Donut Fender

Safety,Stability and Economy are Our Core Product Power

What kind of benefits can Donut Fender bring you in actual application scenarios, how can we ensure its safety andstability, and how can users avoid pitfalls to choose first rate supplier when face to mixed quality foam fender on the market.
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Donut Fender Introduction 

The fenders are made of polyethylene foam with a polyurethane elastomer shell.Special donut fenders have been specifically designed to protect the berthing pipes of the vessels. The internal structure is heavy duty, but it allows the rotation on the support pipe. The polyethylene foam guarantees unsinkability even in case of damage and ensures high energy absorption with low reaction force, which is essential to eliminate the risk of damage to the hulls.They can be purposely created for any pipe type and any pipe diameter.Main construction includes:

  • 100% fully closed cell foam core body.
  • High-tech polyurethane coating.
  • Low-friction UHWM bearing pads.
  • High quality inner steel pipe.
  • Reinforced nylon tire cord skeleton layer.

Donut Fender “Unique” Structure

Donut Fender pays attention to each detail of fender structure
01  UHMW PE Pads

Low-friction UHMW bearing pads

02  Inner Steel Tube

High quality inner steel pipe

03  Skeleton Layer

Reinforced nylon tire cord skeleton layer

04  Laminated Structure

 Laminated foam core body (Non-Winding)

05  Foam Core

Fully closed cell foam core

06  Fender Coating

Black Technology Coating


This Black Technology Material used by Donut Fender may subvert your perception of foam fenders.

You can imagine the result of a watermelon falling from height, but if the watermelon is sprayed with our black technology material and falls from the height of 100 meters, can you still imagine the result?

The almost indestructible coating of Ocean Defender is made of Polyurea,one Black Technology Material ( Polyurea is a branch of polyurethane ). This Black Technology Material is independently developed by us which have very important properties like:extremely strong, stretchable, flexible, anti-deformation, anti-corrosion,UV resistance etc.

The polyurea coating is a direct protective measure for foam core, so the quality and performance of polyurea coating directly determine the strength and service life of foam fender, which is a pitfall point that users need to pay special attention to.

Donut Fender “Authenticity” Superiority

After years of product R&D combined with actual product applications and user feedback, Donut Fender reflects the excellent product performance, and truly exerts its ultimate reliability, safety and stability,empowering world green and smart docks.
  • Freely rotates around a pile.
  • Superior energy absorb and low reaction force.
  • Lower reaction force than rubber fender & keep high energy absorption.
  • Compression & recovery efficiency golden ratio.
  • Extrely low hull pressure,non-marking polyurethane coating.
  • Anti-burst,anti-sinking, ultimate security.
  • Remain functions under accidental damage.
  • Excellent anti-ultraviolet light (UV) resistance.
  • Resistance to acid, alkali and salt and marine biology corrosion.
  • Resist all kinds of rough marine environments (Tropic & Frigid Zone).
  • Material and technical process determine long service life.
  • Suit all sites no matter small or large tidal changes.
  • Customization of fender size and shape.

Application And Leading Extended Field

Corner protection | Turning structures | Lead-in jetties | Simple breasting dolphins | Bridge protection

Donut Fender Operating Guide

Multiple Capacity Performance Parameter

How To Avoid Pitfalls

How users to choose superior performance foam fender.

1Foam Fender Market Status

Foam fenders have a wide range of applications and a broad product market, so there are a large number of product manufacturers, but the quality on the market is uneven. In order to reduce costs, the products lose their basic performance of energy absorption and reaction force, and a large number of accidents caused damage to berthed vessels or impacts on piers. At the same time, due to the high value of the foam fender itself, users suffered huge economic losses.

For Example:

  • Foam fender produced according to lower tolerances to reduce costs.
  • Misleading customers on the basis of foam core density, combined with price (Learn More).
  • Winding structure foam core: low cost, poor performance of energy absorption and reaction force (Used by most manufacturers).
  • The foam core is made of mixed density material, which has low cost and low performance.
  • The foam core is directly filled with waste materials, which loses the basic performance of foam fender.
  • Using poor qualitycentral axis, low cost, low strength, easy to break.
  • Central axis is filled with scrap steel sand/cement to meet the weight requirements of customer.

The above situations exist alone or at the same time. Customers must understand clearly before making a decision when purchasing, otherwise it will bring you a large economic loss. Find us to know more.

2The hazards of low-quality foam fenders

Low-quality foam fenders may be an advantage in terms of purchase cost, but in practical applications, foam fenders essentially test its energy absorption and reaction performance, safety and long-term stability. If the long-term application cost is considered, low-quality foam fenders have no any advantage, which will directly lead to economic losses for customers and threaten the safety of personnel/ships/docks.

  • Inferior foam fender have the problem of foam core collapsed, because foam core material is not properly selected (waste/mixturematerial), cannot withstand high-intensity repeated impacts, and foam fender will have non-elastic deformation, resulting in performance degradation, or even loss of performance and service life greatly reduced,damage to ships and docks.
  • Inferior foam fender have the problem of Polyurethanecoating Due to the insufficient thickness and quality of Polyurethane reinforcement layer on the surface of foam fender, and the unreasonable layout of tire cord layers, the force on the surface is relatively concentrated and will be cracked. After long-term application, the foam core absorbs moisture and performance declines,the cracking gap will become larger and larger, affecting fender service life.
  • Inferior foam fenderhave the problem of central axis damaged. The central axis with low strength will be bent,deformed or even broken during repeated compression. The foam fender loses its supporting function. If the inspection is not timely, it will bring direct economic losses.

Find us to know more.

3How should customers choose foam fenders

The three most important parts of foam fender are: Foam Core, polyurethane Coating, and Central Axis. Customers must pay attention to the quality problems of these three parts when choosing, so as to avoid unnecessary losses.

Foam Core: The foam core is the key factor to reflect the foam fender performance.The closed-cell foam core should be selected. At the same time, according to different expansion ratios, the foam density will be different. It is necessary to communicate with the manufacturer according to the actual application.

Polyurethane Coating: It is the protective layer of foam fender, which has the effect of dispersing the force. The quality and thickness of polyurethane coating can resist the damage to foam fender caused by friction. At the same time, attention should be paid to the structural layout of tire cord layer.

Central Axis: The central axis is the key point to support the foam fender. The material and strength of the central axis determine the service life of foam fender. Central axis’s reasonable size and strength can greatly improve the overall cost performance of the product.

Find us to know more.

4What problems can we solve for customers

NANHAI company has been developing and technically researching on foam fender products for 16 years, and has accumulated a large amount of product and application experience. It can provide customers with a full range of foam fender technical support, guide customer selection of fender, complete fender layout solutions and installation guidance program, etc.

  • Provide customers with economical, safe, reliable and extremely stable foam fender.
  • Standard type foam fender production.
  • Structure optimization and production of non-standard foam fender.
  • R&D foam fender under extreme climate/condition applications.
  • Installation instructions for foam fender (on-site/off-site).
  • Fender installation layout specification and solutions.
  • Quick response mechanism of after-sales service.
  • Inventory system to meet the emergency delivery time.

Find us to know more.

Have Your Attention Please

NANHAI Other Marine Industrial Forms

The development of NANHAI during the past 20 years has involved many maritime fields, providing global customers with overall solutions for Berthing, Mooring, Ship to Ship, Ocean Wind Power, Deep-Sea Farming, Buoyancy and Salvage, Bridge Blocking, Ship Launching, Dock Caisson Moving etc.