Workshop Services Metallic Coatings for Food Industry Applications

Metallic Coatings for Food Industry Applications

Functional metallic surfaces for food processing equipment and components


Equipment used in food production must operate reliably in environments where wear, moisture, corrosion, repeated cleaning, chemicals and demanding hygiene requirements can place significant demands on component surfaces.

In many applications, the surface is critical to both equipment performance and component lifetime.

PR Rolls provides metallic coating and surface engineering solutions for suitable components used in food processing and food manufacturing equipment.

Applications are not limited to rolls and cylinders. Depending on the component, operating environment and applicable requirements, metallic surface solutions can be considered for:

  • Industrial rolls and cylinders
  • Shafts and journals
  • Pump components
  • Valve components
  • Sleeves
  • Wear components
  • Machine parts
  • Filling and packaging equipment components
  • Processing equipment components
  • Tools and production components
  • Other suitable metallic surfaces

PR Rolls combines surface engineering, coating, machining, grinding and precision finishing to create functional surfaces according to the requirements of the application.

The starting point is not the coating itself – it is what the surface needs to withstand and how it needs to perform.


Why Use Metallic Coatings in Food Processing Equipment?


Improve the surface without replacing the complete component

Industrial food production exposes equipment to combinations of mechanical and environmental stresses.

Depending on the process, surfaces may experience:

  • Abrasive wear
  • Mechanical contact
  • Corrosion
  • Moisture
  • Repeated wash-down
  • Cleaning chemicals
  • Temperature variations
  • Product residues
  • Surface damage
  • Dimensional wear

In many cases, the underlying component remains mechanically suitable even though its functional surface has deteriorated.

A metallic coating can provide a way to restore, protect or modify the surface of the existing component.

This can be relevant both for maintenance of existing equipment and for new components where additional surface properties are required from the beginning.


Food Processing Applications


Surface engineering for different types of production equipment

Food production covers a broad range of processes, and the surface requirements can vary considerably between applications.

Metallic coating solutions may be relevant for suitable components used in:

  • Food processing machinery
  • Bakery equipment
  • Dairy processing equipment
  • Meat and protein processing equipment
  • Beverage production
  • Packaging and filling equipment
  • Conveying systems
  • Mixing and handling equipment
  • Pumps and process equipment
  • Production tools and machine components

The suitability of a coating must always be evaluated according to the specific component, process conditions and applicable requirements.

This is particularly important when the coated surface may come into direct or indirect contact with food.


Wear-Resistant Metallic Coatings


Protect components exposed to repeated mechanical wear

Wear can gradually change the geometry, dimensions and surface properties of industrial components.

In food processing equipment, this can occur through repeated mechanical contact, abrasive products, movement between components or continuous production cycles.

For suitable applications, wear-resistant metallic coatings can be used to create a harder and more durable functional surface.

Potential applications can include:

  • Shafts
  • Sleeves
  • Roll surfaces
  • Bearing areas
  • Pump components
  • Valve components
  • Machine parts
  • Wear surfaces
  • Production tooling

Rather than manufacturing the complete component from a highly wear-resistant material, surface engineering allows the required properties to be concentrated where they are needed most:

Structural component + Engineered functional surface

Fine-Particle Carbide Coatings – A Modern Alternative to Hard Chrome


Hard chrome plating has traditionally been used to provide wear-resistant, low-friction and corrosion-resistant surfaces on industrial components. However, environmental and occupational-health concerns associated with hexavalent chromium, Cr(VI), have increased the need for alternative surface technologies.

Under the EU REACH framework, chromium compounds used in conventional hard chrome processes have been subject to strict authorization requirements. This has accelerated the industrial development and adoption of alternative coating technologies.

Fine-particle carbide coatings applied using modern high-kinetic thermal spray processes provide an alternative for suitable industrial applications where hard chrome has traditionally been used.

Carbide systems such as WC-CoCr and Cr₃C₂-NiCr have been developed for demanding applications where high wear and corrosion resistance are required. The source material reviewed by PR Rolls highlights previous industrial replacement of hard chrome in applications including hydraulic cylinders and identifies improved performance and lifecycle economics as important drivers for the transition to HVOF carbide coatings.

 

From Conventional HVOF to Fine-Particle Carbide Technology


Modern thermal spray technology has made it possible to use significantly finer carbide structures and smaller powder particles than were traditionally used with conventional HVOF processes.

The technical material describes a development from approximately 1 µm carbide size and 15–45 µm powder particles in a conventional HVOF coating toward approximately 0.4 µm carbide size and 5–25 µm powder particles with newer CJS/HVAF technology. The lower flame temperature of these newer processes can reduce carbide dissolution while enabling a dense coating microstructure.

This development – sometimes referred to as fine-particle spraying or flash carbide – creates opportunities to produce thinner and smoother carbide coatings.

The development targets presented in the technical material illustrate the potential:

  • Coating thickness reduced from approximately 200–250 µm toward 30–50 µm
  • Surface roughness before finishing reduced from approximately Ra 8 µm toward Ra 2 µm
  • Reduced grinding requirements
  • Dense coating structures
  • Improved corrosion-resistance potential through finer powders and suitable pre-alloyed matrices

For suitable food-industry components, these characteristics can be particularly interesting where the application requires a combination of wear resistance, corrosion resistance, accurate dimensions and a precisely finished metallic surface.

Why This Matters for Food-Industry Components


Fine-particle carbide technology can be especially relevant for high-value components where surface performance must be combined with dimensional accuracy.

Potential applications can include suitable:

  • Shafts and sleeves
  • Pump components
  • Hydraulic components
  • Valve components
  • Rolls and cylinders
  • Wear surfaces
  • Machine components
  • Other precision components exposed to wear and corrosion

Because thinner coatings can require less finishing than conventional thick carbide coatings, the technology can also offer manufacturing and refurbishment advantages for components with demanding dimensional requirements.

The underlying principle is:

Fine carbide structure → Dense coating → Thin functional layer → Reduced finishing → High-performance surface

For PR Rolls, this technology complements the broader approach to industrial component refurbishment: rather than automatically restoring a component with the surface technology originally used, the application can be evaluated to determine whether a modern carbide coating can provide a more appropriate functional surface.


Corrosion-Resistant Surfaces


Protect components in wet and frequently cleaned environments

Food production equipment can operate in environments involving moisture, water, cleaning agents and repeated washing.

Corrosion can damage functional surfaces, affect component dimensions and shorten equipment service life.

Depending on the application, a metallic coating can provide additional corrosion protection to the underlying component.

PR Rolls evaluates factors such as:

  • Substrate material
  • Moisture exposure
  • Cleaning environment
  • Chemicals
  • Temperature
  • Mechanical wear
  • Required surface finish

The coating solution should be selected according to the complete operating environment because corrosion resistance alone may not be sufficient when the same component is also exposed to wear or mechanical contact.


Pumps, Valves & Process Components


Surface solutions for critical fluid-handling equipment

Pumps and valves are important components in many food production processes.

Depending on the process and component position, surfaces can be exposed to wear, corrosion, erosion and repeated cleaning.

PR Rolls can evaluate suitable pump and valve components for surface restoration or coating.

Applications can include:

  • Pump components
  • Shafts
  • Sleeves
  • Valve components
  • Sealing areas
  • Other metallic process components

The objective may be to restore worn dimensions, improve surface durability or provide additional protection against the operating environment.

For existing components, coating can be integrated into a broader refurbishment process:

Inspection → Measurement → Machining → Surface preparation → Coating → Precision finishing → Verification


Shafts, Journals & Bearing Areas


Restore worn functional dimensions

Localized wear can make an otherwise serviceable component unusable.

Shafts, journals, bearing seats and other precision areas may become worn, damaged or undersized while the rest of the component remains in good condition.

PR Rolls can evaluate suitable components for dimensional restoration using metallic coating or plating technologies.

Depending on the application, the repaired area can subsequently be precision-finished to the required dimensions.

This can provide an alternative to replacing a complete high-value component because of localized wear.


Repair of Manufacturing & Machining Errors


Recover components that would otherwise become scrap

Metallic coating technologies can also provide a valuable solution before a component has ever entered production.

A machining error can result in an incorrect diameter, undersized bearing seat or other dimensional defect in an otherwise new component.

Depending on the component, material, tolerance and intended application, PR Rolls can evaluate whether the affected area can be restored.

A typical process can include:

Assess the defect → Prepare the area → Restore material → Precision machine or grind → Verify dimensions

For food-industry components, the final suitability of the repaired surface must also be evaluated according to the intended use and applicable requirements.

This can be particularly valuable for large, specialised or long-lead-time components where replacement would create substantial cost or delay.


Localized Metallic Coating with Brush Plating


Repair only the area that needs restoration

Not every repair requires coating an entire component.

For suitable localized repairs, PR Rolls provides brush plating, an electrochemical process in which metallic material is deposited selectively onto the required area.

Brush plating can be useful for applications such as:

  • Shafts
  • Bearing seats
  • Journals
  • Local wear
  • Scratches and surface damage
  • Dimensional restoration
  • Machining errors
  • Tools
  • Moulds
  • Machine components

Because the process is localized, areas that remain within specification do not necessarily need to be treated.

This can make brush plating particularly useful for recovering high-value components with a limited damaged or undersized area.


Rolls & Cylinders for Food Production


Functional surfaces for rotating process equipment

Rolls and cylinders are used in many food processing, conveying, forming and packaging applications.

Their surfaces can influence:

  • Wear
  • Product handling
  • Friction
  • Corrosion resistance
  • Cleaning
  • Component lifetime

PR Rolls' background in industrial roll surface engineering provides a strong foundation for coating and finishing suitable rolls and cylinders used in food-industry applications.

Depending on the component, services can combine:

Inspection + Grinding + Surface preparation + Metallic coating + Precision finishing + Dynamic balancing

Both existing and newly manufactured rolls can be considered for coating.


Moulds, Tools & Production Components


Extend the service life of specialised manufacturing equipment

Moulds, dies, tools and other production components can represent significant investment.

Repeated production cycles can cause local wear, corrosion or dimensional changes even when the main component remains suitable for continued use.

For suitable food-production applications, metallic surface technologies can be used as part of:

  • Wear repair
  • Dimensional restoration
  • Surface refurbishment
  • Corrosion protection
  • Restoration of damaged functional areas

The repair process is determined according to the component material, geometry, damage and intended operating environment.


New Components with Engineered Metallic Surfaces

Surface engineering does not need to begin with a repair

Metallic coatings are not only used to restore worn equipment.

Surface requirements can also be considered when a new industrial component is manufactured.

Instead of waiting for the original surface to fail, a suitable component can be coated before entering production where there is a known requirement for additional wear or corrosion resistance or another functional surface property.

PR Rolls can coat suitable new components and precision-finish them according to the application requirements.

For new industrial rolls and cylinders, PR Rolls also cooperates with AP-Tela Oy, combining new-component manufacturing with PR Rolls' surface engineering and finishing capabilities.

This creates a lifecycle approach:

New component → Functional surface → Production → Inspection → Refurbishment → Recoating → Continued production


Metallic Coating as Part of Component Refurbishment


More than applying a new surface

The performance of a coating depends on the condition and geometry of the underlying component.

A worn component may therefore require machining or grinding before a new coating can be applied.

PR Rolls can combine several workshop operations within one refurbishment project:

Inspection + Measurement + Machining + Grinding + Surface preparation + Metallic coating + Precision finishing

For rotating components, dynamic balancing can also be incorporated where required.

This means PR Rolls can address both the underlying component and its final functional surface.

Correct substrate + Correct geometry + Appropriate coating + Correct finishing = Functional component


Surface Finish Matters


The final surface is part of the coating solution
Selecting an appropriate coating material is only part of surface engineering.

The final surface condition can be equally important.

Depending on the application, requirements may relate to:

  • Surface roughness
  • Dimensional accuracy
  • Geometry
  • Cleanability
  • Friction
  • Wear behaviour
  • Interaction with other components

PR Rolls combines coating with precision grinding and finishing so that the final surface can be produced according to the requirements of the application.

This is particularly important for components used in food production, where the complete finished surface – rather than the coating material alone – must be considered.


Food Contact & Regulatory Requirements


Coating suitability must be evaluated for the specific application
Food-industry applications require particular attention to materials, hygiene and regulatory requirements.

A distinction should be made between:

  • Components with direct food contact
  • Components with indirect or incidental contact
  • Components located in the food-production environment but without food contact

The requirements are not necessarily the same.

For components intended for food-contact applications, coating suitability must be assessed according to the specific coating system, substrate, finished surface, intended food contact, operating conditions and applicable legislation or customer requirements.

PR Rolls therefore evaluates the application before recommending a surface solution.

A coating should not be considered suitable for food contact solely because it is metallic.

The complete application and relevant compliance requirements must be considered.


Hygienic Design Starts with the Complete Component


A high-performance coating cannot compensate for poor component design.

In food production environments, factors such as geometry, joints, surface condition, accessibility and cleanability can be important alongside material selection.

PR Rolls' role in surface engineering is therefore one part of the complete equipment solution.

Where a component requires coating or refurbishment, attention can be given to:

Material → Geometry → Surface integrity → Coating → Final finish → Intended cleaning environment

This helps ensure that surface treatment is considered as part of the component's actual function rather than as an isolated layer.


Repair, Recoat or Replace?


Evaluate the existing component before replacing it

A worn food-processing component does not automatically need to be replaced.

Where the substrate and component remain suitable, refurbishment may provide an alternative.

PR Rolls can evaluate whether the appropriate solution is to:

Repair – restore a localized defect.

Recoat – renew the functional surface.

Restore dimensions – rebuild a worn or undersized area.

Refurbish – combine machining, coating and finishing.

Replace – use a new component when refurbishment is no longer appropriate.

For components used in food-related applications, the decision must also consider the intended use and applicable material, hygiene and regulatory requirements.

The objective is to select a solution that is technically appropriate for the component and its operating environment.


Metallic Coatings Across Food Production


Metallic surface engineering can potentially be applied at many stages of industrial food production.

Relevant applications can be found in equipment used for:

  • Processing
  • Mixing
  • Conveying
  • Forming
  • Pumping
  • Filling
  • Packaging
  • Handling
  • Cleaning systems
  • Supporting production machinery

Rather than defining the solution according to the industry alone, PR Rolls evaluates the individual component.

The key questions are:

What is the component?

What is damaging the surface?

What does the finished surface need to do?

Does it have direct or indirect food contact?

Which requirements apply to the application?

These answers provide the basis for selecting the appropriate surface engineering solution.


Why Choose PR Rolls for Food Industry Coatings?


PR Rolls combines industrial surface engineering with machining and component refurbishment expertise.

Depending on the application, one workshop project can include:

Condition assessment + Machining + Grinding + Dimensional restoration + Metallic coating + Precision finishing

For suitable rotating components, dynamic balancing can also be integrated into the project.

This provides an important advantage when the challenge involves more than the coating itself.

A worn component may need its geometry restored before coating. A localized defect may only require selective repair. A new component may benefit from surface engineering before it enters production.

PR Rolls approaches each of these situations from the same perspective:

Understand the component and its operating environment first – then engineer the appropriate surface.


Frequently Asked Questions About Metallic Coatings for Food Industry Applications


What components can PR Rolls coat for food-industry applications?
Depending on the application, suitable components can include rolls, cylinders, shafts, journals, pump components, valve components, sleeves, machine parts, moulds, tools and other metallic production components.

Are metallic coatings suitable for food contact?
Potential suitability depends on the specific coating material and system, substrate, finished surface, intended food contact, operating conditions and applicable regulatory requirements. A metallic coating should not automatically be described as food-contact compliant without evaluating the specific application.

Can PR Rolls restore worn food-processing components?
Yes, suitable components can be evaluated for refurbishment. Depending on the damage, the process can include machining, grinding, dimensional restoration, metallic coating and precision finishing.

Can metallic coatings improve wear resistance?
Yes. Suitable metallic and metal-based coating systems can provide increased wear resistance for components exposed to abrasive or mechanical wear. The coating should be selected according to the actual wear mechanism.

Can coatings provide corrosion protection?
Yes. Suitable coating systems can provide additional corrosion protection. Selection depends on factors such as substrate, moisture, chemicals, temperature and mechanical wear.

Can PR Rolls repair shafts and bearing seats?
Suitable shafts, journals and bearing areas can be evaluated for dimensional restoration. Technologies such as brush plating can be particularly useful for localized repair.

Can a machining error on a new component be repaired?
Potentially, yes. If a component has been machined undersize or has localized dimensional damage, PR Rolls can evaluate whether the area can be restored and precision-finished rather than scrapping the complete component.

Can PR Rolls coat new components?
Yes. Metallic surface engineering can be applied to suitable new components before they enter production, provided that the coating and finished surface are appropriate for the intended application.


Functional Metallic Surfaces for Food Production Equipment


Food processing equipment places demanding requirements on industrial surfaces.

Wear, corrosion, moisture, cleaning, mechanical contact and dimensional accuracy can all influence component performance and service life.

PR Rolls provides metallic coating and surface engineering solutions for suitable new and existing food-industry components – from rolls and shafts to pumps, valves, hydraulic components, moulds, tools and other production equipment.

Our approach combines the component and the surface:

Assess → Machine or restore where required → Coat → Precision finish → Verify

For food-related applications, the intended use and applicable material and food-contact requirements are considered when determining the appropriate solution.

Contact PR Rolls to discuss your component, operating environment and surface requirements.