Wear-resistant plastics: materials for moving applications

In modern industries, components are increasingly exposed to high stresses. Moving applications such as conveyor systems, robot systems, production machines or vehicle components place particularly specific demands on them: they must run reliably, must not fail and should have a long service life.

Classic materials such as metals often reach their limits here – for example through corrosion, high weight or complex lubrication. Wear-resistant plastics have established themselves as an alternative in recent decades and in many areas even offer clear advantages. They are lighter, often self-lubricating, resistant to chemicals and can be precisely modified for the respective application. They therefore make an important contribution to increasing efficiency, reducing costs and sustainability in industry.

Basics: What does wear-resistant mean?

Wear describes the gradual loss of material on surfaces through friction, load or external influences. Typical forms are abrasion, surface fatigue, material breakouts or deformation, which over time can impair the functionality of a component. A material is considered wear-resistant if it withstands these stresses over long periods without its surface being heavily worn away or its function declining.

It is not only the hardness of a material that is decisive, but an interplay of various properties such as toughness, elasticity, resilience and the ability to absorb energy. Plastics in particular can be adjusted through their molecular structure as well as through the targeted addition of additives, fibres or lubricants so that they lose less material under friction while at the same time retaining their geometry.

As a result, they are able to support moving applications reliably in the long term, even when high loads, changing temperatures or aggressive media are involved. Wear resistance is therefore a combination of resistance to removal, resistance to environmental influences and the ability to fulfil the desired function even after a long operating period.

Typical areas of application

Wear-resistant plastics are found in a wide variety of industries and applications. They are in demand wherever components are frequently in motion, must withstand high loads or are required to work reliably in aggressive environments:

• Conveyor technology: guide rails, chain guides, deflection rollers, scrapers and chutes that are permanently in contact with conveyed goods.
• Mechanical engineering: bearing bushes, timing belt pulleys, slide guides and spindle nuts that must work precisely and quietly.
• Automotive industry: clutch guides, sliding elements, bearings in the engine compartment or trim parts with permanent friction.
• Food and packaging industry: hygienic scrapers, conveyor rails or cutting guides that must be wear-resistant and food-compliant.
• Medical technology: components in moving diagnostic systems or surgical devices that require high precision.
• Offshore and energy technology: components in wind turbines where high load, weather influences and risk of corrosion coincide.

Important materials at a glance

Polyamide (PA)

Polyamide is one of the most frequently used engineering plastics and is known for its combination of toughness, elasticity and resistance. Particularly noteworthy is its good impact strength, which makes PA reliable even in dynamic applications.

In combination with additives such as molybdenum disulphide or oil, its already good sliding property can be improved further, so that the material is suitable for highly loaded gears, rollers or plain bearings. PA is also frequently used in vehicle construction, for example for clutch guides or fastening elements that combine lightness and durability.

Polyoxymethylene (POM)

POM impresses with its exceptional dimensional accuracy and shape stability. With a high surface hardness and low friction values, it is suitable for precision parts that must retain their functionality even under long-term stress.

The plastic absorbs hardly any moisture and therefore remains stable even in humid environments, which predestines it for applications in mechanical engineering or in the automotive industry. Typical components are gears, bearing bushes, sliders and valves which, thanks to POM, ensure quiet, reliable and long-lasting operation.

Ultra-high-molecular-weight polyethylene (PE-UHMW)

PE-UHMW is, due to its extremely high molecular mass, one of the most wear-resistant plastics of all. It exhibits excellent abrasion and impact resistance and remains dimensionally stable even under high load. Thanks to its very low coefficient of friction, sliding movements can be realised almost silently and without lubrication.

This makes the material indispensable in bulk solids technology, in conveying equipment or as lining in silos. PE-UHMW is also widely used in the food industry because of its resistance to chemicals and moisture.

Polyetheretherketone (PEEK)

PEEK is a high-performance plastic that offers a broad spectrum of properties. It is not only wear-resistant, but also withstands temperatures of up to 250 °C as well as aggressive chemicals. This makes PEEK predestined for extreme operating conditions such as in aviation, in special-purpose machinery construction or in the oil and gas industry.

In addition to its high mechanical load capacity, the material also impresses with excellent dimensional stability, so that it can be used reliably even in highly precise applications such as implants in medical technology.

PTFE (polytetrafluoroethylene)

PTFE is primarily known for its exceptionally low friction values and its almost universal chemical resistance. The material is therefore outstandingly suitable for seals, bearings and guides that must work reliably under extreme conditions. Since PTFE in its pure form has low strength, it is frequently reinforced with glass fibres, carbon or bronze.

In this way, components are created that combine both the excellent sliding properties and significantly higher stability, which predestines them for demanding applications in medical technology, the chemical industry or mechanical engineering.

Further materials and composite solutions

Alongside the established materials, composite solutions are also becoming increasingly important. By combining thermoplastics with fibres or nanoparticles, the mechanical properties can be specifically improved. Such hybrid materials open up new possibilities, for example for components that must be particularly light yet still extremely load-bearing.

These materials are also used in the field of electrical engineering, since they can combine electrical insulating capability with high abrasion resistance.

Practical examples from industry

In the food industry, the benefits of PE-UHMW were particularly impressive: in a large dairy, scrapers and conveyor rails made of stainless steel were replaced with plastic. The result was a clear reduction in noise, lower energy demand and a longer service life without corrosion. The advantages are also noticeable in mechanical engineering.

A manufacturer of packaging machines converted its metal gears to POM and benefited from lower weight, quieter processes and halved maintenance effort. In the automotive industry, metal clutch guides were replaced with PA components with MoS₂ additive, which ran over 200,000 kilometres maintenance-free while at the same time saving weight.

Another example is offshore wind power: PEEK components there withstand salt water, extreme temperatures and high continuous load, as a result of which they achieve a longer service life than metal components. Wear-resistant plastics also play a role in medical technology, for example in PTFE-coated guides in imaging systems that enable precise movements and offer the highest reliability.

Advantages over metals

Substituting metal with wear-resistant plastics brings numerous advantages:

• Lightweight construction: plastics are significantly lighter than steel or aluminium, which leads to energy savings and better efficiency.
• Self-lubrication: many plastics have integrated lubricating properties, which eliminates external lubrication.
• Freedom from corrosion: unlike metals, plastics do not rust, even under high humidity or aggressive chemicals.
• Reduced noise development: plastics damp vibrations and ensure quieter operation.
• Design freedom: injection moulding and CNC machining make it easier and more cost-effective to produce complex geometries.
• Cost-effectiveness: often lower production costs and longer service lives compared with metals.

Quality and testing procedures

For a plastic to function reliably in moving applications, extensive tests are necessary. Common testing procedures include the Taber abrasion test, which measures material loss caused by rotating grinding wheels, and the pin-on-disk test, which determines friction and wear under point load.

Tribometer tests also provide valuable insights, as they analyse friction values under near-real conditions. In addition, long-term tests are carried out that simulate real loads over thousands of operating hours. In this way, the service life of a component can be estimated and the suitability of the respective material for specific applications assessed.

Sustainability and future trends

The development of wear-resistant plastics is increasingly oriented towards sustainable solutions. Bio-based plastics made from renewable raw materials are made wear-resistant through special additives and open up new fields of application. At the same time, recycling is playing an increasingly important role: high-performance plastics are to be processed in such a way that their properties are retained even after multiple use.

Another trend lies in the optimisation of additives that minimise abrasion while being environmentally compatible and resource-saving. In addition, many manufacturers rely on digital simulations that, with the help of AI and digital twins, enable precise prediction of service life and thus shorten development times.

In conclusion

Wear-resistant plastics have established themselves as an indispensable group of materials for moving applications. They impress with low weight, long service life, versatile application possibilities and good machinability. With high-performance polymers such as PEEK or PTFE, even the most extreme conditions can be mastered, while more cost-effective materials such as PA, POM or PE-UHMW score in standard applications.

The practical examples impressively show that plastics are not only an alternative, but often the better choice. In combination with new developments in the field of sustainability and materials science, wear-resistant plastics will further expand their importance in the future – not only as a replacement for metals, but as a key material of modern industry.

Frequently asked questions

Which plastics are particularly wear-resistant? Alongside classics such as PE-UHMW, POM and PA, high-performance plastics such as PEEK and PTFE are among the most resistant materials.

What advantages do wear-resistant plastics offer over metal? They are lighter, corrosion-free, often self-lubricating and enable quieter operation at lower costs.

Where are wear-resistant plastics most frequently used? In conveyor systems, in mechanical and automotive engineering, in the food industry, medical technology and increasingly also in the energy sector.

How is wear resistance tested? Through standardised abrasion and tribology tests that simulate material loss under real conditions.

Are there sustainable variants? Yes, bio-based and recycled plastics with wear-resistant properties are increasingly being developed and used.