An assembly that fails every few weeks stops the line and drags along unplanned costs for repair and downtime. A metal or rubber part that has to be replaced every quarter eats into the maintenance budget faster than it seems at first glance. Cast polyurethane delivers a service life many times longer and moves the maintenance of an assembly from emergency to planned. Below I break down which parts make sense to produce from polyurethane, why it beats traditional materials, and how to order a part to your own drawing.
What cast polyurethane brings to parts manufacturing
Polyurethane replaces rubber, steel, and rigid plastics wherever an assembly works under wear, impact, or in contact with an aggressive environment. The material belongs to the elastomer family: it stretches under load and returns to its original shape, while its wear resistance is 2-5 times higher than standard rubber. This combination of elasticity and hardness lets a single part absorb impacts and resist abrasion at the same time.
At the TIMOL plant, parts are cast using open casting into a mould. This method requires no high pressure, allows parts of complex geometry and large mass, and makes it possible to line finished metal cores with a polyurethane layer. Because casting follows a specific drawing, the part matches the seating dimensions of the assembly exactly, so installation needs no rework.
Polyurethane is not afraid of moisture, so it is fitted into assemblies that work in water, outdoors, and in humid shops. It does not corrode like steel and does not age under the action of oils as quickly as rubber. For a plant this means fewer replacements, less downtime, and a predictable maintenance schedule.
Technical specifications of TIMOL polyurethane
The operating temperature range of TIMOL polyurethane runs from -60 to +100 °C, which covers both cold warehouses and hot production areas. The material keeps its elasticity in the cold, when rubber stiffens and cracks, and it does not flow when heated within its range.
Polyurethane hardness is selected from 50 Shore A to 70 Shore D. Soft grades go into seals, membranes, and dampers, while hard grades go into wear-resistant wheels, rollers, scrapers, and linings. The same polymer, with a different formulation, yields a part tailored to a specific task, from a resilient shock absorber to a rigid support element.
Abrasion of polyurethane per DIN 53516 is 38-39 mm³, whereas for common SBR rubber this figure reaches 100-200 mm³. In plain terms, under the same abrasive conditions rubber loses several times more material and therefore wears out faster. The tensile strength of polyurethane lies in the range of 39-87 MPa against 8-20 MPa for SBR, so the part withstands peak loads without tearing.
Comparison table: polyurethane versus rubber, steel, and plastic
The figures below are taken from standard engineering references (DIN 53516, ISO 4649, Matweb) and show why polyurethane wins in most assemblies that work under wear.
| Material | Abrasion (DIN 53516), mm³ | Operating temperature, °C | Hardness | Tensile strength, MPa | Rebound resilience, % |
|---|---|---|---|---|---|
| Polyurethane (TIMOL) | 38-39 | -60…+100 | 85A-95A | 39-87 | 34-61 |
| SBR rubber | 100-200 | -40…+80 | 40A - 80A | 8-20 | 30-55 |
| NBR rubber | 80-150 | -30…+100 | 40A - 90A | 10-25 | 20-45 |
| Nylon (PA6/PA66) | 30-90 | -40…+100 | 75D - 85D | 60-85 | 5-15 |
| Structural steel | no data | -40…+500 | 120-250 HB | 370-700 | no data |
The key row in the table is abrasion: 38-39 mm³ for polyurethane against 80-200 mm³ for various rubbers means a service life 2-5 times longer under abrasion. Nylon has wear resistance close to polyurethane (30-90 mm³), but its rebound resilience is only 5-15 %, so it is brittle under impact and does not damp vibration. Steel is incomparably stronger in tension, yet it weighs 6-7 times more, corrodes, and transmits impacts through the whole structure, accelerating bearing wear.
Open casting technology: how parts are made
Manufacturing begins with preparation: the engineer studies the drawing or sample, defines the hardness, selects the polymer formulation, and calculates the tooling. To line a metal core, the surface is cleaned of rust and grease, sandblasted for roughness, and coated with an adhesion layer, on which the bond between polyurethane and metal depends.
Next the liquid polyurethane is poured into the mould by open casting. The method produces a part of the required profile and thickness without high pressure, so it suits both massive parts and thin cuffs. Before pouring, the mix is degassed to remove air, because bubbles in the body of the part become stress concentrators and shorten its service life. After pouring, the part polymerises for several hours at a controlled temperature, then it is machined to exact geometry and seating dimensions.
The hardness of the part is set at the formulation stage, not during finishing. The same open casting technology yields both a soft seal at 50 Shore A and a rigid support element at 70 Shore D, depending on the mix composition. This is an important advantage over extrusion or rubber vulcanisation: instead of pulling a ready profile from stock, each assembly gets a material with calculated properties. For parts that work in a pair with metal, polyurethane is cast directly onto the core, producing a non-detachable assembly with a strong adhesive bond.
Engineer’s tip: select hardness to match the character of the load, not on the principle of “the harder the better”. For impact and vibration assemblies, too hard a part transmits the impact to the structure and fails faster at the edges, while too soft a part flows under pressure. If the part is lined onto metal, watch the quality of the sandblast preparation separately: poor adhesion leads to the layer peeling off under load.
The finished product range and typical solutions are gathered in the polyurethane product catalog, and the list of the plant’s manufacturing capabilities is described in the services section.
Where polyurethane parts are used
TIMOL cast polyurethane works in 12 branches of industry, from mining to food. Everywhere a part abrades, takes impacts, or meets oil and water, polyurethane extends the service life of the assembly.
- Mining: linings, scrapers, screen decks, conveyor rollers.
- Metallurgy: support and pressure rolls, tyres, protective coatings.
- Machine building: bushings, silent blocks, shock absorbers, plain bearings.
- Agriculture: machinery parts, coatings, seals.
- Food and pulp-and-paper industry: rolls, scrapers, elements for gentle transport.
- Transport and printing: wheels, rollers, drive rolls of printing machines.
For each industry the part is designed around a specific assembly: the type of abrasive, temperature, pressure, and the chemistry of the environment are all taken into account. The same type of part, a roller for example, is made hard and wear-resistant for ore in mining, but soft for delicate contact with paper in printing. That is why there are no universal polyurethane parts: for different conditions the same assembly gets a different formulation and hardness. Read more about the properties of the material and the technology in the reference information section.
How to order manufacturing to a drawing
To order a polyurethane part, provide a drawing or a sample of the worn part, state the main dimensions, and describe the working conditions of the assembly: abrasive, temperature, pressure, presence of oils or chemicals. The engineer will select the polyurethane grade, calculate the hardness and geometry, and if needed take the measurements from the provided sample without a finished drawing.
After the technical specification is agreed, the plant calculates the lead time and cost of manufacturing, which depend on the complexity of the tooling and the batch size. Production is possible for both single parts and runs, and worn metal cores can be restored by re-lining instead of full replacement. For a quote and consultation, reach out through the TIMOL plant contacts: our specialists will help select the material and produce a part exactly to fit your assembly.