This article was featured in QMI Solutions (Edition 3, November 2014).
In optimising efficiency, companies from a variety of industries should pay attention to the fundamental quality of machine parts used in production facilities. Some of such Australian industries include manufacturing, mining, agricultural, marine, commercial, automotive, and construction.
According to last year’s annual report from Ernst & Young, productivity is the second highest concern for mining businesses. EY global metals and mining leader Mike Elliott suggests boards and CEOs are recognising that critical to long-term profitability is regaining lost productivity and gaining new ground.
For Hubbards Contracting Manager Jason Hubbard of the agricultural industry, his Darling Downs based farm depends on his two harvesters and two laser bucket tractors. In the 4-5 months of high seasonal demand, each machine may experience a breakdown costing him downtime worth thousands of dollars. “A single breakdown can cost us up to $4,000 of downtime a day, per machine. This usually happens once every five days,” he says.
There are now a variety of new engineering plastics available to the market, which not only deliver years of additional service life to the seals that protect the equipment, but also allows them to operate at a higher rate of speed than ever before.
Polyurethanes are the engineering plastics of choice as they combine many of the advantages of rigid plastics, metals and ceramics with the flexibility of rubber. There are three unique types of polyurethanes developed in Australia which are relatively new to the market: Oz Monyt, Aflas Extreme and Food Grade Super Polyurethane. While these are used primarily for seals and bearings, their versatility brings to mind a breadth of ideas for other uses and applications.
For the underground mining and earthmoving industries, the use of high performance seals made of super polymers and custom rubber compounds is imperative to safety and productivity. However for much of the remaining industries, little is known about how easy accessing parts made of these materials can be. According to Hubbard, the main barriers are cost and accessibility.
“We take a list of preventative maintenance to the machines and source all the parts from the dealership and I suppose there’s a degree of convenience to be able to get all the parts for that machine from that one supplier rather than chasing around,” he says.
Genuine seal kits are usually the first point of call for end users who are not aware of other options which are affordable and are just as, if not, more reliable. Wilhelm Prinz, Managing Director of Australian company Oz Seals believes the need for repair business is a major driver for the preference to genuine parts, especially in the automotive industry. He states, “The reason why people use genuine parts is, for instance, in car sales, they have the aftermarket business. They recommend using genuine parts because they have a certain breakdown cycle, whereas there’s always a better solution when it comes to seals and most of the time people are not aware of that.”
Prinz suggests that in less critical areas where a breakdown does not cost any damage or is picked up before the breakdown occurs, consumers can use cheaper polymers which satisfy the job for a certain time span.
“This is what’s commonly used, especially in automotive and other machinery where regular service is required. On the other hand, people who run a production line, like the automotive production lines of BMW and Mercedes Benz, would use our seals because they want to run it 24/7 a day. They cannot have breakdowns because it costs them hundreds of thousands of dollars. We have situations where when production stops, it can cost $300,000 – $400,000 an hour. Therefore, they go for the best quality to prevent breakdowns during operation. In terms of production lines, offshore drill rigs, or underground mining, that’s where they use seals made of the super polymer range, where reliability matters and safety is on the stakes,” he says.
One of such super polymers is Oz Monyt, developed by Oz Seals. Classed as a super strong bearing material, Oz Monyt exhibits greater load bearing capabilities than thermoplastic materials currently in the market. According to Prinz, what makes this material unique is the reinforcing filler used. Conventional polymer materials are unfilled. Oz Monyt uses specially developed glass fibres, which remain dispersed in the material. This gives it a load bearing capability of approximately three times more than conventional polymers.
Oz Monyt has been developed for use in low friction, long life bearing applications. It contains three lubricants, including molybdenum, making the material ideal for applications where friction matters. Since Oz Monyt continues to exhibit high lubricity throughout its long service life, it will not only extend the life of bushes, but also enhances the life of the mating pins and shafts. Oz Monyt provides the load bearing capabilities greater than white metal and self-lubricating characteristics far better than those of ordinary materials.
Oz Monyt is in its element where high loads must be carried with small clearances and in dirty environments where there is little lubrication. The material also works well in moist and corrosive environments. Oz Monyt exhibits superior dimensional stability with minimal swelling (0.8%) in water. This is in contrast to materials like nylon 6 and nylon 66 which tend to absorb up to 3-6% in volume – with the consequent expansion and softening of the material.
For industries requiring excellent chemical and temperature resistance such as chemical industries, refineries and foundries, an improved type of fluorinated rubber called Aflas Extreme was recently released. Based on the Aflas TFE Elastomer produced by Asahi Glass Company, this compound provides a superior combination of high temperature, chemical and electrical resistance properties.
The Aflas Extreme formula improved by Prinz Polymers features an extra PTFE backbone into the structure, making it stronger than standard Aflas. It is the recommended elastomer for conditions subject to extreme temperatures as it can withstand temperatures of up to 316˚C. It is also an affordable alternative to Kalrez by DuPont.
The third material is a specialised food grade compound suitable for the food and drug (FDA) industry. Food manufacturers, food packaging and drug manufacturers using pneumatics on processing plants require parts which exhibit unique physical and chemical properties, where non-toxicity of the material is particularly critical.
Food and drug approved silicone, virgin PTFE or food grade super polyurethane may be used for pneumatic seals, piston pumps and adhesives in food packaging. Not only are they required to meet the chemical and physical requirements for FDA approval, they must be able to withstand high performance levels. For instance, a beverage processing plant would use super polymer pneumatic seals on fillers which are designed to fill up to 80,000 bottles an hour.
The thought of using new engineering plastic innovations is usually accompanied with the perception of high cost. However in reality, spending a few extra dollars on a quality polymer can save you thousands in repairs or even prevent a potential breakdown. Super polymer seals are usually only 30-40% dearer than standard seal kits. If one of Mr. Hubbard’s harvesters, which sees a breakdown once every five days, used a super polymer seal kit, he would effectively eliminate his breakdowns completely. For knowing where to look, the cost of productivity is priceless.