The Material Secrets of Polyurethane Roll Coating
The popularity of polyurethane roll coating lies in the unique properties of its material. Polyurethane elastomers combine the flexibility of rubber with the strength of plastics, and their abrasion resistance is 3-5 times that of ordinary rubber. In terms of material formulation, by adjusting the ratio of isocyanate to polyol, different products with hardness ranging from Shore A60 to D80 can be customized to meet diverse needs from paper machines to steel rolls.
The Three Key Steps of Polyurethane Coating Process:
Surface Treatment: The metal roller core needs to be sandblasted to remove rust, with a roughness controlled between Ra3.2 and Ra6.3. This is fundamental to ensuring the adhesive layer does not peel off.
Casting: Centrifugal casting or compression molding technology is used, with the temperature controlled between 80-120℃ to ensure fluidity and avoid air bubble formation.
Post-Curing: The roller is kept at 100℃ for 12-24 hours to allow the molecular chains to fully cross-link, ultimately achieving stable mechanical properties.
Performance in Industrial Applications:
In the printing industry, polyurethane coated rollers can maintain a radial runout accuracy within 0.02mm; in metallurgical production lines, they can withstand short-term high-temperature impacts below 300℃. Their unique micro-elastic deformation characteristics allow them to effectively absorb vibrations during high-speed operation, reducing noise by more than 15 decibels compared to traditional metal rollers.