Author: Site Editor Publish Time: 2025-07-28 Origin: Site
Marine engineering demands materials that conquer extreme environments—especially for deep-sea operations like ROVs (Remotely Operated Vehicles), AUVs (Autonomous Underwater Vehicles) and subsea installations. Standard buoyancy blocks often fail under structural complexity or depth pressure. That’s where custom-shaped structural rigid PVC foam by UNION COMPOSITES delivers revolutionary performance. As a DNV GL-certified[Certification] manufacturer of StruCell® rigid PVC foam boards, we engineer closed-cell structural foam solutions machined to precise geometries for unmatched marine reliability.
ROV (Remotely Operated Vehicle)
Source: https://marinesanctuary.org/blog/what-is-an-rov/
AUV (Autonomous Underwater Vehicle)
Source: https://oceanobservatories.org/marine-technologies/robotic-auvs/
PVC foam is a lightweight, closed-cell, cross-linked polymer material created by foaming polyvinyl chloride resin. Its honeycomb-like structure (>95% closed-cell content) delivers an exceptional strength-to-weight ratio while resisting water ingress and chemical corrosion. Unlike open-cell foams, PVC foam maintains buoyancy stability even at depths exceeding 1000 meters.
For more details, please refer to the article: <What is PVC Foam and Why PVC Foam?>
PVC FOAM
Structural PVC foam, such as UNION’s StruCell® series, is engineered as a load-bearing core material for composite sandwich structures. Structural PVC foam serves as the rigid core material in sandwich composites, combining lightweight properties with exceptional strength. UNION’s foam is trusted by naval architects and ROV manufacturers. When laminated with fiberglass or carbon fiber, it creates ultra-strong yet lightweight panels ideal for:
· Submersible housings
· Ship hulls and decks
· Offshore platform components
· Buoyancy modules
· Hull reinforcements
· Deep-sea applications
Some Application Scenarios of Rigid Structural PVC Foam
Structural PVC foam acts as the "reinforced steel" in composite sandwich panels, providing:
· Rigidity for load-bearing marine components (hulls, bulkheads)
· Machinability for CNC-shaped buoyancy modules
· Chemical resistance to saltwater, oils, and UV radiation
Structural PVC Rigid Foam in Composite Sandwich Panel
As a DNV GL-certified manufacturer, UNION delivers marine-grade rigid Structural PVC foam that meets ASTM D3575 & ISO 12058-1 standards, offering:
· Density range: 45–250kg/m³ (ISO 845 tested)
· Thermal insulation: 0.035–0.055 W/m·K (ASTM C518)
· Flame resistance: UL94-HB rated (self-extinguishing)
· High compressive strength (up to 6.2MPa)
· Minimal water absorption (<1.5%)
Trusted by naval architects & marine engineers worldwide, UNION's custom-machined rigid PVC foam ensures reliable buoyancy and structural support for harsh marine environments.
Source: DNV GL certification report for marine composites. Certificate No.: TA-DNVGL-CP-0084-04852-0
UNION-StruCell® DNV GL Certification Report & Flame Retardant Report
The Global Marine Composites Market (projected to reach $5.7B by 2028, per MarketsandMarkets[Market Data]) demands materials that:
1. Resist hydrostatic pressure at 100m+ depths
2. Maintain buoyancy stability after prolonged immersion
3. Allow complex geometries for hydrodynamics
Standard buoyancy blocks often fail to meet complex design requirements. UNION’s CNC-machined Structural PVC foam delivers tailored solutions for:
· ROV/Submarines: Precision-cut buoyancy compensators
· Shipbuilding: Lightweight decks and hull cores
· Offshore Platforms: Corrosion-resistant flotation modules
UNION offers CNC-machined rigid PVC foam in densities from P45 (45 kg/m³) to P250 (250 kg/m³), allowing engineers to optimize buoyancy-to-strength ratios. Whether you need low-density foam for shallow-water floats or high-density P200/P250 for deep-sea compression resistance, we transform your 3D designs into reality.
· Available in densities: 45kg/m³, 60kg/m³, 80kg/m³, 100kg/m³, 130kg/m³, 200kg/m³, 250kg/m³
· CNC-machined to match 3D drawings for exact fitment
Density (kg/m³) | Typical Marine Application |
60–80 | Surface-level ROV floats |
100–130 | Subsea equipment housings |
200–250 | Deep-sea buoyancy modules |
Example: A Blue Robotics ROV manufacturer used our P80 PVC foam (1.4MPa compressive strength) to reduce weight by 30% vs. syntactic foam.
StruCell® PVC foam’s sealed cellular structure prevents water intrusion, critical for long-term buoyancy stability. Testing per ASTM D2842[Test Method] shows <1.5% water absorption at atmospheric pressure—and minimal uptake even at 100m depth.
· Near-zero water absorption at atmospheric pressure.
· Stable buoyancy even at 100m+ depths.
UNION-StruCell® PVC Rigid Foam Closed-Cell Structure
Deep-sea pressure can crush inadequate materials. UNION’s rigid PVC foam excels under compression, with P250 foam resisting loads up to 6.2 MPa (equivalent to ~620m depth). The table below compares key mechanical properties:
Item | P60 | P80 | P100 | P130 | P200 | P250 |
Density ( g/m3) | 60 | 80 | 100 | 130 | 200 | 250 |
Compressive Strength(Mpa) | 0.9 | 1.4 | 2.0 | 3.0 | 4.8 | 6.2 |
Compressive Modulus(Mpa) | 70 | 90 | 135 | 170 | 240 | 300 |
Tensile Strength(Mpa) | 1.8 | 2.5 | 3.5 | 4.8 | 7.1 | 9.2 |
Tensile Modulus(Mpa) | 75 | 95 | 130 | 175 | 250 | 320 |
Shear Strength(Mpa) | 0.76 | 1.15 | 1.6 | 2.2 | 3.5 | 4.5 |
Shear Mpdulus(Mpa) | 20 | 27 | 35 | 50 | 85 | 104 |
Shear Strain(%) | 20 | 30 | 40 | 40 | 40 | 40 |
*Data sourced from UNION COMPOSITES lab tests per ASTM C365[Test], D1621[Test], and D7250[Test]. DNV GL-CP-0441 certified.
PVC foam outperforms metals in saltwater environments, resisting electrochemical corrosion and biofouling. It’s also impervious to oils, alkalis and dilute acids (per ISO 175 standards).
Submit 3D Drawings (STEP/IGES) or Physical Samples - Provide design specs.
Receive free DFM (Design for Manufacturing) analysis.
Our engineers recommend optimal density.
Select density/performance grade.
Density optimization using ANSYS FEA simulations.
Processed using CNC cutting technology in our ISO-certified factory.
Tolerance: ±0.15mm (ISO 2768-f)
Density Checks - 100% density verification (ASTM D792)
Pressure Simulations - Pressure testing up to 20MPa
Ultrasonic Scanning
No MOQ
5-7 days for prototypes
15 days for bulk orders
Small batches accepted
Global shipping with IP67 waterproof packaging
Client: A leading subsea robotics company
Challenge: Needed pressure-resistant floats for ROVs operating at 500m depth.
Solution:
· Material: UNION StruCell® P200 Structural PVC Foam with grooved surfaces for resin adhesion
· CNC-machined to fit irregular battery compartments
Result:
· Zero water ingress after 12-month deployment
· 15% weight reduction vs. previous PU foam
· UNION StruCell® Structural PVC Foam exceeded performance requirements for deep-sea deployment
CNC-machined Rigid PVC Foam for Deep-Sea ROV Buoyancy Modules
"Custom PVC foam modules match our design perfectly and can withstand deep sea pressure without deformation." – Marine Engineering Client
In marine engineering, custom Structural Rigid PVC foam is a game-changer for marine applications. Custom-shaped PVC foam is non-negotiable for critical buoyancy and structural applications. UNION COMPOSITES combines DNV GL-certified materials, precision CNC machining and deep-sea expertise to deliver solutions that outperform metals, composites and standard foams. UNION’s Custom-Shaped Rigid Structural PVC Foam ensure:
· Weight reduction vs. traditional materials
· Long-term durability in harsh environments
· Cost savings through optimized designs
Custom-shaped PVC Rigid Foam
Structural Rigid PVC foam is a closed-cell, cross-linked polymer with a honeycomb structure (>95% closed-cell content). It offers:
· High strength-to-weight ratio
· Water resistance (near-zero absorption)
· Chemical/corrosion resistance (saltwater, oils, UV)
· Pressure stability (performs at 1000m+ depths)
UNION’s StruCell® PVC foam is engineered as a load-bearingrigid core for composite sandwich structures (e.g., laminated with fiberglass/carbon fiber). It provides:
· Higher compressive strength (up to 6.2 MPa for P250 foam)
· Machinability for complex geometries (CNC precision: ±0.15mm)
· DNV GL-certified performance for marine environments.
Densities range from 45–250 kg/m³, tailored for different depths:
· 60–80 kg/m³: Surface-level ROV floats
· 100–130 kg/m³: Subsea housings
· 200–250 kg/m³: Deep-sea modules (e.g., 620m+ depth resistance).
Yes! P250 foam resists 6.2 MPa (~620m depth). Custom designs can achieve 1000m+ with optimized geometries.
StruCell® foam has <1.5% water absorption (per ASTM D2842), ensuring long-term buoyancy stability even under pressure.
Yes! UNION offers UL94-HB-rated (self-extinguishing) and IMO FTP Code Part 2-compliant fire-retardant grades.
Absolutely. Our 5-axis CNC machines achieve ±0.2mm precision for hyperbolic curves, grooves and irregular contours.
· Prototypes: 5–7 days
· Bulk orders: 15 days (no MOQ; small batches accepted).
· Lighter than metals (30% weight reduction vs. syntactic foam in some cases).
· Corrosion-proof (unlike metals).
· Cost-effective vs. traditional composites.
Yes! StruCell® foam is 100% recyclable (ISO 15270 compliant).
[Certification] DNV GL Marine Composite Materials Certification Standard, DNV GL-CG-0127 ↩
[Test Method] ASTM D2842 Standard Test Method for Water Absorption of Rigid Cellular Plastics, ASTM Official Site ↩
[Market Data] "Marine Composites Market by Vessel Type, Application, Material - Global Forecast to 2028", MarketsandMarkets Report ↩
[Test] ASTM C365 Standard Test Method for Flatwise Compressive Properties of Sandwich Cores, ASTM C365-16 ↩
[Test] ASTM D1621 Standard Test Method for Compressive Properties Of Rigid Cellular Plastics, ASTM D1621-16 ↩
[Test] ASTM D7250 Standard Practice for Determining Sandwich Beam Flexural and Shear Stiffness, ASTM D7250-16 ↩
