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Sigma Purlin Roll Forming Machine

Sigma and Omega sections that carry more load than a C purlin of the same depth — the right answer where depth is constrained.

Sigma Purlin Roll Forming Machine

Technical Specifications

MaterialGI, galvanised, pre-painted steel
Thickness1.5 – 3.0 mm
Web height100 – 250 mm
Section typesSigma (Σ), Omega (Ω), M-section
Forming speed8 – 20 m/min
Forming stations18 – 22
DriveGearbox chain drive, 11 – 15 kW
PunchingInline web punch, optional
CuttingHydraulic flying cut
ControlPLC + touch-screen HMI
CertificationCE Declaration of Conformity
Lead time45 – 60 days

Need a quote or a custom specification?

See It Running

Sigma Purlin Roll Forming Machine in Our Workshop

Sigma Purlin Roll Forming Machine — Forming Station Detail | ZTRFM 1:10

Sigma Purlin Roll Forming Machine — Forming Station Detail | ZTRFM

a forming station of the sigma purlin machine, shown close up.

Machine specifications →
Output

What This Machine Produces

01

Sigma (Σ) sections from 100 to 250 mm web height — the section that carries more load than a C purlin of the same depth.

02

Omega (Ω) sections — the same stiffening principle with a different fold pattern, common on cladding rails and standing-seam roof support.

03

M-sections — effectively two purlins joined back to back in one strip, used as a heavier beam or rail where a single section would need extra bracing.

04

Sections with stiffening folds rather than a plain web — the folds put more material away from the neutral axis, which is where the extra capacity over a C purlin comes from.

05

Section depths of 100–250 mm in 1.5–3.0 mm galvanised or pre-painted steel, formed through 18–22 stations at 8–20 m/min.

06

Truly flat-bottomed stiffer sections for applications where a C purlin would need additional bracing to stop the web from buckling.

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

    sigma sections are used where depth is constrained, so the section has to be exactly to depth. Strip straightness is the first thing that decides whether it is.

  2. 02

    Sigma purlin roll forming machine

    18–22 stations on a gearbox chain drive at 11–15 kW, forming at 8–20 m/min over a 100–250 mm depth range.

  3. 03

    Hardened rolls for high-yield steel

    the roll load difference between G300 and G550 at 3.0 mm is substantial, so confirm the grade at order stage and specify the roll hardness to match.

  4. 04

    Inline web punch (optional)

    available, though many sigma users do not punch on the line, because connections are made with clips and brackets rather than through the purlin web.

  5. 05

    Hydraulic flying cut

    sections are produced in long runs, so a flying cut keeps the line moving.

  6. 06

    PLC with touch-screen HMI

    depth and section type are selected rather than set by hand across every station.

How It Runs

Production Workflow

  1. 01

    Decoiler

    Coil is loaded and uncoiled at controlled tension. Sigma sections are specified where the depth envelope is tight, so tension variation that would be tolerable on a C purlin is not tolerable here.

  2. 02

    Leveling

    The strip is straightened before forming. Because the section relies on stiffening folds for its capacity, those folds must be formed from flat, consistent strip — a wavy strip produces folds of varying depth.

  3. 03

    Roll forming

    18–22 stations form the sigma, omega or M section progressively in 1.5–3.0 mm material at 8–20 m/min. The station count is higher than a CZ purlin line because forming the stiffening folds without thinning the material takes more passes.

  4. 04

    Punching (optional)

    Where an inline web punch is fitted, it cuts while the strip is flat.

  5. 05

    Cutting

    A hydraulic flying cut cuts to length.

  6. 06

    Output

    Sections leave on the runout table.

Build

Key Components

Forming stations
18–22 — higher than a CZ line because of the stiffening folds
Drive
Gearbox chain drive, 11–15 kW
Web punch
Inline, optional; often not specified because connections use clips
Cutting
Hydraulic flying cut
Control
PLC + touch-screen HMI
Working range
1.5–3.0 mm · web height 100–250 mm
Sections
Sigma (Σ), Omega (Ω), M-section
Made To Order

Customization Options

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

ItemWhat can be changed
Section typeSigma, Omega or M-section — different tooling on the same frame
Web height100–250 mm
Steel grade and thickness1.5–3.0 mm. Below 1.5 mm the stiffening folds do not form reliably; above 3.0 mm you move into a heavier machine class and we quote a custom drive configuration
Roll hardnessHardened rolls for high-yield steel — G550 at 3.0 mm needs a different roll specification from G300
PunchingInline web punch available as an option
Power supply380 V / 50 Hz / 3-phase standard; other voltages to your site
Where This Machine Is Used

Applications

Common Questions

FAQ — Sigma Purlin Roll Forming Machine

Sigma versus Z purlin — which is stronger?
For the same depth and thickness, a sigma section offers a higher second moment of area than a Z section because its stiffening folds put more material away from the neutral axis. The advantage is most noticeable in side-cladding applications where asymmetric loading matters.
Why choose sigma instead of a deeper C purlin?
Because the overall build-up depth is often fixed by the cladding system or the available headroom. Sigma lets you carry a given load within a shallower envelope, which is why it is common on cladding rails and on roofs with limited structural zone.
Can it handle 3.0 mm G550?
Yes, with hardened rolls. Please confirm the yield strength at order stage, because the roll load difference between G300 and G550 at 3.0 mm is substantial.
What is an M-section purlin used for?
The M-section is effectively two purlins joined back to back in one strip, used as a heavier beam or as a rail where a single section would need extra bracing. It runs on the same frame with different tooling.
Does the machine punch holes?
An inline web punch is available as an option. Many sigma purlin users do not punch on the line, because connections are made with clips and brackets rather than through the purlin web.
What thickness range is practical?
1.5–3.0 mm. Below 1.5 mm the stiffening folds do not form reliably; above 3.0 mm you are into a heavier machine class and should discuss a custom drive configuration.
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.
How do we get a price for this line?
Send the profile drawing or section dimensions, the material and thickness, the coil width, and your target output per shift. Price depends on the profile, the coil and the level of automation, so we quote against your actual job rather than a catalogue figure.
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 – 20 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 – 22 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, 11 – 15 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.

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 – 3.0 mm
  • Web height100 – 250 mm
  • Section typesSigma (Σ), Omega (Ω), M-section
PDF, DWG/DXF, image, ZIP or Excel — if your file is larger, send the form and reply to our confirmation email with the file attached.

We reply within 24 hours. Your details are used only to answer this inquiry.

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