Metal-free barrier packaging: what to verify

Replacing an aluminium-foil laminate starts with the product requirements. An oxygen-sensitive dry food, a moist product and a heat-processed pouch need different evaluations. A transparent or metal-free film is a candidate structure, not a guarantee of the same shelf life as the existing pack.

Identify the barrier you need

Write down the intended shelf life, storage temperature and humidity, filling method, and whether light protection matters. Ask for oxygen transmission rate (OTR) and water vapour transmission rate (WVTR) data with the units, test method, temperature and relative humidity. Results measured under different conditions cannot be compared as if they describe the same use.

Compare the complete structure

EVOH is a gas-barrier polymer used in multilayer packaging. Kuraray describes its EVAL material as an oxygen barrier with transparency and aroma-retention properties. The resin name alone does not specify a finished pouch: the grade, layer thickness and surrounding layers still need to be defined. See Kuraray's EVAL product information.

Transparent deposited barrier films offer another route. TOPPAN's GL BARRIER range includes different grades for different applications, including retort-capable grades. Its published performance information considers humidity, temperature and flex resistance. This is a useful reminder to request data for the exact film being quoted, rather than treating every transparent coating as interchangeable. See TOPPAN's barrier-film information.

Check the pack after converting

Set an evaluation plan for the actual printed and laminated structure. Include the intended pouch format, seal areas and handling conditions. If flexing or heat treatment is relevant, agree when the barrier measurements will be taken. Keep an unconverted-film result separate from a result for the finished package.

For a trial, record the film specification and thickness, adhesive and curing requirements, sealing conditions, sample identity and acceptance criteria. Shelf-life approval belongs with the product and its packing conditions; a film data sheet is only one input.

Ask for recycling evidence separately

Metal-free and recyclable describe different things. Ask the supplier to identify the complete structure covered by any recyclability assessment and the collection stream it is intended for. Check that the assessment covers the printing, adhesive, closure and other features of your pack. Avoid changing an on-pack claim solely because aluminium has been removed.

Send the current structure, pack dimensions, product conditions and target barrier values when discussing a replacement with HUAYN. Our packaging formats and printing service help define the production brief before a trial is agreed.