How to Run a PET Strapping Machine Trial Before Changing Suppliers

Step 1: Define the Current Baseline

Record the current strap:

• supplier;
• width;
• thickness;
• g/m;
• breaking force;
• elongation;
• surface;
• core;
• coil format.

Then record the current machine:

• manufacturer/model;
• settings;
• speed;
• tension;
• weld/joint settings;
• dispenser setup.

Without a baseline, a trial is difficult to interpret.

Step 2: Define the Acceptance Criteria

Do not begin the trial with:

“Let's see if it works.”

Define what “works” means.

Possible criteria include:

• no unacceptable feed failures;
• stable cycle completion;
• acceptable applied tension;
• acceptable joint performance;
• clean cutting;
• stable retraction;
• acceptable coil unwinding.

Customer-specific limits should be agreed before the trial.

Step 3: Confirm Candidate Dimensions

Verify the candidate strap dimensions and surface using the agreed methods.

See PET strapping width and thickness consistency.

Step 4: Start With Controlled Machine Settings

Document the initial machine settings.

Do not allow uncontrolled parameter changes throughout the trial without recording them.

Otherwise it becomes impossible to separate strap effects from setup effects.

Step 5: Test Feeding

Observe:

• entry;
• full-track travel;
• curves;
• return/retraction;
• repeated cycles.

If failures occur, investigate camber, curl and twist rather than assuming tensile strength is the issue.

Step 6: Verify Applied Tension

Machine setpoint and actual delivered tension may not be identical.

Where tension is critical, use a defined verification method.

Step 7: Test the Joint

Inspect and mechanically test representative joints.

See PET strapping joint strength.

Step 8: Evaluate Welding Window

Do not qualify a strap only because one narrow machine setting works.

Where practical, determine whether the process has an acceptable operating window rather than a single fragile setup.

Step 9: Run Enough Cycles

A few cycles can miss intermittent failures.

The qualification scope should reflect:

• production speed;
• risk;
• coil size;
• equipment;
• application.

Newton should not publish a universal minimum cycle count without an agreed qualification protocol.

Step 10: Evaluate the Whole Coil

Where machine risk is high, check behavior across:

• outer layers;
• middle;
• inner coil.

This helps identify coil-build or curl issues that may only appear later.

Step 11: Validate the Finished Package

Machine compatibility is not the final objective.

The package itself still needs to meet its performance requirements.

Depending on the application this can include:

• joint performance;
• retained restraint;
• load stability;
• storage;
• distribution testing.

Step 12: Record the Result

A useful machine-trial record should include:

• strap lot;
• machine;
• settings;
• cycle count;
• failures;
• adjustments;
• joint results;
• observations;
• approval decision.

Agree which new specifications or relevant changes require a machine trial. Do not promise compatibility that has not been validated for the intended equipment and conditions.

FAQs

Can I approve a new supplier after one successful coil?

Not automatically.

Should I change machine settings during the trial?

Possibly, but changes should be controlled and recorded.

Does the same strap size mean the trial is unnecessary?

No.

Should joint testing be part of the trial?

Yes, where joint performance is relevant.

Does a successful machine trial prove transport safety?

No. Unit-load performance may require separate validation.

Discuss Your Requirements With Newton

Send Newton your machine model and current strap specification to build a controlled supplier-change trial plan.

Confirm PET Strapping Machine Compatibility through the complete feed, tension, joining and unwind cycle.

Use the findings to qualify Machine-Grade Polyester Strapping for Automatic Packaging Lines on the intended line.

Connect the specification with the shipped lot using the PET Strapping Test Reports & CoA checklist.

Discuss your specification with Newton →