Every insulated lunch bag, grocery delivery tote, pharmaceutical shipper and foil-lined mailer starts as a roll of reflective material. Bag and box makers buy it as cooler bag liner fabric, thermal bag lining, insulated packaging material or foil-lined foam. The roll is one of three constructions, and the right one depends on how the finished product is made and used.
The three constructions
| Construction | What it is | Strengths | Watch for |
|---|---|---|---|
| Foil laminate (foil-PE, foil-PET, metallised film on scrim) | Thin reflective face on a film or woven carrier | Light, cheap, prints and seals well, folds flat | Little thickness, so little resistance to conductive heat; relies on the bag’s other layers |
| XPE foil-foam | Reflective face on closed-cell polyethylene foam | Soft, flat, adds a real insulating layer, cuts and sews cleanly | Heavier per square metre; thickness adds bulk to folded bags |
| Foil-bubble | Reflective face on an air-bubble core | Thick for its weight, cushions contents | Bubbles crease and crush; harder to sew neatly |
Our comparison foil-bubble vs foil-foam vs foil-scrim goes into the cores; the XPE foil-foam guide covers the foam option in detail.
Choosing by the finished product
- Soft bags that are folded and sewn (lunch bags, delivery totes): foil-foam is the usual liner, because it sews without crushing and gives the bag body. Thin foil laminate is used where the bag already has a foam or fabric layer.
- Rigid or semi-rigid boxes (shipper inserts, box liners): foil-bubble or thicker foil-foam, chosen by the box wall and the transit time.
- Mailers and envelopes: foil laminate or thin foil-bubble, where flatness and sealing matter more than thickness.
- Pharmaceutical and food shippers with a validated hold time: the liner is one layer of a tested assembly. Hold-time claims belong to the whole assembly and its test, not to the roll.
A reflective face only reduces radiant heat transfer where it faces an air space; a foil face pressed flat against another layer is not doing that job. See does reflective insulation work without an air gap.
What a quotation needs
- Construction: which of the three, with faces named (foil or metallised film; one side or both; colour of any plain face).
- Core thickness for foam or bubble, in millimetres or by layer count.
- Finished weight in g/m² if you have a target, or a sample of the liner you use now.
- Downstream process: sewing, heat sealing, gluing or ultrasonic welding. Sealing needs a sealable face; say which process you use.
- Food contact or other compliance: name the regulation and the market, and ask whether a document exists for the quoted construction. Do not assume.
- Roll format: slit width matched to your pattern pieces, roll length, core diameter. Our slitting yield calculator shows which widths nest without waste.
Supply scope
We make reflective insulation and aluminium foil laminate rolls in our Shenzhen factory and supply them to cold chain and insulated packaging manufacturers. We supply roll goods only; bags, boxes and liners are made by our customers. Values and compliance are stated only where a document exists for the exact construction. Send a sample of your current liner and the quotation will name the layers, thickness and roll format it covers.