Metallised BOPP, AlOx and MDO-PE: picking a foil replacement barrier

Quick answer: for a mono-material polypropylene pouch that needs foil-level protection, ultra-high-barrier metallised BOPP (the category Innovia’s new Propafilm CHBM sits in) and AlOx or SiOx-coated films are the two realistic routes. For PE pouches, the equivalent is an MDO-PE/EVOH-PE coextrusion. None of these fully matches plain aluminium foil’s near-zero permeability, but the best grades get close enough for most food, aroma-sensitive and even some retort applications. Grades vary a lot within each category, so the supplier data sheet, tested under stated conditions, is what actually decides.

What Innovia just launched

On 15 October 2026, Innovia Films announced Propafilm CHBM, an ultra-high barrier metallized BOPP film engineered to deliver exceptional product protection while supporting the transition to more recyclable flexible packaging solutions. The film is specifically designed to replace aluminum foil in polypropylene-based laminate structures, enabling brands and converters to achieve premium barrier performance while improving recyclability.

It comes in one gauge for now: an 18 μm (0.72 mil) film with ultra-high oxygen and moisture barrier performance, enhanced metal adhesion, high optical density and a reverse-side treatment suitable for lamination or surface printing. The pitch is straightforward: by replacing aluminum foil with a metallized polypropylene film, Innovia aims to help converters simplify laminate constructions and improve their compatibility with polypropylene recycling streams.

Innovia’s launch materials describe the barrier as “ultra-high” without publishing an OTR or WVTR figure or the test method behind it. That’s worth flagging plainly: until a data sheet with numbers is available, nobody outside the company can say exactly where CHBM lands against the rest of the metallised BOPP field. What follows uses published figures from other suppliers’ metallised BOPP, AlOx and MDO-PE/EVOH data sheets to show the range a film in this category typically has to beat.

Why aluminium foil is still the reference point

Every barrier film in flexible packaging gets measured against foil because foil is, for practical purposes, impermeable. A widely cited comparison puts 6 μm aluminium foil’s oxygen and moisture transmission at essentially zero, against 465 mL/m²/day oxygen and 31 g/m²/day moisture for plain 12.7 μm PET film, and 1.2 mL/m²/day oxygen and 0.8 g/m²/day moisture once that same PET is metallised.

That same source makes the point that matters for this whole category: it was once thought that metallised films would become a replacement for aluminium foil laminates, but current films still cannot match the barrier properties of foil. Some very high barrier metallised films are available using EVOH, but are not yet cost effective against foil laminates. Nothing in Innovia’s announcement changes that underlying physics. What’s changed is how close the gap has got, and how much that matters now that recyclability is a design requirement rather than a nice-to-have.

Metallised BOPP vs AlOx/SiOx: how the numbers compare

Plain, uncoated BOPP is a poor oxygen barrier on its own. Its oxygen transmission rate typically sits in the range of 1,500 to 2,500 cc/m²/day at 23°C and 0% RH, though it does offer useful moisture barrier, with WVTR typically 3 to 6 g/m²/day at 38°C and 90% RH. That’s why BOPP on its own is used for snack flow-wrap and label stock, not for coffee or long-life sauces.

Metallising it changes the oxygen number by orders of magnitude. Standard metallised BOPP and PET data sheets typically show oxygen transmission rates of 0.5 to 3.0 cc/m²/day at 23°C and 0% RH for standard metallised PET and slightly higher values for metallised BOPP, while aluminium layers in the thicker, more controlled end of the range of 30 to 100 nm can reduce WVTR to below 0.5 g/m²/day and OTR to below 1 cm³/m²/day. The newest coating-plus-metallisation combinations push further still: one supplier’s synergistic coated-and-metallised film reports OTR performance of less than 0.2 cc/m² 24h at 23°C/0% RH and WVTR performance of less than 0.45 g/m² 24h at 38°C/90% RH, explicitly pitched as an alu-free foil replacement for coffee bags.

AlOx and SiOx coatings take a different route to a similar place, using a vacuum-deposited ceramic layer instead of metal, which keeps the film transparent. Typical commercial AlOx-coated PET grades show water vapour transmission down to 0.25 g/m²/day at 38°C/90% RH and oxygen transmission from about 0.13 to 1.5 cc/m²/day at 23°C, tested to ASTM F1249 and ASTM D3985. A broader literature summary puts a useful bracket on both technologies: standard metallised or ceramic-coated films typically run 1 to 5 cm³/m²/day OTR and 0.5 to 2 g/m²/day WVTR, with high-performance grades below 0.5 cm³/m²/day OTR and below 0.3 g/m²/day WVTR.

Oxygen barrier by material type, typical (23°C/0% RH)

Moisture barrier by material type, typical (38°C/90% RH)

Material	Typical thickness (μm)	OTR, 23°C/0% RH (cc/m²/day)	WVTR, 38°C/90% RH (g/m²/day)	Recycling stream fit
Uncoated BOPP	20-30	1,500-2,500	3-6	PP stream; weak O2 barrier alone
Standard metallised BOPP	15-20	10-65	0.25-1.5	PP stream; thin Al layer generally tolerated, can grey recyclate
Ultra-high-barrier metallised BOPP (category of Innovia Propafilm CHBM)	18	Category typical <1 at the high end; Innovia has not published a figure	Category typical <0.5; Innovia has not published a figure	PP stream, designed as a foil drop-in
AlOx or SiOx-coated BOPP/PET	12-20	0.1-2	0.25-1.5	Compatible with PE stream as a thin coating; PET substrate stays in PET stream
MDO-PE/EVOH-PE coextrusion	25-50 total	<1 to 5	2-5	PE stream if EVOH stays under CEFLEX/APR thresholds
Aluminium foil laminate (6 μm foil ply)	6	<0.1	<0.1	Not mechanically recyclable with plastics; foil recovered separately where facilities exist

Numbers above are typical, grade-dependent figures drawn from published supplier data sheets and barrier literature, not specifications. Use the laminate estimator to get an indicative barrier and weight for a proposed layer stack before you go to a supplier for a quote, and check the material properties table for other typical values across packaging substrates.

Where PE barrier options fit: MDO-PE, BOPE and EVOH

For PE-based mono-material pouches, the same OTR problem shows up and the same two fixes apply: add a thin barrier layer, or add a ceramic/metal coating. Plain MDO-PE has nowhere near enough oxygen barrier for most shelf-stable food. One patent example puts a stretched MDO-PE/tie/EVOH/tie/PE foil at an OTR of approximately 10 ml/(m²·d·bar) at 23°C/50% RH, against roughly 5,000 ml/(m²·d·bar) for the same thickness of unstretched PE without an EVOH barrier, which is the order-of-magnitude gain an EVOH core layer buys.

A more recent comparison of common PE pouch structures found MDOPE/EVOH-PE oxygen transmission reduced to as low as 0.1 to 5 cc/m²/day, compared with 100 to 300-plus cc/m²/day for MDOPE/LLDPE without EVOH, while moisture protection stays broadly similar between the two structures because water vapour barrier is mainly provided by the polyethylene layers themselves. That last point matters for spec writing: adding EVOH buys you oxygen barrier, not moisture barrier. If a pack needs both, the PE layers’ thickness and density still do the moisture job.

BOPE (biaxially oriented PE) earns its place in these stacks less as a barrier layer and more as a stiffness and clarity upgrade over blown PE, used as the outer or middle web with an MDO-PE or metallised layer doing the gas barrier work. Converters increasingly combine MDO-PE, BOPE and a thin EVOH or AlOx layer in one laminate rather than relying on any single film to do everything.

What a coating or metal layer costs you in the recycling stream

Barrier choice and recyclability are decided together now, not separately. The EU Packaging and Packaging Waste Regulation sets recyclability and recycled-content expectations that flow down into how converters spec barrier layers; check the current text for what applies to your packaging format and market.

Under CEFLEX’s Designing for a Circular Economy guidelines, a mono-material package has at least 90 percent of one polymer type, with barrier materials, inks and adhesives making up the remainder. Specifically for coated mono-polyolefin flexible packaging, the CEFLEX guidelines treat the structure as compatible with polyolefin mechanical recycling if each coating layer such as PVOH, EVOH, acrylic, SiOx or AlOx does not exceed 5 percent of the total packaging weight. On the PE side specifically, APR accepts AlOx barrier coatings as a “preferred” additive when applied directly to a polyethylene film for recyclability.

Metal, rather than ceramic, coatings get a more mixed verdict. One review of multilayer flexible packaging redesign options concludes that aluminium lamination and metallisation lead to greying of the recyclate and aren’t considered an optimal barrier choice, though metallisation is mostly tolerated to a certain extent. That’s the trade-off Innovia and other metallised-BOPP suppliers are working against: metallisation gets you most of the way to foil’s barrier number inside a single polymer family, but a reclaimer sorting PP bales still has to deal with a thin aluminium layer that doesn’t belong in a transparent, food-grade PP regrind.

For PA- or EVOH-containing PE films, the rule is less of a free pass. APR’s design guide for PE film notes that if a film contains other non-PE polymers such as EVOH or polyamide, it should be tested to qualify its recyclability with the polyolefin stream, rather than assuming the 90/10 weight split automatically clears it.

Best for: matching the barrier to the pack

None of these is a universal answer. Based on the published data above:

Dry, long-shelf-life snacks in a PP pouch (crisps, nuts): standard metallised BOPP is usually enough; the OTR headroom most dry snacks need doesn’t require the ultra-high-barrier tier.
Coffee, retort pouches, foil-replacement claims in PP: the ultra-high-barrier metallised BOPP category, including Innovia’s new Propafilm CHBM, is built for exactly this; ask for the coated-side OTR and WVTR and the retort stability data before committing.
Clear-window packs where shoppers need to see the product: AlOx or SiOx-coated film, since metallisation makes the pack opaque.
PE pouches needing moderate oxygen barrier with full PE-stream recyclability: MDO-PE/EVOH-PE coextrusion, keeping the EVOH layer under the CEFLEX/APR weight thresholds.
Pharma blister lidding, medical devices or anywhere foil’s absolute, humidity-independent barrier is non-negotiable: aluminium foil laminate remains the benchmark; material choice here is decided with your regulatory and quality teams against the applicable pharmacopoeia, not on barrier numbers alone.

What this means for you

Ask any metallised-BOPP, AlOx or MDO-PE/EVOH supplier for the actual OTR and WVTR figures with test method, temperature and RH stated, not just a marketing claim of “ultra-high” or “foil-equivalent.” A number without conditions is not comparable to anything.

If you’re redesigning a foil-containing laminate into a mono-material PP or PE structure, check both the barrier data sheet and the recyclability certification (cyclos-HTP or an equivalent third-party assessment) separately: a film can clear 90/10 by weight and still fail a recycler’s practical test if pigment, print coverage or coating load is high.

Run a candidate layer stack through the laminate estimator to get an indicative barrier and weight before involving a converter, and use the unit converter when comparing gauge in microns against mil or gsm figures from different regions’ data sheets.

Sources

Values are typical figures from the cited sources. Grades differ between suppliers. Check the supplier's data sheet and test your own structure before you decide.