PE vs FR (B1) vs A2 Core: Which ACP Core Should You Specify?
Two aluminium composite panel quotes can describe the same panel size, the same coating and the same colour, and still be for two completely different products — because the core inside them is different. The core is what decides how the panel behaves in a fire, whether it can be used on a high-rise facade at all, and how much it costs. This guide explains the three cores you will be offered, what the labels PE, FR, B1 and A2 actually mean, and how to verify that the panel delivered matches the panel quoted.
The three cores at a glance
| Core | What it is | Fire behaviour | Typical use | Relative cost |
|---|---|---|---|---|
| PE | Solid polyethylene | Combustible; contributes fuel to a fire | Interior decoration, signage, shopfitting, low-rise non-regulated work | Baseline |
| FR — often sold as B1 | Polyethylene blended with mineral fillers and flame retardants | Resists ignition and slows flame spread, but the polymer is still combustible | General exterior cladding where a B1 / class B reaction-to-fire rating is required | Mid |
| A2 | Mineral-filled core with a very low organic content | Effectively non-combustible; contributes almost no fuel | High-rise and public-building facades, escape routes, transport and infrastructure | Premium |
The order never changes: PE is the economical baseline, FR costs more, A2 costs more again. Where a project is code-driven, the core is not the place to take the cheapest option.
1. PE core — the economical baseline
A PE core is solid polyethylene, the same polymer family as the plastic you handle every day. It is light, easy to process and the cheapest core to make, which is why it dominates interior work, signage and short-life applications. It is also combustible. In a fire it adds fuel, and molten polymer can drip, which is why most façade fire regulations exclude it for tall buildings and escape routes. PE is not a bad product — it is the right product for the applications it was designed for, and the wrong one for a regulated facade.
2. FR core — what most exporters call “B1”
This is where most confusion starts. In China and across much of the export market, a flame-retardant core is routinely called B1, after the B1 class in the Chinese reaction-to-fire standard GB 8624. In Europe the same panel is described as a class B product under EN 13501-1. The two naming systems are not identical, and a supplier who says “B1” may mean the Chinese classification, the European one, or simply “flame retardant”.
An FR core is polyethylene blended with mineral fillers and flame-retardant additives. It resists ignition, slows flame spread and reduces heat release compared with a plain PE core — but the polymer is still combustible, so FR is not the same thing as A2, and it is not a substitute for it. When a project specifies B1, the useful questions are: to which standard, at what test method, and can you send the test report for the exact core being quoted?
3. A2 core — mineral-filled and effectively non-combustible
An A2 core replaces most of the organic polymer with a mineral filler, so there is very little left in the panel to burn. A2 is the grade normally specified for high-rise facades, public buildings, escape routes, tunnels and transport infrastructure, and it is the reason A2 panels carry a clear premium over FR. It is also a heavier core, which is worth knowing for handling and installation planning.
What most buyers do not realise is that A2 is not only a core question. The aluminium skins and the coating have to be compatible with the A2 requirement as well, which is why an A2 panel is best bought as a complete, tested system rather than assembled from a cheap core behind a standard coil.
4. What the codes actually ask for
Reaction-to-fire performance is graded, not binary. Under EN 13501-1 the panel gets a class (A1, A2, B, C, D, E or F) plus smoke and droplet sub-classes, which is why a real specification reads something like A2-s1,d0 rather than just “A2”. Under GB 8624-2012 the equivalent short labels are A (A1 / A2), B1, B2 and B3. Local codes then decide which class is permitted at which building height, in which position, and whether the whole façade assembly — panel, insulation and cavity — has to be assessed together rather than the panel alone.
So “is A2 required” is not a question a supplier can answer for you. It is set by the building code of the destination market, the building height and use, and the fire strategy of the project. Bring us the clause and we will quote the panel that satisfies it.
5. How to verify the core you are quoted
The gap between “FR” on a quotation and “FR” in a delivered container is the single most common substitution risk in this trade — including PE panels carrying a B1 label. A few checks close most of that gap:
- Test report for the exact product — not a generic report, and not one for a different core thickness or a different skin.
- Core density and mineral content — an A2 core is visibly denser and heavier than a PE core. If the panel feels like PE, it is worth asking why.
- Confirm the core in writing — on the PI and on the packing list, with the standard and class named.
- Sample before the container — ask for a sample in your exact core, skin and colour, and check it against the signed-off sample on delivery.
Substitution is not only a compliance problem. The core is where the money is, so a container that quietly dropped from A2 to FR, or FR to PE, is a container you paid too much for.
6. The core is one of three choices
Even a correctly specified A2 core will fail a façade for other reasons if the coating or the skin thickness are wrong. A high-rise exterior panel needs a PVDF coating for colour and gloss retention, and enough skin thickness to hold a fixed panel under wind load — see our A2 sourcing guide for how the three choices fit together, and the price guide for what each one does to the cost per square metre.
Frequently asked questions
Is B1 the same as A2?
No. B1 is a flame-retardant rating; A2 is a much higher classification with a mineral core and a very low organic content. B1 panels resist ignition but are still combustible; A2 panels contribute almost no fuel to a fire.
Is FR the same as B1?
In most export transactions, FR (flame-retardant core) is the product sold under the B1 label. The important detail is which standard the B1 claim refers to, and whether there is a test report for the exact core being shipped.
Can PE core be used outside?
Technically it can be installed outdoors, and it is common on low-rise and non-regulated work. It should not be used where a building code requires a B1 or A2 class, and it is not suitable for high-rise facades or escape routes.
Which core should I order?
Start from the destination market’s building code and the building height and use, not from the price. If the project requires A2, order A2; if it requires a B1 class, an FR core with the right test report is sufficient and cheaper.
About Jinxiang
Zhejiang Jinxiang Panel Industry Co., Ltd. has manufactured aluminium composite panel since 1998, at an 18,000 m² factory in Jinhua, Zhejiang. We run 5 automatic coil coating lines and a dedicated 2-metre-wide A2 line, so the coil, the coating and the composite panel stay under one roof — which is also why our quote can be broken down line by line against the specification, core included. We export to more than 70 countries. MOQ is one standard container for stock colours, with a 500 sqm minimum per colour for custom colours, and lead time is 10–15 days after deposit.
Send us your specification, the destination market and the fire clause you are working to, and we will quote the core that satisfies it. See the A2 fireproof aluminium composite panel range, compare it with the full aluminium composite panel range or the PVDF coating range, or contact us for a quote, a sample kit, or a factory tour — remote or in person.