This article offers a friendly, technically grounded comparison of B1 and B2 xps foam board for fire performance. B1 boards generally require a higher limiting oxygen index (LOI ≥ 30%), stricter Single Burning Item results (notably FIGRA ≤ 120 W/s and lower total heat release), no flaming drips that ignite filter paper, faster self-extinguishing, and lower smoke and CO output. B2 boards sit at a lower LOI threshold (≥ 26%) and allow a wider fire-performance window, making them a budget-friendly option for lower-risk, protected applications. The article also notes the link to GB 8624 and DIN 4102, and reminds readers that neither class is fireproof. In short: B1 is the safer, code-friendly choice for high-stakes buildings; B2 is pragmatic where fire load and exposure are modest.
View More
High-compressive extruded polystyrene (XPS) is a rigid, closed-cell foam that combines serious load-bearing capacity with excellent thermal insulation. Its dense closed-cell structure—often over 99% closed cells—delivers high compressive strength, low thermal conductivity, very low water absorption, dimensional stability, and strong freeze–thaw resistance. These properties make it ideal for demanding applications such as cold-storage and freezer floors, airport runways, highway subgrades, rail beds, inverted roofs, below-grade waterproofing, foundation slabs, and underfloor heating. Lightweight, easy to cut, and durable under sustained loads, high-compressive XPS is the tough, reliable problem-solver of modern insulation—engineered to perform where ordinary foam would simply give up.
View More
Beneath the concrete slab of ballastless high-speed track lies a thin but critical layer: railway-grade extruded polystyrene (XPS) board. Far from simple insulation, it serves three engineered safety functions—an elastic load-bearing cushion that redistributes dynamic wheel loads and softens bridge-end rotation, a thermal barrier that suppresses frost heave in seasonally frozen ground, and a controlled slip/isolation layer that accommodates longitudinal slab movement. Tight specifications (e.g., density ≥30 kg/m³, compressive strength ≥250 kPa, thermal conductivity ≤0.030 W/(m·K), water absorption <0.3%) ensure durability under decades of 350 km/h service. Deployed on major Chinese high-speed corridors such as Beijing–Shanghai, XPS reveals the quiet logic of ballastless track: not maximum rigidity, but the right stiffness, damping, and thermal resistance exactly where loads and environment demand them.
View More