Industrial Roller Engineering Glossary: Technical Terms & Standards

KNOWLEDGE & PRACTICE

Structural Anatomy and Mechanical Geometry

• Core / Tube Shell (Rohrkörper): The cylindrical structural steel, stainless steel, or aluminum weldment providing rigidity against deflection under load.

• Journal / Shaft End (Zapfen / Wellenende): Machined steel shaft ends pressed, welded, or bolted into the core tube, precision-ground to ISO bearing tolerances (m5, k5, j6).

• Total Indicated Runout (TIR / Rundlauffehler): The total radial runout measured with a dial indicator while rotating the roller 360 degrees between centers; standard high-speed tolerance is TIR < 0.015 mm.

• Dynamic Balancing (ISO 1940-1): Two-plane dynamic mass compensation eliminating centrifugal vibration at operating RPM; typical balance grades are G2.5 for converting rollers and G1.0 for ultra-high-speed printing cylinders.

KNOWLEDGE & PRACTICE

Covering Technology and Tribology

• Elastomeric Matrix: Vulcanized rubber compounds (NBR, EPDM, FKM, Silicone) formulated with crosslinking polymers, carbon black, and plasticizers.

• Hot-Cast Polyurethane: Liquid prepolymer reaction casting (TDI, MDI, 1,5-NDI Vulkollan®) delivering extreme cut and abrasion resistance.

• Functional Hard Chrome: Galvanic hexavalent chromium deposit (850–1100 HV, 20–150 µm thickness) polished to mirror finish (Ra < 0.08 µm) for low-friction, scratch-resistant web handling.

• Ceramic Thermal Spray (Cr₂O₃): Plasma-sprayed chromium oxide ceramic (1200–1800 HV) with diamond superfinishing for abrasive slurry metering and laser-engraved anilox cylinders.

KNOWLEDGE & PRACTICE

Contact Mechanics and Process Dynamics

• Nip / Contact Zone (Walzenspalt): The compressed contact band formed when an elastomer-covered roller presses against a mating steel cylinder under load.

• Linear Nip Load (Linienlast): Contact force divided by face width, expressed in N/mm or daN/cm, determining internal elastomer shear stress.

• Loss Tangent (tan delta / Hysterese): Ratio of dissipated thermal energy to stored elastic energy per rotation cycle; low tan delta prevents thermal blowout.

• Camber / Crowning (Bombage): Parabolic or crowned outer diameter profiling (center OD slightly larger than edge OD) compensating for shaft deflection under load to achieve uniform nip footprint across the web.

KNOWLEDGE & PRACTICE

Sleeve Systems and Functional Metering

• Air-Mandrel Sleeve System (EOS Sleeve): Expandable fiberglass or composite sleeve slipped onto a pneumatically pressurized mandrel cylinder; enables 30-minute on-machine covering changes without dismounting bearings.

• Anilox Roller: Ceramic-coated cylinder laser-engraved with microscopic cell grids (cells/cm and cell volume cm³/m²) for high-precision fluid metering in flexography and coating lines.