Executive summary Our master coil wrapper parks heavy steel or non-ferrous coils on dual motorized blocker roller stations while shuttles on an orbital ring traverse through the coil eye. The shuttles carry two or three material rolls simultaneously, allowing an inner protective wrap (crepe paper or VCI film) and an outer protective barrier (stretch film or woven HDPE) to be applied in a single automated pass. Our stainless coil wrapping platform accommodates coil weights from 1,000 to 12,500 kg, while our heavy-duty cold-rolled coil wrapper supports payloads up to 30,000 kg.
Table of Contents
- How master coil wrapping works
- Paper and film layers
- Which design fits your coil
- Planning wraps and material
- Automation features
- Utilities and safety
- Selection checklist
- Engineering FAQ
- Next step
- Related reading
- Sources
How master coil wrapping works
The master coil rests eye-horizontal on two heavy-duty polyurethane-coated blocker roller stations. The orbital wrapping ring establishes an open radial trajectory through the coil bore (eye). Independent, high-speed shuttles carrying packaging rolls travel along the ring circumference, applying protective media across the outer diameter (OD), both side faces, and through the inner diameter (ID) in one continuous motion.
Simultaneously, the blocker rollers rotate the coil around its horizontal axis at a controlled surface speed. This synchronized dual-axis rotation causes each successive material band to overlap the preceding layer uniformly along the entire coil perimeter.
The operator inputs key parameters into the HMI: coil outer diameter, inner bore diameter, and axial width. Integrated PLC algorithms automatically calculate shuttle orbital velocity, roller rotation speed, and axial ring displacement. The machine base shifts transversely on linear guide tracks, while a vertical motorized mast centers the ring aperture precisely on the coil eye centerline.
Paper and film layers
Master coils in transit and sea freight require protection against mechanical abrasion, moisture intrusion, and surface oxidation. Our shuttles can be equipped with dual or triple roll mandrels to apply multi-layer composite packaging in a single operational cycle.
| Layer | Typical material | Job |
|---|---|---|
| Inner | Neutral crepe paper or VCI film | Prevents surface oxidation and neutralizes vapor condensation |
| Outer | LLDPE stretch film or opaque PE/PP woven film | Seals against ambient moisture, dust, and mechanical scuffing |
On the stainless master coil system, packaging media typically consist of clear stretch film combined with an opaque protective outer layer. Standard material roll cores are 76 mm (3 inches), with roll outer diameters between 100 mm and 250 mm and roll widths between 200 mm and 250 mm. Mechanical and electromagnetic web tensioning brakes prevent film neck-down or creasing during high-speed orbit, maintaining uniform surface containment force across all coil corners.
Which design fits your coil
Selection depends primarily on maximum coil weight, inner bore clearance, and production line throughput.
| Parameter | Stainless master coil wrapper | Cold-rolled master coil wrapper |
|---|---|---|
| Coil width | 500–1,800 mm | 800–2,000 mm |
| Coil OD | 800–2,000 mm | 1,000–2,100 mm |
| Coil ID | 500–600 mm | 610–760 mm |
| Coil weight | 1,000–12,500 kg | 2,000–30,000 kg |
| Shuttle speed | Approx. 2–3 m/s | Approx. 2–3 m/s |
| Film overlap range | 20–90% (variable) | 20–90% (variable) |
Primary engineering selection rule: coils with an internal bore diameter of 610 mm or larger, or total mass exceeding 12,500 kg, require the heavy-duty cold-rolled chassis. Final ring cross-section and shuttle clearance profiles are validated against customer coil ranges during mechanical engineering review.
Planning wraps and material
Overlap percentage is calculated at the outside diameter (OD), where the linear distance between successive wrap pitches is greatest.
Sample baseline calculation:
- Coil OD = 1,800 mm
- Coil ID = 600 mm
- Coil Width = 1,200 mm
- Film width = 250 mm
- Programmed OD overlap = 50%
| Step | Calculation formula | Engineering result |
|---|---|---|
| Advance pitch per wrap at OD | 250 mm × (1 – 0.50) | 125 mm |
| Required wraps per single layer | (π × 1,800 mm) ÷ 125 mm | Approx. 46 wraps |
| Cross-sectional coil perimeter | 2 × [Width + (OD – ID) ÷ 2] = 2 × [1,200 + 600] | 3.60 m per turn |
| Total film payout length per layer | 46 wraps × 3.60 m | Approx. 165.6 m |
Note on consumption: Film stretching reduces actual raw film drawn from the spool (payout savings of 15% to 40% depending on pre-stretch settings), whereas reinforcement wraps at the start and tail ends add nominal length. Factory trials confirm exact material consumption.
Automation features
| Feature | Engineering specification |
|---|---|
| Control system | Siemens or Allen-Bradley PLC with color touch HMI |
| Operating modes | Fully automatic cycle and manual inching/setup mode |
| Shuttle configuration | Dual-shuttle counterbalanced track crossing coil ID |
| Positioning axes | Motorized longitudinal trolley drive with laser/photoelectric position sensors |
| Elevation tracking | Motorized vertical column adjusting ring height to match target coil OD |
| Film management | Pneumatic film clamping, cutting, and wiping at cycle completion |
| Overlap control | Closed-loop inverter-controlled roller vs. ring synchronization |
| Home positioning | Automatic ring homing and parking orientation |
Utilities and safety
| Utility | Stainless design platform | Cold-rolled design platform |
|---|---|---|
| Installed power | Approx. 12 kW | Approx. 15 kW |
| Electrical connection | 380–480 V, 3-phase, 5-wire, 50/60 Hz | 380–480 V, 3-phase, 5-wire, 50/60 Hz |
| Hydraulic operating pressure | 140 bar (optional coil lift/pusher) | Specified per plant layout |
| Pneumatic supply | 0.4–0.5 MPa (4–5 bar clean, dry air) | 0.4–0.5 MPa (4–5 bar clean, dry air) |
Heavy cold-rolled installations integrate with factory hydraulics or all-electric screw jacks depending on downstream conveyor designs. Machinery safety features include interlocked perimeter fencing, category-rated emergency stop circuits, soft-start/soft-stop acceleration profiles to prevent coil skidding, and automatic diagnostic fault alarms. Systems destined for European Union plants comply fully with ISO 12100 risk reduction standards and EN 415-10 safety requirements for packaging machines.
Selection checklist for a master coil wrapper
- Complete coil dimensions: Minimum and maximum OD, ID, width, and gross weight.
- Required protective media: VCI film, standard LLDPE, HDPE woven, or crepe paper.
- Number of layers per packaging recipe: Single layer, dual layer, or reinforced edges.
- Material handling interface: Overhead crane with C-hook, coil car, or walking beam conveyor.
- Packaging capacity: Target cycle time and coils per hour/shift.
- Site utilities: Plant voltage, compressed air flow rate, and floor loading capacity.
Engineering FAQ
Q: Can the machine apply paper and stretch film simultaneously? A: Yes. Multi-spindle ring shuttles can hold two or three rolls concurrently, laying inner VCI/paper barrier and outer stretch containment film in a single orbital cycle.
Q: What is the maximum load capacity for this equipment series? A: The stainless coil wrapper is rated up to 12,500 kg, whereas the reinforced cold-rolled coil wrapper supports payloads up to 30,000 kg.
Q: Which inner bore (ID) ranges are compatible? A: Standard shuttle track profiles fit 500–600 mm IDs on stainless systems, and 610–760 mm IDs on cold-rolled systems. Custom low-profile shuttles are available for non-standard IDs.
Q: How is stretch wrap consumption calculated? A: Payout is a function of coil cross-sectional perimeter, OD overlap percentage, and pre-stretch ratio. An 1,800 mm OD coil with 50% overlap requires approximately 46 wraps and 165.6 m of relaxed material payout per layer.
Q: Does an operator have to calibrate ring height and roller speeds manually? A: No. Once coil width, OD, and ID are selected via recipe or entered via barcode reader/HMI, the PLC calculates optimal roller speeds, overlap pitch, and ring center height automatically.
Next step
To size an automated through-the-eye wrapping system for your coil mill or processing center:
- Submit your coil matrix (min/max weights, dimensions, and wrapping requirements) to info@fhopepack.com.
- Receive a formal engineering layout and cycle time simulation within 48 hours.
- Schedule an engineering review to verify coil handling integration and floor loading specifications.
Related reading
- Master Coil Wrappers Series
- Automatic Stainless Master Coil Wrapping Systems
- Heavy-Duty Cold-Rolled Coil Wrapping Lines
- Video: Integrating Stretch Wrapping and Downender Stacking for Heavy Steel Coils
- Video: Coil Packing Machine, Packaging and Handling Integration
Sources
- Material specifications and shuttle mechanics: Fhopepack Master Coil Wrapper Engineering Portal
- Technical parameters (Stainless series): Stainless Master Coil Packaging Data Sheet
- Technical parameters (Cold-rolled series): Cold-Rolled Master Coil Packaging Engineering Sheet
- Industrial machinery safety and compliance: ISO 12100:2010 Safety of Machinery, EN 415-10:2014 Safety of Packaging Machines
Last reviewed: 2026-10-04
