Steel Coil Packaging Line from Strapping to Stacking: Five ROI Metrics and a Payback Formula

Executive summary This 63 s clip walks along one of our steel coil packaging lines: two head stations over the infeed conveyor, an eye-through wrapper, a label unit, a gantry stacker and a pallet conveyor. To judge whether a line like this pays back, we use five metrics: coils per hour against the slitter, labour hours per coil, package defects, material per coil and availability. Payback then follows from one formula with your own inputs.

Table of Contents

The line in the clip, station by station

The clip is titled “Strapping, Labeling, Wrapping to Stacking” and runs 63 s. Times are read from the recording.

Clip time Station
0–6 s A portal over the green infeed conveyor lowers a yellow head onto the top face of the coil.
12–21 s An overhead arm with a cable chain works over the next coil, run from its own HMI column.
24–33 s Eye-through wrapping: a green ring passes through the coil eye; the coil leaves fully covered in film.
36–39 s A label unit beside the roller conveyor, under a yellow frame.
42–48 s A gantry stacker lifts wrapped coils and places them on a pallet.
54–63 s The pallet conveyor carries the stacks towards the outfeed.

Each hand-over is on rollers or by gripper. Two engineers walk the line during the clip; nobody lifts a coil.

Metric 1: coils per hour against your slitter

Output is set by the slowest station. Coils per hour = 3600 ÷ seconds per coil at that station.

Compare the result with the slitter. If the packing line is slower, coils pile up and the slitter waits; if it is much faster, you are paying for capacity you do not use. Our steel coil strapping and wrapping line article breaks a line into its modules. On our proposals we list a cycle per station, so the limiting one is visible before you buy.

Metric 2: labour hours per coil

Labour is usually the largest saving, and the easiest to measure honestly.

Labour hours per year = operators per shift × hours per shift × shifts per day × working days.

Illustrative customer inputs, not a claim about any plant:

Item Manual packing Automatic line
Operators per shift 4 1
Hours per shift 8 8
Shifts per day 2 2
Working days per year 250 250
Labour hours per year 16,000 4,000

Divide by coils packed per year to get hours per coil. Use your own staffing; the formula is what matters.

Metric 3: package defects and transit claims

Count two things for a few months before and after automation:

  • Package defects at dispatch: loose film, missing straps, wrong or unreadable labels, per 1,000 coils.
  • Transit claims: coils rejected for edge damage, rust or loose packs, per 1,000 coils shipped.

Repeatable strapping, programmed wrap tension and overlap, and machine stacking remove most of the variation between operators. The value of each avoided claim is your own figure; we do not put a percentage on it without your data.

Metric 4: material per coil

Film and strap are running costs. Measure them per coil by weighing a film roll before and after a counted batch, and by counting straps per coil. On a programmed line the figure stays flat across shifts. If it drifts, tension or overlap settings have changed. Our KPI article on a coil strapping, labelling and stacking line gives the film-mass formula.

Metric 5: availability

Availability = running time ÷ planned production time.

Log every stop with a reason: film or strap change, label roll, jam, waiting for coils, waiting for forklift. The long list usually shows two or three causes. Most are layout issues, such as no buffer before the slowest station or a forklift route that crosses the stacker outfeed. We fix those at layout stage, which is why we ask for your drawing first.

Putting it together: payback

Payback (months) = line investment ÷ monthly saving.

Monthly saving = labour hours saved × your hourly rate + avoided claims + material saved, minus maintenance and energy.

Use your own rates and your own claim history. A line that only matches the slitter on paper, but stops often, will not reach its payback; that is why availability sits next to throughput in this list.

RFQ checklist for a steel coil packaging line

  • Coil OD, ID, width and weight range, and slitter output per hour.
  • Strapping: PET or steel strap, through-the-eye (radial strapping machine) or circumferential, straps per coil.
  • Wrap: stretch film, paper or woven, and the overlap you specify.
  • Label content and data source (ERP, MES or manual).
  • Stack height, pallet type and forklift access.
  • Current staffing per shift and the stops you log today.

Controls and safety

The standards that apply depend on the destination market. For CE markets, ISO 12100 sets the risk-assessment method and EN 415-10 covers general requirements for packaging machines, which fixes guarding and the emergency-stop arrangement.

The portal heads, the wrapping ring and the stacker gripper are the moving hazards. The stacker zone is fenced, and consumables are changed with the station stopped.

Engineering FAQ

Q: Which metric decides payback most often? A: Labour hours, followed by availability. Use operators × hours × shifts × days for labour, and running time ÷ planned time for availability.

Q: Can we calculate payback before we buy? A: Yes. Payback (months) = investment ÷ monthly saving. Use your staffing, hourly rate, claim history and material use. We supply the cycle per station and the staffing the line needs.

Q: How many operators does an automatic coil line need? A: Plan staff for supervision and consumable changes, not coil handling. The illustrative table assumes one operator per shift, provided coil loading and pallet removal are mechanised.

Q: How is line availability calculated? A: Availability = running time ÷ planned production time. Log every stop with a reason (consumables, jams, waiting for coils or forklifts) to see which two or three causes dominate.

Q: Does a faster line pay back sooner? A: No. Speed above the slitter’s output is unused. Match the slowest station to the slitter and invest in availability.

Next step

We size a steel coil packaging line in three steps:

  1. Submit your layout drawing with the coil sizes, weight, slitter output and current staffing, to info@fhopepack.com.
  2. Receive a proposal within 48 hours, with a cycle per station and the staffing the line needs, so you can run the payback formula.
  3. Book a site survey so we confirm the slitter exit, buffer positions and forklift routes.

Sources

Last reviewed: 2026-10-06

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