Why coat rollers with polyurethane instead of replacing them?

Polyurethane coating returns a worn roller to service while preserving the expensive axle and bearing. It is cheaper than a new roller and is completed faster. Polyurethane simultaneously adds service life: its abrasion per DIN 53516 is 38-39 mm³ versus 100-200 mm³ for rubber, so a restored roller lasts several times longer than the original rubber one.

What polyurethane hardness should I choose for a roller?

Hardness is selected for the roller's function. Transport and support rollers are typically coated in the range of 85-95 Shore A; tension and pressure rollers are selected by force requirement. Hard grades up to 70 Shore D are used where precise geometry and high contact pressure are required. Softer grades around 80 Shore A damp vibration better. The exact hardness is agreed with a technologist based on the load and speed.

Why is polyurethane better than capron and UHMW-PE for rollers?

Capron and UHMW-PE are wear-resistant but almost inelastic: rebound elasticity is only 5-15 % versus 34-61 % for polyurethane. They therefore damp impacts and vibration poorly and chatter at joints. Polyurethane delivers comparable abrasive resistance plus elasticity and tensile strength of 39-87 MPa, so it does not crack under dynamic loading.

How is polyurethane applied to a roller?

The process comprises several stages: removal of the old coating, sandblasting of the axle contact surface, application of adhesion primer, free casting of polyurethane at the required hardness, and polymerisation. There is no seam; the coating bonds firmly to the metal. Adhesion quality depends on surface cleanliness and sandblasting preparation before casting.

Can a roller be restored to an in-house drawing or sample?

Yes. TIMOL factory coats and manufactures rollers to a drawing, to a sample of a dismantled roller, or to a dimensioned sketch. Free-casting technology allows even a single complex-profile roller to be restored. For calculation, supply the diameter, length, axle fit, load, and operating conditions.

Polyurethane Roller Coating: Node Restoration

Q: In which industries are polyurethane rollers used?

Polyurethane rollers work on conveyor lines, in glass and sheet material transport, in printing and pulp-and-paper, in tracked vehicles as support rollers, and in textile and woodworking production. Wherever a roller is in constant motion under load, polyurethane delivers a longer service life than rubber or plastic.

A support roller on a conveyor line wears to grooves in a few months of continuous operation, and every replacement means a line section shutdown. Rubber coating does not withstand abrasive, and hard plastic chatters and cracks. Polyurethane coating returns the roller to service, wears 2-5 times more slowly than rubber, and remains elastic. This article covers how rollers are restored with polyurethane, why it beats capron and UHMW-PE, and how to order restoration for your node.

What Polyurethane Roller Coating Achieves

Polyurethane roller coating simultaneously solves two problems: it restores a worn part without replacing the axle and bearing, and it increases the service life of the rolling surface. The expensive metal core is preserved while the working layer is renewed and made more durable than the original.

The gain in wear resistance is direct. Abrasion of polyurethane per DIN 53516 is 38-39 mm³ versus 100-200 mm³ for SBR rubber, meaning a rubber roller wears three to five times faster than a polyurethane one in the same duty cycle. In addition, polyurethane withstands tensile strength of 39-87 MPa versus 8-20 MPa for rubber, so it handles impacts and changes in dynamic loading well — characteristic of rollers in constant motion. A polyurethane-coated roller also damps vibration and reduces line noise.

Roller Types and Where They Work

A roller is a wheel with a built-in bearing, and by function they are divided into several groups: support rollers carry the belt and load weight, transport rollers convey material, tension rollers set belt tension, and guide rollers orient material in the flow.

Each type works in its own conditions, so requirements for the coating differ. Support and transport rollers face constant abrasive and impact at joints, and here polyurethane gives the greatest service life gain. Pressure and tension rollers work at a defined force, so stable hardness that does not drift is important. Rollers for transporting glass and sheet material must be softer to avoid leaving marks on the delicate surface.

Polyurethane rollers are used on conveyors, in printing and pulp-and-paper industries, in tracked vehicles as support rollers, and in textile and woodworking production. Standard sizes are listed in the polyurethane products catalogue.

Material Comparison for Roller Coatings in Numbers

Real competition for rollers is among four materials: polyurethane, rubber, capron, and ultra-high-molecular-weight polyethylene UHMW-PE. The numbers show why polyurethane is chosen when both wear resistance and elasticity are required simultaneously.

Property	Polyurethane TIMOL	SBR rubber	Capron PA6	UHMW-PE
Abrasion DIN 53516, mm³	38-39	100-200	30-90	15-30
Operating temperature, °C	-60…+100	-40…+80	-40…+100	-200…+80
Tensile strength, MPa	39-87	8-20	60-85	17-45
Rebound elasticity, %	34-61	30-55	5-15	5-10
Shore hardness	85A-95A	40A-80A	75D-85D	60D-70D
Impact damping	good	good	poor	poor

UHMW-PE formally has the highest abrasion resistance (15-30 mm³), but its rebound is only 5-10 %, it creeps under sustained load, and damps impact not at all. Capron is strong but rigid and brittle under impact, with only 5-15 % rebound. Rubber is elastic but wears four times faster than polyurethane. Polyurethane alone holds the balance: abrasion resistance close to plastics, and rebound elasticity of 34-61 % plus tensile strength that gives durability under dynamic loading.

Coating Process and Hardness Selection

Polyurethane is applied to a roller in several defined stages, and the quality of each determines the full coating service life. First the old worn layer is stripped; the axle contact surface is then sandblasted; adhesion primer is applied; polyurethane at the required hardness is free-cast; and it is allowed to polymerise.

Practical tip: the main enemy of adhesion on rollers is residue of old primer and oil in the seat zone. Before casting, the surface must be taken back to clean metal by sandblasting and degreased. If this is not done, the coating will rotate relative to the axle under load, and even high-quality polyurethane will delaminate. Time spent on surface preparation pays back through a service life that is many times longer than a rushed repair.

Hardness is selected for the function. Transport and support rollers are coated in the range 85-95 Shore A; pressure rollers to the required force; where precise geometry and minimum deformation under pressure are needed, hard grades approaching 70 Shore D are used. Technical data for grades are in the reference information section.

How to Order Roller Restoration

Restoration or new roller manufacture can be ordered from a drawing, sample of the dismantled part, or a dimensioned sketch. Free-casting technology allows even a single non-standard-profile roller to be restored without expensive tooling, making it economical to repair both a series of conveyor rollers and a single critical part.

For accurate calculation, specify the roller diameter and length, axle fit, bearing type, load, speed, and ambient temperature. Based on this data the technologist selects the polyurethane grade, hardness, and layer thickness. Place an order and receive a calculation via TIMOL factory contacts. Polyurethane roller restoration reduces line downtime and delivers a service life many times longer than rubber coating.