A roll is not a standard part — it is a component living inside your machine's process. We deliver improved dewatering, runnability and maintenance intervals, not just "close-enough" dimensions.
Lock the position (forming / press / drying / sizing-coating / calendering / reeling) by machine section, then choose covering material, shell material and surface treatment by line load, speed, medium and grade.
NBR / EPDM / CR / IIR — 8–25 mm, ≤ 150 kN/m, ≤ 100 °C. the general workhorse covering. Table ↓
3–5× rubber life; up to 400 kN/m; anti-vibration grades for barring-prone nips. Table ↓
Polymer/mineral calender coverings, 89–92 ShD, > 450 kN/m — replacement for paper-filled rolls. Table ↓
HVOF WC-Co / plasma Cr₂O₃ / Ni-Cr, 0.3–0.8 mm, bonding > 70 MPa, 3× surface life. Table ↓
| Compound | Hardness | Typical positions | Character |
|---|---|---|---|
| NBR nitrile | 70–95 ShA | Guide rolls, size press rolls, reel drums | Oil & wear resistant — the general workhorse |
| EPDM | 75–92 ShA | Dryer-section guides, hot wet areas | Steam, ageing and heat resistant |
| CR polychloroprene | 65–85 ShA | Couch & pick-up roll coverings | Hydrolysis / ozone resistant, good sheet grip |
| IIR butyl | 40–60 ShA | Wide soft nips, shoe-press companions | Resilient, vibration absorbing, nip cushioning |
Common parameters: 8–25 mm covering, ≤ 150 kN/m line load, ≤ 100 °C continuous, Ra 0.8–2.5 µm. Sleeves can be changed on-site for short shutdowns; fits all OEM roll dimensions.
| Grade | Hardness | Position | Line load | Character |
|---|---|---|---|---|
| Standard PU | 85–92 ShA | Size press / coater backing rolls | ≤ 250 kN/m | Wear, tear & solvent resistant — long grinding interval |
| High-load PU | 92–98 ShA | Calender backing, reel drums | ≤ 400 kN/m | High modulus, anti-vibration-mark, doctor-friendly |
| Anti-vibration PU | 90–95 ShA | Barring / vibration-mark positions | ≤ 350 kN/m | Damped formulation suppresses barring |
Common: 6–12 mm covering, 120 °C transient, Ra 0.4–0.8 µm, 3–5× ordinary rubber life.
| Type | Hardness | Position | Character |
|---|---|---|---|
| Soft composite | 89 ShD | Soft calendering | Soft but load-bearing |
| Standard composite | 91 ShD | Soft / multi-nip / super calenders | Universal workhorse |
| Hard wear grade | 92 ShD | Doctor positions / high wear | Harder, longer grinding interval |
| Self-smoothing | 91 ShD | High surface-quality grades | Nano filler, high gloss |
Total 12–15 mm, 145 °C transient, > 450 kN/m, Ra 0.4–0.6 µm — higher speed and temperature capability than paper-filled rolls with less grinding loss.
| Material | Process | Hardness | Application |
|---|---|---|---|
| WC-Co | HVOF | HV 1100–1300 | Press center rolls, wire rolls, lead rolls, size press faces — most wear resistant, felt-friendly |
| Cr₂O₃ | Plasma | HV 900–1100 | Dryer faces, coater backing rolls, chilled-iron calender repair — corrosion resistant, mirror Ra 0.1 |
| Ni-Cr self-fluxing | Flame + fusing | HRC 55–65 | Corrosive zones, journals, suction-roll end seal areas — high bond strength |
0.3–0.8 mm coating, bond strength > 70 MPa, 3× life vs. base metal, field-grindable.
Compatible with in-service rolls of all major OEM brands. Incoming inspection → repair → dynamic balancing → outgoing report, one-stop. Max Ø1500 mm × 12,000 mm × 40 t.
Roundness ≤ 0.02 mm; crown restored to drawing; Ra 0.2–0.8 µm.
Suction roll straight / stepped hole re-drilling; grooving; journal repair.
G2.5, on-site or in shop; vibration ≤ 2.5 mm/s.
Cracked / worn journals; hydraulic shrink-fit repair; dedicated pullers protect the shell.
Rubber / PU re-covering; bow roll sleeves changed on-site; old rubber stripping & surface prep.
Dimension records, hardness, roughness, balancing report, MT/UT — traceable with every roll.
Detachable axial seals replace old seals — maintenance interval 6 months → 2 years. High-pressure oscillating showers keep drilling open; edge blow-out solves wet-edge profiles.
Old sleeve stripped, bow roll surface cleaned and inspected; steel-reinforced sleeve installed on-site — no shop return. NBR 75 ShA, fits all brands.
Oil-chamber seal replacement, circuit flushing, dual oil-loop verification, crown curve calibration, eccentric bearing housing check.
Scratches, dents and corrosion ground and built up; WC / Cr₂O₃ spray then grind-back; dryer face corrosion repaired without cylinder replacement.
Data from real upgrade projects, customer names anonymized; gains confirmed by on-site condition assessment.
At 1500 m/min+, a badly balanced guide roll is a web-break source. Thin-wall steel shells with optimized wall thickness — critical speed ≥ 130% of operating speed.
| Parameter | Typical range |
|---|---|
| Roll diameter | Ø100 – Ø400 mm |
| Face length | ≤ 12,000 mm |
| Operating speed | ≤ 2000 m/min |
| Surface roundness | ≤ 0.02 mm |
| Balancing grade | G2.5 |
Typical positions: dryer-section guide rolls, turning rolls, stretch rolls, post-size-press guides, unwind stand rolls.
| Shell material | Condition | Relative life |
|---|---|---|
| Standard stainless | Clean water | 1× |
| Duplex 2205 | Corrosive / wet-strength | 2.5× |
| Duplex 2304 | Moderate corrosion, light load | 1.8× |
| Super duplex | High corrosion / high speed | 3× |
Positions: couch rolls, pick-up rolls, suction press rolls. Survey-based replacement for all brands.