PROEXPORT / TECHNICAL KNOWLEDGE
Rubber vs Polyurethane Roller Coverings: Engineering Comparison
Durometer Shore hardness is merely the starting point. Compare chemical contact, dynamic nip load, tear propagation, blade cutting resistance, and DIN 53516 abrasion resistance before selecting.
KNOWLEDGE & PRACTICE
Mechanical and Operational Properties Comparison
| Performance Metric | Rubber Elastomers (NBR / EPDM / FKM) | Cast Polyurethane (PU / Vulkollan®) |
|---|---|---|
| Abrasion Resistance (DIN 53516 / ISO 4649) | 70–120 mm³ volume loss | 15–40 mm³ volume loss (3 to 6 times higher wear resistance than rubber) |
| Cut & Tear Propagation Resistance | Moderate (cuts propagate rapidly under tension) | Outstanding (engineered formulations stop micro-cuts from knife slitting) |
| Linear Nip Load Capacity (N/mm) | Up to 25–35 N/mm without overheating | Up to 80–120 N/mm (Vulkollan® handles extreme static and dynamic loads) |
| Compression Set (22h / 70°C ISO 815) | 15–25% (excellent elastic recovery) | 20–35% (higher risk of flat-spotting if parked under continuous load) |
| Coefficient of Friction (dry steel) | High (CoF 0.8–1.2, excellent web traction) | Adjustable (CoF 0.4–0.9, lower drag option available) |
| Maximum Continuous Temperature | Up to +130°C (EPDM) / +200°C (Silicone / FKM) | +70°C to +85°C continuous (+100°C peak in NDI systems) |
| Resistance to Ketones & Polar Solvents | Excellent in EPDM; poor in NBR | Poor (swells and softens rapidly in polar solvents) |
| Hot Water & Hydrolysis Resistance | Excellent in EPDM and Silicone | Demands dedicated polyether polyols (polyester hydrolyzes above 50°C) |
KNOWLEDGE & PRACTICE
When Polyurethane Outperforms Rubber
Cast polyurethane is the superior engineering choice in three major industrial scenarios:
1. Grooved glue spreaders (PVAc, PUR, EVA): Rubber grooves wear flat within 2 to 3 months, causing glue over-consumption. Grooved PU rollers hold precise thread crest geometry for 10 to 12 months.
2. Slitting and cutting anvil counter-rollers: Polyurethane compounds reinforced against cut propagation survive continuous slitter blade contact without surface chunking.
3. High-load drive and steering wheels (AGVs, cranes): PU delivers extreme load capacity with zero black carbon soot marking on industrial floors.
KNOWLEDGE & PRACTICE
When Rubber Remains Indispensable
Elastomeric rubber is mandatory whenever high temperatures or aggressive polar solvents are present. UV-curable printing and coating lines utilize acrylic monomers and ketone washdown solvents that dissolve polyurethane within days; here, specialized EPDM is required. In lamination processes operating above 90°C, technical silicone or peroxide-cured EPDM compounds are irreplaceable.
KNOWLEDGE & PRACTICE
Do Not Substitute Without Engineering Verification
Replacing rubber with polyurethane often alters the contact nip footprint because PU exhibits a higher elastic modulus at equivalent Shore A durometer. Machine nip adjustments, crown geometry, and drive motor torque should always be verified by PROEXPORT engineers prior to conversion.
PROEXPORT / INDUSTRIAL ROLLERS
From technical drawing to line-ready solution.
Submit dimensions, photos, and operating conditions. We will determine the optimal manufacturing or reconditioning scope.