Dryer Cylinder Grinding & Coating for Paper and Board Machines

Restore dryer cylinder surfaces, improve release and optimise dryer section performance

The condition of dryer cylinder surfaces has a direct impact on the performance of a paper or board machine.

Wear, corrosion, surface irregularities, contamination and sticky build-up can affect paper release, doctoring, heat transfer, runnability and sheet quality. As cylinder surfaces deteriorate, mills may experience increased cleaning requirements, web instability, higher draw, uneven drying and more frequent maintenance.

PR Rolls provides complete on-site dryer cylinder grinding and coating services for paper, board and tissue machines.

Instead of removing cylinders from the machine and transporting them to a workshop, PR Rolls brings specialised grinding and coating equipment directly to the mill. Grinding restores the cylinder geometry and surface condition, while the selected functional coating provides the surface properties required for the specific dryer position.

The result is not simply a newly coated cylinder.

The objective is to create a complete functional dryer cylinder surface that supports better release, cleaner operation, effective doctoring, reliable heat transfer and long-term runnability.

PR Rolls can perform several grinding and coating operations simultaneously during planned shutdowns, significantly reducing the total maintenance time compared with removing cylinders from the machine.

Why Dryer Cylinder Surface Condition Matters

Dryer cylinders perform several functions simultaneously.

They transfer heat to the paper, support the sheet through the dryer section and provide the surface from which the paper must release reliably as it continues through the machine.

For this reason, dryer cylinder performance depends heavily on the condition of the cylinder surface.

Common surface-related problems include:

• Corrosion and rust
• Uneven cylinder geometry
• Surface wear
• Scratches and mechanical damage
• Sticky contamination
• Fibre and dust build-up
• Coating residues
• Poor paper release
• Excessive doctoring
• Uneven coating condition
• Reduced heat transfer
• Surface-related vibration

Left untreated, these problems can contribute to poor runnability, increased draw, web breaks, quality variations and reduced drying efficiency.

Restoring the dryer cylinder surface can therefore be an important part of improving the performance of the entire dryer section.

Grinding Before Coating – Restore the Cylinder Before Creating the New Surface

A functional coating starts with the correct cylinder geometry
Applying a new coating to a worn or geometrically incorrect cylinder does not solve the underlying mechanical problem.

This is why PR Rolls combines dryer cylinder grinding and coating.

On-site grinding can remove:

• Corrosion
• Rust
• Surface contamination
• Scratches
• Scuff marks
• Old or damaged coating
• Local surface defects
• Uneven wear

More importantly, grinding restores the required cylinder geometry and surface condition before coating. PR Rolls describes this same principle in its TecnoClean process: damaged cylinders are first ground to remove defects and restore the correct shape before the functional coating is applied.

This creates the correct foundation for the new surface.

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

Where required, the cylinder can also be field balanced as part of the same maintenance project.

On-Site Dryer Cylinder Grinding

Removing a large dryer cylinder from a paper machine can require extensive maintenance work.

The process may involve:

• Machine dismantling
• Heavy lifting
• Cylinder removal
• Transportation
• Workshop repair
• Return transportation
• Reinstallation
• Alignment
• Restart

PR Rolls avoids many of these steps by performing precision grinding directly in the paper machine.

Specialised mobile equipment is installed around the cylinder, allowing the surface to be restored without removing the cylinder from its operating position.

This can significantly shorten the maintenance schedule while reducing unnecessary lifting and transportation.

On-Site Dryer Cylinder Coating

After grinding and surface preparation, PR Rolls can apply the selected coating directly at the customer's mill.

PR Rolls' dryer-cylinder coating technologies are designed to provide functional properties such as:

• Non-stick performance
• Improved paper release
• Wear resistance
• Corrosion resistance
• Reduced contamination
• Easier doctoring
• Harder doctoring possibilities
• Surface cleanliness
• Long service life

The correct coating depends on the dryer position, paper grade, contamination, doctoring conditions, temperature, wear mechanism and required release properties.

There is no single optimal coating for every dryer cylinder.

The objective is to select the surface according to the actual operating problem.

Dryer Cylinder Coatings for Better Paper Release

Reliable release between the paper and dryer cylinder is essential for stable runnability.

If the sheet adheres too strongly to the cylinder surface, higher draw may be required to transfer the paper to the next position.

This can increase sheet tension and make the dryer section more sensitive to disturbances.

PR Rolls' non-stick and release coatings are designed to reduce adhesion between the paper and cylinder surface.

Improved release can support:

• Lower draw requirements
• More stable sheet transfer
• Reduced web-break risk
• Better runnability
• Cleaner cylinder surfaces
• More stable paper profiles

PR Rolls specifically identifies improved release and reduced need for draw among the benefits of its TecnoClean and TecnoCeraHybrid technologies.

Keep Dryer Cylinders Cleaner

Dirt, fibres, dust, coating residues and stickies can gradually accumulate on dryer cylinder surfaces.

The consequences can extend beyond cleaning requirements.

Deposits may affect:

• Paper release
• Doctoring
• Heat transfer
• Surface uniformity
• Sheet quality
• Sheet breaks
• Dryer fabric cleanliness
• Machine runnability

A functional non-stick coating reduces the tendency of contaminants to adhere to the cylinder.

PR Rolls' TecnoClean and TecnoCeraHybrid technologies are specifically designed to combat dirt, dust, fluff and sticky build-up while maintaining a functional dryer surface.

The goal is not simply to make the cylinder easier to clean during a shutdown.

The goal is to help the cylinder stay cleaner during production.

Dryer Cylinder Coatings and Heat Transfer

The dryer cylinder is fundamentally a heat-transfer surface.

Steam heats the cylinder from the inside, and the cylinder surface transfers that energy to the sheet.

For efficient operation, maintaining a clean and functional surface is therefore important.

Contamination and surface deterioration can interfere with the intended contact conditions between the paper and cylinder.

PR Rolls' dryer coatings are designed to maintain clean functional surfaces while supporting heat transfer. PR Rolls associates its TecnoClean and TecnoCeraHybrid technologies with increased drying capacity and more efficient energy use.

Coating selection should therefore consider both:

surface functionality and the cylinder's role as part of the drying process.

Coating for Heavily Doctored Dryer Cylinders

Not every dryer cylinder operates under the same doctoring conditions.

In some positions, aggressive or continuous doctoring creates significant mechanical wear.

A conventional release coating may not provide the required durability.

For heavily doctored dryer cylinders, PR Rolls can evaluate harder and more wear-resistant coating systems such as TecnoDiamond, depending on the operating conditions.

TecnoDiamond is based on a dense carbide coating applied using thermal spraying and is designed for applications requiring very high wear resistance. PR Rolls specifies a hardness of approximately 1400 ±100 HV for the coating.

This gives PR Rolls the ability to select different surface technologies depending on whether the dominant challenge is:

release, contamination, corrosion or extreme mechanical wear.

TecnoClean – Non-Stick & Wear-Resistant Dryer Cylinder Coating

TecnoClean is PR Rolls' carbide and PTFE composite coating for rolls and cylinders where wear resistance and non-stick properties are required simultaneously.

The hard carbide base provides mechanical durability while the PTFE treatment provides release characteristics.

For dryer cylinders, TecnoClean can help:

• Reduce sticky build-up
• mprove paper release
• Keep the cylinder cleaner
• Reduce draw requirements
• Improve doctoring conditions
• Protect against wear
• Maintain heat-transfer conditions

PR Rolls specifies a carbide-base hardness of approximately 1200 ±50 HV, coating thickness of 100–150 µm and an operating-temperature range of 20–200°C.

TecnoClean is particularly relevant where the dryer cylinder requires a combination of release + wear resistance + cleaner operation.

TecnoCeraHybrid – Advanced Dryer Cylinder Surface Solution

TecnoCeraHybrid is PR Rolls' advanced carbide and nano-fluoride composite solution for demanding dryer-cylinder applications.

It is particularly relevant for cylinders at the forward end of the dryer section and cylinders following sizing and coating stations, where paper release and contamination can create significant runnability challenges.

TecnoCeraHybrid is designed to:

• Improve paper release
• Reduce dirt and sticky build-up
• Resist wear and corrosion
• Reduce dust and fluff
• Support lower draw
• Maintain cylinder cleanliness
• Support drying performance
• Improve runnability

Importantly, PR Rolls can deliver TecnoCeraHybrid as part of a complete dryer cylinder surface solution, rather than as an isolated coating.

That solution can combine:

Cylinder grinding + Functional coating + Doctoring solution

with additional services such as field balancing and dryer section optimisation where required.

TecnoDiamond – Extreme Wear Resistance for Demanding Dryer Positions

Where severe wear or heavy doctoring is the dominant problem, a harder surface may be required.

TecnoDiamond provides a dense carbide surface designed for extremely high wear resistance.

Although TecnoDiamond is also used for other demanding roll applications, it can be evaluated for dryer cylinders exposed to particularly aggressive doctoring or mechanical wear.

The objective is different from a primarily non-stick coating.

TecnoClean / TecnoCeraHybrid:
Release + cleanliness + wear resistance

TecnoDiamond:
Maximum hardness + wear resistance + resistance to demanding doctoring

The correct choice depends on the actual dryer position and operating conditions.

Coating and Doctoring Should Work Together

This is an area I would emphasise significantly more than on the current page.

A dryer cylinder coating does not operate independently.

It continuously interacts with the doctor blade and doctoring system.

If the surface and doctoring solution are poorly matched, the result can be:

• Excessive coating wear
• Poor cleaning
• Blade wear
• Surface damage
• Contamination
• Reduced coating lifetime

PR Rolls can therefore approach dryer cylinder restoration as a complete surface system:

Grinding + Coating + Doctoring solution

The coating provides the required functional surface, while the doctoring solution is selected and adjusted to maintain that surface under the actual operating conditions.

This system approach is particularly important for demanding dryer positions and forms part of PR Rolls' broader TecnoCeraHybrid solution.

Grinding, Coating and Field Balancing in the Same Shutdown

Surface condition is only one aspect of dryer cylinder performance.

A cylinder may also have imbalance or other mechanical issues affecting machine operation.

PR Rolls can combine:

• Dryer cylinder measurement
• Grinding
• Coating
• Surface finishing
• Field balancing

during the same planned maintenance shutdown.

This is a significant advantage of PR Rolls' on-site model.

Instead of bringing several separate suppliers into the machine at different stages, multiple maintenance operations can be coordinated within the same service window.

PR Rolls has demonstrated this capacity in large dryer-section projects, including a project involving 45 dryer cylinders completed in only 12 days.

Multiple Dryer Cylinders Can Be Restored Simultaneously

Large dryer sections can contain dozens of cylinders.

If every cylinder were treated sequentially, maintenance time could become impractical.

PR Rolls has developed the equipment, organisation and capacity to perform multiple grinding, coating and balancing operations simultaneously.

This enables mills to include extensive cylinder restoration programmes within relatively short planned shutdowns.

For larger projects, this parallel-working capability can be one of the most important factors in reducing the overall maintenance schedule.

Dryer Cylinder Surface Restoration as Part of Dryer Section Optimisation

Sometimes the cylinder surface is only one part of a broader dryer-section performance problem.

PR Rolls can combine grinding and coating with its wider dryer section optimisation services.

These can include:

• Cylinder measurement
• Field balancing
• Vacuum roll modification
• Vacuum roll drilling
• Stabilisers
• Suction boxes
• Pocket ventilation
• Airflow optimisation
• Vacuum optimisation
• Web stabilisation
• Moisture-profile improvements

PR Rolls works with technology partner Runtech on stabilisation, ventilation and related dryer-section solutions.

This means a project can address both the mechanical condition of the dryer cylinders and the process conditions surrounding them.

When Should Dryer Cylinders Be Ground and or Coated?

Grinding and or coating should be considered when the existing surface is no longer providing the required functional performance.

Typical indicators include:

• Visible corrosion or rust
• Scratches or surface damage
• Uneven cylinder surfaces
• Poor paper release
• Increasing draw requirements
• Frequent sticky build-up
• Excessive dust or contamination
• Frequent cylinder cleaning
• Heavy doctoring
• Rapid doctor blade wear
• Coating deterioration
• Uneven drying behaviour
• Surface-related sheet quality problems
• Cylinder vibration combined with surface issues

The appropriate maintenance action depends on the root cause.

Some cylinders may require grinding only.

Others may benefit from grinding + coating, while demanding positions may require a complete grinding + coating + doctoring solution.

Which Dryer Cylinder Coating Should You Choose?

There is no universal dryer cylinder coating.

PR Rolls selects the surface according to the actual problem and dryer position.

The selection should consider factors such as paper grade, cylinder position, contamination, temperature, doctoring, wear, release requirements and existing cylinder condition.

This application-based approach is important because major paper-machine suppliers similarly emphasise selecting dryer roll covers and coatings according to runnability, cleanliness, wear, corrosion and doctoring requirements.

A Typical PR Rolls Dryer Cylinder Project

A dryer cylinder surface restoration project can typically follow these stages:

1. Inspection and Measurement
Evaluate cylinder condition, geometry, surface damage and operating problems.

2. Grinding
Restore the cylinder geometry and remove corrosion, contamination, scratches and damaged surface material.

3. Surface Preparation
Prepare the restored substrate for the selected coating technology.

4. Thermal Spray Coating
Apply the selected functional coating according to the dryer position and operating requirements.

5. Surface Finishing
Finish the coating to achieve the required functional surface characteristics.

6. Doctoring Solution
Where required, select or optimise the doctoring system to work correctly with the new cylinder surface.

7. Field Balancing
Correct cylinder imbalance where necessary.

8. Final Verification
Verify the finished cylinder surface and required mechanical condition.

This creates a complete restoration process rather than treating grinding, coating and balancing as unrelated maintenance operations.

Why On-Site Dryer Cylinder Grinding & Coating?

For large paper machine cylinders, on-site restoration can provide significant practical and economic advantages.

Reduced downtime
Avoid the time required for cylinder removal, transportation and reinstallation.

Less dismantling
The dryer cylinder remains in the paper machine.

No unnecessary transportation
Large cylinders do not need to be transported to an external workshop.

Parallel working
Several cylinders can be ground, coated and balanced simultaneously.

Complete surface restoration
Geometry and functional surface properties can be addressed during the same project.

Longer cylinder service life
Existing cylinders can be restored and upgraded rather than prematurely replaced.

Better use of planned shutdowns
Extensive restoration programmes can be scheduled within defined maintenance windows.

For mills, the relevant comparison is therefore not simply the cost of coating.

It is the total cost and production impact of restoring the cylinder versus removing, transporting, repairing or replacing it.

Why Choose PR Rolls for Dryer Cylinder Grinding and Coating?

PR Rolls combines capabilities that are often treated as separate services:

Measurement + Grinding + Thermal spray coating + Surface finishing + Doctoring + Field balancing + Dryer section optimisation

This makes it possible to evaluate the dryer cylinder as part of the complete production process.

PR Rolls has solved more than one thousand cylinder-related problems globally and has demonstrated the ability to execute large-scale dryer projects within demanding shutdown schedules.

The objective is not simply to make an old cylinder look new.

It is to create a functional dryer cylinder surface that improves the performance and lifetime of the existing equipment.

Frequently Asked Questions About Dryer Cylinder Grinding & Coating

Why are paper machine dryer cylinders ground?
Grinding restores cylinder geometry and removes corrosion, contamination, scratches, scuff marks and other surface defects. It also creates the correct substrate for subsequent coating.

Can dryer cylinders be ground without removing them from the paper machine?
Yes. PR Rolls specialises in grinding dryer cylinders directly in the paper machine, avoiding unnecessary removal and transportation.

Can dryer cylinder coating also be applied on-site?
Yes. PR Rolls' mobile coating technologies allow suitable dryer cylinder coatings to be applied directly at the mill.

Why should a dryer cylinder be coated?
A functional coating can provide improved release, reduced contamination, wear resistance and corrosion protection. The required properties depend on the cylinder position and operating conditions.

Which coating is best for a dryer cylinder?
There is no single coating for every application. TecnoClean is suitable where non-stick properties and wear resistance are required, while TecnoCeraHybrid is designed for demanding dryer positions requiring excellent release. TecnoDiamond can be considered where extreme wear or heavy doctoring is the dominant challenge.

Can coating improve paper release?
Yes. PR Rolls' TecnoClean and TecnoCeraHybrid technologies are designed to improve release and reduce the need for draw.

Can dryer cylinder coating reduce sticky build-up?
Yes. PR Rolls' non-stick coating systems are designed to reduce dirt, dust, fluff and sticky build-up on roll and cylinder surfaces.

Can PR Rolls combine grinding and coating with field balancing?
Yes. Grinding, coating and field balancing can be combined within the same on-site maintenance project. PR Rolls can also perform multiple operations simultaneously to shorten the shutdown.

Can PR Rolls optimise the doctoring system together with the coating?
Yes. For suitable dryer-cylinder applications, PR Rolls can provide a complete surface solution combining grinding, functional coating and doctoring solutions.

How quickly can multiple dryer cylinders be restored?
The schedule depends on cylinder condition and project scope. PR Rolls cites one project where 45 dryer cylinders were machined, coated and balanced within 12 days, demonstrating the company's capacity for parallel on-site work.

Restore the Surface – Improve the Dryer Section
A worn or contaminated dryer cylinder is not necessarily a cylinder that needs to be replaced.

PR Rolls restores dryer cylinder geometry and creates new functional surfaces directly in the paper machine through on-site grinding and coating.

Depending on the application, the solution can combine:

Grinding → TecnoClean / TecnoCeraHybrid / TecnoDiamond → Doctoring → Field balancing → Dryer section optimisation

The result is a complete approach designed to support better paper release, cleaner cylinders, reliable doctoring, improved runnability, longer component life and efficient dryer-section operation.

And because the work is performed directly at the mill – with several cylinders treated simultaneously when required – extensive dryer cylinder restoration can be completed within demanding planned shutdown schedules.