of the harshest working environments for transmission chain. Fine particles and fibres are released from handling the paper and these stick to exposed lubricant and are absorbed. Once in suspension the particles form a fine and extremely effective abrasive paste inside the chain. The paste then creates a 'lapping' process that can wear down moving metal parts extremely quickly, causing chains to become loose, lose accuracy and require replacement within weeks.
MCP Watford initially sought to resolve this problem by operating roller chains without lubrication (i.e. dry). It did solve the immediate problem, but in the process reduced the life span of the chain to approximately three months, resulting in frequent maintenance and high replacement costs.

As a final solution to these problems, Tsubaki Lambda Lube-free roller chain was introduced in 1998 and is still in operation. The longevity of the chain is due to the 'lube-free' technology. Lambda chain rollers are forged with lubricant included in the material structure of the steel. During operation, the lubricant forms a micro thin layer between the roller surfaces. Meanwhile the exterior of the chain is dry to the touch, a condition that stops it acting as a surface receptor for harmful paper particles.

An additional benefit is that the motion of the lubricant within the rollers in Lambda chain is from the centre outwards, the opposite direction to conventionally lubricated chains that draw lubricant in from the exterior. As a result of this, any debris from the atmosphere that does settle on the surface of a Lambda chain is excluded from the load bearing surfaces of the rollers and does not cause excess wear.

The chains at MCP Watford perform an integral role in a system where each print run is completed in one continuous process and any failure would bring the entire operation to a halt. Printing is carried out seven days per week, leaving only a few hours each morning for maintenance and creating a short and pressurised window between printing runs.

The relative infrequency of chain replacements since the employment of Tsubaki Lambda Lube-free chain has transformed maintenance procedures at MCP Watford, greatly reducing the time and effort required for replacement work. As a result, the printing operation is running more smoothly and the pressure on maintenance time has been significantly reduced.
An added benefit of using Lambda Lube-free chain is the elimination of occurrences where lubricant previously marked papers during forwarding or transfer operations. With Tsubaki's Lambda chain the lubricant is retained within the roller, so there is no lubricant build-up that could find its way onto the printed material during high-speed operations.

In-house assembly and local distribution ensure total support:

MCP Watford are so impressed with Tsubaki's Lambda Lube-free chain, they insist that any replacement chain, used as part of routine maintenance or emergency work, is automatically a Lambda chain. Tsubaki now assemble the chain complete with attachments and hold stock at their UK headquarters in Nottingham. Tsubaki also sources the special attachments direct from the supplier, cutting down on fitting time and inventory costs for the customer.

The chain is stocked and supplied locally by Wyko Industrial Distribution from their Watford branch. Using a local distributor ensures that supply is guaranteed and delivery times are as short as possible; it also means that experienced engineering support is on hand locally. For added ordering convenience 'Frog chain' is inventoried using the customer's own stock numbering system.

Mirror Group (MCP Watford) prints various papers such as The Mirror, The Sunday Mirror and the Racing Post. Lambda chain is a lube-free drive chain that is uniquely available in attachment, roller, conveyor and corrosion resistant variants. It is available direct from Tsubaki UK or from your local distributor.

Lambda Lasts 5 Years Where Standard Chain Only Lasted 8 Weeks

1998-07-01T06:24:03Z

Tsubaki's Lambda lube-free chain has just completed 5 years service without elongation or wear, in an environment where previously, standard lubricated BS roller chains from another manufacturer were seizing and breaking within 6-8 weeks of being fitted. The self-lubricating properties of Lambda chain result in it being dry to the touch, in this application it means that small fibres do not stick to the chain and soak up lubricant, causing chains to wear excessively, dry out and become prone to breakages.

The 3M plant in County Durham manufactures disposable respirators for the worldwide market, exporting over 70% of production to mainland Europe, Africa and Asia. The respirators are produced on a 24 hour per day, 365 day per year cycle. They are manufactured on large converting machines where the filter material is layered and sealed. The fibre material is highly absorbent, so much so that similar material is used in booms by operators in the North Sea to mop up oil spills.

Unfortunately, this quality causes problems where conventional power transmission equipment is concerned, especially where externally lubricated equipment is exposed. In applications where fine particles and fibres are involved in the process, they tend to stick to exposed lubricant and are absorbed. Once in suspension the particles form a fine abrasive paste inside the chain that can wear down moving metal parts extremely quickly, causing chains to become loose, lose accuracy and require replacement within weeks.

Prior to 1997, 3M used standard lubricated roller chains that suffered from this problem. These were lubricated regularly, and much care had to be exercised to ensure that no contamination of the product occurred. In spite of this regime the chains were drying out totally, wearing and within 6-8 weeks breakages became a frequent occurrence leading to high replacement costs and unacceptable levels of downtime.

In an effort to overcome the problem, the maintenance engineers at the plant replaced the standard roller chain with Tsubaki's lube-free Lambda chain. This was over 5 years ago and since then breakages have stopped completely. "We stripped a system down recently and the Lambda chain was as good as new, says Alan Wayper, the Maintenance Team Leader at the plant. "The chain hadn't stretched or worn. Previously breakages were frequent, now we just don't have any".

The Lambda chain achieves such excellent resistance to wear thanks to roller bushes that are forged with lubricant included in the material structure of the steel. During operation, the lubricant forms a micro thin layer between the pin, the bushing and the inner surface of the roller. Meanwhile the exterior of the roller and supporting chain leaves are dry to the touch, a condition that stops the chain acting as a surface receptor for harmful fibres and other particles of debris. This virtually eliminates wear and also prevents the possibility of product contamination from external lubricants.

Lambda was developed specifically to meet industry demands for "clean", maintenance free operation where lubrication is neither practical nor desirable. It directly replaces standard ANSI and BS roller chains and other types of roller chain including attachment versions. The maintenance team at 3M recognise the contribution made to the smooth running of the plant and the reductions in replacement costs that Lambda has brought, whenever a chain is replaced now, Lambda is always specified.