| Typical Material Structure | Single-wall or double-wall polyethylene shell with UV stabilizers. | High-density polyethylene formulated for higher stress-crack resistance and pressure performance. | Seamless hollow shell produced by rotational molding, normally with consistent wall thickness. | HDPE outer shell combined with closed-cell foam filling for additional buoyancy security. | Choose the construction according to load, impact exposure, maintenance access, and consequences of puncture. |
| Density | Approximately 0.94–0.97 g/cm³. | Approximately 0.94–0.97 g/cm³. | Approximately 0.94–0.97 g/cm³ for the polyethylene shell. | Approximately 0.94–0.97 g/cm³ for the shell; the complete unit is lighter than water because of the foam core. | All listed HDPE shells are less dense than water and can provide positive buoyancy when properly designed. |
| Typical Tensile Strength at Yield | Approximately 20–30 MPa, depending on grade and processing. | Approximately 20–30 MPa, depending on the specified PE100 compound. | Approximately 20–30 MPa for the molded material, subject to wall thickness and molding quality. | Approximately 20–30 MPa for the shell; foam properties must be evaluated separately. | Do not select by tensile strength alone. Wall thickness, ribs, welds, fittings, and load distribution are equally important. |
| Impact Resistance | Good Resists ordinary handling and moderate contact with floating structures. | Very Good Suitable for demanding service when the grade and design are correctly specified. | Very Good Seamless construction reduces the number of potential weak points. | Very Good The foam can limit water ingress and preserve shape after localized shell damage. | For wave action, vessel contact, or frequent handling, prioritize impact-tested designs and protected connection points. |
| Resistance to Stress Cracking | Good Performance depends strongly on resin quality, residual stress, and chemical exposure. | Excellent PE100 materials are designed for high resistance to slow crack growth in pressure applications. | Good Rotational molding can produce durable parts, but sharp corners and uneven walls should be avoided. | Good Shell formulation and manufacturing quality remain the primary factors. | For long-term marine service, request slow-crack-growth data or an applicable material standard from the supplier. |
| UV and Solar Resistance | Good Requires carbon black or another verified UV-stabilization system for outdoor exposure. | Excellent When the compound includes proven UV stabilization and is intended for outdoor use. | Good Color and stabilizer selection are important because the entire shell is exposed to sunlight. | Good HDPE shell needs UV protection; foam performance should also be verified after prolonged exposure. | For permanent outdoor use, specify UV-stabilized material and avoid unprotected natural or translucent polyethylene. |
| Saltwater and Freshwater Resistance | Excellent HDPE generally has very low water absorption and good resistance to saltwater. | Excellent Suitable for continuous contact with freshwater and seawater under normal conditions. | Excellent Seamless shells help reduce pathways for water penetration. | Excellent Closed-cell foam can provide additional protection against waterlogging if the shell remains intact. | Check fasteners, inserts, hinges, and welds separately because these components may corrode even when HDPE does not. |
| Chemical Resistance | Good Resistant to many dilute acids, alkalis, salts, and water-based chemicals. | Very Good Generally suitable for a broad range of aqueous environments. | Good Depends on the specific chemical, temperature, concentration, and exposure duration. | Moderate to Good The shell may resist chemicals while the foam, adhesive, or fittings may have different limits. | Confirm compatibility before exposure to aromatic hydrocarbons, chlorinated solvents, strong oxidizers, or high temperatures. |
| Water Absorption | Very Low HDPE typically absorbs less than 0.01% water by weight in standard short-term tests. | Very Low Comparable to other well-processed HDPE compounds. | Very Low Seamless construction helps maintain low water uptake. | Low Closed-cell foam reduces water absorption, but damaged shells and joints must be repaired. | Low water absorption helps preserve buoyancy and dimensional stability, but it does not replace inspection of cracks and fittings. |
| Operating Temperature | Commonly suitable for approximately −40°C to +60°C, subject to design and load. | Commonly suitable for approximately −40°C to +60°C, subject to the compound and application. | Usually suitable within a similar range, but wall thickness and molded-in stresses affect performance. | Shell may tolerate similar temperatures; foam and adhesive limits must be checked separately. | Reduce mechanical loads at elevated temperatures and verify the lowest service temperature for cold regions. |
| Buoyancy Security After Local Damage | Moderate A hollow chamber can lose buoyancy if punctured or flooded. | Moderate Material strength does not prevent buoyancy loss after a large breach. | Moderate Seamless construction lowers leak risk but does not eliminate puncture risk. | High Closed-cell foam can maintain residual buoyancy after limited shell damage. | Use multiple independent chambers or foam filling where safety, rescue access, or critical equipment support is involved. |
| Maintenance Requirements | Low; inspect for UV embrittlement, abrasion, cracks, loose fittings, and water ingress. | Low; periodic inspection remains necessary despite the higher crack-growth resistance. | Low; inspect molded surfaces, connection points, and any drilled or welded areas. | Low to Moderate; inspect shell integrity and confirm that foam has not become waterlogged. | Establish a documented inspection schedule based on wave conditions, impact frequency, and operating criticality. |
| Recyclability at End of Life | High Clean, single-material HDPE is widely recyclable where suitable collection exists. | High Recycling is simplest when additives and inserts are clearly identified. | High Single-material shells are relatively straightforward to process. | Limited Foam, adhesives, metal fittings, and HDPE must usually be separated before recycling. | Request material identification, disassembly instructions, and an end-of-life plan before purchase. |
| Best-Fit Applications | General floating walkways, light-duty pontoons, markers, and protected-water applications. | Heavy-duty pontoons, marine infrastructure, industrial floats, and applications requiring improved crack resistance. | High-impact environments, custom shapes, modular floats, and products requiring a seamless shell. | Safety-critical flotation, high-value equipment support, and areas where residual buoyancy is important. | Match the floater to design load, freeboard, wave climate, impact risk, temperature, and inspection capability. |