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Truss & Roof Purlin Roll Forming Machine

Truss and lattice purlin sections for long-span roofs where a single purlin cannot carry the span.

Truss & Roof Purlin Roll Forming Machine

Technical Specifications

MaterialGI, galvanised, pre-painted steel
Thickness1.5 – 3.5 mm
ProfilesTruss purlin chord, web member, lattice section
Section depth100 – 400 mm
Forming speed8 – 18 m/min
Forming stations18 – 24
DriveGearbox chain drive, 15 – 22 kW
PunchingInline chord punch, optional
CuttingHydraulic flying cut
ControlPLC + HMI, batch counter
CertificationCE Declaration of Conformity
Lead time50 – 65 days

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Output

What This Machine Produces

01

Truss purlin chords — the top and bottom members of a triangulated purlin, roll formed on this line.

02

Web members — the separate short lengths that zig-zag between the chords, produced on a smaller machine or bought in.

03

Lattice sections — the assembled truss purlin, made by welding or connecting the web pieces between the two chords.

04

Section depths of 100–400 mm — deeper than a single cold-formed purlin can sensibly reach.

05

Distributed depth rather than a deep thin web: because the two chords sit apart, the section gets its bending capacity from geometry rather than from web depth alone, which avoids the local buckling limit that governs a very deep single C or Z.

06

Chords in 1.5–3.5 mm galvanised or pre-painted steel, formed through 18–24 stations at 8–18 m/min.

Line Composition

Recommended Configuration

A complete working line, not just the forming machine. Each item below is quoted as one package.

  1. 01

    Decoiler and leveling unit

    chords carry the bending in the assembled section, so chord straightness has a direct effect on how the truss purlin performs.

  2. 02

    Truss purlin roll forming machine

    18–24 stations on a gearbox chain drive at 15–22 kW, forming chords at 8–18 m/min.

  3. 03

    Inline chord punch (optional)

    punches connection positions in the chord while the strip is flat, which is what allows the webs to be located accurately at assembly.

  4. 04

    Assembly arrangement (separate from this line)

    the chords come off this machine; the truss is built by welding or connecting the web members between them. This line does not produce a finished truss in a single pass, and no machine does.

  5. 05

    Hydraulic flying cut

    chords are cut to the purlin length.

  6. 06

    PLC with HMI and batch counter

    chord lengths are cut per truss, so the batch counter is what keeps a set together.

How It Runs

Production Workflow

  1. 01

    Decoiler

    Coil is loaded and uncoiled at controlled tension. At 1.5–3.5 mm the chord is a structural member, so tension consistency shows directly in the straightness of the assembled truss.

  2. 02

    Leveling

    The strip is straightened before forming. A truss purlin is assembled from two chords; if one is bowed, the truss cannot be closed squarely in the jig.

  3. 03

    Chord punching (optional)

    Connection positions are punched while the strip is flat, so the web members can be located accurately at assembly.

  4. 04

    Roll forming

    18–24 stations form the chord section in 1.5–3.5 mm steel at 8–18 m/min.

  5. 05

    Cutting

    A hydraulic flying cut cuts chords to the truss length, with a batch counter keeping a set together.

  6. 06

    Assembly (separate step)

    The two chords are jigged apart and the web members are welded or connected between them. This is a fabrication step, not part of the roll forming line.

Build

Key Components

Forming stations
18–24
Drive
Gearbox chain drive, 15–22 kW
Chord punch
Inline, optional
Cutting
Hydraulic flying cut with batch counter
Control
PLC + HMI
Working range
1.5–3.5 mm · section depth 100–400 mm
Note on scope
Produces the chords; assembly of the truss is a separate fabrication step
Made To Order

Customization Options

Every line is built to order. These are the points buyers most often change.

ItemWhat can be changed
ProfilesTruss purlin chord, web member, lattice section — tell us which members you intend to produce on this line and which you will buy in
Section depth100–400 mm
Thickness1.5–3.5 mm. Chords take the bending and are usually thicker; webs carry mainly shear and can be thinner — getting that combination right is a structural design decision
Chord punchingInline punch for connection positions, optional
Power supply380 V / 50 Hz / 3-phase standard; other voltages to your site
Where This Machine Is Used

Applications

Light Steel Framing → Auxiliary Equipment →
Common Questions

FAQ — Truss & Roof Purlin Roll Forming Machine

What is a truss purlin and when is it used?
A truss purlin is a triangulated section made from two chords joined by a zig-zag web, used where the roof span is too long for a single cold-formed purlin. Because the two chords sit apart, the section has a much higher bending capacity for its weight than a single C or Z section.
Why not just use a deeper C purlin?
Because there is a limit to how deep a single cold-formed section can be formed and handled before local buckling governs. A truss section gets its depth from geometry rather than from a single deep web, so it can span further without a disproportionate increase in weight.
Can one machine make both chords and webs?
Not in a single pass. The chords are roll formed on the main line; the web members are separate short lengths produced on a smaller machine or bought in. The final truss purlin is assembled by welding or by connecting the web pieces between the chords.
What thickness is used?
1.5–3.5 mm. The chords take the bending and are usually the thicker members; the webs carry mainly shear and can be thinner. Getting the thickness combination right is a structural design decision.
Is this line suitable for a start-up producer?
Usually not as a first machine, because truss purlins are a specialist product with a structural design process attached and a relatively narrow customer base. Most producers add it once they already run a CZ purlin line and want to quote longer spans.
How does the truss purlin compare on cost?
Per metre it costs more than a plain purlin because of the assembly step, but per unit of span it is often cheaper than a heavier single section. The comparison has to be made against the engineer's span table for the specific roof.
Can the machine be built for our own profile?
Yes. Send the profile drawing with the section dimensions, the material and thickness, and the coil width you intend to run. We confirm the roll design, forming stations and line layout against that drawing before quoting, so the machine matches the section you actually sell.
Which coil materials can the line run?
The line forms GI, galvanised, pre-painted steel. Confirm the exact grade with your order so the tooling and drive are matched to it — that is decided at the design stage, not on site.
What is the production speed?
Forming speed is 8 – 18 m/min. Treat this as the line speed: real shift output also depends on cut length, coil reloading and how often the profile is changed.
How many forming stations does it use?
The line uses 18 – 24 forming stations. Station count follows the section — more bends and tighter tolerances need more forming steps, which is why two profiles rarely share one roll set.
What is the drive and installed power?
Drive: Gearbox chain drive, 15 – 22 kW. Final drive sizing is confirmed against your profile and coil, because a wider or thicker section needs more torque to hold the same line speed.
How is the finished profile cut to length?
Cutting is by Hydraulic flying cut. Cut length and batch quantity are entered at the control panel, so a job runs to a fixed schedule instead of being measured by hand.
Related Machines

You May Also Need

Purlin Roll Forming Machine (all sections) → CZ Purlin Machine → Sigma Purlin Machine → Light Gauge Steel Framing Machine → All Auxiliary Equipment Machines →

Send us your profile and output target

Tell us the profile and the numbers that matter to you. We confirm the configuration against the specification table above and quote FOB Tianjin within 24 hours.

  • MaterialGI, galvanised, pre-painted steel
  • Thickness1.5 – 3.5 mm
  • ProfilesTruss purlin chord, web member, lattice section
  • Section depth100 – 400 mm
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