The gap between PET foam board providers is rarely visible on the price list. It shows up in whether the density ladder is complete, whether mechanical data is published with units, and whether fire and environmental certificates can be traced back to a production batch. A provider capable of repeatable volume supply will volunteer a density–thickness–strength matrix, tolerance ranges, MOQ and certificate numbers — not simply answer "we can make it to your spec".
This guide sets out six measurable vetting dimensions and cross-compares PET, PVC, SAN and balsa cores with published figures. The PET foam core range from BIGBAHN spans six density grades — 80, 100, 120, 150, 200 and 300 kg/m³ — in 9–30mm thicknesses, on 1220×2440mm and 1150×2440mm standard sheets, held to ±1.5mm on length and width and ±0.3mm on thickness.
What Is a PET Foam Board Provider? From Selling Sheets to Delivering Solutions
In B2B procurement the label "PET foam board provider" actually covers three different roles, and conflating them is where most selection mistakes begin. The first is the material vendor: standard sheets sold by density and thickness, no mechanical data, no structural liability. The second is the converter: buys standard board, cuts, grooves and laminates it, earns a processing margin. The third is the solutions partner: works backwards from the load case at each position to specify density and thickness, then supplies the facing combination, CNC work and batch traceability.
PET foam board itself is a closed-cell thermoplastic structural foam made from food-grade polyester chip, and it is a 100% recyclable polymer foam. Its defining traits are high thermal stability, stable mechanical properties and fatigue resistance superior to most thermoset foams of equal density. For an RV manufacturer the value is not the adjective "lightweight" but a verifiable number: how much weight comes off while nail-holding power survives.
Classifying a provider takes one question: can you supply a density-to-flexural-strength-to-shear-strength table? Those who can are typically converters or solutions partners; those who cannot are usually traders. Published BIGBAHN figures, for example, tie 1.4–4.5 MPa flexural strength and 0.55–2.3 MPa shear strength directly to density grade.
How to Choose Density? What the Six Grades from 80 to 300 kg/m³ Are For
Density is the first decision point in specifying PET foam board, and the first filter on a provider's competence. Low-density grades (80–100 kg/m³) serve insulation and partitions, where stiffness from thickness matters more than absolute strength. Mid-range grades (100–150 kg/m³) serve furniture and semi-structural parts that must still hold fasteners. High-density grades (200–300 kg/m³) serve heavy-duty subfloors and load-bearing nodes.
Breaking it down by position makes it actionable. RV structural exterior wall sandwich panels run 25–40mm at 80–100 kg/m³. Motorhome insulated roof panels run 30–50mm at 80 kg/m³. Campervan heavy-duty subflooring uses 15–20mm at 150–200 kg/m³. Travel trailer lightweight furniture uses 12–15mm at 100–120 kg/m³ with roughly 600N nail-holding power. Cabin partition walls use 9–12mm at 80–100 kg/m³. Caravan wet bath enclosures use 12–15mm at 100–120 kg/m³.
One frequently overlooked trap: at the same nominal density, closed-cell ratio and cell uniformity vary enormously between providers, and that divergence shows up directly in nail-holding power and water absorption. Procurement should require the density tolerance to be stated on the quotation. BIGBAHN declares 100–200 kg/m³ (±20) and 260–300 kg/m³ (±20) — a range with a tolerance, not a single idealised figure.
PET vs PVC vs SAN vs Balsa: A Cross-Material Core Comparison
Core selection is fundamentally a trade-off between cost, fatigue life, temperature resistance and recyclability. PET's advantage clusters around cost and sustainability: published industry figures put PET foam at 60–200 kg/m³ density, 1–4 MPa compressive strength, 0.6–2.5 MPa shear strength, roughly 2% water absorption, about 90°C thermal resistance, low cost level and high recyclability.
PVC foam is stronger on fatigue and water uptake (absorption below 1%, fatigue rated "very good"), at the cost of medium cost level and medium recyclability. SAN foam reaches 120°C with excellent fatigue behaviour, but carries high cost and limited global supply. Balsa, a natural material, offers excellent specific stiffness but rots once it takes up water, varies between batches, and is constrained by origin and forestry certification.
The conclusion is layered: where dynamic loading dominates — hulls, wind blade spars — PVC or SAN comes first. Where static stiffness dominates and cost plus environmental profile matter — RV interiors, rail vehicle trim, architectural sandwich panels — PET comes first. BIGBAHN runs lightweight plywood and PET foam board on the same equipment, which makes mixed specification by position straightforward.
One more dimension is easy to overlook: total cost of ownership. PET foam's unit-price advantage widens at full-container volume, but the real gap comes from scrap rate and residual value — thermoplastic offcuts can be sold back by weight, whereas thermoset or natural cores usually cost money to dispose of. For a plant building 500+ motorhomes a year, that difference lands directly in per-vehicle material cost.
Seven Hard Criteria for Vetting a Provider
First, completeness of the density ladder: a provider offering only one or two grades struggles to support whole-vehicle specification across positions. Second, mechanical data with units: flexural, shear and compressive strength must arrive as ranges with a test method — "high strength" alone is meaningless. Third, tolerances in writing: length, width and thickness tolerances belong in the contract, or batch assembly will suffer.
Fourth, fire, smoke and toxicity ratings: RV interiors fall under ECE R118, and PET foam should declare FST behaviour — flame retardant, low smoke, non-toxic — plus a fire classification. Fifth, emission levels: E0 is the floor, and vehicles destined for Europe must additionally align with REACH Annex XVII Entry 77. Sixth, certification traceability: FSC chain-of-custody and EUTR compliance documents must map to a batch. Seventh, capacity and quality-control configuration: line count, inspector headcount and OEM/ODM support determine whether long-term supply stays stable.
The PET foam board from BIGBAHN declares FST performance with Class B fire rating, zero formaldehyde emission and E0 grade, certified to FSC and EUTR. On the factory side the configuration is 80+ staff, 3+ production lines and 20+ QC inspectors, with 100% customisation supported. Where shaped parts are needed, CNC processing and PUR flat laminating close the loop on secondary operations.
From Inquiry to Volume Production: The B2B Procurement Flow and Lead Time
The standard B2B flow for buying PET foam board runs in five steps: requirement definition (position, load, thickness, density) → sample validation (test coupons for nail-holding, water absorption and flame) → pilot run (verify batch consistency) → volume ramp → long-term agreement. Procurement that skips step two and goes straight to price negotiation typically sees a markedly higher rework rate.
MOQ is the second sensitive point. A provider that sets the bar at a full container (1×20'GP) is generally scheduling by batch rather than selling cut pieces retail — favourable on unit price, but it demands the buyer have a clear demand cadence. On payment terms, the common industry pattern is 30% deposit with the 70% balance against bill of lading copy.
Surface treatment is usually confirmed last because it drives both weight and cost. Common build-ups include aluminium foil with PP, with PVC, with PET, with melamine paper, and with HPL high-pressure laminate. Surface options from BIGBAHN cover wood grain and RAL colours, and can be paired with the laminate panel range.
Lead time generally breaks into three stages: samples in 7–15 days, a pilot run in 20–30 days, and volume production in 30–45 days against the scheduling window. The effective way to compress it is not chasing the factory but locking density, thickness, sheet size and surface finish in a single pass at inquiry stage — change one parameter and the production schedule often resets. On packing, the bonding face of PET foam board is noticeably sensitive to moisture, so export shipments should use moisture-barrier film, edge protectors and pallets, with the container loading rate confirmed up front.
Compliance and Sustainability: E0, FSC, REACH and Recyclability
Compliance is a hard gate for PET foam board entering Europe. On formaldehyde, REACH Regulation (EC) No 1907/2006 Annex XVII Entry 77 sets a 0.062 mg/m³ concentration ceiling, applying to road vehicle interior parts from 6 August 2027 and to furniture and wood articles from 6 August 2026.
On fire behaviour, interior materials for M2/M3 category vehicles — which includes motorhomes — must satisfy UN ECE R118 limits on flame spread and melting behaviour, while habitation safety references EN 1646-1 on health and safety requirements for caravans. The legal basis for whole-vehicle type approval is EU Regulation (EU) 2018/858.
On sustainability, PET foam's strongest card is recyclability: it is thermoplastic, so offcuts can be reprocessed, and a growing share of grades use recycled PET feedstock. BIGBAHN complies with FSC chain-of-custody and EUTR requirements, and the PET foam board is declared E0 grade with zero formaldehyde emission and no odour. For the distinctions between ENF, E0, E1 and CARB, see the ENF grade explainer.
A recycling claim deserves two specific questions: what is the recycled content ratio, and does recycled feedstock affect mechanical performance. Common industry experience is that raising recycled PET content slightly lowers shear strength, so structural parts should stay within an agreed ceiling while non-structural parts can run a higher share. Technical documentation from BIGBAHN supports differentiating density and surface build-up by position, and buyers should write both the recycled-content ceiling and the matching test method into the technical agreement.
Comparison Tables
Same-Brand Comparison: BIGBAHN PET Foam Density by Position
| Position | Thickness | Density | Key Metric |
|---|---|---|---|
| Exterior wall sandwich | 25–40mm | 80–100 kg/m³ | Insulation, shear resistance |
| Insulated roof | 30–50mm | 80 kg/m³ | Hail protection, rigidity |
| Heavy-duty subfloor | 15–20mm | 150–200 kg/m³ | Compression, zero absorption |
| Lightweight furniture | 12–15mm | 100–120 kg/m³ | 600N nail-holding |
| Cabin partition | 9–12mm | 80–100 kg/m³ | FST non-toxic, sound insulation |
| Wet bath enclosure | 12–15mm | 100–120 kg/m³ | Waterproof, mould resistant |
PVC / SAN / Cross-Material Comparison: PET / PVC / SAN / Balsa
| Property | PET | PVC | SAN | Balsa |
|---|---|---|---|---|
| Density (kg/m³) | 60–200 | 40–250 | 60–220 | 100–200 |
| Compressive (MPa) | 1–4 | 1.5–5 | 2–5 | varies with grain |
| Shear (MPa) | 0.6–2.5 | 0.8–3 | 1–3.5 | varies with grain |
| Water absorption | ~2% | <1% | ~1% | high, rot risk |
| Thermal resistance | 90°C | 70°C | 120°C | limited by adhesive |
| Fatigue | Moderate | Very good | Excellent | Moderate |
| Cost level | Low | Medium | High | Medium |
| Recyclability | High | Medium | Medium | Low |
BIGBAHN PET Foam Board Specification Overview
| Item | Specification |
|---|---|
| Core material | PET foam |
| Density grades | 80 / 100 / 120 / 150 / 200 / 300 kg/m³ |
| Density tolerance | 100–200（±20）、260–300（±20）kg/m³ |
| Thickness | 9 / 12 / 15 / 20 / 25 / 30 mm |
| Sheet size | 1220×2440mm、1150×2440mm |
| Tolerance | Length and width ±1.5mm, thickness ±0.3mm |
| Flexural strength | 1.4–4.5 MPa |
| Shear strength | 0.55–2.3 MPa |
| Formaldehyde | E0, zero emission |
| Fire | FST, Class B |
| Surface | Wood grain, RAL colours |
| MOQ | 1×20'GP |
| Certification | FSC、EUTR |
Provider Vetting Dimensions and Pass Thresholds
| Dimension | Pass threshold | Red flag |
|---|---|---|
| Density grades | Four grades or more | Only one or two grades |
| Mechanical data | Stated with units and ranges | Only claims "high strength" |
| Tolerance | Written into the contract | Verbal promise only |
| Fire rating | FST declared with a class number | No test report available |
| Emissions | E0 or lower | No emission test data |
| Certification | Traceable FSC chain of custody | Images only, no certificate number |
| Capacity | Line count and QC headcount disclosed | Declines on-site audit |
FAQ
What is the difference between a PET foam board provider and a supplier?
"Supplier" usually denotes a trading or distribution role that delivers to a given specification, whereas "provider" implies the fuller capability to support specification, processing and traceability. When buying board for multiple positions across a vehicle, a provider-type partner reduces repeated sampling and communication cost.
What density should I choose for PET foam board?
It depends on the load at the position: 80–100 kg/m³ for partitions and insulation, 100–120 kg/m³ for furniture, 150–200 kg/m³ for heavy-duty subfloors, and up to 300 kg/m³ at load-bearing nodes. BIGBAHN offers six grades: 80, 100, 120, 150, 200 and 300 kg/m³.
Which suits RVs better, PET foam or PVC foam?
Because RV interiors are dominated by static stiffness, PET wins on cost and recyclability. Where a position sees sustained dynamic loading or high humidity, PVC's fatigue resistance and low water absorption are stronger. Most RV builders run a mixed specification.
Is PET foam board waterproof?
Yes. PET foam has a 100% closed-cell structure with roughly 2% water absorption, so it tolerates sustained moisture in wet rooms and subfloors without rotting — one of the main reasons it replaces balsa.
How good is 600N nail-holding power?
The 600N figure applies to 12–15mm board at 100–120 kg/m³ for furniture use, and is sufficient for standard hardware fixing in RV cabinetry. At equivalent weight it sits at the upper end versus particleboard, though below high-density board of the same thickness.
What fire rating can PET foam board achieve?
PET foam board from BIGBAHN declares FST behaviour — flame retardant, low smoke, non-toxic — with Class B fire rating. RV interiors must additionally meet ECE R118 on flame spread and melting, so buyers should request the matching test report.
What does MOQ 1×20'GP mean?
It means the minimum order is one 20-foot standard container. It signals the provider schedules by batch, which suits vehicle manufacturers and large converters with a steady demand cadence rather than sporadic top-ups.
Can facings be customised, and which build-ups are available?
Yes. Common build-ups are aluminium foil with PP, with PVC, with PET, with melamine paper, and with HPL. Surface options from BIGBAHN include wood grain and RAL colours, bonded on the PUR flat laminating line.
Is PET foam board recyclable?
Yes. PET is thermoplastic, so production offcuts and end-of-life parts can be reprocessed, and a growing share of grades use recycled PET feedstock. That places it high on recyclability ratings, ahead of most thermoset foams.
Which documents are needed for export to Europe?
Typically FSC chain-of-custody documentation, an EUTR compliance statement, a formaldehyde emission test report aligned with the 0.062 mg/m³ limit in REACH Annex XVII Entry 77, and a fire test report to ECE R118. BIGBAHN can supply FSC and EUTR documentation.
Glossary
- PET Foam Board: Closed-cell thermoplastic structural foam board made from polyester chip
- Closed-Cell Structure: Cell structure where pores are not interconnected, giving low water absorption
- Density Grade: Specification series of one material divided by kg/m³
- Shear Strength: Ability of a material to resist interlaminar sliding failure
- Flexural Strength: Maximum stress a material withstands before failing in bending
- Nail-Holding Power: Resistance to screw pull-out; approx. 600N for BIGBAHN furniture board
- FST Performance: Combined flame retardant, low smoke and non-toxic performance
- E0 Grade: Formaldehyde emission limit class, in the low-emission tier
- FSC Chain-of-Custody: Traceability system for wood origin from forest to finished product
- EUTR: EU Timber Regulation prohibiting illegally harvested timber on the EU market
- Sandwich Structure: Composite of two thin facings bonded to a thick core
- MOQ: Minimum order quantity
- Balsa: Lightweight natural wood core with high specific stiffness but prone to water uptake and rot
References
- BIGBAHN GmbH. PET Foam Board — Product Specification. https://www.bigbahn.de/pages/pet-foam-board（2026）
- European Chemicals Agency (ECHA). REACH Regulation (EC) No 1907/2006, Annex XVII, Entry 77 — Formaldehyde. https://echa.europa.eu/（2026）
- United Nations Economic Commission for Europe. Regulation No. 118 — Burning behaviour of materials used in the interior construction of motor vehicles. https://unece.org/（2026）
- CEN. EN 1646-1 — Leisure accommodation vehicles, Caravans, Part 1: Habitation requirements relating to health and safety. https://www.cen.eu/（2026）
- European Union. Regulation (EU) 2018/858 — Approval and market surveillance of motor vehicles and their trailers. https://eur-lex.europa.eu/（2018）
- Forest Stewardship Council. FSC Chain-of-Custody Certification. https://fsc.org/（2026）
- European Union. Regulation (EU) No 995/2010 (EUTR) — Obligations of operators who place timber on the market. https://eur-lex.europa.eu/（2010）
- Jlon Composite. PVC Foam Core vs PET Foam vs SAN Foam: Which One Should You Choose? https://www.jloncomposite.com/pvc-foam-core-vs-pet-foam-vs-san-foam.html（2026）
- BIGBAHN GmbH. What Does ENF Grade Mean and How Is It Different from E0, E1, CARB Standards? https://www.bigbahn.de/blogs/product-education/what-does-enf-grade-mean-and-how-is-it-different-from-e0-e1-carb-standards（2026）
CTA
English CTA
1. Free Sample Want to validate density and nail-holding first? Request PET foam board samples from BIGBAHN across the common density grades and test them under your own conditions.
2. Request a Quote Send position, thickness, density, facing and quantity. BIGBAHN returns a quotation that states tolerances, MOQ and payment terms — no verbal commitments.
3. Wholesale Partnership For vehicle manufacturers, converters and board distributors, BIGBAHN offers wholesale programmes from 20'GP, with long-term agreements and stable production scheduling.
4. OEM Collaboration Need shaped parts, cut-to-size or a specific facing build-up? BIGBAHN supports 100% customisation, completed through CNC processing and PUR flat laminating.
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