Separate machine seal settings from the evidence used to decide whether the filled pouch is acceptable for its intended product and distribution route.
Heat-seal temperature, pressure and dwell must be developed for the stated laminate, sealant layer, pouch geometry, product and speed condition. Visual quality, seal strength and leak/integrity methods provide different evidence and should not be treated as interchangeable.
Check continuous seal width and position, wrinkles, channels, folds, contamination, distortion, burn-through, zipper/spout interference and code encroachment. Visual checks are essential but may not identify every leak path.
A controlled peel test measures the force required to separate a defined seal specimen and records the failure mode. ASTM F88/F88M describes seal-strength measurement for flexible barrier materials; use the current method and a competent test plan where it is applicable.
Gross-leak bubble methods, vacuum or pressure-decay approaches, dye methods and other validated techniques answer different questions. Select the method and sensitivity from the product risk, pack design, distribution and quality system.
Every result should identify the packaging batch, product, dose, machine settings, line condition, cooling and test method.
| Evidence layer | Question answered | Information to record |
|---|---|---|
| First-off visual inspection | Is the seal present, aligned and free from obvious defects? | Pack/film batch, settings, seal width/position, defect location and approved sample. |
| Seal-strength test | How does a defined seal specimen separate under the stated test? | Method/version, specimen preparation, width, speed/configuration, results and failure mode. |
| Gross-leak test | Is there an observable leak above the method’s detection capability? | Method, pressure/vacuum, time, sample conditioning and leak location. |
| Validated integrity method | Does the pack meet the risk-based integrity requirement? | Validated procedure, equipment status, sensitivity, sample plan, results and deviations. |
| Distribution/handling challenge | Does the filled pouch remain acceptable after relevant handling? | Conditioning, drop/vibration/compression plan where applicable and post-test results. |
Empty pouches are useful for setup, but the accepted process should be confirmed with the intended product and dose. Dust, liquid strings, particles, fill temperature, filled-pouch tension and cooling can change the result.
When contamination is foreseeable, challenge the detection and rejection process rather than assuming the seal will tolerate product in the seal band. Use the coding, inspection and reject guide to define how an affected pouch is tracked and removed.
Material evidence is covered in the pouch laminate guide.
The appropriate procedure depends on the package and quality requirement. ASTM publishes F88/F88M for seal strength and lists package-integrity methods including bubble emission, pressure decay, vacuum decay, dye and visual inspection. The project quality team should confirm the current edition, applicability, equipment, validation and acceptance limits.
General machinery trials do not replace product shelf-life, food safety, pharmaceutical, transport or regulatory validation. Those responsibilities should be assigned in the project brief and completed by competent personnel.
Not necessarily. The required strength must suit containment, distribution and opening. Excessive heat or pressure can distort or damage the material even when the seal is difficult to pull apart.
Visual inspection finds many important defects but does not demonstrate every leak path or sensitivity. Use an additional method where the product and quality plan require it.
They can support setup, but the final process should be checked with the intended product, dose and filled-pouch condition because contamination, temperature and tension may change sealing.
Change one controlled factor where practical, record the reason and result, and retain samples. Temperature, pressure, dwell, jaw condition, film movement and cooling interact, so unrecorded adjustments make root-cause work difficult.
The responsible manufacturer and quality team should define the limit from the product, packaging, distribution, regulatory and customer requirements, using a validated method where required.
Send the laminate, product, filled reference, current quality method and retained samples required for the machine trial.
