Line 04
Continuous Color Coating Line (CCL)
2-coat/2-bake and 3-coat/3-bake colour coating lines for prepainted steel, from cleaning and pre-treatment through coating, curing and film lamination.
- 2C2B / 3C3B
- 30,000 - 200,000 t/yr
- Thickness 0.15 - 2.0 mm
- PE / SMP / HDP / PVDF / FEVE
What the line delivers
The line applies protective and decorative coatings to pre-galvanized or cold-rolled strip. The coil passes through cleaning, chemical pre-treatment, primer, curing, topcoat, curing, cooling and optional film lamination, and leaves as prepainted coil.
Coating system, colour and finish are agreed from the end use. Roofing and cladding, appliance panels, interior panels and transport panels each carry different durability and appearance requirements, so the line is configured around that mix.
2C2B and 3C3B
Two or three coating and curing cycles built on the same line platform.
Five coating systems
PE, SMP, HDP, PVDF and FEVE chemistries, with the oven profile matched to each.
Surface options
Smooth, embossed, wood grain, metallic, pearlescent and easy-clean finishes.
Fume treatment in scope
RTO or TO incineration specified with the ovens rather than retrofitted later.
Where prepainted coil goes
| Market | Products |
|---|---|
| Construction | Metal roofing, wall cladding, sandwich panels, cleanroom panels, gutters, roller shutters |
| Appliances | Refrigerator side panels, washing machine tops, microwave housings, air conditioner casings |
| Interior | Ceiling panels, partition boards, wall panels, blinds |
| Transportation | Truck body panels, container side panels, trailer interiors |
| General industry | Electrical cabinets, cable trays, ventilation ducts, storage rack shelves |
Process sequence
The sequence is fixed; what changes between products is the number of coating and curing cycles and the coating chemistry.
| Stage | Operation |
|---|---|
| Coil entry | Double-mandrel uncoiler, pinch leveler, hydraulic shear, stitcher or narrow-lap welder |
| Entry looper | Accumulates strip for non-stop coil change |
| Cleaning | Alkaline spray with brush scrubbing and counter-flow rinsing |
| Pre-treatment | Passivation conversion coating applied by two-roll coater, then dried |
| Primer | Reverse-roll primer coating |
| Primer curing | Oven 1 with multi-zone temperature control, then cooling |
| Topcoat | Reverse-roll topcoat, with optional back coat at the same station |
| Topcoat curing | Oven 2 with an independent temperature profile, then cooling |
| Exit | Optional film lamination, exit looper, shear, recoiling and packaging |
Configuration options
| Configuration | Description | Typical application | Cost level |
|---|---|---|---|
| 2-coat/2-bake (2C2B) | Primer and topcoat with two curing cycles | Standard construction panels | Baseline |
| 3-coat/3-bake (3C3B) | Primer, intermediate coat and topcoat with three curing cycles | High-end appliances, automotive | Higher |
| With back coat | Back side coated during topcoat application | Sandwich and composite panels | Moderate |
| With film lamination | Protective film applied after topcoat curing | Appliance exteriors, high-gloss surfaces | Moderate |
Coating systems and finishes
The coating chemistry sets the durability and the market the product can serve. The oven profile, coating thickness and pre-treatment are matched to the system rather than treated as interchangeable.
| Coating system | Durability | Typical applications | Market tier |
|---|---|---|---|
| Polyester (PE) | 5 - 8 years | General industrial buildings, warehouses, simple structures | Economy |
| Silicone-modified polyester (SMP) | 8 - 12 years | Industrial plants, commercial building exteriors | Mid-range |
| High-durability polyester (HDP) | 12 - 15 years | Premium buildings, airports, transit stations | Mid to high |
| Polyvinylidene fluoride (PVDF) | 20+ years | Landmark buildings, coastal structures, curtain walls | Premium |
| Fluoroethylene vinyl ether (FEVE) | 25+ years | High-rise buildings, chemical plant structures | Ultra-premium |
Service life is indicative and depends on coating thickness, substrate, exposure and maintenance. The system is selected against the environment the panel will face.
Surface finishes
| Finish | Method | Effect |
|---|---|---|
| Smooth | Standard roll coating | Matte, semi-gloss or high-gloss |
| Embossed | Embossing roll | Three-dimensional pattern |
| Wood grain or leather | Engraved roll | Realistic wood or leather appearance |
| Metallic | Aluminium pigment addition | Metallic sparkle |
| Pearlescent | Pearl pigment addition | Iridescent colour shift |
| Easy-clean | Hydrophobic coating | Dirt-resistant surface |
Technical specifications
The range below is the standard offer. Widths, speeds and coating thicknesses outside it are engineered against the product mix.
| Parameter | Range | Notes |
|---|---|---|
| Annual capacity | 30,000 / 50,000 / 100,000 / 150,000 / 200,000 t | Standard tiers; custom available |
| Substrate | GI / GL / ZAM / cold-rolled | Pre-galvanized substrate recommended for outdoor use |
| Strip width | 600 - 1,250 mm, up to 1,550 mm | Wider strip needs wider coating rolls |
| Strip thickness | 0.15 - 1.2 mm standard, up to 2.0 mm | Thicker strip needs tension adjustment |
| Maximum line speed | 60 / 80 / 100 / 120 / 150 m/min | Higher speeds need more oven capacity |
| Coating systems | PE / SMP / HDP / PVDF / FEVE | Client-specified or recommended |
| Coating thickness | Topcoat 15 - 25 µm; primer 5 - 10 µm per side | Adjusted to the product requirement |
| Peak metal temperature | 180 - 240 °C | Set by the coating chemistry |
| Installed power | approx. 800 - 2,000 kW | Depends on capacity and heating method |
| Approx. footprint | 1,000 - 3,000 m² | Includes raw material and finished goods storage |
Entry and pre-treatment
Coating adhesion is decided before the paint is applied, so cleaning and passivation are specified as a process rather than as auxiliary equipment.
Entry section
| Equipment | Function | Detail |
|---|---|---|
| Double-mandrel uncoiler | Supports the coil and unwinds at controlled tension | Non-stop coil change with dual mandrels |
| Pinch leveler | Flattens the strip lead end and feeds the line | 5-roll or 7-roll configuration |
| Hydraulic shear | Crops irregular coil head and tail | Hold-down for a clean cut |
| Stitcher or narrow-lap welder | Joins coils end to end for continuous production | Weld strength ≥ 90% of parent metal |
| Entry looper | Accumulates strip for non-stop coil change | Storage capacity ≥ 3 minutes of line operation |
Cleaning and pre-treatment
| Equipment | Function | Detail |
|---|---|---|
| Alkaline spray cleaning | Removes oil, dirt and contaminants | Multi-stage spray with brushes |
| Brush scrubbing | Mechanical removal of stubborn residue | Nylon or stainless brush rolls |
| Rinsing | Removes residual alkaline solution | Counter-flow, 3 - 5 stages |
| Passivation | Forms the conversion coating for paint adhesion | Two-roll coater application |
| Hot-air dryer | Dries the strip before coating | Uniform temperature across the width |
Coating and curing
The coaters and the ovens are specified together. Coating thickness control, booth ventilation and oven zoning all affect the same result, so they are reviewed as one system.
Coating section
| Equipment | Function | Detail |
|---|---|---|
| Primer coater | Applies primer by reverse roll | 3-roll or 4-roll, thickness within ± 0.5 µm |
| Topcoat coater | Applies topcoat and optional back coat | Independent servo control for each roll |
| Coating thickness control | Closed-loop adjustment of roll speed and pressure | Online gauge feedback optional |
| Enclosed booth | Contains solvent vapour and protects the workplace | Negative pressure, solvent-resistant materials |
| Colour change system | Shortens the transition between colours | Automatic wash cycle, changeover under 30 minutes |
| Paint supply | Delivers paint at consistent viscosity | Temperature-controlled, filtered circulation |
Curing section
| Equipment | Function | Detail |
|---|---|---|
| Primer oven | Cures the primer | Bridge or catenary design with multi-zone control |
| Topcoat oven | Cures the topcoat | Independent temperature profile |
| Hot-air circulation | Distributes heat across the strip width | Temperature uniformity within ± 3 °C |
| Heating options | Heat source for the ovens | Gas, electric or thermal oil |
| RTO or TO incineration | Purifies solvent-laden exhaust | Destruction efficiency ≥ 98%, heat recovery ≥ 85% |
Cooling, exit and automation
Cooling and recoiling set the surface the customer receives, while the control layer ties the sections together and records what was produced.
Cooling and exit
| Equipment | Function | Detail |
|---|---|---|
| Air cooling | Cools strip from curing temperature | Forced-air blowers with adjustable flow |
| Water quench (optional) | Rapid cooling for certain systems | Recirculated water with temperature control |
| Film laminator (optional) | Applies protective film | Uniform tension, no bubbles |
| Exit looper | Accumulates strip for non-stop recoiling | Storage ≥ 2 minutes |
| Flying or disc shear | Cuts strip at target coil weight | Precise cut length |
| Dual recoilers | Winds the finished coil | Alternating operation for continuous production |
| Packaging station | Straps, wraps and labels coils | Automatic or semi-automatic |
Electrical and automation
| System | Function | Detail |
|---|---|---|
| PLC control | Line sequence, speed and tension | Platform agreed with the plant standard |
| HMI workstations | Operation, recipe management and diagnostics | Touch screen, multi-language |
| AC drives | Speed control per section | Independent drive for each section |
| Coating thickness gauges | Online coating weight measurement | X-ray, infrared or beta backscatter, optional |
| Colour measurement (optional) | Online colour verification | Spectrophotometer with closed-loop feedback |
| Production reporting | Data logging and traceability | MES or ERP integration optional |
Substrates and finished products
The substrate determines the pre-treatment and the corrosion base. Aluminium and stainless need dedicated lines or dedicated pre-treatment, so they are reviewed before the scope is fixed.
Suitable substrates
| Substrate | Representative standards | Thickness | Notes |
|---|---|---|---|
| Hot-dip galvanized (GI) | ASTM A653 / EN 10346 / JIS G3302 | 0.15 - 1.2 mm | Most common substrate |
| 55% Al-Zn (GL) | ASTM A792 / EN 10346 | 0.15 - 1.2 mm | Higher corrosion resistance |
| Al-Zn-Mg (ZAM) | Proprietary / JIS | 0.15 - 1.2 mm | Premium corrosion performance |
| Cold-rolled steel | ASTM A1008 / EN 10130 | 0.15 - 1.2 mm | Needs prior galvanizing for outdoor use |
| Aluminium | ASTM B209 / EN 485 | 0.2 - 1.5 mm | Dedicated line or pre-treatment |
| Stainless steel | ASTM A240 / EN 10088 | 0.2 - 1.0 mm | Specialised pre-treatment |
Finished product range
| Product | Thickness | Coating system | Application |
|---|---|---|---|
| Construction panel | 0.3 - 0.8 mm | PE / SMP / HDP | Roofing and wall cladding |
| Appliance panel | 0.3 - 0.8 mm | HDP / PVDF | Refrigerator, washer |
| Architectural panel | 0.4 - 1.0 mm | PVDF / FEVE | Curtain wall, landmark |
| Sandwich panel face | 0.3 - 0.6 mm | PE / SMP | Composite panels |
| Interior panel | 0.3 - 0.6 mm | PE / SMP | Ceiling, partition |
Standard scope of supply
Scope is offered as a full turnkey line or as core equipment with auxiliaries procured locally. The coating and curing sections stay under our supervision either way.
| Module | Included equipment | Package |
|---|---|---|
| Entry section | Uncoiler, pinch leveler, shear, welder, entry looper | Full line only |
| Cleaning and pre-treatment | Alkaline spray, brush scrubber, rinsing, passivation coater, dryer | Available separately |
| Coating section | Primer coater, topcoat coater, optional back coater, paint supply, enclosed booth | Core, supervised supply |
| Curing section | Primer oven, topcoat oven, hot-air circulation, RTO or TO system | Core, supervised supply |
| Cooling and exit | Air cooling, optional water quench and film laminator, exit looper, shear, recoilers | Available separately |
| Electrical and automation | PLC, HMI, AC drives, coating thickness gauges, production reporting | Full line only |
| Auxiliary systems | Hydraulic station, compressed air, optional wastewater treatment | Available separately |
Upgrade and support
Existing lines can be upgraded in steps, whether or not we supplied them. Emission, coating system and automation upgrades are the most common requests.
- Oven temperature, line speed and coating thickness data uploaded in real time
- Coating roll wear prediction and replacement scheduling
- Mobile dashboard with alerts and production reporting
| Retrofit | Scope | Typical driver |
|---|---|---|
| Capacity upgrade | Higher-power motors, upgraded drives, oven expansion | Demand growth on an existing line |
| Coating system upgrade | Additional curing zones, modified booth ventilation | Moving from PE to PVDF or FEVE products |
| Fume treatment retrofit | Add or replace the RTO incinerator | Tighter emission standards |
| Automation upgrade | Coating thickness closed loop, online colour measurement | Product consistency requirement |
| Heat recovery retrofit | Flue gas heat recovery on the ovens | Energy cost |
| MES or ERP integration | Production data interface | Traceability requirements |
Configuration inputs
What we need to specify this line
- 01Substrate type and coating system
- 02Coating thickness and colour requirements
- 03Strip width, thickness and coil weight
- 04Target output, energy source and emission limits
Questions
Questions we hear on this line
2C2B or 3C3B — how is the choice made?
It follows the product. Standard construction panels usually need two coats, while high-end appliance and automotive panels need an intermediate coat and a third curing cycle.
Can one line run PE, HDP and PVDF?
The coating section can serve several chemistries, but the oven profile and peak metal temperature have to suit the system being run. The changeover procedure is agreed at specification stage.
Is fume treatment part of the line?
Yes, RTO or TO incineration is specified with the ovens. It is not treated as a separate environmental package added after the line has been designed.
Related terms
What engineers search for on this line
- color coating line
- CCL
- prepainted steel line
- color coated steel
- coil coating line
- 2C2B
- 3C3B
- PVDF coating line
- RTO fume treatment
Other lines
Sections planned in the same scope
Pickling Lines (PPL & CPL)
Turnkey push-pull and continuous pickling lines for hot-rolled strip, covering scale breaking, acid pickling, rinsing, fume treatment and acid regeneration.
Reversing Cold Rolling Mills (CRM & TCRM)
Turnkey single-stand and tandem reversing cold rolling mills for carbon, silicon, stainless and HSLA strip, with hydraulic gauge and automatic flatness control.
Continuous Hot-Dip Galvanizing Line
Turnkey continuous hot-dip galvanizing lines for GI, 55% Al-Zn and Al-Zn-Mg coatings, from cleaning and annealing through the zinc pot, skin-pass and chemical treatment.
Planning a new line or an upgrade?
Send the product mix and target capacity, and we will review the configuration.