Many people assume inspection is just "checking if the quantity is correct and the packaging isn't damaged." But sealing film isn't an ordinary consumable — skip one inspection item, and the production line might end up down for two extra hours.

Check the packaging first, then the labels

Outer carton inspection is the first step. Look for damage, water stains, deformation, and whether the sealing tape is intact. Sealing film is sensitive to moisture — a damp carton often means the film inside has absorbed moisture. Then verify the label information — product name, specifications, quantity, batch number, production date — against the order one by one.

Specifications and dimensions — sampling is sufficient

After unpacking, pull a few pieces and use calipers to measure diameter, thickness, roll width, and inner diameter. Thickness tolerance should be kept within ±3μm. For custom-printed versions, check whether the print content, color, and position match the design proof. No need to check everything, but samples should cover goods from different layers.

Appearance inspection cannot be skipped

In a well-lit environment, spread the film out and check for bubbles, scratches, wrinkles, impurities, and obvious color differences. Then hold a few pieces up to a light source to inspect the aluminum foil layer for pinholes or uneven coating. For batches that fail appearance inspection, take photos as evidence and communicate with the supplier directly.

Sealing performance testing is the core

Appearance passing doesn't mean it can seal. Take a few bottle mouth samples consistent with your production line and seal them using normal parameters. Then perform three tests: tear open to check if peel force is smooth and if there's any adhesive residue; invert or pressurize to check for leakage; for products requiring high-temperature sterilization, conduct a simulated retort test. Only after all three pass is the batch truly qualified.

Retain samples for traceability — don't skip this step

Keep a few samples from each batch, labeled with batch number and arrival date, for future reference. If quality issues arise later, retained samples are the key basis for traceability and determining responsibility.

Leadtra Packaging recommends that customers incorporate incoming inspection into their standard procedures and communicate promptly if any issues are found. If you're unsure about a specific indicator, we can assist in analyzing samples and verifying test reports. Spending twenty extra minutes on inspection can save two hours of downtime on the production line.