Sep . 22, 2026 09:53 Back to list

XPS, EPS, PU, or PP Honeycomb? Choosing the Right Core Material for Your Sandwich Panel Project

FRP (Fiberglass Reinforced Plastic) sandwich panels are lightweight, highly durable composite structures engineered for demanding applications. By combining high-strength glass fiber outer skins with lightweight core materials, these panels deliver high impact resistance, chemical protection, and structural stability.

Choosing the appropriate core material—XPS, EPS, PU, or PP Honeycomb—is crucial for balancing load capacity, thermal insulation, moisture resistance, and overall project cost.

Core Material Selection Guide

PU (Polyurethane) Core — Premium Thermal Insulation

• Key Features: Outstanding thermal efficiency, seamless bonding, and rigid structural integration.

• Best For: Cold storage rooms, refrigerated truck bodies, climate-controlled cleanrooms, and freezer boxes.

XPS, EPS, PU, or PP Honeycomb? Choosing the Right Core Material for Your Sandwich Panel Project

XPS (Extruded Polystyrene) Core — High Moisture Resistance & Compression

• Key Features: Closed-cell structure, zero moisture absorption, excellent compressive strength, and steady thermal resistance.

• Best For: RV side walls and roofs, cold chain logistics, marine decks, and underfloor insulation.

XPS, EPS, PU, or PP Honeycomb? Choosing the Right Core Material for Your Sandwich Panel Project

PP (Polypropylene) Honeycomb Core — Ultra-Lightweight & Impact Resistant

• Key Features: Exceptional strength-to-weight ratio, vibration damping, shock absorption, and 100% water resistance.

• Best For: Dry freight truck bodies, commercial vehicle flooring, portable cabins, and lightweight partition walls.

XPS, EPS, PU, or PP Honeycomb? Choosing the Right Core Material for Your Sandwich Panel Project

EPS (Expanded Polystyrene) Core — Cost-Effective Structural Insulation

• Key Features: Lightweight, low thermal conductivity, highly economical for large-scale coverage.

• Best For: Prefabricated buildings, temporary shelters, modular housing, and general wall panels.

XPS, EPS, PU, or PP Honeycomb? Choosing the Right Core Material for Your Sandwich Panel Project

Technical Specifications & Core Comparison

Specification / Property	PU (Polyurethane)	XPS (Extruded Polystyrene)	PP Honeycomb	EPS (Expanded Polystyrene)
FRP Skin Thickness	1.0 mm – 3.0 mm	1.0 mm – 3.0 mm	1.0 mm – 3.0 mm	1.0 mm – 3.0 mm
Panel Thickness Range	20 mm – 150 mm	20 mm – 100 mm	10 mm – 80 mm	20 mm – 150 mm
Core Density Range	38 – 50 kg/m³	30 – 45 kg/m³	80 – 120 kg/m³	15 – 30 kg/m³
Thermal Conductivity	~0.020 – 0.024 W/m·K	~0.028 – 0.032 W/m·K	N/A (Structural Core)	~0.035 – 0.040 W/m·K
Water Absorption	Very Low (< 2%)	Negligible (< 1%)	Zero (Waterproof)	Low to Medium (< 3%)
Compressive Strength	Medium to High	High	Very High	Low to Medium
Max Panel Size	12,000 mm × 3,000 mm	12,000 mm × 3,000 mm	12,000 mm × 3,000 mm	12,000 mm × 3,000 mm
Surface Finish Options	High Gloss, Matte, Gel-coated, Smooth, Woven Roving Textured	High Gloss, Matte, Gel-coated, Smooth, Woven Roving Textured	High Gloss, Matte, Gel-coated, Anti-slip Textured	High Gloss, Matte, Smooth
Primary Advantage	Maximum Insulation	Moisture & Load Resistance	Ultra-Lightweight & Strong	Economical & Versatile

Contact our engineering experts today to discuss your technical specifications, request material samples, or get a factory-direct quote for your next project.

Phone / WhatsApp: +86-13111538632

Website: [www.zjcomposites.com]

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