Wet Filament Winding

Wet Filament Winding

The Wet Filament Winding (WFW) process is used to manufacture cylindrical or hemispherical composite structures by winding fiber from a bobbin. The fiber is impregnated with resin just prior to being wound onto the mandrel. The main automotive applications are pressure vessels for CNG or hydrogen, drive shafts and other rotationally symmetrical parts.

Resin Systems with Low Viscosity and Long Latency

Huntsman designs resin systems based on anhydride or amine chemistries that meet the processing and performance requirements of WFW applications. Our systems offer a wide range of glass transition temperatures, from 80° to over 200° C, and various combinations of mechanical performance. All our systems present low viscosity, which facilitates wetting of the fibers, long latency at room temperature, which allows running the bath for a long period of time (and reduces waste of unused resin) and appropriate reactivity to manage curing time and safety aspects (low or controlled exothermic behavior).

Huntsman is a pioneer of the Wet Filament Winding process, and has a long track record of providing systems to produce pressure vessels for compressed natural gas (CNG), and now for hydrogen. Our simulation capabilities help customers to reduce development time by speeding resin system selection, process parameters determination and process safety measures (avoiding risk of local exotherm).

Lower Costs, Faster to Market Whatever your Process

Lower Costs, Faster to Market Whatever your Process

Our leading composite expertise, broad product range and unique simulation capabilities can reduce development cycles by up to 50 %.

New Solutions for Hydrogen Pressure-Vessel Manufacturers

New Solutions for Hydrogen Pressure-Vessel Manufacturers

Huntsman Advanced Materials offers innovative solutions that support manufacturers in the design and production of composite pressure vessels for hydrogen storage and transportation. 


Frequently Asked Questions

What are the key advantages of Wet Filament Winding?

Wet Filament Winding (WFW) is a well-established technology. The equipment and process have been optimized for computer-controlled automation, so labor requirements are lower compared to other open molding processes. Continuous fibers can be used over a whole component area (without joints) and, to a certain extent, fibers be applied at various angles, in order to orient them in the load direction. WFW allows highly repetitive fiber placement, and delivers a high degree of fiber loading, which provides the high tensile strength and high strength-to-weight ratio required for cylindrical products such as pressure vessels.

What are the disadvantages?

WFW can only produce rotationally symmetrical parts. The angle of reinforcement is controlled by the ratio of the carriage speed and the rotation speed of the mandrel. Maximum winding speed is 1-2 meters per second. WFW is an open process that can expose workers to liquid resin, so hygienic conditions must be maintained.

What are the main resin requirements for Wet Filament Winding applications?

Optimal winding viscosity is 800-1,000 mPa for good fiber impregnation. Optimal pot life is several hours at impregnation temperature. Cure temperature should be as low as possible in order to avoid internal stresses in the final part.

Which specific Huntsman products are recommended for Wet Filament Winding processes?

Huntsman's range of ARALDITE® resin systems includes both epoxy/anhydride and epoxy/amine chemistries, with a range of glass transition temperatures. All systems are qualified for CNG and hydrogen pressure vessels. All feature long latency (long pot life) and low viscosity for fast impregnation.

Resin Systems for Composite Parts

Discover our wide range of composite applications to improve safety, efficiency and integrate alternative fuels into your designs.

Applications for Composites

Composite Resin Systems

Our solutions for automotive composites offer superior mechanical performance at lower weight, chemical and particularly corrosion resistance, as well as minimal cycle time.

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