Bundle Making and Film Binding Machine for Industrial Tubes

Executive Summary An automatic bundle making and film binding machine gathers loose industrial tubes into rigid, transport-ready bundles, securing them with controlled orbital film bands rather than conventional steel strapping. The automated packaging line conveys loose tubes across a powered roller conveyor into an integrated orbital binding station, where high-tensile stretch film from an external motorized supply carriage is wrapped concentrically under regulated tension. Film consumption is directly governed by bundle cross-section geometry, programmed band pitch (spacing), and the designated reinforcement turns per band, allowing complete recipe control per product specification.

Table of Contents

Line Configuration and Operational Overview

The integrated automated packaging line organizes, indexes, and bundles finished metallic tubes into secure master packs. In continuous production, extruded or rolled tubes transfer across heavy-duty motorized roller conveyors driven by variable-frequency gearmotors. Pneumatic side-alignment guides square the leading ends and compress the loose batch into a predetermined profile at the infeed of the orbital binding station.

[Infeed Incline/Conveyor]
           │
           ▼
[Pneumatic Aligning & Layer Stacking] ──> Master Bundle Profile Formed
                                                   │
                                                   ▼
[Top & Lateral Pneumatic Press Clamps] ──> bundle locked in true alignment
                                                   │
                                                   ▼
[Orbital Ring Binding Module] ──> External Powered Pre-Stretch Carriage
                                                   │
                                                   ▼
[Synchronized Indexing Conveyor] ──> Finished Bundle Outfeed

The system separates the mechanical film dispensing unit from the rotating orbital ring. An external floor-mounted frame holds master film rolls, routing film through precision tensioning rollers and driven pre-stretch carriages directly to the orbiting ring. This design minimizes the rotational inertia of the ring, reduces drive wear, and maintains constant film tension across square, hexagonal, or rectangular bundle profiles without point-stress deformation.

How Bundle Making and Film Binding Works

The bundling and securing cycle runs through four synchronized mechanical phases:

Process Step Mechanical Action and Machine Execution
1. Gathering & Layering Loose incoming tubes are accumulated, counted, and shifted by pneumatic sweeps into a tight profile on the polyurethane-sleeved roller conveyor.
2. Guiding & End-Aligning Low-friction lateral polymer guide bars square the tubes lengthwise while centralizing the bundle with the rotational axis of the orbital binding ring.
3. Film Binding & Clamping Vertical and horizontal pneumatic press rollers engage to lock the bundle profile; the rotary arm winds multiple overlapping layers of stretch film at programmed stations.
4. Step-Index Outfeed The clamp releases incrementally; the conveyor advances by a set pitch distance to apply the next band, discharging the fully secured bundle to the sorting buffer.

Orbital film binding replaces rigid steel strapping on thin-wall tubes, round conduit, and precision-finished hollow sections. The resilient elastic recovery of stretch film maintains bundle compression without causing surface gouges, localized crimping, or edge crushing. Additionally, the banded zones seal out particulate contamination, oil, and moisture during indoor transit and racking.

Planning Film Consumption per Bundle

Stretch film usage depends on bundle geometry, indexing pitch along the product axis, the number of turns applied per band, and the mechanical pre-stretch ratio applied by the film carriage.

Mathematical Formulation

Film per Band (m) = [Bundle Perimeter (m) × Applied Turns] / Pre-Stretch Factor
Total Film per Bundle (m) = Film per Band (m) × Number of Bands along Bundle Length

Reference Engineering Calculation

Consider a square pack of 25 tubes configured in a 5 × 5 array (outer diameter 30 mm per tube, total length 6.0 m), wrapped at 1.0 m intervals using a standard 150% pre-stretch factor (elongation ratio = 2.5):

Technical Parameter Specification / Metric Value
Individual tube outer diameter 30 mm
Bundle cross-section array 5 × 5 square configuration (150 mm × 150 mm)
Calculated bundle perimeter 4 × 150 mm = 600 mm (0.60 m)
Bundle total length 6.0 m
Band distribution pitch Applied every 1.0 m (7 bands total: both ends plus 5 intermediate)
Programmed turns per band 2 complete revolutions per station
Unstretched web required per band 2 turns × 0.60 m = 1.20 m equivalent web
Actual film consumption per band (at 150% pre-stretch) 1.20 m / 2.5 = 0.48 m linear master roll consumption
Gross master roll film consumed per 6 m bundle 7 bands × 0.48 m = 3.36 m (8.4 m unstretched equivalent web)

Note: Decreasing the band pitch spacing improves bundle structural stiffness during high-acceleration gantry handling, but increases cycle time and consumables usage. Target pitch and revolution counts can be saved as separate recipe codes in the machine HMI.

Technical Evaluation: Film Bands vs. Steel Strap

Selecting between elastic polymer film binding and traditional high-tensile steel strapping involves trade-offs between surface preservation and dynamic load containment:

Operational Consideration Rotary Film Banding High-Tensile Steel Strapping
Tube Wall Surface Integrity Zero damage. Polyethylene film spreads clamping loads uniformly across tube outer walls. High risk of mechanical indentations, scoring, and paint/coating fracture on gauge walls < 1.5 mm.
Protection from Environmental Dust Encloses the entire contact band perimeter, blocking dust, grit, and moisture ingress. Open strapping allows industrial grit infiltration between bundled tubes.
Dynamic Tension Retention Elastic memory adapts to bundle settling and vibration relaxation during flatbed shipping. Static strap slackens if tubes settle or nest closer under transit vibration.
Bundle Holding Strength Ideal for light-to-medium structural tubes, conduit, and profiles (< 2,500 kg master loads). Required for ultra-heavy carbon structural pipe (> 3,000 kg bundles) handled with wire slings.
Unpacking Hazard & Disposal Cut safely with a standard utility knife; 100% recyclable LLDPE scrap. Requires heavy mechanical snips; uncoiling strap creates sharp-edge puncture hazards for operators.

Film binding is preferred for surface-treated carbon steel, thin-wall structural tubing, architectural aluminum, copper refrigeration lines, and painted conduits that must arrive at job sites free of scratches and cosmetic defects.

Control Architecture and Safety Compliance

Modern automated packaging machinery requires integrated monitoring, fault isolation, and functional safety systems to prevent operator injury during high-speed rotational cycles:

[Optical Perimeter Light Curtain / Safety Interlocks] ──> Safety PLC (ISO 13849-1 PLd)
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         ┌──────────────────────────────────────────────────────────┴─────────────────────────┐
         ▼                                                                                    ▼
[Dual VFD Drives] ── Safe Torque Off (STO)                              [Pneumatic Clamping] ── Lockout Exhaust
Rotary Ring & Roller Motors Halted                                      Air Depressurized via Monitored Dump Valve
  • Control Interface: The machine is managed by a centralized Siemens or Allen-Bradley programmable logic controller (PLC) paired with an industrial color touchscreen HMI. Operators can recall saved recipe profiles, adjust ring rotation speed, modify indexing pitch, and change film pre-stretch tension on the fly.
  • Functional Safety Protocols: High-speed orbital rings pose pinch and shearing hazards. Equipment built for industrial service incorporates Class 4 optical safety light curtains at infeed/outfeed points and hard-wired safety interlocks on all access panels.
  • Emergency Isolation: In compliance with international standards, emergency-stop circuits operate on dual-channel fail-safe relays (ISO 13849-1, Performance Level d / Category 3). Tripping an e-stop activates Safe Torque Off (STO) on all VFD motor drivers and depressurizes pneumatic clamping circuits through an automated, monitored exhaust dump valve.
  • Regulatory Compliance: Systems destined for European and global installations comply with ISO 12100:2010 (Risk Assessment and Reduction Principles) and EN 415-10:2014 (Safety Requirements for Modular Packaging Machines).

Selection Checklist for a Tube Film Binding Machine

Prior to system engineering and layout confirmation, review the following design criteria with your packaging automation supplier:

  • Tube Dimensions: Minimum and maximum tube outside diameters (OD), nominal wall thicknesses, and raw cut length tolerances (e.g., 3.0 m to 12.0 m).
  • Bundle Profiles: Desired geometric arrays (hexagonal, square, rectangular, or irregular flat-packs) and maximum outer circumscribed bundle diameter.
  • Target Throughput: Cycle time requirements in parts per minute or finished master bundles per hour.
  • Strapping vs. Banding Strategy: Determine whether stretch film bands provide sufficient bundle stiffness alone, or if high-shear transport regulations require secondary hybrid PET/steel strap stations.
  • Material Feed Interfaces: Integration upstream with high-speed cut-off saws, eddy-current testing benches, or automatic dipping stations.
  • Outfeed Handling Logic: Downstream transfers, such as powered side-kickers, gravity storage ramps, chain transfers, or automatic crane pick-up bunks.

Engineering FAQ

Why choose film binding over steel strapping for precision tubing?

Film binding distributes clamping force evenly around the tube bundle. Steel strapping applies localized compressive stress at edge contact points, which can dent thin-wall tubes (under 1.5 mm wall thickness) or scratch mirror-polished, zinc-galvanized, and powder-coated surfaces.

How is actual film consumption calculated on an orbital bander?

Film consumption is calculated from the bundle cross-sectional perimeter, multiplied by the programmed turns per band, divided by the active pre-stretch ratio, and then multiplied by the total number of bands per bundle length. Using a powered 150% pre-stretch system, actual master roll film usage drops by 60% compared to non-pre-stretched wrapping.

Where is the stretch film mounted on the machine?

Unlike compact orbital wrappers that place small film rolls directly onto the rotating ring, industrial tube bundlers feed from a separate, floor-mounted film supply unit. This external carriage holds large-diameter rolls, using driven pre-stretch rollers to feed film directly onto the orbital ring mechanism.

Can film banding support heavy bundles lifted by overhead crane?

Film bands provide high radial containment against loose tube rattling and transit vibrations. However, if massive bundles (> 3,000 kg) are hoisted with raw wire rope chokers, the sharp shear force can slice through stretch film. In such cases, hybrid packaging lines apply high-tensile PET or steel straps for crane handling, using film bands for surface protection and profile containment.

Does the system bundle loose tubes automatically without manual staging?

Yes. Turnkey packaging lines use an automated stacking and gathering station. Tubes advancing down the run-out conveyor are separated by indexing cams, grouped into defined counts, and compressed into uniform square, rectangular, or hexagonal profiles by pneumatic side clamps before entering the binding module.

Next Step

Our engineering team configures custom tube bundling and film binding lines to match individual plant layouts and production line speeds:

  1. Submit Factory Layout & Specs: Send your plant drawing, target tube diameter ranges, material grades, and bundle profiles to info@fhopepack.com.
  2. Receive 48-Hour Engineering Proposal: We evaluate your cycle times, supply a layout proposal, and calculate precise film consumption models based on your project requirements.
  3. Arrange Technical Review & Site Survey: Finalize mechanical interfaces, conveyor heights, upstream saw synchronization, and control network architectures with our engineering team.

Related Reading

Sources

Last reviewed by Principal Packaging Systems Engineer: 2026-10-04

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