FR Raw Material for Fire-Resistant Aluminum Composite Panels: A2 vs B1 Grade Comparison

What FR Raw Material Is and Why It Matters

FR raw material refers to the flame-retardant or non-combustible compound that forms the core layer of a fire-rated aluminum composite panel, sandwiched between two thin aluminum skins during lamination. Unlike standard polyethylene core material, FR raw material is formulated with a high proportion of inorganic mineral filler, which reduces the amount of combustible polymer available to sustain fire once ignition occurs. The two grades most commonly referenced in the industry, A2 and B1, are defined under China's GB 8624-2012 national standard for classifying the burning behavior of building materials and products, a standard that has achieved technical alignment with the European EN 13501-1 fire classification system. A2 core material is formulated to meet the non-combustible classification threshold, while B1 core material meets the flame-retardant classification threshold, which sits below A2 but still represents a significant improvement over standard, non-fire-rated core compounds. Both grades are supplied to panel manufacturers in two physical forms: granules, which are compounded pellets ready for extrusion through a T-die, and core roll or core coil, which is the continuous flat core sheet produced after extrusion and calendering, wound onto a coil for storage and transport ahead of the lamination stage.

Understanding the distinction between granules and core roll matters for procurement planning, since the two forms serve different points in a production workflow. A manufacturer that already operates dry mixing, extrusion, and calendering equipment on its own panel production line generally purchases FR raw material in granule form and processes it in-house, giving direct control over core thickness and surface finish. A manufacturer without in-house core extrusion capacity, or one looking to supplement in-house output during periods of high demand, may instead purchase pre-extruded A2 non-combustible core roll or FR B1 core coil directly, feeding it straight into the lamination stage. Both approaches are common in the industry, and the choice generally depends on a manufacturer's existing equipment, order volume, and the degree of process control it wants to maintain over final panel fire performance.

Comparing A2 Non-Combustible and B1 Flame-Retardant Composition

The practical difference between A2 non-combustible core material and B1 flame-retardant core material comes down largely to filler content and the resulting combustion behavior. Industry technical literature aligned with GB 8624-2012 and the GB/T 17748 aluminum composite panel standard commonly cites B1-grade core compound as containing roughly 55% flame-retardant filler, typically based on aluminum oxide and magnesium oxide, while A2-grade core compound is commonly cited as containing roughly 88% to 90% flame-retardant filler, typically based on aluminum hydroxide and magnesium hydroxide. This higher filler loading in A2 material is what allows it to approach a genuinely non-combustible classification, since there is comparatively little combustible polymer binder left in the compound once mineral content reaches that level. The table below summarizes the typical distinguishing characteristics referenced in technical literature for each grade, presented as general industry reference points rather than a specification for any single product batch, since exact formulations vary by manufacturer and application.

These distinctions are not simply academic. A manufacturer supplying panels for a high-rise façade project in a jurisdiction requiring A2-level fire performance cannot substitute B1 flame-retardant granules without risking project rejection at the certification stage, since inspectors and certification bodies test the finished panel against the classification specified in project documentation. Conversely, specifying A2 non-combustible core roll for a project where B1 performance is sufficient may involve unnecessary material cost and processing considerations, since higher mineral filler content generally increases core density and can affect calendering and lamination parameters compared with lower-filler B1 compound. For this reason, procurement teams generally confirm the required fire classification with project architects or code officials before finalizing an FR raw material order, rather than defaulting to one grade for all projects regardless of specification.

Global Demand for Flame-Retardant Filler Materials

Because aluminum hydroxide and related mineral fillers are the dominant ingredients in FR raw material, published market data on flame-retardant fillers provides a useful proxy for understanding broader demand trends affecting A2 and B1 core material supply. Aluminum hydroxide, also referred to as ATH, is used across multiple industries beyond panel manufacturing, but construction remains one of its largest end-use segments, which links its overall market trajectory closely to demand for fire-rated building materials, including the aluminum composite panel core compounds discussed in this article. The chart below shows how the construction segment compares to all other end-use segments combined within the global aluminum hydroxide market, based on published industry research, to illustrate how significant construction-related demand is relative to the broader market for this filler material.

According to Grand View Research, the construction segment accounted for approximately 41.9% of global aluminum hydroxide end-use demand in 2024, making it the largest single end-use segment ahead of pharmaceuticals, water treatment, and general industrial applications combined. This is a meaningful figure for FR raw material buyers, because it confirms that construction-driven demand is not a marginal factor in the broader aluminum hydroxide supply market but rather its single largest consumption channel, which has implications for supply availability and long-term pricing stability. Within construction specifically, aluminum hydroxide is used as a flame retardant and smoke suppressant across multiple building material categories, with fire-rated composite panel cores representing one significant application alongside cable insulation, roofing membranes, and sealants. For a manufacturer specifying A2 non-combustible granules or B1 flame-retardant granules as part of a production order, this scale of demand suggests that flame-retardant filler supply is backed by a large, diversified industrial base rather than a narrow niche market dependent solely on panel production. It also means that shifts in construction-sector fire safety regulation, which tend to increase demand for higher-filler A2 material relative to standard B1 material, can influence flame-retardant filler markets broadly, not just the segment supplying aluminum composite panel manufacturers. Manufacturers and trading companies sourcing FR raw material at scale generally benefit from monitoring this broader filler market alongside panel-specific demand, since raw material availability for aluminum hydroxide and magnesium hydroxide ultimately affects lead times and consistency for both A2 non-combustible core roll and B1 flame-retardant core coil production. The construction segment's leading position within this market also reinforces a pattern already visible in the broader aluminum composite panel industry: fire safety regulation and construction activity are the primary forces shaping demand for the raw materials that go into fire-rated panel cores, rather than short-term shifts in any single downstream application.

Market Growth Trajectory for Flame-Retardant Filler Supply

Beyond understanding where current demand is concentrated, it is useful for manufacturers to understand how quickly the underlying flame-retardant filler market is expected to grow, since sustained growth generally supports long-term investment in FR raw material sourcing and processing capacity rather than short-term, order-by-order purchasing. The chart below traces the projected growth of the global aluminum hydroxide market from 2024 through 2030, based on a compound annual growth rate published by Grand View Research. As with any multi-year projection, the figures represent an estimated trajectory derived from a stated base value and growth rate, rather than a guaranteed outcome for any individual year.

Grand View Research estimated the global aluminum hydroxide market at approximately USD 12.05 billion in 2024, projecting growth to roughly USD 15.31 billion by 2030, which reflects a compound annual growth rate of about 4.1% across the 2025 to 2030 period. Steady, mid-single-digit growth of this kind is generally interpreted by production planners as a sign of a maturing but still expanding market, rather than either a saturated market or a speculative, high-volatility one. For manufacturers of A2 non-combustible core roll and FR B1 core coil, this growth pattern supports planning for gradually increasing raw material volumes over a multi-year horizon rather than either rapid overexpansion or conservative underinvestment. It is also worth noting that a separate, broader market category covering all flame retardant chemistries, not just aluminum hydroxide, was estimated at approximately USD 9.7 billion in 2024 with a projected compound annual growth rate of about 5.7% through 2034, according to published industry research, suggesting that flame-retardant demand as a whole may be growing slightly faster than the aluminum hydroxide segment specifically, potentially reflecting increased use of complementary filler chemistries such as magnesium hydroxide alongside aluminum hydroxide in advanced FR raw material formulations. Asia Pacific has been identified in multiple industry reports as the largest regional market for aluminum hydroxide, which aligns with the region's dominant position in aluminum composite panel production and construction activity discussed in related industry research. Taken together, these figures support a reasonably confident planning assumption: flame-retardant filler supply, and by extension FR raw material availability for A2 and B1 core production, is likely to keep expanding at a moderate, sustainable pace over the coming years, supported by construction-sector fire safety regulation rather than short-term demand spikes.

From Granules to Core Coil: How FR Raw Material Is Processed

Understanding how A2 non-combustible granules or B1 flame-retardant granules become finished core roll or core coil helps clarify why processing equipment choice matters as much as raw material grade selection. The transformation from granule to core sheet generally follows a defined sequence on a metal composite panel production line, starting with material preparation and ending with a wound coil ready for lamination. A dry mixer first blends the granules, ensuring filler particles are evenly distributed throughout the compound before extrusion, since uneven mixing at this stage can create inconsistent fire performance across a finished panel even when the overall formulation is correct. The blended compound then passes through a T-die, which shapes the molten material into a continuous flat sheet of controlled width and thickness as it exits the extruder.

After extrusion, the core sheet typically passes through a calender machine, which compresses and smooths the material to achieve the target thickness tolerance before it cools and solidifies. An auto filter exchanger is commonly positioned ahead of the T-die on continuous production lines, removing particulate contamination from the molten compound stream without requiring the line to stop, which is particularly relevant for A2-grade material given its higher mineral filler content and correspondingly higher potential for particulate buildup during continuous extrusion. Once cooled, the finished core sheet is wound into A2 non-combustible core roll or FR B1 core coil form, ready either for direct sale to other panel manufacturers or for immediate use in the same facility's lamination process, where it is bonded between two aluminum skins using a coater and associated bonding equipment. This sequence illustrates why FR raw material sourcing and production line equipment selection are closely linked decisions rather than separate ones: a manufacturer purchasing granules rather than pre-extruded core roll takes on responsibility for maintaining consistent mixing, extrusion, and calendering quality throughout this process, which requires equipment capable of handling the specific characteristics of high-filler A2 compound or moderate-filler B1 compound reliably across long production runs.

Relative Performance Characteristics of A2 and B1 Core Material

Beyond filler percentage, A2 and B1 core material differ across several operating characteristics that matter to both panel manufacturers and the project teams specifying finished panels. These differences affect not only fire performance but also processing behavior during extrusion and calendering, as well as the finished panel's mechanical properties. The radar chart below compares A2 non-combustible and B1 flame-retardant core material across five characteristics on a relative one-to-five scale, intended as an illustrative comparison grounded in generally recognized industry technical patterns rather than a precise laboratory measurement for any specific product batch.

As the radar comparison illustrates, A2 non-combustible core material generally scores higher on filler content, ignition delay, self-extinguish speed, and weight per sheet, reflecting its substantially higher mineral loading compared with B1 flame-retardant material. Technical literature commonly cited in the industry indicates that B1-grade panels can begin burning within roughly five minutes of flame exposure and typically self-extinguish within about ten seconds once the flame source is removed, while A2-grade panels are commonly described as resisting ignition for approximately twenty minutes and self-extinguishing immediately once the flame source is removed. This gap in ignition delay and self-extinguish behavior is the practical reason A2 material is specified for high-rise and public infrastructure projects where fire safety margins matter most. On the other hand, B1 flame-retardant material generally scores higher on sheet flexibility and lower on processing complexity, since its lower filler content results in a core compound that behaves more like conventional polymer during extrusion and calendering, requiring less specialized equipment tuning than high-filler A2 compound. Processing complexity is a meaningful factor for manufacturers evaluating whether to invest in A2-specific production capability, since high mineral content can increase wear on extrusion and calendering components over time compared with standard or B1-grade compound, which is one reason auxiliary equipment such as auto filter exchangers and precisely tuned calender rollers are particularly relevant on lines processing A2 non-combustible granules at scale. Weight per sheet also differs meaningfully between the two grades, since mineral fillers are denser than the polymer they replace, meaning A2 core roll is generally heavier per unit area than B1 core coil of equivalent thickness, a factor that affects both handling equipment requirements and finished panel weight considerations for building design teams. None of these differences make one grade universally preferable to the other; rather, they explain why project fire classification requirements, not cost or convenience alone, should drive the choice between A2 non-combustible core roll and FR B1 core coil for any given application.

Regulatory Pressure Behind Rising A2-Grade Demand

Fire safety regulation has become one of the strongest forces reshaping demand within the FR raw material market, particularly for higher-filler A2 non-combustible compound relative to standard B1 flame-retardant compound. Following a series of high-profile building fire incidents in various regions over the past decade, regulators in multiple countries have tightened requirements for facade and cladding materials used on high-rise and public buildings, often specifying non-combustible or near-non-combustible core classifications where B1-level performance was previously acceptable. The gauge chart below illustrates the projected compound annual growth rate for the broader global flame retardant market, based on published industry research, to show how this regulatory-driven demand is reflected in overall market growth expectations.

Published industry research estimates the global flame retardant market at approximately USD 9.7 billion in 2024, with growth projected to around USD 16.8 billion by 2034, representing a compound annual growth rate of roughly 5.7%, alongside volume growth from an estimated 3.2 million metric tons in 2024 toward more than 5.0 million metric tons by 2034. This volume growth trajectory is a useful indicator for FR raw material buyers, since it confirms that demand expansion is occurring in physical material terms, not solely in revenue terms inflated by pricing changes. For panel manufacturers, this regulatory-driven growth pattern reinforces a practical planning point: demand for A2 non-combustible granules and A2 non-combustible core roll is likely to keep growing as more jurisdictions adopt stricter fire classification requirements for high-rise and public buildings, even in regions where B1-level material was historically the accepted standard. Manufacturers positioned to supply both A2 and B1 grades are generally better placed to serve customers across different project types and regulatory environments than manufacturers offering only one grade, since project requirements vary considerably by building height, occupancy type, and local code interpretation. It is worth noting that this growth trend reflects industry-wide regulatory and market dynamics rather than a guarantee for any individual supplier or project, and manufacturers should confirm current code requirements with relevant authorities for each specific project rather than relying solely on general market trend data. Even with that caveat, the consistency of this growth pattern across multiple independent research sources supports treating rising A2-grade demand as a durable, multi-year trend rather than a short-term fluctuation, which has direct implications for how manufacturers plan FR raw material sourcing and core-line processing capacity going forward.

Inside a Fire-Resistant Panel Core: Layer Structure

To make the relationship between FR raw material and the finished panel easier to visualize, the diagram below shows a simplified axonometric cross-section of a fire-resistant aluminum composite panel, with the aluminum skins and FR core layer labeled. This view illustrates how the core material discussed throughout this article, whether A2 non-combustible core roll or FR B1 core coil, sits within the finished panel structure once lamination is complete.

As the cross-section shows, the finished panel consists of a top aluminum skin, the FR core material layer, and a bottom aluminum skin, bonded together along the bond line during lamination. The core layer, whether produced from A2 non-combustible granules or B1 flame-retardant granules, occupies the majority of the panel's total thickness and is what determines the panel's fire classification, since the thin aluminum skins themselves, while non-combustible individually, cannot by themselves prevent fire from spreading through a combustible core if one is used. This is why panel fire classification is always determined by core material performance rather than by the aluminum skin alone, and why FR raw material selection has such a direct bearing on which projects a finished panel can legally be used on. The bond line between each aluminum skin and the core material also plays a role in overall panel performance, since a properly bonded panel maintains structural integrity under normal conditions and during a fire event, whereas a poorly bonded panel can delaminate under thermal stress, which is one reason ACP delamination testing equipment is used during quality control to verify bond strength between the FR core and aluminum skins before panels are approved for shipment.

FR Raw Material Product Range from Hongyang Machinery

The images below show representative examples of FR raw material in both supply forms discussed throughout this article: A2 non-combustible core roll and FR B1 core coil in finished sheet form, alongside A2 non-combustible granules and B1 flame-retardant granules in raw pellet form. Having access to both grades and both supply forms allows a panel manufacturer or trading company to match material sourcing to specific project requirements, whether that means purchasing granules for in-house extrusion or sourcing pre-extruded core roll or core coil for direct lamination.

A2 non-combustible core roll, A2 non-combustible granules, FR B1 core coil, and B1 flame-retardant granules.

Reviewing both granule and coil forms side by side also helps illustrate the physical transformation described earlier in this article: the grey granules on the left of each pair represent the compounded raw material before extrusion, while the wound coils represent the same formulation after passing through a T-die and calender machine. For manufacturers evaluating a supplier, requesting samples of both forms, along with documentation confirming fire classification test results, is a reasonable step before committing to a large-volume FR raw material order, since visual inspection alone cannot confirm fire performance and formal classification testing remains the only reliable basis for confirming A2 or B1 compliance.

How to Evaluate FR Raw Material for a Production Line

Selecting FR raw material involves more than choosing between A2 and B1 grades. The following factors are commonly used by production planners and procurement teams to evaluate FR raw material suppliers and formulations before committing to a supply agreement or production line configuration built around a specific compound.

1. Confirm the fire classification required by the target project or market, since building codes vary by region and building type, and this requirement should drive the choice between A2 and B1 material rather than cost or availability alone.
2. Request classification test documentation for the specific formulation being purchased, since fire performance can vary between suppliers even within the same nominal grade.
3. Evaluate whether granules or pre-extruded core roll or core coil better fits existing production line capability, particularly whether in-house dry mixing, T-die extrusion, and calendering equipment can reliably process the filler content of the chosen grade.
4. Assess equipment wear implications, since higher-filler A2 compound is generally more abrasive on extrusion and calendering components than lower-filler B1 compound over extended production runs.
5. Plan handling and storage capacity for the weight difference between A2 and B1 material, since A2 core roll is generally heavier per unit area than B1 core coil of equivalent thickness.
6. Review supplier capacity to provide both grades, since manufacturers serving multiple project types benefit from a supplier able to deliver both A2 non-combustible and B1 flame-retardant material consistently.

Working through these factors systematically before finalizing an FR raw material order helps manufacturers avoid two common issues: specifying a fire classification that does not match project requirements, and underestimating the equipment or handling adjustments needed when switching between B1 and A2 grade production. Both issues are considerably less costly to address during the planning stage than after a large material order has already been placed or a production run is already underway.

About Zhangjiagang Hongyang Machinery Equipment Co., Ltd.

Zhangjiagang Hongyang Machinery Equipment Co., Ltd. is a national enterprise specializing in the research, development, and manufacturing of intelligent equipment for metal composite materials, providing systematic production line solutions for the global construction materials industry. The company served as a drafting unit for the industry standard governing non-combustible metal composite panels used in architectural decoration, and it holds a standing council member position within the Metal Branch of the China Building Materials Federation, reflecting its ongoing role in shaping technical standards relevant to FR raw material and fire-rated panel production. Hongyang Machinery's core product range spans three main technology systems: fire-resistant aluminum composite panel production lines, aluminum honeycomb core machines and aluminum honeycomb core metal composite panel production lines, and multifunctional customized metal composite panel production lines. Together these systems cover twelve categories of high-end production lines, including equipment for A2 and B1-grade fire-resistant materials, three-dimensional aluminum-core metal composite panels, and aluminum honeycomb series products. This means Hongyang Machinery's equipment portfolio is designed with direct awareness of how FR raw material, whether supplied as A2 non-combustible granules, A2 non-combustible core roll, B1 flame-retardant granules, or FR B1 core coil, needs to be processed reliably at production scale, connecting raw material characteristics to the dry mixing, extrusion, calendering, and lamination equipment described throughout this article.

Frequently Asked Questions

Q1: What is FR raw material used for?

FR raw material is the flame-retardant or non-combustible compound used as the core layer of fire-rated aluminum composite panels, supplied as granules for extrusion or as finished core roll or core coil for direct lamination.

Q2: What is the difference between A2 non-combustible and B1 flame-retardant material?

A2 material contains a substantially higher mineral filler content, commonly cited at around 88% to 90%, compared with roughly 55% for B1 material, giving A2 material a longer ignition delay and faster self-extinguish behavior once flame exposure ends.

Q3: Should I buy FR raw material as granules or core roll?

The choice depends on whether a manufacturer has in-house dry mixing, extrusion, and calendering equipment; granules suit facilities with core-line capability, while pre-extruded core roll or core coil suits facilities focused on lamination alone.

Q4: Which fire classification standard applies to FR raw material?

A2 and B1 classifications originate from China's GB 8624-2012 national standard, which has achieved technical alignment with the European EN 13501-1 fire classification system used internationally.

Q5: Does A2 material require different processing equipment than B1 material?

A2 material's higher mineral filler content is generally more abrasive during extrusion and calendering, so production lines processing A2 compound at scale typically benefit from equipment tuned for higher-filler material and more frequent filter maintenance.

Q6: Can one production line process both A2 and B1 core material?

A well-specified production line with adjustable dry mixing, extrusion, and calendering parameters can generally process both grades, though switching between them typically requires parameter adjustments to account for differing filler content and material density.