Executive summary A two-stage coil packaging line decouples wrapping and stacking into two synchronized automated stations. Stage one applies protective packaging through the eye of the coil using an orbital ring wrapper, while stage two transfers the wrapped coils with an overhead gantry manipulator to form stable eye-to-sky stacks. This separation balances cycle times and prevents downstream handling damage.
Table of Contents
- The short answer
- What the machine does
- Stage one: the ring wrapper
- Stage two: the overhead gantry
- What sets the line pace
- Coil range for conveyor-fed lines
- Selection checklist for a two-stage line
- Controls and safety
- Engineering FAQ
- Next step
- Related reading
- Sources
The short answer
- A slit coil arrives flat (eye-to-sky) on a powered roller conveyor without requiring an upender.
- An orbital ring wrapper shuttles protective wrap through the coil bore while motorized rollers rotate the coil, sealing the outer diameter, inner bore, and both side faces.
- The wrapped coil indexes downstream via roller conveyor directly into the overhead gantry pick-up station.
- The gantry stacker engages the coil perimeter, lifts it vertically, and deposits it onto a pallet or dedicated stacking station.
- The completed multi-coil stack exits the packaging cell on heavy-duty conveyors for forklift or crane dispatch.
What the machine does
The system processes slit steel coils in an eye-to-sky orientation. Coils travel along a powered roller platform directly into a high-speed orbital ring wrapper, which guides stretch wrap or protective film through the coil center.
Downstream from the wrapping station, a heavy-duty overhead gantry lowers custom mechanical gripper arms over the wrapped unit. The gantry lifts the coil straight up, travels horizontally, and deposits it precisely onto an accumulation stack. By separating eye-through wrapping from vertical pallet stacking, each mechanical station operates independently without cycle-time interference.
Stage one: the ring wrapper
The orbital ring carries the film dispenser shuttle on precision track rollers and traverses through the open coil eye on every rotation. As the ring rotates, support rollers beneath the coil turn it about its vertical axis, creating a uniform helical overlap across successive layers. Once the coil completes a 360° rotation on the rollers, the stretch film fully encapsulates the outer diameter (OD), inner bore (ID), and both flat side faces.
Integrated PLC and touch-screen HMI controls allow operators to adjust centering, film pre-stretch tension, and overlap percentage (typically adjustable between 20% and 90%) according to coil specifications. The station accommodates stretch film, paper wrap, or woven compound tape, and can be integrated with automated radial/circumferential strapping units as well as inline ERP/MES barcode labeling systems.
Stage two: the overhead gantry
Once fully wrapped, slit coils require precise transfer without compromising the newly applied protective layers. The overhead gantry stacker automates this handling from above, eliminating the need for manual hoist hooks or forklift interventions inside the automated perimeter.
- The gripper arms close on the outer edge of the coil using regulated mechanical clamping to prevent film tearing or coil edge distortion.
- The carriage lifts the coil straight up, travels along overhead structural beams, and accurately lowers the unit onto a target pallet or floor position.
- The stack grows eye to sky, accommodating up to 6 coils per stack on our automatic coil packing line based on specified coil widths and weight limitations.
Custom gripper heads are tailored to the exact coil dimension envelope and surface finish requirements specified for each plant layout.
What sets the line pace
A two-stage line operates according to the cycle time of its slowest bottleneck station. In typical operations, this is governed either by the ring wrapper (which requires a complete rotational cycle of the coil) or by the overhead gantry (which performs dedicated pick, transfer, deposit, and return strokes).
| If the slowest station is | Typical fix |
|---|---|
| Ring wrapper | Adjust overlap percentage or wrap layers to the minimum required for transport protection. |
| Gantry stacker | Minimize carriage travel distance by locating stack accumulation positions adjacent to the conveyor. |
| Outfeed conveyor | Integrate powered accumulation buffer conveyors to hold finished stacks during forklift transit. |
Target coils-per-hour requirements determine the rotational speed of the wrapping ring, gantry axis acceleration, and intermediate conveyor buffer lengths.
Coil range for conveyor-fed lines
Standard conveyor-loaded orbital wrapper specifications:
| Model | Coil ID | Coil OD | Coil width | Max coil weight |
|---|---|---|---|---|
| FPCA-1000 | 508 / 610 mm | 700–1600 mm | 20–400 mm | 2000 kg |
| FPCA-1200 | 508–610 mm | 800–1400 mm | 20–500 mm | 2500 kg |
These conveyor-fed models are engineered for horizontal slit coil packaging. All dimensions and capacities represent standard machine frames; custom systems are adapted to specific industrial coil ranges.
Selection checklist for a two-stage line
- Required throughput (coils per hour, accounting for peak production shifts).
- Complete coil dimensional envelope: ID, OD, slit width range, and maximum unit weight.
- Wrapping media selection (stretch film, VCI anti-corrosion film, crepe paper, or woven tape), target overlap percentage, and strapping requirements.
- Maximum stack height, maximum pallet weight, and target stacking configurations.
- Available shop-floor footprint for buffer conveyors, pallet infeed, and stack discharge tables.
- Factory automation protocols: fieldbus networks, ERP/MES production tracking, and automated labeling integration.
Controls and safety
System safety depends on regional compliance standards and factory safety classifications. For CE-marked installations, ISO 12100 provides the overarching risk-assessment framework, while EN 415-10 defines the specific safety requirements for automated packaging machinery, dictating perimeter guarding, access interlocks, and emergency-stop circuit architecture.
The high-speed orbital wrapping ring and the linear overhead gantry both constitute dynamic mechanical zones. Machine layouts feature physical perimeter fencing, light curtains at conveyor transfer apertures, and category 4 / PLe safety interlocks evaluated through comprehensive layout risk assessments.
Engineering FAQ
Q: Why use two stages instead of a single combi-machine? A: Splitting wrapping and stacking into independent stations allows simultaneous processing of adjacent coils. While the gantry stacks a previously wrapped unit, the ring wrapper encapsulates the next inbound coil, maximizing line throughput and keeping mechanical assemblies modular.
Q: How many coils go in a single stack? A: Up to 6 coils per stack on our automatic coil packing lines, depending on coil slit width, total package weight, and downstream warehouse handling limits.
Q: How does the gantry avoid damaging the fresh wrap? A: The custom gripper head applies controlled radial clamping force exclusively to the outer circumference of the coil and performs a true vertical lift. This eliminates internal bore contact, friction chafing, and sling damage.
Q: Which coil widths suit a conveyor-fed line? A: Our standard FPCA-1000 processes widths from 20 to 400 mm, while the FPCA-1200 handles widths from 20 to 500 mm.
Q: Can the line apply automated tracking labels to each coil? A: Yes. Inline ERP/MES automated print-and-apply labeling stations can be integrated along the transfer conveyor between the wrapping and stacking operations.
Q: What decides the overall line cycle time? A: The line speed is governed by the critical path cycle time of either the ring wrapper or the gantry stacker. Target throughput in coils per hour establishes the required ring RPM, conveyor index speed, and gantry motion profiles.
Next step
We engineer turnkey two-stage coil packaging lines through a structured process:
- Submit your layout drawing including target coils per hour, coil dimensional parameters, and stack requirements to info@fhopepack.com.
- Receive a proposal within 48 hours, including machine sizing, conveyor footprints, gantry travel spans, and layout drawings.
- Book a site survey to confirm plant floor clearances, foundation requirements, utility supplies, and forklift traffic paths.
Related reading
- Slit Coil Stretch Wrapping and Stacking Line: Eye-Through Ring to Gantry Stacker
- Two-Stage Copper Coil Packing Line: Eye-Through Wrapping, Then Stacking on Timber Runners
- Steel Coil Packaging Line from Strapping to Stacking: Five ROI Metrics and a Payback Formula
- Automatic coil packing line
Sources
- Machine operational reference: Automatic Steel Coil Stretch Wrapping Machine and Stacker on YouTube
- Automatic coil packing line specifications (stacking parameters, HMI control of tension and overlap, ERP/MES options): Automatic coil packing line
- FPCA-1000 and FPCA-1200 dimensional tables: Steel coil wrapping machine
- Machinery safety directives: ISO 12100:2010 (Safety of machinery — General principles for design); EN 415-10:2014 (Safety of packaging machines — General requirements)
- Engineering response schedule: OEM standard proposal turnaround (within 48 hours)
Last reviewed: 2026-10-29
