Tribo-polymers showcase their strengths in maintenance- and lubrication-free iglidur bearing technology
Assessing the service life of a machine must take account of the costs of purchase, procurement and installation, as well as all the costs incurred in the long term operation, maintenance and repair of the machine, points out igus. Using wear-resistant materials and low-maintenance components reduces not only running costs, but also the risk of unscheduled shutdowns and extensive maintenance work.
Motion plastics specialist igus has many years' experience and knowledge in the developing and producing of wear-resistant solutions made of tribo-polymers, and it keeps a large database of these products in its own test laboratory. "Many machines today are well engineered and work hard, often running constantly. With high physical demands on machines, searching for the most tribologically optimised component is time well spent for every mechanical engineer," states igus.
Studying friction and wear on moving parts
Design engineers are trained to select the best material for the product or component, and often seek tribologically-optimised components – tribology being the study of friction and wear on moving parts. igus is often chosen as the preferred supplier, says the company, because of its development of polymers specifically for dry, lubrication-fee operation.
Base polymers, solid lubricants and fibre reinforcing are combined to develop even better materials for increasingly challenging applications and to achieve better wear results. While some of these materials are developed for individual customers with special requirements, others become part of the catalogue portfolio. In more than 12,000 wear tests per year carried out on over 450 test stands, igus engineers in Cologne systematically analyse how materials wear.
Here, more than 135 trillion test movements take place annually over a range of conditions and variables, including temperature, humidity, the type of movement and the contact materials.
All these factors affect the wear patterns in individual scenarios and have to be taken into account by machine operators. The analysis is used both to evaluate the materials’ performance and to calculate the service life of components in any application; a unique service in the motion polymer industry.
Test laboratory as a reflection of industrial reality
The many parameters that influence wear shows how much work goes into research involved in the successful development of high-strength polymer components, which is why plastics specialist igus operates a 3,800 square metre test laboratory (bigger than half a standard football pitch). Here, the tribological quality of the polymers is tested with linear, rotating and flexing types of motion, in combination with other materials.
But it is not just mechanical properties that are important for the continuous improvement of customer solutions, adds the company. igus components are used in different industry sectors and must be able to withstand different external influences.
For example, classical manufacturing equipment and methods involving a normal degree of dirt as well as extremely dirty environments, or the presence of aggressive chemicals, such as when tribo-polymer components are used in agriculture, construction or offshore installations. Other fields of industry present different challenges, making the tests in the igus laboratory so important.
Agricultural work is exposed to a lot of dirt, the building materials industry is an aggressive environment due to chemicals and the offshore industry is also corrosive, due to salt water. Components that are used in pharmaceutical industry cleanrooms or where they come into contact with food have to cope with other conditions, where hygienic design is of the utmost importance.
igus laboratory engineers are trained to prepare and test for all the challenges their components may encounter, from tests underwater to the simulation of very dirty environments, and testing in different temperatures and in a cold chamber.
“This thorough research has resulted in products such as iglidur plain bearings, drylin linear bearings, xiros ball bearings, energy chains and cables whose polymers have the best tribological properties for almost any application,” states igus.
Growing database calculates service life
“Every year, the laboratory's test databases are supplemented with more research data from which new materials are created, whose technical performance today is at the level of what customers will need tomorrow,” igus adds. “Analysing this huge amount of recorded test data means the service life of a product can be calculated in an expert system specially developed for this purpose. The accuracy of these results is a unique service in the plastics industry.
"Accurate service life benefits the customer, especially for bearing technology products that are central to the operational performance of machines and installations. Also, the consequences of the wrong choice of material can be problematic.”
If you are planning to run a safe and reliable production process on a large scale, you should first think of the small things, namely the bearings, igus continues. “Bearings should be as wear-resistant as possible, so that everything operates smoothly and for a long time. There are many types of bearing, such as rolling bearings, linear bearings and plain bearings, where the latter are supplied by igus as lubrication-free polymer bearings.
"A product range with over 8,500 catalogue dimensions and specialist parts made of more than 60 different tribologically optimised materials gives the user a huge range of choices.”