A shaft on a transport or process line does not wear gradually — it deteriorates sharply: first it starts to run out of round, then it knocks out bearings, then it stops the line. Quarterly replacement of metal or rubber shafts is not only expensive — it creates the risk of emergency downtime at the worst possible moment. Polyurethane shaft lining from TIMOL delivers a service life several times longer than rubber, protects the metal core from abrasion and corrosion, and converts maintenance from emergency to planned. This article covers which nodes benefit from polyurethane, how it compares with competing materials, and how to order lining to size.
What Polyurethane Shaft Lining Is For
Lining protects the metal shaft from direct contact with abrasive, chemical media, or the material being processed. The polyurethane layer acts as a sacrificial element: it wears instead of the metal and is replaced when necessary without touching the core shaft. The high elasticity of polyurethane (rebound elasticity 34-61 %) also allows impact loads to be absorbed, which reduces bearing and seat wear.
Polyurethane lining is optimal for nodes where wear resistance and vibration damping must be combined. In mining — bucket elevator rollers and conveyor belt rollers, drum shells. In metallurgy — rollers of transport and processing lines. In printing and food industries — drive shafts with delicate contact with the processed material. In oil and gas — pipe-handling rollers resistant to petroleum products.
TIMOL’s free-casting technology allows a polyurethane layer of any thickness and profile to be reproduced directly on the metal core. Surface profiling (grooves, channels, knurling) is performed at the casting stage — additional machining is not always required.
Comparison Table: Shaft Lining Materials
| Material | Abrasion DIN 53516, mm³ | Operating t, °C | Hardness | Tensile strength, MPa | Rebound elasticity, % |
|---|---|---|---|---|---|
| Polyurethane TIMOL | 38-39 | -60…+100 | 85A-95A | 39-87 | 34-61 |
| NBR rubber | 80-150 | -30…+100 | 40A - 90A | 10-25 | 20-45 |
| SBR rubber | 100-200 | -40…+80 | 40A - 80A | 8-20 | 30-55 |
| Natural rubber NR | 60-130 | -50…+70 | 30A - 80A | 20-30 | 40-75 |
| Capron PA6/PA66 | 30-90 | -40…+100 | 75D - 85D | 60-85 | 5-15 |
| Structural steel | n/a | -40…+500 | 120-250 HB | 370-700 | n/a |
Polyurethane shows the lowest abrasion among elastomers (38-39 mm³) while retaining elasticity that capron lacks. This explains why polyurethane-lined shafts last 2-5 times longer than rubber-lined ones in impact nodes and do not crack like capron.
SBR rubber (abrasion 100-200 mm³) and NBR (80-150 mm³) have lower tensile strength (8-25 MPa vs 39-87 for polyurethane) and a lower upper operating temperature limit. Natural rubber, while having higher rebound (40-75 %), has poor oil resistance and an upper limit of only +70 °C — unsuitable for most industrial conditions. Rubber also ages from ozone and UV in outdoor operation.
Capron (PA6/PA66) is a rigid structural plastic with hardness 75-85D. Its abrasion (30-90 mm³) is comparable to polyurethane, but rebound elasticity is only 5-15 % — under impact load it cracks. Polyurethane in the 80-95 Shore A range delivers similar wear resistance while remaining elastic: it withstands impact and recovers its shape.
Steel is not a substitute for an elastomer: it does not damp vibration, does not absorb impacts, corrodes quickly in a wet environment, and is 6-7 times heavier than polyurethane.
Engineer’s tip: choose polyurethane lining hardness in the upper part of the Shore A range, 80-95 Shore A, for heavy transport and abrasive nodes. For drive shafts in printing, food production, or delicate lines, 50-60 Shore A is better. Remember: the quality of metal surface preparation for adhesion is critical — an uncleaned or non-degreased substrate causes the layer to peel at the first impact or vibration.
Application Industries
Mining is the largest consumer of polyurethane shaft lining due to intensive abrasive wear during ore, coal, and stone transport. Shells and rollers with a polyurethane layer withstand quarry and underground mine conditions without frequent replacement.
Metallurgy uses polyurethane shafts in metal processing roller lines, where wear resistance combined with corrosion protection is critical. Pipe mills choose polyurethane for pipe-handling rollers — the material does not scratch and provides even contact along the pipe length.
The printing industry values polyurethane for its ability to produce a shaft with a precisely specified surface profile that delivers even pressure on the web without deformation. Food and pulp-and-paper industries choose polyurethane for chemical inertness — the material does not affect product taste or quality and cleans easily.
The oil and gas sector uses polyurethane shafts in combined petroleum-product and abrasive conditions. The full product list is in the product catalogue.
Manufacturing Technology and Installation
The process begins with metal surface preparation: the shaft is cleaned of old coatings, rust, and grease, shot-blasted to the required roughness, degreased, and coated with adhesion primer. This preparation ensures reliable bonding of polyurethane to metal for the full service life.
The polyurethane elastomer is then free-cast into a mould. Layer thickness, surface profile (knurling, grooves, straight cylinder), and hardness are all set at this stage. Polymerisation occurs at controlled temperature over several hours. Machining is then performed to achieve final geometry to drawing tolerances.
Installation of the lined shaft is standard: the part is mounted on bearings or in mounting nodes without modifying the equipment. For worn shaft restoration — the old layer is stripped mechanically or chemically, the surface is re-prepared, and new polyurethane is cast. Full technology detail in the reference information section.
How to Order Shaft Lining to Size
To place an order, supply a drawing or sample with dimensions and fits. Describe the operating conditions: load type (abrasive, impact, sliding), working medium (oils, water, chemicals), temperature range, and duty cycle. This allows the optimal polyurethane formulation to be selected and the layer thickness to be calculated.
Production is possible for new shafts and for restoration of worn ones (for the latter, the shaft itself is sent to the factory). Order volume ranges from one shaft to production batches. For consultation and ordering, contact TIMOL factory. Engineers will help select the material, calculate parameters, and organise production to your requirements.