On-site Grooving Services for Pulp & Paper Mills

Precision grooving of rolls and cylinders directly at your mill

PR Rolls provides specialised on-site grooving services for rolls, cylinders and rotating equipment in the pulp and paper industry. Our field service teams machine, modify and restore grooves directly at the mill, helping customers improve equipment functionality, machine runnability and production reliability.

Grooves on rolls and cylinders can perform several important functions – from controlling air and supporting web runnability to assisting dewatering, rope guidance and leak detection. Over time, existing grooves may also become worn or damaged and require precision restoration.

PR Rolls performs grooving during planned shutdowns, rebuilds and machine optimisation projects. By carrying out the machining on-site, large rolls and cylinders can often remain installed, reducing dismantling, transportation and maintenance lead time.

Our grooving services can also be combined with measurement, grinding, drilling, machining and field balancing as part of a complete on-site maintenance project.

What is On-site Grooving?

On-site grooving is the precision machining of grooves into the surface of a roll, cylinder or other industrial component directly at the customer's mill.

Depending on the application, grooving can be used to create new functional surface patterns, modify existing grooves or restore worn and damaged groove geometry.

PR Rolls performs both new grooving and groove repair, with the groove dimensions and pattern defined according to the component and its operating requirements.

Typical applications include:

• Dryer cylinder grooving
• Pope cylinder grooving
• Pressroll grooving
• Groove repairs
• G-band rolls
• Venta-nip grooving
• Rope grooves
• Division plane repairs and grooving
• Grooves for leak detection

Why Grooving Matters in Pulp and Paper Production

Grooves are not simply surface features. Their geometry can directly influence how a roll or cylinder functions within the production process.

Depending on the application, correctly machined grooves can support:

• Improved web control
• Better machine runnability
• Reduced air-related web instability
• Improved dewatering
• Controlled air movement
• Reliable rope guidance
• Improved roll functionality
• Leak detection
• Restoration of worn roll surfaces
• Longer component service life

The correct groove design depends entirely on the application. This makes accurate measurement, machining and verification important parts of every grooving project.

Dryer Cylinder Grooving

PR Rolls provides on-site grooving of dryer cylinders for paper and board machines.

Air movement between the paper web, dryer fabric and rotating cylinders can affect web stability, particularly during threading and at higher operating speeds.

PR Rolls' current service experience includes dryer cylinder grooving intended to improve cylinder performance and reduce paper flutter caused by air pressure.

Grooving can be performed on existing dryer cylinders during planned shutdowns, allowing the cylinder surface to be modified without transporting the component to an external workshop.

Depending on the project, the service may include:

• Inspection of the cylinder
• Measurement of the existing surface
• Definition of the groove pattern
• Installation and alignment of machining equipment
• Precision grooving
• Deburring and grinding
• Balancing
• Inspection and verification

Grooving for Improved Web Runnability

Web stability is a critical factor in efficient paper production.

At machine speed, air can become trapped or move between the web, fabrics and rotating surfaces. Uncontrolled air movement can contribute to flutter and unstable web behaviour.

Correctly engineered grooves can provide controlled paths for air and support more stable web behaviour in selected applications.

For PR Rolls, this is particularly relevant for dryer cylinders and Pope cylinders, where grooving can form part of a wider machine runnability improvement project. PR Rolls specifically identifies reduced paper flutter and prevention of air-pressure-related breaks as objectives of its existing grooving work.

Pope Cylinder Grooving

PR Rolls performs on-site grooving of Pope cylinders.

The reel section requires controlled and reliable interaction between the paper web, reel spool and Pope cylinder. Surface condition and functional surface geometry can therefore be important for reliable operation.

Existing Pope cylinders can be machined directly at the mill to create or restore the required groove pattern.

On-site execution reduces the need for cylinder removal and allows the work to be coordinated with other reel section maintenance activities during the same shutdown.

Grooving of Press and Suction Roll Applications

Grooving is also used in paper machine press applications.

In a grooved press roll, the grooves provide void volume and shorter paths for water removal from the sheet and felt during the nip. Grooved surfaces can therefore form part of the overall press dewatering concept.

In suction roll applications, grooving can further shorten the path for water transfer and can change the compliance characteristics of the roll cover.

The exact groove dimensions and configuration must always be selected according to the roll design, cover, machine configuration and process requirements.

PR Rolls can support projects where existing roll surfaces require precision grooving, groove modification or restoration.

Groove Repair and Restoration

Existing grooves can become worn, damaged or lose their required geometry during operation.

Replacing the complete component is not always necessary.

PR Rolls provides on-site groove repair and restoration to restore the required groove geometry and functionality.

Depending on the component, groove repair can include:

• Inspection of existing grooves
• Measurement of groove dimensions
• Removal of damaged areas
• Re-machining of grooves
• Modification of existing groove geometry
• Surface finishing
• Final verification

This can provide a cost-effective way to extend the service life of existing rolls and cylinders.

Venta-nip Grooving

PR Rolls has experience in performing Venta-nip grooving directly on-site.

Precision machining allows existing rolls to be modified according to the required groove specification without unnecessary transportation to an external workshop.

The work can be integrated with other roll maintenance activities during the same planned shutdown.

G-Band Roll Grooving

PR Rolls also performs machining and grooving work on G-band rolls.

As with other grooved roll applications, accurate groove geometry and surface condition are important for maintaining the intended functionality of the component.

PR Rolls can inspect the existing condition, restore worn grooves or machine the required groove pattern according to the project specification.

Rope Groove Machining and Modification

Rope systems are used for tail threading and web handling in paper machines.

The grooves guiding the ropes must maintain the required geometry to ensure reliable operation.

PR Rolls provides:

• Machining of new rope grooves
• Modification of existing rope grooves
• Restoration of worn grooves
• Geometry corrections
• Surface finishing

The work can be performed directly at the mill and coordinated with other machine maintenance activities.

Division Plane Repair and Grooving

PR Rolls also provides repair and grooving of division planes as part of its specialised on-site machining services.

Worn or damaged surfaces can be restored and subsequently machined to the required geometry.

Combining repair and precision machining on-site reduces the need for extensive component dismantling and allows critical surfaces to be restored within the available shutdown window.

Grooves for Leak Detection

Grooving can also have an important diagnostic function.

PR Rolls machines grooves designed for detecting leaks in industrial equipment.

These grooves provide a controlled path that can help reveal leakage between critical surfaces or sections of a component.

Because this is a specialised application, groove location and geometry are machined according to the requirements of the specific equipment.

Precision Measurement Before Grooving

Accurate grooving starts with accurate positioning and measurement.

Before machining begins, PR Rolls can evaluate the component and existing surface to determine the required machining scope.

Depending on the project, this may include verification of:

• Component geometry
• Existing groove dimensions
• Groove position
• Surface condition
• Diameter
• Runout
• Machining reference points

The machining equipment is then accurately positioned relative to the component.

This measurement-based approach helps ensure that new or restored grooves correspond to the required engineering specification.

On-site Grooving During Planned Shutdowns

One of the main advantages of PR Rolls' approach is the ability to perform grooving directly at the pulp or paper mill.

Large cylinders and rolls can be difficult and expensive to remove and transport. On-site machining can significantly simplify the maintenance process.

Benefits include:

• Reduced dismantling
• No unnecessary transportation
• Shorter maintenance lead times
• Modification of existing equipment
• Coordination with other shutdown activities
• Multiple maintenance operations during the same shutdown
• Faster return to production

PR Rolls plans the machining work around the customer's shutdown schedule and the requirements of the individual component.

Combining Grooving with Grinding and Other On-site Services

Grooving is often only one part of restoring or modifying a roll or cylinder.

Before new grooves are machined, the component may first require grinding to restore the underlying surface geometry.

A project could therefore include:

• Inspection and measurement
• Grinding of the roll or cylinder
• Precision grooving
• Surface finishing
• Field balancing where required
• Final measurement and verification

PR Rolls can combine grooving with:

• On-site grinding
• On-site drilling
• On-site machining
• Precision measurement
• Coating
• Field balancing

This enables pulp and paper mills to coordinate several specialised maintenance operations through one experienced on-site service partner.

Our On-site Grooving Process

1. Inspection
The component, existing surface and required groove functionality are evaluated.

2. Measurement
Existing geometry and machining reference points are measured where required.

3. Grooving Plan
The groove pattern, dimensions and machining requirements are defined according to the project specification.

4. Equipment Installation
Portable machining equipment is installed and accurately aligned directly at the mill.

5. Precision Grooving
New grooves are machined or existing grooves are restored according to the required geometry.

6. Deburring and Grinding

7. Balancing

8. Inspection and Verification
The completed grooves are inspected and measured to verify the result.

9. Additional Maintenance
Where required, grinding, machining, field balancing or other on-site services can be performed during the same shutdown.

Why Choose PR Rolls for On-site Grooving?

PR Rolls combines pulp and paper industry expertise with specialised on-site machining capabilities.

Our customers benefit from:

• Experience with paper machine rolls and cylinders
• Dryer cylinder grooving expertise
• Pope cylinder grooving
• Groove repair and restoration
• Venta-nip grooving
• G-band roll experience
• Rope groove machining and modification
• Precision measurement
• Portable on-site machining equipment
• Grinding, drilling and grooving from one service partner
• Field balancing capability
• Efficient shutdown execution

Our objective is not simply to machine grooves. We ensure that the groove geometry is accurately produced or restored according to the functional requirements of the component and production process.

Frequently Asked Questions

What is on-site grooving?
On-site grooving is the precision machining of grooves into rolls, cylinders and other industrial components directly at the pulp or paper mill. It allows existing equipment to be modified or restored without unnecessary transportation to an external workshop.

What components can PR Rolls groove?
PR Rolls' current references include dryer cylinders, Pope cylinders, G-band rolls and Venta-nip applications, as well as rope grooves, division planes and specialised grooves for leak detection.

Why are dryer cylinders grooved?
In selected applications, grooves can provide controlled paths for air and help reduce web flutter and air-pressure-related production disturbances.

Can PR Rolls repair existing grooves?
Yes. PR Rolls performs groove repair, restoration and modification directly at the mill.

What is suction roll grooving used for?
Grooving of suction press rolls can shorten water-transfer paths in the press nip and alter the compliance of the roll cover. The appropriate design depends on the specific roll, cover and process conditions.

Can rope grooves be modified on-site?
Yes. PR Rolls can machine new rope grooves and modify or restore existing rope grooves directly at the mill.

Can grooving be combined with grinding?
Yes. Where necessary, PR Rolls can first restore the underlying roll or cylinder geometry through precision grinding and then machine the required grooves.

Does the component need to be transported to a workshop?
In many applications, no. PR Rolls uses portable machining equipment to perform the work directly at the customer's site.

Restore and Optimise Critical Surfaces Directly at Your Mill

Grooves play an important functional role in many pulp and paper machine components.

PR Rolls combines precision on-site grooving, grinding, drilling, measurement and field balancing to create, modify and restore functional surfaces directly at the mill.

From dryer and Pope cylinders to G-band rolls, Venta-nip applications, rope grooves and specialised groove repairs, our on-site machining expertise helps pulp and paper producers extend equipment service life, improve machine functionality and minimise maintenance downtime.