In the Filament Winding process a roving is fed from a creel through a bath containing resins plus curing system, and then wound onto a suitably designed mandrel. Several layers of roving are built up on the mandrel in order to reach the desired thickness. Filament Winding uses continuous reinforcement to achieve efficient utilization of glass fiber strength. Glass content is 40-70 % by weight, depending on the specific application and winding method.
The angle or helix of winding is usually within the range of 25-85 ° to the axis of rotation. The roving can be wound longitudinally, circumferentially, helically, or a combination of all three winding patterns. The strength performance requirements determine the angle of wind.
The most common shape in Filament Winding is the cylindrical shape, used for the production of tanks and pipes. The interior surface of a filament wound structure does not need to have the same configuration as the outer surface. For instance, in corrosion resistant applications often a resin-rich corrosion layer is used with a veil reinforcement, while the outer structural laminate is made from resin and continuous roving. The wall thickness of filament wound structure is generally kept constant, because variations tend to create inter-laminar shear stresses which can lead to premature failure.
Compared to processing techniques like Hand lay-up and Spray-up, the Filament Winding process brings benefits like improved control of laminate properties, variable strength capability, low manual labor requirement, possibilities for process optimization, and a flexibility to choose from a wide variety of resin and reinforcement options.
Typical applications of components made in Filament Winding include chemical storage tanks, process equipment, pressure pipes for transportation of liquids and gasses, cooling and firewater networks, filtration vessels, chimneys and FGD (Flue Gas Desulfurization) systems.
Aliancys has a broad range of products at hand for Filament Winding processes, sold under Atlac®, Palatal®, Synolite™, and Daron® brands. Depending on the required chemical resistance and mechanical properties, solutions are available in Vinyl Ester, Orthophthalic and Isophthalic chemistries.
For applications in contact with food and drinking water, Aliancys has developed dedicated products that comply with EU regulation 10/2011 and Code of Federal Regulations, issued by Food and Drug Administration (FDA), paragraph 21 CFR 177.2420 Polyester resins, cross-linked (version April 1st, 2005; for repeated food contact).
These resins are manufactured in line with GMP (Good Manufacturing Practice) according to EU Commission Regulation No. 2023/2006, a standard that is a prerequisite for the production of plastic articles in contact with food.
This allows for the production of components that are suitable for food processing companies, and do not have a negative impact on food safety for consumers.
More information on the chemical resistance of the products sold by Aliancys can be found in the Chemical Resistance Guide. For more detailed advice on the chemical resistance of our products, Aliancys is offering its customer a Chemical Resistance Advice service.
Please also read case studies on A2 Road tunnel (firewater system), Tankwell (composite tank containers), CEZ Power (FGD piping), Taizhou Guodian Power (electrostatic precipitators), and Haase (chemical storage in Reichstag building).