Material guide
PUR, polyurethane
PUR, polyurethane, is the wear resistant elastomer. Tough and rubbery rather than hard, with a wear resistance few materials come close to. It sits where things wear, chafe and take knocks, from scrapers and wheel treads to damping and wear liners.
What it is
PUR, polyurethane, is an elastomer, that is, a rubbery material rather than a stiff engineering plastic. It sits between soft rubber and hard plastic: tough and elastic, but with a wear resistance and tear strength that ordinary rubber does not reach. That makes PUR a first choice of material for parts that have to withstand wear, impact and pressure over a long time without wearing down. The material is available in different hardnesses, from soft and flexible to hard and almost plastic like, which means that the same base material solves everything from shock absorption to heavily loaded wear surfaces. More about hardnesses and variants under grades.
Properties
Wears slowly even under hard and repeated load
Withstands blows and impacts without cracking
Returns to its shape after load and damps well
Resists oil and grease better than many other elastomers
From soft and damping to hard and wear resistant
Holds up where harder plastics crack and softer rubber wears out
Common applications
PUR sits where things wear and chafe. Typical parts are material for scrapers and wipers, wear liners and lining in chutes and pockets, wheel treads and roller coverings, plus damping elements, buffers and shock absorbers. The material is common in transport and materials handling equipment where the same surface is exposed to wear around the clock, and in parts where a rubber would wear out too quickly but a hard plastic would be too rigid. When a customer describes something that keeps wearing through and wants a tough, wear resistant material instead, the choice often lands on PUR.
Limitations
PUR is no stiff engineering plastic and does not carry load to tight tolerances the way POM or PA does. The material gives way under load, which is the whole point of an elastomer. Nor is it a high temperature material, and it softens in heat, so keep it away from hot environments. Moisture and certain chemicals can break the material down over time through hydrolysis, so for prolonged contact with water or aggressive media you want to check the grade and the environment. For a pure sliding surface without wear requirements, an engineering plastic is often a cheaper and more stable choice.
Grades and variants
PUR is available in a wide hardness range, and the choice of grade is governed above all by how hard or soft the part is to be.
Hardness grades
- Soft grades, flexible and damping, for shock absorption, buffers and parts that are meant to give way.
- Medium hard grades, a balance between elasticity and wear strength, for scrapers, wear liners and wheel treads.
- Hard grades, almost plastic like, for heavily loaded wear surfaces where maximum wear resistance weighs heaviest.
Hardness is normally stated in Shore. We state actual Shore values per product only when they are given in the datasheet. Unsure which hardness your part needs? Get in touch and we will go through the load together.
Machining
PUR is sawn, milled, drilled and turned, but the material is tough and would rather deform than be cut, so sharp tools and a calm feed rate apply. Choose the hardness to suit the job: softer qualities damp, harder ones hold up against wear.
Formats we can supply
Formats and dimensions you see in the range. Would you like a piece cut to size? Enter the dimensions in VisualCutter and you will see the price straight away.
Buy or request a quote
Do you know the dimensions and the hardness? Go to the range and filter on format and dimension. If you want a piece cut to exact size, add it in VisualCutter and see the cutting fee straight away, or send us a list and we will price it. Unsure which PUR grade or hardness suits your wear part? Get in touch and we will work it out.
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