Sigma Purlin Roll Forming Machine User Manual | Setup, PLC Controls & Operation Guide

Sigma Purlin Roll Forming Machine Manual

Complete Setup, Operation, Controls and Production Guide

Introduction

This Sigma Purlin Roll Forming Machine Manual provides a complete guide for safely setting up, operating, and maintaining a roll forming production line used to manufacture sigma purlins.

Sigma purlins are structural steel profiles used in heavy-duty steel building systems where additional load capacity and stiffness are required compared to standard C or Z purlins.

Sigma profiles provide:

  • higher structural strength
  • improved load distribution
  • longer span capability
  • improved resistance to bending

Sigma purlins are commonly used in:

  • large industrial buildings
  • heavy steel structures
  • warehouse buildings
  • commercial steel buildings
  • long-span roof systems

This manual explains:

  • loading steel coil onto the uncoiler
  • preparing and feeding strip into the machine
  • aligning strip and forming stations
  • programming purlin length and hole positions
  • operating PLC controls and jog functions
  • testing punching and cutting systems
  • inspecting finished sigma purlins
  • troubleshooting production problems

This manual is intended for:

  • roll forming machine operators
  • steel building manufacturers
  • structural steel fabricators
  • metal fabrication companies
  • maintenance technicians

1. Machine Overview

A Sigma Purlin Roll Forming Machine forms flat steel strip into sigma-shaped structural purlins using multiple roll forming stations.

Sigma purlins have a complex profile shape designed to provide additional structural strength compared to traditional purlins.

The machine gradually bends the steel strip through multiple forming stations until the finished sigma profile is produced.

Sigma purlins are widely used in:

  • steel structure roof systems
  • heavy industrial buildings
  • distribution centers
  • steel warehouses
  • large commercial construction projects

Typical Materials Processed

Common materials include:

  • galvanized structural steel
  • high tensile steel
  • hot rolled structural steel

Typical Material Thickness

2.0 mm – 4.0 mm

Heavy-duty machines may process material up to 5.0 mm thick depending on machine capacity.

Typical Production Speed

8 – 20 meters per minute

Production speed varies depending on:

  • punching operations
  • profile complexity
  • material thickness

2. Typical Machine Layout

A typical sigma purlin roll forming production line includes:

  • Hydraulic Uncoiler
  • Coil Leveling System
  • Entry Guide System
  • Hydraulic Punching Unit
  • Heavy-Duty Roll Forming Stations
  • Encoder Length Measuring System
  • Hydraulic Cutting System
  • PLC Control Panel
  • Runout Table or Automatic Stacker

Material flow through the machine:

Steel Coil → Leveler → Punching Unit → Roll Forming Stations → Encoder → Hydraulic Cutoff → Finished Sigma Purlins

3. Safety Before Operating the Machine

Operators must complete safety checks before starting production.

Pre-Start Safety Inspection

Before starting the machine ensure:

  • emergency stop buttons function correctly
  • machine guards are installed
  • hydraulic hoses are secure
  • electrical cabinets are closed
  • no tools are left inside the machine

Required Personal Protective Equipment

Operators should wear:

  • safety glasses
  • steel toe boots
  • gloves for handling steel
  • hearing protection

Important Safety Rules

  • never reach between roll forming stations
  • never stand near punching tools during operation
  • never remove safety guards while machine is running
  • stop machine before making adjustments

4. How to Load Steel Coil onto the Uncoiler

Step-by-Step Procedure

  1. Stop the roll forming machine completely.
  2. Retract the uncoiler mandrel.
  3. Lift coil using forklift or overhead crane.
  4. Position coil in front of the mandrel.
  5. Slide the coil onto the mandrel.
  6. Expand mandrel until coil is secured.
  7. Center the coil evenly.
  8. Install hold-down arm if available.
  9. Adjust uncoiler brake tension.

What to Watch For

  • coil not centered
  • coil slipping on mandrel
  • excessive brake pressure
  • loose mandrel expansion

Improper loading can cause strip tracking problems and punching misalignment.

5. Preparing the Coil Leading Edge

Before feeding strip into the machine the coil edge must be prepared.

Procedure

  1. Carefully remove steel banding.
  2. Prevent sudden coil expansion.
  3. Inspect first 300–500 mm of strip.
  4. Cut away damaged material.
  5. Square the leading edge.
  6. Remove burrs if necessary.

Why This Step Matters

Damaged strip edges can cause:

  • feeding problems
  • punching misalignment
  • machine jams
  • inaccurate forming

6. Threading the Coil Through the Machine

Procedure

  1. Open entry guides fully.
  2. Feed strip into leveling system.
  3. Feed strip through punching unit.
  4. Use jog mode to move strip forward.
  5. Continue feeding through roll forming stations.
  6. Guide strip through cutting section.
  7. Feed strip onto runout table.

Safety Warning

Never place hands near punching tools or forming rolls while machine is running.

7. Aligning and Centering the Strip

Correct strip alignment ensures accurate punching and forming.

Procedure

  1. Observe strip entering punching unit.
  2. Adjust entry guides left or right.
  3. Ensure strip runs parallel to machine centerline.
  4. Maintain equal clearance between guides.
  5. Run machine slowly to observe strip tracking.

Signs of Poor Alignment

  • hole misalignment
  • purlin twisting
  • uneven flange shape
  • strip drifting sideways

8. Complete Sigma Purlin Machine Setup Parameters

Material Type: Structural steel / galvanized steel
Material Thickness Range: 2.0 – 4.0 mm
Coil Width: 200 – 450 mm depending on profile
Coil Weight: Up to 10 tons
Coil Inner Diameter: 450 – 520 mm
Entry Guide Clearance: Coil width + 1–2 mm
Forming Stations: 18 – 24 stations
Machine Speed (Setup): 4 – 8 m/min
Machine Speed (Production): 8 – 20 m/min

Roll Gap Setup

Roll gap should be set to:

Material thickness + 0.05–0.10 mm clearance

Example:

Material thickness = 3.0 mm
Recommended roll gap = 3.10 mm

Incorrect roll gap may cause:

  • profile distortion
  • excessive roll wear
  • inaccurate purlin shape

9. PLC Control System Overview

Modern sigma purlin machines use a PLC touchscreen control system.

The PLC controls:

  • machine start and stop
  • purlin length programming
  • punching position programming
  • machine speed control
  • hydraulic cutting timing
  • encoder measurement

10. PLC Control Panel Functions

Typical controls include:

Start Button – starts machine
Stop Button – stops machine
Emergency Stop – emergency shutdown
Manual Mode – used for setup
Automatic Mode – used for production
Purlin Length Input – sets length
Punch Position Input – sets hole positions
Production Counter – displays quantity

11. Jog Mode Operation

Jog mode allows slow machine movement during setup.

Jog Mode Uses

  • feeding strip through machine
  • aligning strip
  • positioning punching operations

Jog Procedure

  1. Switch machine to Manual Mode
  2. Press Jog Forward
  3. Machine moves slowly
  4. Release button to stop

12. Programming Purlin Length

Procedure

  1. Open PLC production screen
  2. Enter required purlin length
  3. Confirm measurement units
  4. Run test purlin
  5. Measure finished length
  6. Adjust encoder calibration if required

13. Programming Punch Hole Positions

Procedure

  1. Open punching control screen
  2. Enter hole spacing and positions
  3. Confirm punching sequence
  4. Run test purlin
  5. Verify hole positions

14. Encoder Length Measurement System

Purlin length is measured using an encoder wheel contacting the strip.

Typical accuracy:

±1 – 2 mm

15. Hydraulic Punching Operation

The punching system creates bolt holes in the purlin.

Punching sequence:

  1. Strip reaches programmed position
  2. PLC activates hydraulic punch
  3. Punch presses through strip
  4. Punch retracts

16. Hydraulic Cutting Operation

The hydraulic shear cuts sigma purlins to programmed length.

Cutting sequence:

  1. Encoder measures programmed length
  2. PLC activates hydraulic valve
  3. Hydraulic cylinder moves cutting blade
  4. Purlin is cut

17. Inspecting Finished Sigma Purlins

Operators should inspect purlins during production.

Inspection checklist:

  • purlin length
  • web width
  • flange height
  • hole positions
  • hole diameter
  • straightness

18. Sigma Purlin Production Troubleshooting Guide

Purlin Twisting
Possible Causes: strip misalignment.
Recommended Solution: adjust entry guides.

Incorrect Hole Position
Possible Causes: punching timing incorrect.
Recommended Solution: adjust PLC punching program.

Profile Distortion
Possible Causes: roll gap incorrect.
Recommended Solution: adjust roll stations.

Surface Scratches
Possible Causes: debris on rollers.
Recommended Solution: clean rollers.

22. Sigma Purlin Roll Forming Machine Technical Specifications

Forming Stations: 18 – 24 stations
Material Thickness Range: 2.0 – 4.0 mm
Production Speed: 8 – 20 m/min
Drive System: Gearbox or chain drive
Punching System: Hydraulic punching unit
Cutting System: Hydraulic cutoff
Control System: PLC touchscreen control
Coil Weight Capacity: 5 – 10 tons
Coil Inner Diameter: 450 – 520 mm
Electrical Power Requirement: 380 – 480V three-phase power

23. Best Operator Practices

Experienced operators follow these practices:

  • inspect the first purlin carefully
  • verify hole positions before production
  • maintain proper strip alignment
  • keep rollers clean
  • stop machine immediately if abnormal noise occurs

Proper operation ensures accurate sigma purlin production and long machine life.

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