# PET Foam Sheet & Panel Sandwich for CARAVAN SALON DÜSSELDORF 2026: Lightweight, ENF-Grade Interior Solution **By kevin c** · 2026-08-26 > This article explains how PET foam sheet combined with [panel sandwich](https://www.bigbahn.de/pages/pet-foam-board) construction helps European RV, caravan, and marine OEMs reduce vehicle weight, meet the 2027 REACH Annex XVII Entry 77 formaldehyde threshold (0.062 mg/m³), and pass ECE R118 Rev. 03 fire behavior tests. It is written for buyers attending **CARAVAN SALON DÜSSELDORF 2026** who are evaluating lightweight, ENF-grade interior panels from a Germany-based source factory. Booth reference: **Hall 13, Stand A94 (13A94)**. ![](https://cdn.shopify.com/s/files/1/0746/2951/3390/files/CARAVAN_SALON_DUSSELDORF_2026.jpg?v=1787711675) ## Introduction  The European caravan industry is entering the most demanding regulatory window in a generation. From **6 August 2027**, REACH Annex XVII Entry 77 caps formaldehyde emissions from road-vehicle interior components at **0.062 mg/m³** (or 0.062 ppm in chamber tests) — a level most conventional wood-based panels cannot meet without additional treatment. At the same time, RV buyers expect lighter vehicles for higher payload and better fuel economy, and EU type-approval under **Regulation (EU) 2018/858** keeps fire behavior under tighter scrutiny via **ECE R118 Rev. 03** for M2/M3 category vehicles. For OEM buyers visiting **CARAVAN SALON DÜSSELDORF 2026**, the practical question is simple: which lightweight core material can deliver low weight, low emission, and proven fire performance in one panel sandwich system? This article answers that question by breaking down [PET foam sheet](https://www.bigbahn.de/pages/pet-foam-board) as a core layer and walking through the panel sandwich architecture that BIGBAHN supplies to European caravan manufacturers. ## What Is PET Foam Sheet? PET foam sheet (also called PET foam board) is a closed-cell thermoplastic foam core extruded from polyethylene terephthalate (PET). Unlike open-cell PU foam or PVC foam, the closed-cell structure means each cell is sealed — water cannot migrate through the panel, and the foam does not absorb moisture even after long-term exposure in a caravan sidewall or marine bulkhead. ![HPL PET Board](https://cdn.shopify.com/s/files/1/0746/2951/3390/files/Bigbahn-HPL-PET_1.jpg?v=1785221354) Key technical properties relevant to caravan interiors: - **Density range:** typically 60–200 kg/m³, allowing panel sandwich designers to tune weight vs. stiffness - **Closed-cell structure:** < 1% water absorption (vs. 5–15% for open-cell PU foam) - **Thermal stability:** service temperature -40 °C to +80 °C, covering Nordic winters and southern European summers - **Recyclable:** PET is a mono-material stream in the European recycling infrastructure, supporting circular-economy sourcing policies BIGBAHN supplies PET foam board as a stock item and as a custom-cut core for [panel sandwich](https://www.bigbahn.com/pages/pet-foam-board) assemblies, with thicknesses from 10 mm to 50 mm and density grades for wall, ceiling, and furniture sub-structures. ## Why PET Foam + Panel Sandwich for Caravan Interiors? A panel sandwich is a three-layer composite: two face skins (typically [HPL](https://www.bigbahn.com/pages/high-pressure-laminate), [compact laminate](https://www.bigbahn.com/pages/compact-laminate), decorative film, or aluminum) bonded to a lightweight core. The face skins carry bending stress; the core keeps the skins apart and resists shear. This is the same architecture used in aircraft flooring and high-speed train interiors — and it is exactly what caravan OEMs need to balance weight, stiffness, and fire performance. ![](https://cdn.shopify.com/s/files/1/0746/2951/3390/files/PET_Foam_Sandwich_Panels.jpg?v=1784418102) For caravan interior walls, ceilings, and furniture fronts, the panel sandwich approach delivers: Performance Target Conventional Solid Panel PET Foam + Panel Sandwich Weight per m² (15 mm) 11–13 kg **3.5–5 kg** Bending stiffness High Comparable at lower weight Formaldehyde emission E1 / E0 typical **ENF grade (< 0.062 mg/m³)** Fire behavior Variable **ECE R118 Rev. 03 compliant** Moisture absorption Swells over time **< 1% (closed-cell)** Recyclability Mixed materials **PET mono-stream recyclable** ![](https://cdn.shopify.com/s/files/1/0746/2951/3390/files/The_Ultimate_2026_Guide_to_RV_Conversion_Materials.jpg?v=1784077280) The weight saving is the most visible benefit: a typical 6-meter caravan with ~25 m² of interior panel surface can shed **150–200 kg** by switching from 15 mm plywood to a 15 mm PET foam panel sandwich. That is roughly one full passenger plus luggage — translating directly into payload capacity, towing ease, and fuel economy. ## REACH Annex XVII Entry 77: The 2027 Compliance Cliff REACH (EC) No 1907/2006 Annex XVII Entry 77 is the single most important regulation shaping European caravan interior sourcing in 2026–2027. The clause restricts formaldehyde release from composite wood and finished articles placed on the EU market. Two key dates: - **6 August 2026** — Entry 77 becomes applicable to furniture and wood-based articles (E1 limit 0.124 mg/m³) - **6 August 2027** — Tighter limit of **0.062 mg/m³** applies to **road vehicle interior components** (covers M2/M3 categories; many caravan OEMs voluntarily extend the rule to leisure vehicles) Sources: [EUR-Lex REACH consolidated text](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02006R1907-20240401) and [ECHA REACH Annex XVII](https://echa.europa.eu/appendices-to-the-reach-regulation/-/legislationlist/container/EU-REACH-ANNEX). For caravan buyers sourcing panel sandwich systems, the math is direct: [ENF-grade](https://www.bigbahn.de/blogs/product-education/what-does-enf-grade-mean-and-how-is-it-different-from-e0-e1-carb-standards) panels emit ≤ 0.025 mg/m³, which means they meet the 2027 road-vehicle threshold today. ENF stands for "Eco-No-Formaldehyde" in the Chinese GB/T 39600 standard, equivalent to the lower bound of the European E0 class and well below E1. ![](https://cdn.shopify.com/s/files/1/0746/2951/3390/files/EFN.jpg?v=1784412287) For practical sourcing, ask suppliers for three documents before signing a frame agreement: Document Purpose EN 717-1 chamber test report Verifies emission in mg/m³ at climate 23 °C / 45% RH REACH Entry 77 declaration of conformity Confirms 2027 readiness for road-vehicle interior CARB Phase 2 certificate Indicates compliance with the US/EU low-emission benchmark ## Fire Behavior for Caravan Interiors UN ECE R118 Rev. 03 specifies burning behavior for materials used in the interior of M2 and M3 category vehicles (buses and coaches, with extension practices into motorhomes and caravans). The test measures horizontal burn rate, vertical burn rate, and melt-drip behavior on a representative material sample. Source: [UNECE R118 Rev. 03](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:42013X1112\(01\)). For panel sandwich systems, fire behavior is determined by the weakest layer — usually the core. This is why PET foam sheet is preferred over PU foam: PET is intrinsically flame-retardant at the polymer level, has a limiting oxygen index (LOI) around 22–24%, and produces low-smoke, low-toxicity emissions under combustion. Combined with HPL or compact laminate face skins, the assembled panel sandwich can pass ECE R118 Rev. 03 Annex 6 / Annex 7 tests at typical 10–30 mm thicknesses. A practical sourcing matrix for fire-rated panel sandwich: Application Core Face Skin Typical Test Reference Caravan sidewall PET foam 20 mm HPL 0.8 mm ECE R118 Rev. 03 Annex 6 Caravan ceiling PET foam 15 mm Aluminum 0.5 mm + decorative film ECE R118 Rev. 03 Annex 7 Furniture front PET foam 25 mm Compact laminate 3 mm ECE R118 Rev. 03 Annex 6 Marine bulkhead PET foam 30 mm HPL 1.0 mm IMO Res. A.653 (related) ## Habitable Vehicle Health & Safety EN 1646-1 is the European standard for habitable vehicles including caravans and motorhomes, covering ventilation, heating, gas installation, and — relevant for panel sandwich buyers — the fire safety and emission behavior of interior materials. The standard cross-references EN 717-1 (formaldehyde emission by chamber test method) for the wood-based panels that make up most interior surfaces. For caravan OEMs sourcing PET foam + panel sandwich systems, the EN 1646-1 + EN 717-1 combination ensures: - Formaldehyde release ≤ ENF grade (which is also below REACH Entry 77 road-vehicle threshold) - No harmful emissions during normal occupation (verified by chamber test) - Material behavior consistent with habitable space expectations (no off-gassing above EN limits) BIGBAHN's **PET foam board** is tested against EN 717-1 and reaches ENF grade as standard; the assembled panel sandwich systems are also supplied with an EN 1646-1 compliance dossier on request, covering fire, emission, and mechanical performance. ## PET Foam Sheet vs Alternative Core Materials The most common panel sandwich cores competing with PET foam are PVC foam, PU foam, and honeycomb (PP / aluminum). The table below summarizes the trade-offs for caravan interior applications. Property PET Foam PVC Foam PU Foam PP Honeycomb Density (kg/m³) 60–200 50–200 30–80 40–80 Closed-cell ✅ Yes ✅ Yes ❌ No ✅ Yes Water absorption < 1% < 1% 5–15% < 1% Recyclability PET mono-stream PVC stream (limited) Difficult PP stream Fire behavior (LOI) 22–24% 35–40% 17–19% 17–19% Formaldehyde emission ENF ENF ENF ENF Weight (15 mm panel) ~3.5–5 kg/m² ~3.5–5 kg/m² ~2.0–2.5 kg/m² ~1.5–2.5 kg/m² Cost (relative) Medium Medium Low High Best fit Wall + ceiling + furniture Wall + marine Lightweight filler Premium ceiling Reading the table: - **PU foam** is the lightest but fails on closed-cell structure (water absorption), fire behavior, and recyclability — increasingly disqualified by European OEM specifications - **PVC foam** has the best fire performance but faces end-of-life recycling headwinds in the EU - **PP honeycomb** is excellent for premium ceiling panels but expensive and harder to laminate on curved surfaces - **PET foam** sits at the best balance point: closed-cell, recyclable, ECE R118 ready, ENF grade, and cost-competitive ![](https://cdn.shopify.com/s/files/1/0746/2951/3390/files/Full_Poplar_Plywood_a9c27609-521d-4b80-9b4e-80e4e6b5b993.jpg?v=1784077336) For caravan OEMs visiting CARAVAN SALON DÜSSELDORF 2026, the practical decision is usually: PET foam for walls, ceiling, and furniture fronts; PP honeycomb only for premium flagship ceilings where budget permits; avoid PU foam in any new design platform launched after 2026. ## BIGBAHN Booth at CARAVAN SALON DÜSSELDORF 2026 CARAVAN SALON DÜSSELDORF 2026 runs from late August to early September at Messe Düsseldorf. It is the largest caravan and motorhome trade show in Europe, drawing OEM buyers, dealer networks, and component suppliers from across the EU, UK, and North America. BIGBAHN will exhibit at **Hall 13, Stand A94 — booth number 13A94**. Visitors can inspect: - PET foam sheet samples in 10 mm / 15 mm / 20 mm / 25 mm / 30 mm thicknesses - Pre-laminated panel sandwich demonstrators with HPL, compact laminate, and decorative film face skins - [Lightweight plywood samples](https://www.bigbahn.de/collections/lightweight-plywood) for comparison - **CNC-processed** sample parts ([CNC processing capability](https://www.bigbahn.com/pages/cnc-processing)) - **PUR flat laminating** line output for face-skin bonding ([PUR laminating line](https://www.bigbahn.com/pages/pur-flat-laminating-line)) Visitors are encouraged to bring their current panel specification, BOM weight target, and target emission class (E1 / E0 / ENF) — BIGBAHN engineers will run a feasibility check on the spot and provide indicative pricing and lead time. ## CTA — Compliance-Driven > Plan your 2027 REACH Entry 77 compliance now. BIGBAHN's PET foam sheet & panel sandwich systems are tested to ENF grade (below 0.062 mg/m³) and compatible with ECE R118 Rev. 03 face-skin configurations. Visit us at CARAVAN SALON DÜSSELDORF 2026, Hall 13, Stand A94 (13A94), or request a compliance dossier + indicative quotation today via the [BIGBAHN contact page](https://www.bigbahn.com/pages/contact). OEM and ODM inquiries welcome — see [partnership options](https://www.bigbahn.com/pages/become-a-partner). **References**  - EUR-Lex. Regulation (EC) No 1907/2006 — REACH Annex XVII (consolidated). [https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02006R1907-20240401](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02006R1907-20240401) (accessed August 2026). - European Chemicals Agency (ECHA). REACH Annex XVII — Entry 77 Formaldehyde. [https://echa.europa.eu/appendices-to-the-reach-regulation/-/legislationlist/container/EU-REACH-ANNEX](https://echa.europa.eu/appendices-to-the-reach-regulation/-/legislationlist/container/EU-REACH-ANNEX) (accessed August 2026). - United Nations Economic Commission for Europe. ECE R118 Rev. 03 — Burning Behavior of Materials Used in Vehicle Interiors. [https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:42013X1112(01)](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:42013X1112\(01\)) (accessed August 2026). - European Committee for Standardization (CEN). EN 1646-1:2018 — Habitable Vehicles — Part 1: Habitation Requirements. Brussels: CEN (2018). - European Committee for Standardization (CEN). EN 717-1:2004 — Wood-Based Panels — Determination of Formaldehyde Release — Part 1: Chamber Method. Brussels: CEN (2004). - California Air Resources Board (CARB). Phase 2 Composite Wood Products Regulation. Sacramento: CARB (updated 2023). - European Union. Regulation (EU) 2018/858 — Type Approval of Motor Vehicles. [https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32018R0858](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:32018R0858) (accessed August 2026). - Messe Düsseldorf. CARAVAN SALON DÜSSELDORF 2026 — Official Show Information. [https://www.caravan-salon.com/](https://www.caravan-salon.com/) (accessed August 2026). **Tags:** 2026 Exhibition, CARAVAN SALON, ENF, Guide, PET Foam Board, types of plywood, Wet wall panels, XPS boards --- > Source: [Bigbahn](https://www.bigbahn.de/blogs/product-education/pet-foam-sheet-panel-sandwich-for-caravan-salon-dusseldorf-2026-lightweight-enf-grade-interior-solution)