Flexo Sleeve Runout Checks: Find the Cause Before Remounting the Plates

Describe the fault by position and frequency

Start with the printed symptom. Mark the cross-web position, machine direction, colours affected and whether the variation repeats at the sleeve circumference. Keep a sample showing register marks, solids and screens. A defect that follows one sleeve when it moves to another station points in a different direction from a defect that remains at one press station.

Record the sleeve identification, repeat, width, plate, tape, adaptor, mandrel, press station and production speed. Also note whether the problem appeared immediately after mounting or developed during the run. Without this record, the team may compare different assemblies and call the result a sleeve problem.

Inspect the sleeve before putting it on a measuring mandrel

Remove the plate and tape using the approved method, then inspect both sleeve ends, the inner surface and the full mounting surface. Look for cuts, bruised edges, dried ink, adhesive, raised repairs and areas affected by heat. A small contaminant between the sleeve and mandrel can change how the sleeve seats, while a cut or high spot on the outside can telegraph through the tape and plate.

POLYWEST instructs users to check sleeve front faces and edges for damage, burrs and abrasion before mounting. Its care note also warns against cutting on the sleeve, soaking it in cleaning agent and using hot air to remove plates. Those actions can damage the surface or change the geometry. Clean the component according to the sleeve supplier's instructions and allow it to dry before measurement.

Do not force a sleeve that is difficult to mount. POLYWEST specifies sufficient, freely flowing air and says the sleeve should move with little force once it covers the first row of radial air holes. A hammer may turn a seating problem into permanent internal damage.

Measure TIR on a known and repeatable reference

Total indicated runout, or TIR, records the radial variation seen while the sleeve rotates. The reading only has meaning when the measuring mandrel, support, sensor position, sleeve temperature and mounting method are controlled. Clean the mandrel, confirm that its own condition is acceptable and install the sleeve with the same method used for the baseline record.

Measure at several bands across the working width rather than at one convenient point. Save the maximum and minimum reading, angular position and axial location. If the result is unexpected, remove the sleeve, clean and reinstall it, then repeat the scan. A repeatable high point suggests a component condition. A high point that moves after reinstallation suggests seating, contamination or the reference system needs attention.

Use the sleeve manufacturer's or press supplier's acceptance limit. Do not copy a tolerance from another sleeve construction, repeat or application. ISO 15341:2014 defines a method for determining the external radius of printing cylinders and was confirmed as current in 2025. The practical lesson is to use a documented measurement method so results taken months apart can be compared.

Separate radial runout from local surface damage

A TIR trace and a surface map answer different questions. TIR shows radial variation as the sleeve turns. A surface scan can locate a local high spot, low spot, cut or damaged area that may not explain the complete circumference. Use both when the print fault is local but the basic runout reading appears acceptable.

Heaford's sleeve inspection systems use contact or laser measurement to record radial points across the sleeve width, and its surface-scanning option produces a contour map for identifying local irregularities. The appropriate sensor depends on the sleeve surface and construction. Confirm compatibility before measuring an adhesive or otherwise sensitive surface.

Link every saved trace or map to the sleeve ID and date. A result without the sleeve identity, mandrel reference and measuring positions cannot support a release decision or show whether the condition is changing over time.

Check plate mounting only after the sleeve is cleared

Once the bare sleeve and reference mandrel are within their approved limits, examine the mounting process. Check tape joint position, overlap or gap, trapped air, plate edge condition, plate register targets and laydown pressure. Rotate the mounted sleeve slowly and compare the plate surface with the saved bare-sleeve scan where the system allows it.

Heaford describes sleeve TIR and surface scanning as part of the plate-mounter workflow, with condition records retained against the sleeve. This is useful because the prepress team can verify the base component before mounting and keep the measurement with positional plate data and the job record.

Do not correct a geometric high point with extra impression. The heavy area may look better for a few metres, but the rest of the circumference then runs under unnecessary pressure. If a clean, verified sleeve still shows the same press-station symptom, continue with adaptor, mandrel, bearing and press checks under the press manufacturer's procedure.

Build a sleeve release and hold rule

Give each sleeve a condition record with identification, nominal repeat, construction, receipt inspection, baseline TIR, measuring bands, surface images, repairs and subsequent checks. Define when to remeasure, such as after impact, difficult removal, heat exposure, a recurring print band or a specified number of production cycles.

Use three clear outcomes: release for production, hold for technical review or remove from service. The decision should use the supplier's dimensional limit, the repeatability of the reading, the location of any surface damage and the print requirement. A sleeve used for critical process work may need a tighter internal control than one used for less demanding coverage, but the limit must be approved and recorded rather than decided at the press.

Royal Coat represents POLYWEST sleeve and adaptor technology and Heaford plate-mounting and sleeve-inspection systems in India, Bangladesh, Sri Lanka, Nigeria and Kenya. For an application review, send the Royal Coat team the sleeve type and repeat, web width, press and mandrel details, current measuring method, recent TIR records, photographs and a marked print sample showing the fault.