Tissue Industry

On-site maintenance, Yankee cylinder services and surface engineering for tissue machines

Tissue production places demanding requirements on machine surfaces, geometry, doctoring, web handling and rotating equipment.

High production speeds, continuous operation, moisture, heat, chemicals, contamination and mechanical wear can gradually affect critical machine components. Even relatively small changes in surface condition or geometry can influence runnability, tissue quality and production reliability.

PR Rolls provides specialised on-site services, workshop maintenance and surface engineering solutions for tissue mills.

A particular area of expertise is the maintenance and lifecycle management of Yankee cylinders, including precision grinding, profile restoration, superfinishing and thermal spray coating performed directly at the mill. PR Rolls' tissue-industry capabilities also extend to dryer cylinders, vacuum and suction rolls, guide rolls, spreader rolls and other critical rotating equipment.

Depending on the component and maintenance requirement, PR Rolls can provide:

• Yankee cylinder grinding
• Yankee cylinder superfinishing
• Yankee cylinder thermal spray coating
• Cylinder inspection and measurement
• On-site grinding
• On-site machining
• Industrial coatings and surface engineering
• Measurement and alignment
• Field balancing
• Workshop refurbishment
• Dynamic balancing
• Spreader roll manufacturing and refurbishment

The objective is not simply to repair a worn surface – it is to restore the geometry and functional surface required for reliable tissue production.

Maintenance Challenges in Tissue Production

Small surface changes can have a large process impact

Tissue machines operate with close interaction between rotating components, machine clothing, paper web, doctoring systems and process chemistry.

Over time, production-critical surfaces can develop:

• Chatter marks
• Uneven wear
• Profile deviations
• Grooves and scratches
• Corrosion
• Surface roughness variations
• Coating deterioration
• Contamination and build-up
• Dimensional changes
• Vibration and imbalance
• Bearing and journal wear

The visible surface defect is not always the complete problem.

For example, recurring Yankee wear may be related to the interaction between cylinder geometry, surface condition, coating, doctoring and operating conditions.

PR Rolls therefore approaches maintenance by first understanding the component and the reason for deterioration.

Measure → Identify the problem → Restore geometry → Engineer the surface → Verify

Yankee Cylinder Grinding

Restore cylinder geometry and profile directly at the mill

The Yankee cylinder is one of the most critical assets in a tissue machine.

Continuous production, doctoring, corrosion and mechanical wear can gradually change both its surface condition and geometrical profile.

PR Rolls provides specialised on-site Yankee cylinder grinding using purpose-built mobile equipment.

Grinding can be required when the cylinder has developed:

• Chatter marks
• Uneven cross-machine wear
• Profile deviations
• Grooves
• Scratches
• Corrosion
• Doctoring-related damage
• Irregular surface condition

The objective is not simply to create a smoother cylinder.

Precision grinding removes a controlled amount of material to restore the required geometry, profile and surface condition.

This distinction is important because every grinding operation removes material from the cylinder.

The goal is to remove only what is necessary to restore the required cylinder condition.

Yankee Cylinder Profile Grinding

Surface roughness is only part of the equation

A Yankee cylinder can appear relatively smooth while still having an incorrect geometrical profile.

Wear does not necessarily develop uniformly across the cylinder face.

Over time, this can result in profile deviations that cannot be corrected through polishing alone.

PR Rolls can inspect and measure the cylinder before grinding to determine:

• Existing surface condition'
• Wear pattern
• Cylinder profile
• Areas requiring correction
• Appropriate maintenance scope

Material can then be removed in a controlled manner according to the actual cylinder condition.

This supports a lifecycle approach where cylinder material is preserved whenever possible rather than removed unnecessarily during repeated maintenance cycles.

Yankee Cylinder Superfinishing

Engineer the final functional surface

Grinding restores geometry and removes defects, but the final surface may require additional finishing.

PR Rolls provides on-site superfinishing of Yankee cylinders for applications requiring a highly controlled final surface.

Superfinishing can be used to:

• Reduce microscopic surface irregularities
• Create a highly uniform surface
• Achieve low surface roughness where required
• Support consistent contact conditions
• Prepare the cylinder for demanding production conditions
• Produce a mirror-like finish where required

The required surface finish depends on the cylinder, production conditions and intended surface functionality.

Superfinishing is therefore more than a cosmetic operation.

It is the final engineering of the functional Yankee surface.

Yankee Cylinder Thermal Spray Coating

Create a new functional surface on the existing cylinder

Repeated grinding is not always the optimum long-term maintenance strategy.

When the cylinder has experienced significant wear, corrosion or repeated material removal, a new functional surface may provide a more appropriate lifecycle solution.

PR Rolls provides on-site thermal spray coating for Yankee cylinders.

Depending on the application, a correctly engineered coating can provide properties such as:

• High wear resistance
• Corrosion resistance
• Controlled surface hardness
• Stable surface characteristics
• Long service life
• Reduced need for repeated material removal from the original cylinder

The coating system is selected according to factors such as:

Cylinder material + Existing surface condition + Tissue grade + Doctoring conditions + Process environment + Required surface functionality

The coating is not simply an additional protective layer.

It becomes the new functional surface of the Yankee cylinder.

Grinding & Coating as One Complete Yankee Surface Solution

Correct the geometry before engineering the new surface

A coating cannot correct incorrect cylinder geometry underneath it.

Where both geometry and surface properties need restoration, PR Rolls combines grinding and coating as one complete process.

A typical Yankee cylinder restoration project can include:

Inspection & Measurement → Profile Assessment → Precision Grinding → Superfinishing → Surface Preparation → Thermal Spray Coating → Final Grinding & Finishing → Verification

This integrated approach means that the coating is applied onto a correctly prepared and geometrically restored foundation.

It also allows PR Rolls to evaluate the complete surface rather than treating grinding and coating as unrelated maintenance operations.

Yankee Cylinder Surface & Doctoring

The cylinder and doctoring system operate together

The Yankee surface does not operate independently.

It continuously interacts with the doctor blade, tissue web, coatings and process conditions.

Changes in:

• Cylinder geometry
• Surface roughness
• Surface hardness
• Coating condition
• Doctor blade conditions
• Alignment
• Process chemistry

can influence how the complete system performs.

Likewise, incorrect doctoring conditions can contribute to accelerated or uneven cylinder wear.

For this reason, recurring chatter or surface damage should not automatically be treated as an isolated grinding problem.

The important question is not only how to remove the damage – but why the damage developed.

PR Rolls considers the required Yankee surface according to the actual production and doctoring environment.

Chatter Marks & Yankee Surface Damage

Treat the cause as well as the symptom

Chatter marks are among the surface problems that can develop on Yankee cylinders.

Depending on severity, surface damage can affect doctoring behaviour, tissue quality and machine runnability.

Grinding can restore a damaged surface when the defects have progressed beyond what can reasonably be corrected through polishing or normal finishing.

However, if chatter or uneven wear repeatedly returns, simply grinding the surface again may not address the underlying cause.

PR Rolls can therefore combine surface inspection, profile measurement, grinding and coating assessment to determine the appropriate restoration strategy.

The objective is to restore the cylinder while supporting a more sustainable maintenance cycle.

 

Yankee Cylinder Leak Repair

Specialised on-site repair of steam and condensate leaks

A Yankee cylinder is one of the most critical components in a tissue machine. It is also a large rotating pressure vessel operating with pressurised steam, which means that any suspected leakage requires careful assessment and an appropriately engineered repair procedure.

PR Rolls provides specialised on-site leak repair services for Yankee cylinders, combining inspection, machining, surface restoration and other repair methods according to the location and cause of the leakage.

Yankee cylinder leaks can involve steam or condensate and may occur in several areas, including:

• Through the cylinder shell
• Head-to-shell joints'
• Flanges and bolted connections
• Manway areas
• Steam and condensate system connections
• Journals and related areas

A visible steam leak should not be treated simply as a surface defect. The source and extent of the leakage must first be established, as it may indicate deterioration that requires further investigation.

Locate → Inspect → Determine the cause → Select the repair method → Repair → Restore the surface → Verify

Through-Shell Leak Repair

Steam leaking through the Yankee shell can be associated with casting porosity, corrosion, local deterioration or cracking.

Because the shell forms part of the pressure-retaining structure, the condition must be carefully assessed before determining the appropriate repair method.

Depending on the Yankee construction, shell material, type of defect and applicable requirements, repair methods for suitable defects can involve plugging and approved filling or sealing methods.

Through-wall indications require particular attention because the complete leakage path should be evaluated from both the internal and external sides of the shell.

After the pressure-boundary repair has been completed, the external functional surface may also require restoration.

PR Rolls can combine the repair with:

Local machining → Grinding → Thermal spray coating → Precision finishing

This allows both the leak and the functional Yankee surface to be addressed within the same maintenance project.

Importantly, a thermal spray coating restores and protects the functional external surface; it should not be regarded as restoring the pressure-containing strength of the shell.

Head-to-Shell Joint & Flange Leaks

Steam leakage can also develop around head-to-shell joints, flanges and bolted connections.

Possible causes include corrosion between mating surfaces, loss of clamping force, deteriorated sealing elements, bolt problems or deviations in flange geometry.

In these situations, repairing the visible leak alone may not address the underlying problem.

Depending on the condition and Yankee design, the repair process can involve:

• Inspection of the joint and surrounding structure
• Assessment of bolts and fastening components
• Restoration or replacement of appropriate sealing components
• Approved sealing procedures
• On-site machining of damaged mating surfaces where required
• Dimensional verification after machining

PR Rolls' on-site machining capabilities are particularly valuable where sealing or flange surfaces require restoration without removing the Yankee cylinder from the tissue machine.

Steam & Condensate System Areas

Steam enters the Yankee and condensate must be continuously removed during operation.

Leaks around steam and condensate connections or associated components can therefore require a different maintenance approach from a through-shell leak.

The first step is to establish where the leakage originates and which component has failed.

Depending on the findings, maintenance may involve sealing components, mechanical parts, mating surfaces or associated steam and condensate equipment.

Where journals or other precision surfaces have suffered mechanical or dimensional damage, PR Rolls can also evaluate the need for machining and surface restoration.

Inspection Before Yankee Leak Repair

Find the complete defect – not only the visible leak

A visible steam leak identifies where steam escapes, but it does not necessarily reveal the complete extent or cause of the defect.

The affected area should therefore be inspected before the repair method is selected.

Depending on the Yankee construction and defect, inspection can include suitable non-destructive examination methods and dimensional measurements.

National Board guidance for Yankee dryers identifies inspection methods including visual inspection, liquid penetrant, magnetic particle, ultrasonic and acoustic examination, depending on the material and situation.

Particular attention may also need to be given to:

• Remaining shell thickness
• Corrosion
• Cracking or other indications
• Previous repairs
• Joint condition
• Bolt condition
• Shell geometry
• Surrounding material condition

The findings provide the basis for determining whether a local repair is appropriate or whether more extensive corrective action is required.

On-Site Yankee Cylinder Repair

Bring the repair technology to the cylinder

Because of the size and integration of a Yankee cylinder, machining and surface restoration are typically performed with the cylinder installed in the tissue machine. National Board guidance similarly notes that machining is generally carried out with the Yankee still in the papermaking machine.

This is an area where PR Rolls' broader on-site capabilities provide an important advantage.

Depending on the repair, PR Rolls can combine:

Inspection → On-site machining → Leak repair → Grinding → Surface restoration → Thermal spray coating → Precision finishing → Verification

This can reduce the need for extensive dismantling and allows several specialist operations to be coordinated within the same planned shutdown.

Surface Restoration After Leak Repair

A successful pressure-boundary repair does not necessarily mean that the Yankee is ready for production.

If the repair affects the external cylinder face, the functional surface must also meet the requirements of the tissue-making process.

The repaired area may therefore require:

• Precision grinding
• Profile restoration
• Superfinishing
• Thermal spray coating
• Final surface finishing
• Geometry and runout verification

The objective is to integrate the repaired area with the surrounding Yankee surface so that it provides the required interaction with the tissue web and doctoring system.

Pressure integrity and surface functionality are two different requirements – and both need to be considered.

Yankee Cylinder Repairs & Pressure Vessel Requirements

Safety and compliance are fundamental to the repair

A Yankee cylinder is pressure-containing equipment, and leak repairs must therefore be performed according to the requirements applicable to the specific cylinder and installation.

The appropriate repair procedure depends on factors including:

• Cylinder construction
• Shell material
• Original design
• Type and location of damage
• Remaining material thickness
• Previous repairs
• Operating steam pressure
• Applicable pressure vessel regulations and codes
• OEM requirements
• Requirements of the responsible inspection authority

National Board guidance specifically addresses repairs and alterations of Yankee dryers, including shell repairs, thermal spraying, plugging, joint leakage and pressure-retaining components. Current applicable code requirements must always be checked for the particular repair.

This is particularly important because a repair method that is appropriate for one Yankee construction or defect cannot automatically be applied to another.

PR Rolls therefore approaches Yankee leak repair as an engineered maintenance operation rather than simply sealing the visible point of leakage.

From Leak Repair to Complete Yankee Surface Restoration

A leak can also provide an opportunity to evaluate the wider condition of the Yankee cylinder.

If inspection identifies wear, corrosion, surface deterioration or geometry deviations, additional maintenance can be incorporated into the same shutdown.

PR Rolls can combine:

Leak repair + On-site machining + Precision grinding + Profile restoration + Superfinishing + Thermal spray coating + Final verification

This allows the mill to address both the immediate leakage problem and the condition of the functional Yankee surface.

The objective is not simply to stop the leak.

The objective is to return the Yankee cylinder to safe, reliable and production-ready condition.

Dryer Cylinder Grinding & Coating

Surface restoration beyond the Yankee cylinder

PR Rolls' tissue-machine expertise is not limited to the Yankee.

Dryer cylinders and other large cylindrical surfaces can also deteriorate through wear, corrosion, contamination and mechanical interaction.

PR Rolls performs dryer cylinder grinding and coating directly in tissue machines, reducing the need to remove and transport large cylinders for workshop restoration.

Depending on the application, a complete restoration can include:

Inspection → Measurement → Grinding → Surface preparation → Functional coating → Precision finishing

Functional surfaces can be engineered for properties such as:

• Wear resistance
• Corrosion protection
• Improved release
• Reduced contamination
• Resistance to demanding doctoring
• Application-specific surface roughness

 

Industrial Coatings for Tissue Machines

Different machine positions require different surface properties

A functional surface should be engineered according to what the component needs to do.

Depending on its position in the tissue machine, a roll or cylinder may require:

• Release
• Non-stick performance
• Wear resistance
• Corrosion resistance
• Resistance to doctoring
• Controlled friction
• Traction
• Reduced contamination
• Easier cleaning

PR Rolls provides thermal spray and other functional coating technologies for rolls, cylinders and industrial equipment.

The coating solution should therefore be selected according to:

Component → Machine position → Wear mechanism → Process conditions → Required surface functionality

rather than simply applying the same coating throughout the machine.

Guide Rolls, Felt Rolls & Other Rotating Equipment

Maintain components throughout the tissue machine

The performance of a tissue machine depends on considerably more than its Yankee cylinder.

Guide rolls, felt rolls and other rotating components operate continuously and can be exposed to moisture, heat, contamination, corrosion and mechanical wear.

PR Rolls can provide maintenance and surface engineering for suitable rotating components throughout the machine.

Depending on the application, services can include:

Inspection → Mechanical maintenance → Grinding → Coating → Precision finishing → Dynamic balancing

This allows both mechanical condition and surface functionality to be considered within the same refurbishment project.

Spreader Rolls – Manufacturing & Refurbishment

New and refurbished spreader rolls for web and fabric handling

Spreader rolls can be used to support stable handling of webs and machine clothing and to reduce unwanted wrinkles.

PR Rolls provides both new spreader rolls and complete refurbishment of existing spreader rolls.

Depending on the application and roll construction, services can include:

• New spreader roll manufacturing
• Fixed or adjustable bow solutions
• Bearing and seal maintenance
• Coupling replacement
• Bow inspection and correction
• Surface restoration
• Functional coating
• Dynamic balancing
• Test running

This allows the spreader roll to be evaluated as a complete mechanical system rather than simply as a coated roll surface.

Measurement & Alignment

Good maintenance begins with knowing the actual condition

Accurate measurement helps determine what corrective work is actually required.

PR Rolls provides measurement and alignment services for suitable tissue-machine equipment.

Applications can include:

• Cylinder profile measurement
• Roll alignment
• Cylinder alignment
• Geometry measurements
• Dimensional verification
• Runout measurements
• Maintenance planning
• Verification after corrective work

Measurement can therefore be used both before maintenance to determine the scope and after maintenance to verify the result.

Measure → Analyse → Correct → Verify

Field Balancing

Correct imbalance in the machine

Rotating components can develop imbalance through wear, deposits, coating, repairs or other changes in mass distribution.

Excessive imbalance can contribute to:

• Vibration
• Increased bearing loads
• Mechanical wear
• Noise
• Production disturbances
• Reduced machine reliability

PR Rolls provides field balancing directly at the customer's production site for suitable rotating equipment.

Where required, balancing can be combined with grinding and other mechanical restoration work.

Importantly, imbalance is only one possible cause of vibration. Geometry, alignment, bearings and mechanical condition should also be considered when diagnosing the problem.

Workshop Maintenance & Refurbishment

Complete refurbishment for removable components

Not every tissue-machine component needs to be maintained on-site.

When a component can be efficiently removed and transported, PR Rolls can provide complete workshop refurbishment.

Depending on the component, the process can include:

• Inspection
• Measurement
• Disassembly
• Mechanical maintenance
• Machining
• Grinding
• Surface restoration
• Industrial coating
• Precision finishing
• Dynamic balancing
• Reassembly
• Final inspection

This creates two complementary maintenance routes:

Large or fixed component → PR Rolls performs the work on-site

Removable component → Complete refurbishment at the PR Rolls workshop

Planned Tissue Mill Shutdown Services

Combine specialist operations within the available maintenance window

Shutdown time is valuable.

Large tissue-machine components may require several specialist operations during the same maintenance window.

PR Rolls can coordinate multiple on-site capabilities within one project:

Measurement → Machining → Grinding → Surface preparation → Coating → Finishing → Balancing → Verification

The ability to perform several operations on-site can reduce unnecessary dismantling and transportation and allow work to be coordinated with the mill's planned shutdown. PR Rolls' broader on-site service model is specifically built around restoring large production-critical components at the customer's premises.

Yankee Cylinder Lifecycle Management

Preserve a critical production asset

A Yankee cylinder is a long-term production asset.

Its maintenance strategy should therefore extend beyond the next shutdown.

Over its operating life, the cylinder may undergo:

Inspection → Measurement → Polishing/Superfinishing → Grinding → Continued production

At a later stage:

Profile restoration → Functional coating → Final finishing → Continued production

Eventually, condition assessment may determine that more extensive repair or replacement is required.

The objective is to avoid unnecessary material removal while maintaining the geometry and functional surface required for production.

This turns Yankee grinding from an isolated maintenance operation into part of a planned cylinder lifecycle strategy.

Repair, Refurbish or Replace?

Make the decision according to actual component condition

A worn tissue-machine component does not automatically need replacement.

Depending on condition and future production requirements, PR Rolls can evaluate whether the appropriate strategy is to:

Repair – correct local damage.

Grind – restore geometry and surface condition.

Recoat – create a renewed functional surface.

Refurbish – restore both mechanical and surface condition.

Modernise – modify an existing component for changed production requirements.

Replace – install a new component when restoration is no longer technically appropriate.

The appropriate decision should be based on component condition, process requirements and the required future function.

Why PR Rolls for Tissue Mills?

Specialist Yankee expertise combined with broader machine capabilities

PR Rolls combines several specialist capabilities within one service offering:

Measurement + On-site machining + Precision grinding + Superfinishing + Thermal spray coating + Alignment + Field balancing + Workshop refurbishment

Yankee cylinders are a particularly important area of expertise, where PR Rolls can combine profile assessment, precision grinding, superfinishing, coating and final verification within one on-site restoration project.

At the same time, our capabilities extend to dryer cylinders, vacuum and suction rolls, guide rolls, felt rolls, spreader rolls and other critical tissue-machine components.

The objective is not simply to perform an individual maintenance operation.

The objective is to understand the component, identify what is affecting its performance and restore the geometry, mechanical condition and functional surface required for reliable production.

Frequently Asked Questions About Tissue Machine Maintenance

Does PR Rolls grind Yankee cylinders on-site?
Yes. PR Rolls performs precision Yankee cylinder grinding directly at the customer's mill using mobile equipment designed for on-site cylinder restoration.

Can PR Rolls superfinish a Yankee cylinder?
Yes. PR Rolls provides on-site superfinishing when a highly controlled, very smooth final cylinder surface is required.

Can a Yankee cylinder be thermally coated?
Yes. PR Rolls provides on-site thermal spray coating for Yankee cylinders. The coating system is selected according to the cylinder, existing surface, doctoring and production conditions.

Can grinding and coating be performed as one project?
Yes. PR Rolls can combine inspection, profile assessment, precision grinding, superfinishing, surface preparation, thermal spray coating and final finishing within the same Yankee restoration project.

Does PR Rolls only work with Yankee cylinders in tissue mills?
No. PR Rolls' on-site services can also be applied to dryer cylinders, vacuum and suction rolls, press rolls, guide rolls, felt rolls and other critical rotating equipment.

Can PR Rolls manufacture new spreader rolls?
Yes. PR Rolls provides new spreader rolls as well as refurbishment and modernisation of existing spreader rolls.

Does PR Rolls provide field balancing?
Yes. Suitable rotating components can be balanced at the customer's production site, and balancing can be combined with grinding and other restoration work.

Can PR Rolls refurbish tissue-machine rolls at its workshop?
Yes. Suitable removable components can be maintained and refurbished at the PR Rolls workshop, including mechanical maintenance, machining, grinding, coating, precision finishing and dynamic balancing.

Does a damaged Yankee surface always need grinding?
No. The appropriate method depends on the depth of the damage, cylinder profile and required final surface. Minor surface irregularities may require finishing, while deeper damage or profile deviations can require precision grinding.

Why is Yankee profile measurement important?
The cylinder can wear differently across its face. Profile measurement helps determine where correction is actually required and supports controlled material removal during grinding.

Protect the Yankee. Maintain the Machine. Keep Production Running.

Tissue production depends on critical surfaces and rotating equipment operating together.

When cylinder geometry changes, surfaces deteriorate or rotating components require maintenance, PR Rolls combines measurement, on-site machining, precision grinding, superfinishing, industrial coatings, balancing and workshop refurbishment to restore the equipment.

From the Yankee cylinder to dryer cylinders, vacuum rolls, guide rolls, spreader rolls and other rotating components, the process begins with understanding the actual condition and production requirement.

Measure the condition → Identify the cause → Restore the geometry → Engineer the surface → Verify the result → Return to production

Contact PR Rolls to discuss Yankee cylinder maintenance, tissue-machine surface engineering or other maintenance requirements.