- Food packaging films are multilayer laminates — each layer contributes a specific function: barrier, structure, print surface or heat-seal.
- WVTR (water vapour transmission rate) and OTR (oxygen transmission rate) are the two primary barrier parameters for food film selection.
- EVOH is the most effective plastic oxygen barrier available — a 3–5 µm layer reduces OTR to below 1 cm³/m²/day.
- Recyclability requirements under EU PPWR are driving a shift from PET/PE laminates to all-PE and all-PP mono-material structures.
- Aluminium foil laminates deliver near-zero gas and moisture transmission — essential for long shelf-life ambient products like coffee, spices and retort pouches.
Table of Contents
- What Are Food Packaging Films?
- Types of Food Packaging Films
- Barrier Layers and How They Work
- Choosing the Right Film Structure
- Film Properties Comparison Table
- Sustainability and Recyclability in 2026
- Industry Insight: Mono-Material Transition
- Frequently Asked Questions
What Are Food Packaging Films?
Food packaging films are flexible, sheet-form materials — typically multilayer polymer laminates — used to wrap, enclose or seal food products for storage, distribution and retail display. Unlike rigid packaging such as glass jars or metal cans, flexible packaging films deform to the shape of the product and add minimal weight to the pack, making them highly material-efficient and cost-effective across a wide range of food categories.
Modern food packaging films are almost never single-layer structures. A typical food film laminate consists of two to five functional layers, each contributing a specific property: an outer print-receptive layer for brand communication, one or more structural layers for mechanical strength, a barrier layer to control gas and moisture transmission, and an inner heat-sealable layer to bond the film to itself or to a tray during packaging.
Film selection is one of the most consequential decisions in food packaging design. The film determines product shelf life, packaging line runnability, consumer convenience and — increasingly in 2026 — recyclability compliance under regulations such as the EU Packaging and Packaging Waste Regulation (PPWR). Getting the specification right requires understanding the interplay between product requirements, process conditions and end-of-life obligations. The broader context of sustainable film selection is explored in depth in the Sustainable Packaging Materials Guide.
Types of Food Packaging Films
Polyolefin Films: PE and PP
Polyethylene (PE) and polypropylene (PP) are the workhorses of flexible food packaging. Oriented polypropylene (OPP) is a high-clarity, printable film used as the outer layer in snack packaging, bread bags and confectionery. Cast polypropylene (CPP) and cast polyethylene (CPE) are used as sealant layers — they melt at lower temperatures and bond reliably on form fill seal lines. PE is the dominant sealant material globally; LDPE, LLDPE and mLLDPE variants offer different seal strength, hot-tack performance and puncture resistance profiles.
All-PE and all-PP mono-material laminates — where every functional layer is based on the same polymer family — are the primary focus of sustainable film development in 2026. These structures can be recycled in polyolefin flexible film streams, unlike conventional mixed-polymer laminates.
Polyester Films (PET)
Biaxially oriented polyethylene terephthalate (BOPET or PET film) is the most widely used structural outer layer in food packaging laminates. Its combination of high tensile strength, excellent printability, good temperature resistance and moderate oxygen barrier makes it the default choice for ready meal trays, stand-up pouches and retortable laminates. PET/PE is the most common two-layer food laminate construction globally. Recycled PET (rPET) film — from post-consumer bottle or film recyclate — is increasingly available and mandated under PPWR recycled-content targets.
Polyamide Films (PA / Nylon)
Biaxially oriented polyamide (BOPA) film offers exceptional puncture resistance, excellent oxygen barrier relative to its thickness, and good low-temperature performance. PA/PE laminates are the standard for vacuum and MAP packaging of fresh meat, cheese, processed meat and fish — the polyamide outer layer resists puncture from bone and sharp edges, while the PE sealant provides reliable heat sealing. PA film is also used in boil-in-bag and cooking-in-pack applications where conventional PE or PP would deform.
Aluminium Foil Laminates
Aluminium foil — typically 6–9 µm thickness in flexible packaging — provides near-total barrier to moisture, oxygen, light and aroma. Foil laminates are used for products where long ambient shelf life (12–36+ months) is required: coffee, tea, spices, nuts, dehydrated food, infant formula, confectionery and retort pouches. A standard coffee bag construction is OPP or PET outer / Al foil / PE sealant, with the optional addition of a kraft paper layer for appearance and stiffness.
The recyclability limitation of aluminium foil laminates is significant: separating the polymer layers from the aluminium in mixed-material laminates is industrially challenging, and most foil-based flexible packaging is not collected in European kerbside recycling. This is driving investment in high-barrier vacuum-deposited aluminium oxide (AlOx) and silicon oxide (SiOx) coatings on polymer films — thin-film barrier alternatives that can match foil performance for many applications while remaining recyclable in polymer streams.
EVOH Barrier Films
Ethylene vinyl alcohol (EVOH) is the most effective plastic oxygen barrier available. A 3–5 µm EVOH layer can reduce the oxygen transmission rate of a film laminate to below 1 cm³/m²/day — comparable to aluminium foil for dry products. EVOH is not used as a standalone film; it is co-extruded as a core layer within a multilayer structure, typically PA/EVOH/PE or PP/EVOH/PP, protected from moisture by the surrounding polymer layers (EVOH barrier performance degrades significantly under humid conditions).
EVOH-containing films are used for MAP trays, vacuum skin packs, high-barrier pouches and applications where the product requires oxygen exclusion but the foil barrier is unnecessary. The recyclability of EVOH co-extrusions is improving — thin EVOH layers (below 5% by weight) are increasingly accepted in PE and PP recyclate streams by major reprocessors.
- Shelf life requirements exceed 12 months at ambient temperature
- Light exclusion is required (oils, coffee, infant formula)
- Near-total oxygen and moisture exclusion is needed
- The product will be retorted or thermally processed in-pack
- High oxygen barrier is required but full foil barrier is not necessary
- Recyclability in polymer streams is a priority
- The film must remain transparent (see-through pack)
- The application is MAP tray sealing or vacuum packaging of chilled food
Barrier Layers and How They Work
Barrier performance in food packaging films is quantified by two primary parameters: Water Vapour Transmission Rate (WVTR) measured in g/m²/day at defined temperature and relative humidity, and Oxygen Transmission Rate (OTR) measured in cm³/m²/day at defined conditions. Lower values indicate better barrier performance.
Barrier layers function by reducing the diffusion rate of molecules through the film. Polymer chains with high polarity or crystallinity offer more resistance to gas diffusion. EVOH's barrier properties stem from its strong hydrogen bonding and high crystallinity; aluminium foil's barrier properties stem from the near-complete absence of diffusion pathways through a metallic solid. Thin-film inorganic coatings (AlOx, SiOx) deposited by physical vapour deposition create a glass-like barrier layer on the polymer surface that is impermeable to gas molecules at the nanometre scale.
Film Properties Comparison Table
| Film / Layer | OTR (cm³/m²/day) | WVTR (g/m²/day) | Key Property | Recyclability |
|---|---|---|---|---|
| LDPE (50 µm) | 2,000–8,000 | 4–8 | Sealant, flexibility | PE stream |
| OPP (20 µm) | 1,500–2,500 | 3–6 | Print, stiffness | PP stream |
| BOPET (12 µm) | 40–80 | 8–15 | Strength, print | PET stream |
| BOPA (15 µm) | 30–60 | 60–100 | Puncture resistance, O₂ barrier | Limited |
| EVOH (5 µm, 32 mol% ethylene) | 0.5–3 | N/A (core layer) | O₂ barrier | Improving |
| Al foil (9 µm) | <0.01 | <0.01 | Total barrier, light exclusion | Complex/Low |
| AlOx coating (on PET) | 0.5–5 | 0.1–1 | High barrier, transparent, recyclable | Good (PET stream) |
Frequently Asked Questions
What is a packaging film laminate?
A packaging film laminate is a composite material made by bonding two or more layers of different films or coatings together. Each layer contributes a specific function: an outer layer provides printability and mechanical protection; intermediate layers provide structural strength or barrier properties; and an inner sealant layer provides the heat-seal bond to close the pack. Layers are bonded by adhesive lamination, extrusion lamination or co-extrusion depending on the construction.
What is OTR in food packaging?
OTR stands for Oxygen Transmission Rate — the rate at which oxygen molecules pass through a packaging film under specified conditions, measured in cm³/m²/day (or cm³/m²/24h). Lower OTR means a better oxygen barrier. OTR is one of the two primary barrier specifications for food packaging films; the other is WVTR (water vapour transmission rate). The required OTR for a food pack depends on the product's oxygen sensitivity, the target shelf life and the pack's headspace volume.
What is the difference between EVOH and aluminium foil as barriers?
EVOH and aluminium foil are both high-performance barriers but differ fundamentally in mechanism, performance level and recyclability. Aluminium foil provides near-zero oxygen and moisture transmission — essentially a complete barrier — but makes the laminate non-recyclable in standard polymer streams and adds opacity. EVOH provides an excellent oxygen barrier (OTR 0.5–3 cm³/m²/day) in dry conditions, but its performance degrades at high humidity, and it provides no moisture barrier. EVOH laminates remain transparent and are increasingly accepted in polymer recycling streams at low inclusion levels.
What does WVTR mean in packaging?
WVTR stands for Water Vapour Transmission Rate — the rate at which water vapour passes through a packaging film under specified temperature and humidity conditions, measured in g/m²/day. A low WVTR indicates a good moisture barrier. WVTR is critical for products that deteriorate if they absorb moisture (biscuits, snacks, dried goods, pharmaceuticals) or if they lose moisture (fresh meat, cheese, produce). Polyethylene and polypropylene films offer good moisture barrier; EVOH and polyester films have moderate moisture barrier; aluminium foil has near-zero WVTR.
What is a mono-material flexible packaging film?
A mono-material flexible packaging film is a laminate structure in which all functional layers are made from polymers within the same family — for example, all polyethylene (all-PE) or all polypropylene (all-PP). Because the layers share the same base chemistry, the laminate can be sorted and recycled within a single polymer stream. Mono-material films are more challenging to engineer than conventional mixed-polymer laminates because a single polymer family must provide all the functional properties — stiffness, barrier, sealant performance and print surface — that are normally achieved by combining different polymers.
What is retort packaging film?
Retort packaging film is a laminate designed to withstand the high temperature and pressure conditions of retort sterilisation (typically 121°C for 20–60 minutes). Retort pouches — a lightweight alternative to metal cans — use constructions such as PET/Al/PP or PET/EVOH/PP, where the inner PP layer provides thermal stability and heat-seal performance during sterilisation. The retort pouch market is growing rapidly in military rations, pet food and shelf-stable ready meal segments.
How does film selection affect packaging machine performance?
Film selection has a direct impact on packaging machine runnability. Film stiffness (Young's modulus) affects tracking and tension control on form fill seal lines. Sealant layer melt temperature determines jaw temperature settings and dwell time, which in turn affects line speed. Coefficient of friction affects film feed consistency. Thin or stiff films are more prone to tracking errors; very flexible films may tunnel or wrinkle at high speeds. Any change in film specification — even within the same laminate construction but from a different supplier — should be revalidated on the machine before production release.
For guidance on how packaging films are processed on form fill seal lines, see the Form Fill Seal (FFS) Packaging Guide. For film selection in the context of thermoforming and tray sealing, refer to the guides on Thermoforming Packaging and Tray Sealing Packaging.
Sources: Packaging Digest — Sustainable Packaging Predictions 2026 | Packaging World — AI, Automation, and Sustainability Trends