If your product loses crispness, aroma or flowability once the pack is opened, the problem is rarely the outer carton — it is the barrier between your product and the air. A foil liner adds that barrier: a laminate of aluminium foil, film and paper engineered to block moisture, oxygen and light, then converted to sit cleanly inside your pack.
At Kayu we convert both major liner formats — aluminium foil composite liners for single-use protection, and reclosable barrier liners that let the consumer open and close the pack while keeping the barrier working. Both are specified against your product, your shelf-life target and your packing line. Specify your barrier →
Aluminium Foil Composite Liners (single-use)
Our standard barrier liner: aluminium foil laminated to paper and film, supplied as roll stock, sheets or pre-formed inserts. It is the workhorse specification where the pack is opened once and the contents are consumed quickly — dry goods, powdered products, confectionery, bakery and personal-care products that need protection from humidity.
- Structure — structure and thickness are matched to your product and filling line (PET/AL/PE and PET/VMPET/PE laminates available).
- Foil thickness — matched to your product and filling line.
- Barrier performance — verified per project; test reports available on request.
- Formats — roll stock, cut sheets, or formed inserts.
- Printing — plain, or printed with your brand and handling marks; colour count confirmed at quotation.
Reclosable Barrier Liners
A reclosable liner keeps working after the first opening: the pack can be opened and closed repeatedly while the foil laminate continues to protect the contents. This is the specification to ask for when aroma retention and shelf life after opening actually matter — whole-bean and ground coffee, snack and nut products, powdered drinks, and premium dry goods.
- Opening mechanism — confirmed against your packing line and storage conditions.
- Structure — structure and thickness are matched to your product and filling line.
- Re-seal performance — confirmed against your filling and storage requirements; details on request.
- Compatibility — applied to cartons, tubes and rigid boxes; we confirm against your packing line.
Typical Substrate Structures
A liner is only as good as its layer stack. Below are the components we commonly work with — the right combination depends on what you are blocking and for how long.
| Layer | What it does | Common options |
|---|---|---|
| Outer film | Print surface, scuff resistance | PET, BOPP, paper |
| Barrier layer | Blocks moisture, oxygen, light | Aluminium foil, metallised film |
| Seal layer | Bonds liner to pack, seals cleanly | PE, CPP, heat-seal coating |
| Adhesive | Holds the laminate together under heat and flexing | Solventless / dry lamination — food-grade options available |
Barrier Performance — What We Need From You
Barrier is a specification, not a sales claim. To quote accurately, these are the numbers our engineers need — and the numbers you should be demanding from any supplier:
- WVTR (water vapour transmission rate) — how much moisture gets through, per m² per day
- OTR (oxygen transmission rate) — how much oxygen gets through, per m² per day
- Target shelf life — and whether that is unopened, opened, or both
- Product characteristics — fat content, acidity, hygroscopic or abrasive, any aroma migration risk
- Packing line — heat or cold seal, line speed, sealing temperature window
Give us these and we will come back with a recommended structure, a sample and a price — usually within one working day. If you do not have them yet, send the product; we size protection from what it is and where it will be sold.
Converting Capabilities
- Lamination — wet and dry lamination; roll width, core size and roll diameter are produced to your specification.
- Slitting & sheeting — roll width, core size and roll diameter are produced to your specification.
- Printing — gravure or flexo, colour count confirmed at quotation, Pantone matching.
- Reclosable application — in-line or off-line, confirmed against your packing line.
- Forms supplied — roll stock, cut sheets, pre-formed inserts.
How We Specify Your Liner
- Send the product and the pack — or the specification you already have.
- We recommend a structure — layer stack, foil thickness and seal layer matched to your barrier target.
- Sample for verification — you test the liner on your own line and your own product.
- Production with inspection — film, seal and dimensions checked on every run.
The Liner Range
Browse the whole range in the Barrier Liners collection, or see our custom printed pouches when the pack itself is part of the design.
What Customers Usually Ask
What is the minimum order quantity?
From 500 pieces, with trial runs often possible.
Can I get a sample before ordering?
Yes — structure samples are free for most enquiries. Free samples, 3-5 working days plus shipping.
Do you supply food-contact compliant materials?
Food-contact compliant materials are used, and declarations and certificates are provided on request.
Can you match a liner we are already using?
Yes — send us the current liner or its specification and we will reverse-engineer the structure and quote a like-for-like sample.
What is the lead time for production?
7-15 working days after artwork approval. Repeat runs are faster.
Specify Your Barrier
High-barrier liners are specified, not bought off the shelf. Tell us what you are packing, what you need to keep out, and how long it has to last — our engineers will come back with a recommended structure, samples and pricing.
Pricing is available on inquiry — MOQ varies by structure.
Request a free quote and samples