Pipe Coil Wrapping and Strapping: Solutions for Industry

Executive summary

Pipe coil wrapping and strapping work as an interdependent production cell. The coiler winds a continuous extruded pipe to a targeted length and straps it through the eye to mechanically secure its elastic tension; the wrapper then orbital-seals the stable coil in stretch film to prevent environmental contamination and handling abrasion. Sizing these two machines together is a critical engineering requirement: a coil dimension produced within the coiler’s envelope can easily exceed the physical clearance of the downstream wrapper. Our FCL series coilers handle pipe outer diameters (OD) from 4 to 63 mm, while our upright FPH-300N wrapper processes finished coils with an OD up to 1,000 mm and a coil width up to 300 mm.

The vertical ring-orbit system operates behind rigid interlocked safety framing. The strapped pipe coil is loaded onto motorized polyurethane support rollers, aligning the hollow core (eye) with the orbital ring plane so the rotary film carriage dispenses continuous tensioned wrap through the coil geometry.

Table of Contents

Why pipe coils are strapped and then wrapped

Strapping and stretch wrapping serve fundamentally different structural functions in automated pipe packaging:

  • Straps bear the structural radial load. Extruded plastic pipes (such as HDPE, PEX, and PERT) retain significant residual bending stress. High-tension polypropylene (PP) or polyester (PET) strapping mechanically counteracts this springback force, preventing catastrophic coil unwinding during lifting, transfer, and pallet stacking.
  • Stretch film provides environmental protection and unit integrity. The orbital wrap protects the package against moisture, UV radiation, and grit ingress. Crucially, the film layer prevents the high-tension strapping bands from abrading adjacent pipe outer walls during multimodal transport.

Executing this process in reverse causes immediate line failure: wrapping an unstrapped coil allows internal elastic springback to tear the film envelope from the inside out. Strapping first locks the mechanical geometry; wrapping second seals the dimensionally stable unit.

The coil-strap-wrap sequence

An integrated coil-strap-wrap packaging station follows a controlled five-stage process:

  1. Coil. The automated coiler synchronizes with the extrusion line or pay-off accumulator, meters the precise pipe length via an optical encoder, cuts the trailing end cleanly, and traverses the pipe evenly onto an adjustable expanding mandrel.
  2. Strap. Once winding concludes, an integrated strapping head indexes through the coil eye to apply 2, 3, or 4 radial straps at pre-programmed angular positions. Strap placement and tension levels are managed via PLC recipe control.
  3. Transfer. The mandrel collapses radially, and the strapped coil is discharged onto an intermediate buffer table or driven conveyor. Transfer to the wrapper can be manual for lower-speed lines or automated via an inline walking beam or kick-off mechanism.
  4. Wrap. The coil centers onto the motorized cradle rollers of the wrapper. The rotating ring drives a film dispenser carriage through the coil eye, applying an overlapping stretch film layer as the cradle rollers index the coil through 360°.
  5. Label and stack. An integrated film clamp and cut unit finishes the cycle, allowing the stabilized coil to move downstream for outer barcode labeling and pallet loading.

For structural reference, our standard industrial strapping units (including the FPCL-W500 series) run 8–10 mm wide virgin PP strap (0.8 mm thickness) with a precision friction-weld joint delivering 75–80% joint efficiency relative to the strap break strength. Strap tensile ratings and welding parameters are verified during system engineering for each specific pipe stiffness.

Coiler sizes: FCL automatic pipe coiling range

The heavy-duty FCL coiling range covers flexible to semi-rigid pipe outer diameters from 4 mm to 63 mm across six machine platforms:

Model Pipe OD Range Coil Internal Diameter (ID) Max Coil Outer Diameter (OD) Max Coil Width
FCL100 4–12 mm 150 mm 300 mm 150 mm
FCL200 8–28 mm 200–400 mm 650 mm 200 mm
FCL400 6–25 mm 300–500 mm 680–1,200 mm 250 mm
FCL600 8–28 mm 380–600 mm 1,050 mm 300 mm
FCL800 12–32 mm 490–860 mm 1,200 mm 350 mm
FCL1000 20–63 mm 600–1,300 mm 1,600 mm 400 mm

Wrapper limits: FPH-300N

The FPH-300N is an upright orbital stretch wrapper engineered specifically for eye-through-the-ring coil wrapping:

Parameter Specification (FPH-300N) Engineering Constraint
Coil ID 300–700 mm Minimum clearance for ring cross-section and film carriage pass-through
Coil OD 500–1,000 mm Maximum physical clearance inside the rotating aluminum ring
Coil Width 100–300 mm Bounded by support roller barrel length and safety side-guide limits
Coil Weight 10–100 kg Maximum dynamic load rating of driven support cradle rollers
Cycle Time 23–35 s per coil Function of preset film overlap percentage (30%–70%) and coil dimensions
Ring Speed Up to 120 RPM Regulated via inverter with soft-start and deceleration braking
Connected Load 1.9 kW, 380 V 50/60 Hz 3 ph Integrated electrical cabinet with low-voltage operator controls

Note on matching limits: The higher-capacity coilers (FCL800 and FCL1000) can wind coils with widths up to 350–400 mm and ODs up to 1,600 mm. Those coils exceed the processing envelope of the FPH-300N and require our larger orbital ring frames (such as FPH-500 or custom overhead models), which are dimensionally validated at project quotation. The FPH-300N accepts standard stretch film rolls of 90–100 mm width on a 50 mm core, equipped with adjustable mechanical friction-brake tensioning.

Worked example: matching coiler and wrapper

Design Case: Match a target production coil of 100 m of 32 mm OD PE pipe wound on an FCL800 coiler with a 600 mm core ID, feeding downstream into an FPH-300N wrapper.

Step Design Calculation Physical & Mechanical Output
Full Coiler Width Check 350 mm mandrel width ÷ 32 mm pipe OD 10.9 turns → 10 turns per layer = 320 mm wide package
Wrapper Clearance Check Compare 320 mm coil width to FPH-300N capacity Fails: 320 mm exceeds 300 mm max wrapper roller width
Coiler Traverse Adjustment Set PLC traverse pitch to 9 turns per layer 9 × 32 mm = 288 mm effective coil width (Passes: ≤ 300 mm)
Layer 1 Length (Mean ID = 632 mm) 9 turns × π × 0.632 m 17.87 m of pipe accumulated
Layers 1–4 Cumulative Length 17.87 m + 19.68 m + 21.49 m + 23.30 m 82.34 m accumulated across 4 full layers
Layer 5 Residual Calculation 100.0 m target − 82.34 m 17.66 m required on layer 5 (partial wrap: ~7 turns)
Coil Outer Diameter (OD) 600 mm ID + (2 × 5 layers × 32 mm) 920 mm theoretical OD (nominal)
Material Expansion Factor Add 2% allowance for pipe ovality and core release 920 mm × 1.02 ≈ 938 mm actual OD
Final Envelope Validation ID 600 mm (within 300–700 mm); OD 938 mm (≤ 1,000 mm); Width 288 mm (≤ 300 mm) System Verified: Fully matches FPH-300N operating limits

Pacing & Throughput Analysis: When running with an inline pay-off and accumulator, the FCL800 produces approximately 40 to 45 coils per hour, representing an average complete cycle time of 80 to 90 seconds per coil (winding, indexing, strapping, and ejecting). The downstream FPH-300N wraps the identical coil in 23 to 35 seconds. This creates a net operational buffer of 45 to 60 seconds per cycle, comfortably absorbing coil staging, operator inspection, or automated conveyor transfer lag without bottle-necking extrusion.

Engineering Conclusion: Operating the coiler at its maximum mechanical traversing width produces a 320 mm wide coil that cannot enter the FPH-300N ring throat. Restricting the traverse to 9 turns per layer creates a stable 288 mm wide, 938 mm real-OD package that fits safely within machine tolerances. A final check must confirm that total coil weight (linear weight kg/m × 100 m) does not exceed the 100 kg roller threshold.

Selection checklist

Before freezing machine build specifications, verify these six technical parameters:

  1. Pipe Material & Dimensions: Nominal OD, minimum/maximum wall thickness (SDR rating), and linear weight (kg/m).
  2. Target Coil Geometry: Mandatory finished ID, nominal and maximum relaxed OD, and maximum allowed stacked package width.
  3. Extrusion Line Pacing: Extruder line speed (m/min), coil changeover window, and target finished coils per hour.
  4. Strapping Specification: Number of radial straps per coil (typically 3 or 4), strap material (PP vs. PET), band width, and joint type.
  5. Wrapping Specification: Film material (PE stretch vs. woven/paper composite), target overlap percentage (typically 50%), and automatic cut/clamp requirements.
  6. Material Handling Topology: Transfer between coiler discharge and wrapper infeed (manual operator handling vs. automated gravity roller vs. driven powered conveyor).

Safety: EN 415-10 and ISO 12100

Both machine cells are engineered in compliance with European machinery directives:

  • Safety Compliance (EN 415-10): Specific safety requirements for packaging machines are fully addressed. The high-speed orbital wrapping ring and the expanding coiling mandrel are isolated behind fixed perimeter perimeter barriers and interlocked access doors monitored by dual-channel safety relays.
  • Risk Assessment (ISO 12100): System risk evaluations identify all in-running nip points between driven rollers and the coil mass, as well as pinch zones created by rotating orbital carriages. Mechanical guarding, optical light curtains at infeed/outfeed stations, and hardwired E-stop circuits ensure zero-energy states during maintenance or coil clearing.

Engineering FAQ

Q: Why must plastic pipe coils be strapped prior to orbital stretch wrapping? A: Plastic pipe retains high hoop stress. Strapping through the eye applies localized tensile constraint to physically hold the wound layers against the mandrel core. If a coil is wrapped without straps, the pipe’s natural springback will stretch and puncture the film envelope immediately upon transfer, leading to rapid unraveling.

Q: Can a single wrapper serve two upstream coiling lines? A: Yes, provided coil geometry matches and overall throughput is balanced. Because an FPH-300N completes a full wrapping cycle in 23–35 seconds while an automatic coiler typically requires 70–90 seconds per coil, one wrapper possesses sufficient operational capacity to handle the combined output of two upstream coilers via a cross-transfer conveyor layout.

Q: What strap properties are recommended for flexible pipe coiling? A: Standard installations utilize 8–10 mm wide polypropylene (PP) strapping with a 0.8 mm nominal thickness. Polypropylene provides an optimal modulus of elasticity, absorbing dynamic shock when coils are handled by clamp trucks while maintaining sufficient residual tension. Friction-vibration welding guarantees joint stability without introducing thermal degradation to the pipe surface.

Q: How does film overlap percentage affect wrapper cycle speed? A: Cycle time is directly tied to the ratio between ring rotational speed (RPM) and coil rotation speed on the cradle rollers. Increasing the film overlap from 30% to 60% (for enhanced waterproofing) requires slower roller rotation relative to ring speed, shifting total cycle duration from ~23 seconds to the upper ~35-second threshold.

Next step

  1. Submit Production Data: Send your pipe material, OD range, wall thickness, and coil length targets to info@fhopepack.com.
  2. System Compatibility Match: Our engineering team calculates winding profiles, strap counts, and orbital clearances to configure the coiler and wrapper as a unified, non-bottlenecked cell.
  3. Receive Integration Package: Receive a formal CAD layout drawing, cycle-time simulation, and comprehensive commercial quotation within 24 hours.

Sources

  • FHOPE Technical Documentation: Automatic Pipe Coiling & Strapping Systems (FCL Platform Specifications); Orbital Eye-Through Wrapper Series (FPH-300N Technical Manual).
  • EN 415-10: Safety of packaging machines – Part 10: General requirements.
  • ISO 12100:2010: Safety of machinery – General principles for design – Risk assessment and risk reduction.

Last reviewed: 2026-10-19

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