Color Steel Polyurethane Sandwich Panel | PU Sandwich Panel, B1 Fire-Rated, Low Thermal Conductivity, Cold Storage & Constant Temperature Insulation Panel
1. Product Overview
Color Steel Polyurethane Sandwich Panel, commonly known as PU Sandwich Panel, is a high-end prefabricated tongue-and-groove metal-faced enclosure material. It serves as a professional dedicated panel for cold storage and constant-temperature insulation engineering. Manufactured in strict compliance with GB/T 23932 national standard for building thermal insulation sandwich panels, the product meets GB 8624 B1 flame-retardant standard and complies with EN 13501-1 Class B1 for overseas export projects.
The panel adopts a composite structure consisting of double-layer color-coated galvanized or aluzinc steel sheets and high-density rigid polyurethane foam core. It is integrally molded through automated high-pressure foaming, constant-temperature bonding and precision tongue-and-groove forming processes. Featuring a high closed-cell ratio, ultra-low water absorption and industry-leading thermal insulation performance, the product integrates energy-saving insulation, lightweight structural design, waterproof sealing, weather corrosion resistance and B1 flame-retardant safety. It is widely applied in cold storage rooms, constant-temperature workshops, dust-free cleanrooms and high-standard industrial buildings, acting as the optimal prefabricated envelope solution for modern energy-efficient construction projects.
2. Core Structural Composition
Metal Surface Sheet
Adopts premium color-coated galvanized or aluzinc steel sheets. The standard double-sided zinc coating weight reaches ≥80g/㎡, upgradable to ≥180g/㎡ for outdoor high-corrosion environments. Available substrate grades include DC51D and S250GD, matched with PE, HDP and PVDF weather-resistant coating systems. The compact and smooth surface delivers excellent UV resistance, acid and alkali resistance, and anti-ageing stability, ensuring long-term service life without fading, peeling or surface deterioration.
PU Thermal Insulation Core
Constructed with high-density rigid polyurethane foam core with a closed-cell rate ≥90%. The dense uniform cellular structure provides ultra-low water absorption and superior vapor barrier performance, effectively resisting moisture penetration, mildew growth and core swelling in high-humidity working conditions. Featuring ultra-low thermal conductivity and outstanding dimensional stability, the PU core maintains consistent insulation performance during long-term constant-temperature and humid operation. It achieves B1 flame-retardant grade with self-extinguishing, low-smoke and low-toxicity characteristics, meeting high-standard building fire safety requirements.
Precision Tongue-and-Groove Connection Structure
Adopts standardized male-female tongue-and-groove interlocking design for tight seamless assembly. The optimized structural joint delivers excellent airtightness and watertightness, effectively reducing air convection loss, heat transmission, water penetration and surface condensation. It fundamentally solves common problems such as cold energy dissipation and internal moisture accumulation in cold storage and constant-temperature building envelopes.
3. Core Product Advantages
Industry-leading Constant-temperature Insulation & High Energy Savings
The PU core features ultra-low thermal conductivity ≤0.024W/(m·K) (tested at 25℃), providing top-tier thermal insulation performance among conventional building insulation materials. The high-density closed-cell structure stably locks indoor temperature, greatly reducing cooling and heating energy consumption for cold storage and constant-temperature facilities, delivering significant long-term energy-saving benefits.
B1 Grade Flame Retardant & Reliable Fire Safety
The integral panel fully complies with GB 8624 B1 flame-retardant standard. With self-extinguishing, flame-resistant, low-smoke and non-toxic properties, it effectively restricts flame spreading and heat radiation, satisfying fire safety specifications for high-standard factories, constant-temperature buildings and storage warehouses.
High Closed-cell Structure & Superior Moisture Resistance
With a closed-cell rate ≥90% and minimal water absorption, the compact core structure thoroughly blocks water vapor infiltration. It remains structurally stable without dampness, mildew or deformation in long-term high-humidity environments, perfectly adapting to cold chain logistics, humid regions and other harsh scenarios.
Lightweight Design & High Structural Stability
The lightweight composite structure effectively reduces the overall load of the steel building frame. The integrally bonded panel features high rigidity, excellent compression and bending resistance, flat surface finish and stable dimensional performance, avoiding long-term structural deformation and warping.
Seamless Tongue-and-Groove Sealing & Cold Bridge Prevention
Precision interlocking tongue-and-groove joints, combined with professional hidden-fastener roofing systems, achieve full tight sealing. The structure delivers outstanding windproof, waterproof and airtight performance, significantly reducing cold bridge generation and condensation risks and optimizing overall building envelope thermal insulation efficiency.
Full Factory Prefabrication & Efficient Construction
All panels are integrally prefabricated and formed in the factory, supporting direct on-site assembly. No secondary insulation treatment, plastering or waterproof construction is required, simplifying working procedures and greatly shortening the overall project construction cycle.
4. Standard Specifications & Technical Parameters
Execution Standards: GB/T 23932, GB 8624, EN 13501-1 (optional for export)
Qualification Documents: Full performance test reports for thermal insulation, fire resistance and physical indicators are available
Available Thickness: 50mm, 75mm, 100mm, 150mm, 200mm
Standard Effective Width: 950mm, 1150mm
Steel Sheet Thickness: 0.25mm–0.6mm (fully customizable)
Substrate & Coating Solution: DC51D / S250GD galvanized & aluzinc substrate; PE / HDP / PVDF weather-resistant coatings optional
Zinc Coating Weight: ≥80g/㎡ (standard), upgradable to ≥180g/㎡ for harsh outdoor corrosive environments
Custom Length: Max standard length 12m; extended customized lengths available
Profile Type: Flat wall panel, corrugated roof panel, hidden-fastener roof panel
Roof Uniform Load Capacity: ≥1.5kN/㎡ (refer to engineering technical data)
Compressive Strength: ≥150kPa (tested per GB/T 23932)
Thermal Conductivity: ≤0.024W/(m·K) @25℃
Overall Heat Transfer Coefficient (U-value): Approximately 0.22 W/(m²·K) for 100mm thickness
PU Core Density: ≥35kg/m³ (conventional range: 35–45kg/m³)
Closed-Cell Rate: ≥90%
Fire Rating: GB 8624 B1 Flame-Retardant (self-extinguishing, low smoke, non-toxic)
Long-term Operating Temperature: -50℃ ～ +120℃
5. Application Scenarios
Cold Chain & Cold Storage Engineering: Professional insulation panels for low-temperature cold rooms, fresh-keeping warehouses, cold chain logistics stations, quick-freezing workshops and refrigerated facility insulation systems.
Dust-free & Constant-temperature Workshops: Specialized enclosure panels for pharmaceutical factories, food processing plants, dust-free workshops and constant-temperature & humidity-controlled production spaces.
High-end Steel Structure Buildings: Thermal insulation and decorative wall & roof enclosure systems for high-standard industrial factories, exhibition centers and commercial buildings.
High-standard Prefabricated Buildings: Insulated constant-temperature prefab houses, medical shelters and customized energy-saving temporary buildings.
High-humidity Insulation Scenarios: Enclosure insulation for agricultural constant-temperature greenhouses and humid industrial workshops.
Extreme Climate Adaptation Projects: Wall and roof thermal insulation for buildings in severe cold regions, featuring stable low-temperature resistance and anti-condensation performance.
6. Standard Installation Method
This tongue-and-groove prefabricated panel supports flexible wall and roof integrated installation, featuring neat appearance, high airtightness and excellent cold bridge suppression performance, fully adapted to cold storage and constant-temperature high-standard engineering requirements.
Wall Panel Installation: Interlock panels tightly and fix them on steel purlins with galvanized or stainless steel anti-corrosion self-tapping screws at a maximum spacing of 300mm. Calibrate verticality via laser level to ensure flat and firm wall surface. For cold storage projects, fully fill all panel joints with professional sealant to eliminate cold bridge gaps.
Roof Panel Installation: Adopt hidden-fastener mounting system with concealed fixers under panel ribs to achieve screw-free exterior. Install dedicated sealing gaskets at overlapping joints and apply waterproof sealant for dual protection to effectively prevent water infiltration and indoor condensation.
Special Cold Storage Detailed Treatment: Adopt arc transition processing at wall-floor connection positions to eliminate dead corners, ensuring overall airtightness and continuous thermal insulation performance.
Ceiling Installation Standard: For load-bearing ceiling applications, strictly calculate and arrange hanger spacing according to actual load demands to guarantee long-term structural safety and stability.
Integrated Detail Sealing: Match professional trimming accessories for eaves, ridges, gables and internal & external corners to fully block cold bridges and improve overall building thermal insulation and airtight performance.
Construction Environment Requirements: Avoid construction under ambient temperature of 5℃ or below to ensure normal curing and bonding effect of foaming layers and sealing materials.
Cutting & Anti-corrosion Protection: Use fine-tooth saws for precise cutting to prevent core damage. All cutting sections are coated with epoxy zinc-rich primer for anti-rust treatment to extend panel service life.
7. Product Summary
Complying with GB/T 23932 and GB 8624 B1 flame-retardant standards, Color Steel Polyurethane Sandwich Panel features ultra-low thermal conductivity, ≥90% high closed-cell rate and lightweight composite structure. With outstanding constant-temperature insulation, excellent moisture resistance and safe flame-retardant performance, it supports full factory prefabrication and fast on-site assembly. As a high-efficiency energy-saving building envelope material, it is widely used in cold storage cold chain systems, dust-free constant-temperature workshops and various high-humidity, high-standard insulated building projects.For other thermal insulation solutions for steel structures, please check Glass Wool Blanket and Rock Wool Blanket.
