PROEXPORT / TECHNICAL KNOWLEDGE
Standard Cast Polyurethane vs Vulkollan®: Technical Guide
Vulkollan® is Covestro’s premium hot-cast elastomer based on 1,5-NDI (naphthalene diisocyanate) and polyester polyol. Compare dynamic hysteretic heat, tear resistance, and load capacity up to 10,000 kg.
KNOWLEDGE & PRACTICE
Technical Properties: Standard TDI/MDI PU vs Vulkollan® (1,5-NDI)
| Engineering Specification | Standard Cast PU (TDI / MDI) | Licensed Vulkollan® (1,5-NDI) |
|---|---|---|
| Isocyanate Precursor Base | TDI (Toluene) or MDI (Diphenylmethane) | 1,5-NDI (Naphthalene-1,5-Diisocyanate Covestro license) |
| Dynamic Loss Factor (tan delta at 50°C) | 0.08 – 0.15 (moderate to high internal damping) | 0.03 – 0.05 (minimal damping, ultra-low heat build-up) |
| Maximum Dynamic Load Capacity | 35–50 kg/cm² projected area | Up to 120–160 kg/cm² (3 times higher carrying capacity) |
| Abrasion Volume Loss (DIN 53516) | 35–55 mm³ | 18–28 mm³ (industry benchmark in wear resistance) |
| Tear Propagation Resistance (ISO 34-1) | 30–50 kN/m | 55–75 kN/m (extreme resistance to sharp cuts) |
| Maximum Continuous Operating Speed | Up to 6–8 m/s without cooling | Up to 15–20 m/s in heavy continuous operation |
| Rebound Elasticity (ISO 4662) | 45–55% | 60–70% (spring-like dynamic recovery) |
| Hydrolysis Vulnerability in Hot Water | High in polyester; polyethers resist water | Sensitive to steam > 50°C (demands dry or oiled duty) |
KNOWLEDGE & PRACTICE
NDI Chemistry: Why Vulkollan® Eliminates Thermal Destruction
Standard polyurethanes based on TDI or MDI suffer from significant mechanical energy dissipation under cyclic deflection. Under heavy loads or high rotational speeds, this energy converts into heat within the polymer mass.
Because polyurethane has low thermal conductivity (λ ~ 0.2 W/m·K), this internal heat cannot escape quickly. Once the core reaches ~110°C, the polymer chains melt internally, leading to a catastrophic blowout rupture.
The rigid, aromatic molecular structure of 1,5-NDI in Vulkollan® exhibits an exceptionally low loss tangent (tan delta). Internal heat generation is reduced by up to 70%, allowing heavy AGV drive wheels and high-load pinch rolls to operate 24/7 without thermal runaway.
KNOWLEDGE & PRACTICE
When Standard PU Is Sufficient vs When Vulkollan® Is Mandated
- Standard TDI/MDI PU is cost-optimal: Guide rollers, low-speed conveyors (< 3 m/s), glue applicator rolls, and secondary idlers where static loads remain under 40 kg/cm².
- Vulkollan® is strictly required: AGV heavy drive wheels carrying 1,000–10,000 kg, high-speed slitter pull rolls, continuous pipe transport rollers, and high-nip laminators.
PROEXPORT / INDUSTRIAL ROLLERS
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