In marine work, marine fender pads (also known as ship cushion pads and dock anti-collision pads) can avoid direct collisions between ships and docks and quaysides, thereby reducing equipment damage and safety hazards. Traditional fender pads wear out quickly, have high maintenance costs, and are susceptible to corrosion from the marine environment. It wasn’t until the advent of UHMWPE sheets that this predicament was completely broken.
What is UHMWPE Sheet? Core characteristics
UHMWPE, Ultra-High Molecular Weight Polyethylene, is a special category of the polyethylene family. Its molecular weight is usually between 3.5 million and 10 million g/mol, far exceeding that of ordinary polyethylene materials. This UHMWPE has an extremely high molecular weight and is more mechanically and chemically stable than ordinary plastics.
The characteristics of UHMWPE boards, such as excellent wear resistance, extremely low friction coefficient, extremely high toughness and impact resistance, and excellent chemical resistance, can perfectly meet the needs of marine fender pads.
What are marine fender pads?
Marine fender pads are also called marine cushion pads and dock anti-collision panels. They are mainly installed on the dock wall, ship sides, floating docks and other locations. It can absorb the kinetic energy of ships when they are berthed, buffer the impact of collisions, and protect ship shells and terminal infrastructure from damage.
Why use UHMWPE as marine fender pad?
The core requirements of marine fender pads are “wear resistance, impact resistance, low maintenance”, and the characteristics of UHMWPE perfectly match these requirements.
The UHMWPE fenders are non-slip, allowing the ship to slide smoothly when berthing and reducing scratches on the hull.
Moreover, the wear-resistant UHMWPE marine fender can extend its service life and reduce the frequency of replacement.
UHMWPE hardly absorbs water. The near-zero water absorption rate can prevent the material from expanding and degrading when immersed in seawater for a long time, ensuring long-term stable operation. UHMWPE sheets have excellent chemical resistance and can resist the erosion of various acids, alkalis and salts. Finally, UHMWPE fender pad maintenance is simple and only requires regular cleaning of surface debris to maintain normal use.
Common Types of Traditional Marine Fenders
Before UHMWPE sheets became widely used, there were three main types of traditional marine fenders, each with its own limitations:
Rubber fenders: They are cylindrical or conical in design, which has good energy absorption effect, but poor wear resistance, easy aging, easy cracking after long-term use, and high maintenance costs;
Foam fenders: Lightweight and floatable, suitable for temporary or offshore operations, but weak impact resistance, not suitable for high-flow docks;
Inflatable fender: It adopts inflatable design and is mostly used for ship-to-ship and ship-to-dock operations, but it is easy to break and leak air, and requires regular inspection and maintenance.
If fender pads with poor materials and substandard performance are used, they will bring many hidden dangers: first, they cannot effectively cushion the impact force, resulting in scratches on the ship shell and damage to the dock concrete, resulting in high maintenance costs and accident risks. Second, it is easy to age and break.
Application scenarios of UHMWPE marine fender pads
Ports and Terminals
At present, UHMWPE fender pads have been widely adopted by large ports at home and abroad to replace traditional materials. UHMWPE fender pads can be installed directly on the quay quay surface to cushion the impact of collisions of various types of ships, protect the quay infrastructure from damage, and reduce ship maintenance costs.
Marine terminals
Dedicated terminals for large ships such as oil tankers and container ships (such as oil and gas terminals and container terminals) have large ship tonnage and high berthing frequency. With its excellent wear resistance and impact resistance, UHMWPE marine fender pads can withstand high-frequency collisions and friction of large ships, avoiding safety hazards caused by damaged fender pads.
Locks and canals
In narrow waters such as locks and canals, the maneuvering space for ships is limited, and the accuracy requirements when berthing are high, resulting in a greater risk of collision. UHMWPE fender pads can be installed on the inner wall of the lock and both sides of the canal to provide precise protection for ships and avoid collisions between ships and the shore wall. At the same time, their self-lubricating properties can reduce ship navigation resistance and help ships pass smoothly through narrow channels.
Floating dock and buoy system
Floating docks and buoy systems are movable or semi-fixed facilities that require high lightness and durability of fender pads. UHMWPE board is lightweight (density is only 1/8 of steel), easy to install, and can effectively protect floating docks and pontoons.
Military and naval bases
The terminal facilities of military and naval bases are highly sensitive and require much higher protection than ordinary ports.
UHMWPE fender pads can resist the high-frequency berthing and collision of military ships, and will not create safety hazards due to aging or damage of materials. They can effectively protect sensitive terminal facilities and ensure the safe docking of military ships.
UHMWPE vs HDPE Sheets: Comparison of Marine Fender Mat Material Selection
In the selection of marine fender mat materials, UHMWPE and HDPE are the two most commonly used polyethylene materials, but the performance differences between the two are significant, which directly affects the service life and use effect of the fender mat.
UHMWPE Sheet is more wear-resistant
The molecular weight of UHMWPE plate far exceeds that of HDPE, and its wear resistance is 3-5 times that of HDPE. It can withstand long-term, high-frequency hull friction and collisions, and is not prone to surface wear and damage. The HDPE plate has weak wear resistance and needs to be replaced frequently, making it suitable for use in small docks with light loads and low frequency.
UHMWPE Sheets have better costs
HDPE fender pads have a short service life, frequent maintenance, and high long-term costs; while UHMWPE fender pads have a long service life, low maintenance costs, and lower long-term costs, making them particularly suitable for high-flow, high-load dock scenarios.
UHMWPE Sheets last longer
In harsh marine environments, the service life of UHMWPE fender pads can usually reach 10-15 years, while the service life of HDPE fender pads is only 3-5 years. This is because UHMWPE can resist erosion by various factors such as seawater, salt spray, and friction; while HDPE has a high water absorption rate and is prone to aging and deformation after long-term immersion.
How to Choose UHMWPE Marine Fender Pads?
Choosing the right size UHMWPE plate is the key to ensuring the protective effect of the side mat and extending its service life. Factors such as scenario, vessel tonnage, and berthing frequency need to be used in combination, focusing on the following three core dimensions.
Thickness selection
The thickness of UHMWPE sheet directly affects the impact and wear resistance of the fender pad. Different load scenarios correspond to different thickness ranges:
Light-load fenders: Suitable for berthing small ships (such as yachts and fishing boats). Choose 10-20mm UHMWPE fenders to meet basic protection needs, taking into account both lightness and economy;
Medium load fender: Suitable for berthing small and medium cargo ships and passenger ships, the thickness of the 20-30mm UHMWPE fender is selected to effectively buffer the impact force of the ship and resist long-term friction;
High-load fender: Suitable for berthing large container ships, tankers, and military ships. The thickness is selected to be 30-50mm UHMWPE fender, which has stronger impact resistance and wear resistance to ensure long-term stable use.
Size and customization
The size of the marine fender pad must be accurately matched with the dimensions of the dock wall, ship side, and fender body to avoid installation difficulties or protection loopholes.
Standard size: Common size 1000×2000mm UHMWPE fender pad, 950×950mm UHMWPE fender pad, which can be directly adapted to most conventional fender systems;
Customized service: If the existing fender system has special dimensions, you can choose to communicate with Xinxing Plastic about CNC machining, drilling, shaping and other customized UHMWPE plastic plate services to improve the protection effect.
Color and UV stability
Marine fender pads are exposed to sunlight and salt spray for a long time. The color selection and UV stability directly affect their service life.
Color selection: Common colors are black and white, among which black UHMWPE board is the first choice for marine scenes. At the same time, you can also choose customized colors such as blue UHMW plastic sheet, green, yellow UHMWPE sheet, etc. according to your needs to improve recognition.
UV stability: UHMWPE plastic sheets are added with anti-UV additives, and they will not crack, age or discolor after long-term outdoor use, and have long-term stability performance in marine environment.
How to Install UHMWPE Marine Fender Pad？
The installation quality of UHMWPE fender pads directly affects the protection effect and service life. It is necessary to select an appropriate method and standardize the operation based on the scenario.
Bolt fixing
Suitable for fixed facilities such as quay quays, concrete, etc., easy to operate. Drilled holes in the sheet and countersinked, secured with stainless steel bolts and washers, it resists seawater corrosion and avoids scratching the hull.
Embedded steel plate installation
Suitable for high-energy collision scenarios such as frontal panels and barges, UHMWPE plates are vulcanized or bonded to steel plates, which are then welded/bolted to improve overall impact resistance.
Welded installation with back plate
Suitable for unevenly stressed parts such as barge sides and dock corners, use steel back plates or angle irons to fix the edges of the plates, and then weld/bolt them to the mounting surface to improve protective stability.
Custom CNC cutting UHMWPE fender pad
Suitable for large docks and custom fender systems, UHMWPE plastic sheet manufacturers can accurately cut dimensions, pre-drill holes, chamfer and sharpen edges, and install directly on site, saving time and ensuring accuracy.
The installation quality of UHMWPE fender pads directly affects their protection effect and service life. It is necessary to choose the appropriate installation method according to the usage scenario and follow the standardized operation process.
Frequently Asked Questions (FAQ): UHMWPE Fender Pad
Q: Can UHMWPE sheet withstand extreme temperatures?
A: Yes. UHMWPE plates have an extremely wide temperature range and can operate stably between -200℃ and +80℃. They can adapt to the low temperature environment in high latitudes and withstand the high temperature exposure in tropical regions, and are fully suitable for all types of marine environments.
Q: UHMWPE board is more expensive than HDPE, is it worth choosing?
A: Worth it. Although the initial investment of UHMWPE plates is higher than that of HDPE, in the long run, their service life is longer and maintenance costs are lower, which can significantly reduce replacement costs and downtime costs. For high-load, high-frequency berthing scenarios, the long-term cost-effectiveness of UHMWPE is much higher than that of HDPE.
Q: What is the core difference between UHMWPE and HDPE sheet?
A: The core difference between the two is molecular weight: UHMWPE has ultra-high molecular weight (3.5 million-10 million g/mol) and longer molecular chain, so it has better wear resistance, impact resistance and corrosion resistance; HDPE has lower molecular weight, weaker strength and wear resistance, and is only suitable for light load scenarios.
Q: How long does the UHMWPE marine fender pad last?
A: The service life depends on the use scenario. Generally speaking, in medium and high load port scenarios, the service life can reach 10-15 years; in light load scenarios, the service life can reach more than 15 years, far exceeding traditional rubber and HDPE fender pads.
Q: Can UHMWPE fender pads be recycled?
A: Yes. Most UHMWPE materials are recyclable plastics. Discarded fender pads can be professionally recycled and reprocessed for reuse. This is both environmentally friendly and reduces resource waste, meeting the green development needs of the modern maritime industry.
