Roll Coater Machines

What Is a Roll Coater Machine?

A Roll Coater Machine is a precision-engineered system used to apply uniform coatings to both sides of a metal strip simultaneously. This modern solution offers a superior alternative to outdated spray or immersion methods by delivering better control, cleaner application, and higher coating efficiency.

Typical Uses for Bronx Roll Coater Machines

We provide a variety of coater configurations tailored to meet diverse application needs:

• Passivation
• Pretreatment
• Resin Coatings
• Paints (Standard Paint Systems and High Build Paint Systems)

Standard Paint Systems

These paints can be solvent-based or water-based, typically with a 35–50% solids content and an operating viscosity of 35–90 seconds through a FORD-4 Viscosity Cup. They are applied with a Dry Film Thickness of 5–7 µm for primer paints and reverse backing coats, and from 15–25 µm for top coats. Typical standard build systems include polyester, acrylic, silicone modified polyester, PVDF, and water-based coatings.

High Build Paint Systems

These are more specialty paints than common-use paints. They are used for specific purposes, either for high levels of environmental exposure or for decorative pattern requirements. These paints are manufactured with very high percentage solids and must be applied with high viscosity. Generally, their application requires the Roll Coater Machine to have a ‘three-roll head’ configuration. Typical High Build Paint Systems include urethanes and plastisols.

Bronx Roll Coater Machines can operate in multiple modes, including:

• Forward coating
• Reverse coating
• Two-roll-head configuration
• Three-roll-head configuration (either in-line or V configuration)
• Solution-tray feed method
• Solution-nip feed method

Bronx Roll Coater Machine Models

We offer a range of Roll Coater configurations, each tailored to specific production environments and material needs. The name of the coater — “U-Wrap,” “S-Wrap,” etc. — refers to the shape the strip passes through in the coater.

1. Standard Horizontal Roll Coater

This machine is the most basic of Roll Coater Machine designs. The strip travels horizontally through the centre of the machine, so this machine can be added to most lines at minimal cost. It is used mostly for chemical applications but is also used for paint applications on smaller Paint Lines.

Advantages

• Most cost-effective solution
• Operates in both forward and reverse coating modes
• Requires minimal space and infrastructure changes
• Strip passes in a straight horizontal path — no deflector rolls needed
• Only one over-head crane required for roll change operation

Limitations

• May struggle to evenly coat strips with poor shape or flatness, especially on reverse
• Access to top coating head may be limited for cleaning

2. Vertical Roll Coater

The Vertical Roll Coater Machine has similar characteristics to the Horizontal Roll Coater Machine but in the Vertical machine the strip travels vertically upwards through the machine. This machine is mainly used for chemical applications on both Paint Lines and Galvanising Lines. Operator access is very good but there is no Back-U Roll to hold the strip perfectly flat.

Advantages

• Compact vertical design saves floor space
• Ideal for fitting into existing lines
• Requires minimal space and infrastructure changes
• Supports both forward and reverse coating methods
• Operator-friendly with consistent top/bottom roll access

Limitations

• Building height constraints may limit feasibility
• Less effective on poorly shaped strip

3. S-Wrap Roll Coater

The S-Wrap Roll Coater Machine is the most popular machine used around the world. The main advantage of this machine is that the Top Head paints the strip as the strip is supported around a large diameter Back-Up Roll. This Back-Up Roll supports the strip and keeps it very flat so the painting process can be done very accurately. This machine provides very good operator access and visibility on both the top and bottom sides of the strip.

Advantages

• Excellent top-side coating, especially on uneven strips
• It is used for all solutions, including paints and chemicals
• Operates equally in both Forward and Reverse Coating method
• Only one crane required for roll changing requirements
• Safe, operator-friendly access

Limitations

• Requires deflector rolls
• May not achieve full-width bottom coating on poorly shaped strip

4. U-Wrap Roll Coater

The U-Wrap Roll Coater Machine is a modification of the S-Wrap Roll Coater Machine. It provides all the charactistics and benefits of the S-Wrap Roll Coater Machine but also provides the excellent advantage of being a ‘Quick Change Coater’. A Quick Change Roll Coater is a machine that has two painting Heads for the top side of the strip. While one Head is painting the strip, the second Head is being made ready. When it is time to change paint colour, the first Head is retracted off the strip and the second Head with a different colour is applied onto the strip. This eliminates the ‘down-time’ associated with changing paint. Once the second head is painting, the operator can now change the paint on the first Head and make it ready for another different colour whilst the line remains in full production.

Advantages

• Quick change capability for the top side painting system
• All heads provide safe and operator friendly access
• Operators have full access to the strip at ground level
• Efficient upgrade for existing lines seeking quick-change functionality
• One crane required for all roll change requirements

Limitations

• Requires several additional deflector rolls inside the Coater room and a larger coater room
• Bottom and top coating heads are separated
• Large machine

5. C-Wrap Roll Coater

The C-Wrap Roll Coater is a modification of the S-Wrap Roll Coater Machine. It operates in a similar manner to the U-Wrap Coater Machine in that it is also a Quick Change Roll Coater. The main difference here is that the two Back-Up Rolls are positioned vertically above each other whereas in the U-Wrap Coater Machine, the Back-Up Rolls are positioned horizontally apart from each other.

Whether a U-Wrap Machine or a C-Wrap Machine is used depends on the application area. The U-Wrap machine requires more space horizontally whereas the C-Wrap machine requires more space vertically. In both cases, the complete painting operation takes place in one room and this has good advantages for line manning and paint movement and storage logistics.

Advantages

• Quick change capability for the top system in one machine
• Operates entirely at floor level—no mezzanine required
• Only one crane needed for roll change requirements
• Good system for upgrading existing lines to provide quick change capability without major line configuration changes.

Limitations

• The strip height exiting the machine is quite high, too high for operators to reach from floor level
• Requires a larger coater room
• Access to upper top coating system needs a platform

6. S-Wrap A & B Dual Coater System

To achieve the advantage of the Quick Change Coater technology, but not use the U-Wrap or C-Wrap Coater Machines, an option is to use part of the S-Wrap Coater machine at ground floor level and then have a second S-Wrap Coater Machine on the mezzanine floor level directly above the first machine. One of the disadvantages of the C-Wrap and U-Wrap Quick Change Coater Machines is that they are physically quite large and require a larger than normal Coater Room. Having part of an S-Wrap machine on the ground floor and another S-Wrap machine on the mezzanine floor keeps the room sizes relatively smaller but now you have the disadvantage of two separate painting areas and this option is a more expensive option than a U-Wrap of C-Wrap option.

Advantages

• Proven, globally used quick-change solution
• Very safe and operator friendly

Limitations

• Requires two coater rooms on different floors
• Most expensive quick-change setup
• Additional lifting equipment needed for paint and roll handling
• Operators have to move between two different coater rooms on two different floor levels

Pattern Coating

Bronx Coaters also offer an optional pattern coating service — a precision process that applies decorative ink patterns (woodgrain, brick, marble, and more) over a uniform base coat on metal coil. Using offset rotogravure printing, a chrome-plated pickup roll engraved with your chosen design picks up ink, a doctor blade removes the excess, and a polyurethane applicator roll transfers the pattern onto the base-coated strip. Depending on your line configuration, multiple passes — or even simultaneous wet-on-wet clear coating — deliver a flawless, durable finish on steel or aluminum.

Two roll direct flexographic patterning, utilizing a patterned polyurethane applicator roll can also be organised.

Operational Features of All Bronx Roll Coater Machines

• All applicator and pick-up rolls driven by vector drive A.C. motors
• Linear rails on all coating head movements
• Heavy-duty, stress-relieved steel plate construction
• Zero operational vibration
• Hard chrome-coated pick-up and back-up rolls
• Low-ratio gearboxes for fine roll pressure adjustments
• Drip trays provided on all coating heads
• Seamless molded polyurethane applicator rolls
• Quick release couplings on all drive shafts for rapid roll changes
• Quick release bearing caps on all rolls for rapid roll changes
• Cartridge-type scraper blades on back-up rolls
• Manual and automatic roll speed control
• Automatic and Manual Stitch/Weld pass capability
• All rolls are provided with heavy duty Link Belt bearings
• Optional load cells for pressure monitoring
• Three-roll head options (in line and V configurations)
• All hydraulics on the machine is hard piped to one common terminal block for line connection
• All electrical cables are wired to one common terminal block for line connection
• Removable trays with lift systems for cleaning
• Lift system air operated for positive positioning
• A low-ratio gearbox precisely controls roll pressure for fine thickness application, adjustable either simultaneously or independently side-to-side.
• Complete solution handling system (pumps, stirrers, valves, filters)
• Pneumatic drives to avoid electrical ignition risks
• Easy clean, self-levelling weirs for paint level control
• Internal tray weirs for vortice reduction to reduce pigment and gloss streaking
• Nip feeding capability as standard

Safety Features of All Bronx Roll Coater Machines

• Emergency stop safety cables on every coating head
• Pinch-point guards with optional interlocks
• Fully enclosed, see-through guarding with proximity protection
• Isolation switches on each head for safe roll changes
• Protective drive shaft shields

Need Help Choosing the Right Roll Coater?

Whether you’re building a new line or upgrading an existing system, Bronx expert engineers can recommend the ideal solution based on your layout, coating type, space constraints, and budget.

Contact us today for a tailored consultation and discover why manufacturers worldwide trust Bronx for roll coater excellence.