中文简体
English
49 clicks
1.1 High salt spray (NaCl) & extreme humidity (over 90%): Conventional PA6 is prone to hydrolysis and sharp strength decline.
1.2 Long-term seawater immersion: Materials require low water absorption, excellent dimensional stability and hydrolysis resistance.
1.3 Intense ultraviolet radiation (1.5–2 times that on land): Easily causes chalking, discoloration and cracking.
1.4 Cyclic temperature variation (-40℃ ~ +120℃): Thermal expansion and contraction may lead to warpage and sealing failure.
1.5 Persistent vibration, impact and abrasion: Caused by wind, waves and propeller operation under long-term load.
1.6 Fire resistance (SOLAS standard): Low-smoke halogen-free and flame-retardant performance is mandatory for ship interior parts.
2. Mainstream Modified Nylon Grades for Marine Use
2.1 Resin Matrix Selection (Ranked by seawater resistance & low water absorption)
- PA12: Water absorption ≈ 1.3% (only 1/4 of PA6), dimensional change < 0.1%. First choice for deep-sea and outdoor exposed components.
- PA612: Low water absorption, outstanding hydrolysis and salt spray resistance. Ideal for sealing and high-pressure parts.
- PA66: Excellent strength and heat resistance, commonly used for indoor non-immersed components.
- PA6: Cost-effective. Must be modified with reinforcement, weather resistance and flame retardancy; only applicable to dry indoor areas on ships.
2.2 Key Modification Technologies for Marine Service
- Glass fiber reinforcement (GF15–40%): Improves rigidity, mechanical strength and heat resistance, and reduces creep. Typical grades: PA6-GF40, PA12-GF15.
- Carbon fiber reinforcement (CF20–30%): Delivers higher strength and modulus, better lightweight effect, creep resistance and fatigue resistance. Used for high-end structural and sealing parts.
- Seawater & hydrolysis resistance: Formulated with hydrolysis stabilizers. Strength retention rate exceeds 90% after 1000 hours of seawater immersion.
- Weather & UV resistance: Compounded with carbon black and UV stabilizers. Strength retention rate above 90% after 1500 hours of salt spray testing.
- Flame retardancy (V-0 / Low-smoke halogen-free): Complies with SOLAS regulations, required for cabin interior materials.
- Toughening modification: Enhances low-temperature impact resistance (no brittle fracture at -40℃), suitable for handrails, brackets and housings.
3. Typical Application Scenarios (By Component Location)
3.1 Exposed Hull & Deck Components (Salt spray + UV + Rain)
Vent grilles, window frames, handrails, bollard guards: PA6-GF30 weather-resistant grade. Replaces aluminum alloy; no painting required, service life extended from 2 years to 5 years, maintenance cost reduced by 60%.
Propellers for yachts and lifeboats: Long glass fiber reinforced PA6-GF40. Only 1/5 the weight of copper propellers, higher thrust and excellent seawater resistance, with much lower cost.
Deck brackets and railing bases: PA66-GF40 weather-resistant grade. High rigidity and resistance to vibration caused by sea wind.
Water pump impellers, valve seals and pipe connectors: PA612-GF30 / PA12-GF20. Volume change < 1% and hardness retention over 90% after 1000 hours of seawater immersion.
Deep-sea seals and pressure vessel gaskets: PA612-CF30. Under 30 MPa pressure at 3000 meters deep sea, sealing performance remains 99.7% after 5000 working cycles, and abrasion loss is only 1/5 of traditional PU materials.
Submarine cable sheaths and buoys: PA12 flame-retardant & weather-resistant grade. Low water absorption and anti-marine organism adhesion property.
3.3 Cabin Interior & Structural Parts (High humidity + Salt spray + Fire hazard)
Cabin partitions, ceiling panels and equipment bulkheads: PA6-GF15 flame-retardant grade. Low smoke, halogen-free, dimensionally stable and vibration-resistant.
Electrical control box housings, terminal blocks and switch enclosures: PA66-GF30 flame-retardant V-0 grade. Good electrical insulation, prevents short circuit caused by salt spray corrosion.
Seat frames, storage compartment frames and interior panels: Toughened & weather-resistant PA6-GF20. Lightweight, impact-resistant and easy to clean.
Gears, bearing seats, pulleys and piston rings: Wear-modified PA6-GF40 (added with PTFE/silicone oil). Self-lubricating, maintenance-free, low noise, resistant to seawater and lubricants.
Engine peripheral brackets and radiator parts: PA66-GF40 heat-stabilized grade. Continuous service temperature up to 150℃ and above, resistant to coolant.
4. Recommended Commercial Grades & Application Guidance
4.1 PA B3WG8 (PA6-GF40, long glass fiber reinforced & heat-stabilized)
Application: High-rigidity indoor brackets, engine peripheral parts and non-submerged structural components. Features excellent heat resistance, low creep and good dimensional stability. Not recommended for long-term seawater immersion due to relatively high water absorption of PA6 matrix.
4.2 PA 73G40T BK416 (PA6-GF40, short glass fiber reinforced, heat-stabilized & toughened)
Application: Outdoor exposed parts, deck brackets, handrails and equipment housings. High impact resistance, good salt spray and weather resistance with cost advantages, an ideal alternative to aluminum alloy.
4.3 PA12 L-GF15 (PA12-GF15, flame-retardant & weather-resistant)
Application: Deep-sea components, window frames, cabin partitions and ceiling panels. Low water absorption, superior hydrolysis and salt spray resistance, flame retardant. Top choice for long-term immersed and outdoor marine parts.
4.4 Carbon Fiber Reinforced PA612-CF30
Application: Deep-sea seals, high-pressure components and high-end structural parts. Ultra-high strength and modulus, low creep and outstanding seawater resistance. Specially developed for high-end deep-sea equipment.
5. Material Selection Guidelines & Notes
5.1 For long-term seawater immersion: Prioritize PA12 / PA612. Ordinary PA6 is not applicable due to high hydrolysis risk.
5.2 For outdoor components under strong UV radiation: Must adopt weather-resistant grade with carbon black addition, otherwise cracking will occur within 1–2 years.
5.3 For cabin interior materials: V-0 flame retardant + low-smoke halogen-free formulation is required to meet SOLAS standards.
5.4 For heavy-load & long-term stressed parts: Select long glass fiber (LGF) or carbon fiber (CF) reinforced grades for better creep resistance.
5.5 Cost optimization: Use PA6-GF30/40 for indoor parts, weather-resistant PA66-GF40 for outdoor deck parts, and PA12-GF20 for underwater components.
