Strapping/banding Machine Not Tensioning Correctly
Incorrect strap tension - too loose, too tight or inconsistent - is usually caused by tension motor wear, worn gripper components, incorrect settings, or a strap specification that does not match the machine calibration.
Common symptoms
Each of these points to a tension problem. If you're seeing more than one, the fault is mechanical rather than a settings issue.
Strap feels loose on the load after strapping
The machine completed its cycle but the tension set point was never reached. Often a gradual deterioration rather than a sudden failure.
Strap is cutting into the product
Over-tension. Usually a settings issue after a strap spec change, or the tension control is not limiting correctly.
Tension varies from cycle to cycle
Inconsistency like this typically points to gripper wear - the strap is slipping before tension is fully applied, and the slip amount varies.
Machine shows tension alarm without completing
The machine timed out trying to reach the set tension. The motor is working but can't get there - worn motor or slipping gripper.
Strap breaks during tensioning
Tension spiked beyond the strap's break strength. Can happen if the tension control is faulty, or if the strap spec is lighter than the machine is set for.
Tension looks fine but seals are still weak
Tension and sealing are separate processes. If tension reads correctly but seals fail, the problem is in the seal head, not the tension system.
Typical causes
Tension motor wear
The tension motor has worn over time and can no longer reach the set tension before timing out. Common on high-usage machines and often a gradual deterioration.
Gripper pad or jaw wear
The gripper that holds the strap during tensioning has worn pads or jaws. The strap slips before full tension is reached, giving a consistent under-tension result.
Tension setting incorrect
The tension setting has been changed - intentionally or accidentally - and is no longer appropriate for the strap specification or load type being run.
Strap specification mismatch
A change in strap width, thickness or material has altered how the machine achieves tension. Settings that worked for the previous strap may not be correct for the new one.
What to check first
Work through these in order. If you get a clear answer at any step, that's your starting point. If you get through all four and can't pin it down, call us.
Check what the tension setting actually is
Go into the machine settings and note the current tension value. Then check what it should be - either in the manual or your own records. If nobody knows what it was set to, that's likely part of the problem.
Run several cycles on the same load and watch
Consistent under-tension across every cycle points to a mechanical fault - motor or gripper. If the tension varies cycle to cycle, the gripper is the more likely culprit. Either way, you're getting useful diagnostic information.
Isolate the machine and inspect the gripper
With the machine isolated, check the gripper pads or jaws. Worn pads have a distinct look - smooth, compressed, often with strap marks. If they're worn, that's your answer.
Confirm the strap spec hasn't changed
Check the strap width and thickness against what the machine was last calibrated for. A switch in supplier or grade can shift how tension behaves. If the strap changed and the settings didn't, that's where to start.
If any of these apply, don't wait
- The motor is audibly struggling or consistently timing out before reaching tension
- Gripper pads are visibly worn - smooth, compressed or marked by strap slip
- Tension varies widely between identical cycles despite consistent settings
- The fault keeps coming back after resets
At this point, further resets or adjustments are unlikely to hold. A call-out now is cheaper than multiple visits for the same underlying fault.