1. Problem Description and Scope
Conveyor mistracking is a primary cause of premature wear, material spills and unplanned downtime. This guide focuses on systematically identifying root causes in industrial transportation systems. The severity of the problem is classified as critical if the belt touches fixed structures, causing frictional overheating or structural damage to the belt carcass.
ATTENTION: Always operate according to LOTO procedures (Lockout/Tagout). The conveyor belt is a machine with high stored energy (mechanical tension) and dangerous pinch points.
2. Safety Precautions
DANGER: Before any intervention, carry out the locking and tagout procedure of the main power supply. Make sure the belt is unloaded or the load is stabilized to prevent uncontrolled movement due to gravity or residual tension. Always use adequate PPE: cut-proof gloves, safety shoes (S3), protective glasses and helmet.
3. Diagnostic Tools Required
| Tool | Specification/Model | Measuring range | Purpose |
|---|---|---|---|
| Laser level | Rotary with precision +/- 1mm/10m | N/A | Check parallelism of rollers and frame |
| Tension meter | Mechanical or ultrasonic | 0-50 kN | Check ribbon tension |
| Thermal imaging camera | Range -20°C to +500°C | Emission 0.95 | Roller/friction overheating detection |
| Laser meter | Range 50m | +/- 2mm | Check frame squaring |
4. Initial Assessment Checklist
| What to Observe | Status/Records |
|---|---|
| Point of misalignment (fixed or wandering) | [ ] |
| Load conditions (centered/off-centered) | [ ] |
| Condition of the rollers (wear/free rotation) | [ ] |
| Recent history (interventions, replacements) | [ ] |
5. Systematic Diagnosis Flow
- Step 1: Visual Inspection
- If the misalignment is fixed (same position along the frame) -> Roller or frame alignment problem.
- If the misalignment is wandering -> Splicing or tensioning problem.
- Step 2: Check Load
- Check that the material is loaded centrally onto the hopper. Lateral loads move the belt.
- Step 3: Check the Rollers and Pulleys
- Check that all the rollers are perpendicular to the running line of the belt.
6. Fault-Cause Matrix
| Symptom | Probable Cause (Rank) | Diagnostic Test | Expected Result |
|---|---|---|---|
| Tape always deviates at the same point | 1. Roller misaligned | Check roller squaring | Perpendicular |
| Tape deviates randomly | 1. Joint not square | Measure junction diagonals | Difference < 5mm |
| Tape deviates on startup | 1. Insufficient voltage | Measurement of operating voltage | Nominal value +/- 5% |
7. Root Cause Analysis
Not squared joint: A vulcanized or mechanical joint not made at 90° with respect to the longitudinal axis forces the belt to twist.
Pulley Alignment: If the return or head pulleys are not perfectly aligned, the belt will seek the path of least resistance, becoming misaligned.
8. Resolution Procedures
- Roller Correction: Loosen the roller fixing bolts. Rotate the roller in the opposite direction of the belt drift. Retighten.
- Junction check: If the junction is deviated, the only definitive solution is to remake it, ensuring squaring with laser templates.
9. Preventive Measures
| Root Cause | Strategy | Method | Interval |
|---|---|---|---|
| Material accumulation | Constant cleaning | Visual inspection | Weekly |
| Roller wear | Preventive replacement | Rotation control | Monthly |
10. Spare parts and components
| Description | Specify | When to replace | UNITEC category |
|---|---|---|---|
| Carrier roller | Diam. 89mm/108mm | Wear/Noise | Conveyor Rollers |
| Tensioner | Plumber/Mechanic | Voltage loss | Tension Systems |
To purchase certified spare parts, consult our e-catalog: https://www.unitecd.com/e-catalog/
11. References
UNI EN ISO 14890: Conveyor belts with textile core. Safety rules for use.
