Filament winding machines are increasingly popular for the manufacture of a very wide range of products. The cylindrical carbon or fibre-glass vessels that they produce are used for pipes, cylinders, machinery parts, drive shafts, ship masts, storage tanks and pressure vessels, to name just a few.
What Is a Filament Winding Machine?
A filament winding machine is basically quite simple. Filaments, usually made of carbon or glass, are wound around a cylindrical “mandrel” to create cylindrical vessels in a range of sizes. Occasionally tape is used in addition to the fibres. The filament is often bathed, or impregnated, with resin as part of the process. The mandrel rotates, and the filament is laid down along its axis at a steady pace. The filament is laid down by a delivery eye which is fixed to a carriage.
A great advantage of the modern filament winding machine is that the filaments are wound very specifically and precisely. The machine is capable of winding them in a pattern or at an angle, and the final thickness can be very precisely judged. This means that uniform and precision vessels can be manufactured for use in high-tech industries such as medicine, scientific research or aerospace.
The vessels created by the filament winding process can be closed or open-ended, depending on the final use to which they will be put. These can be gas, water or sewage pipes, bicycle forks, golf clubs and rowing oars, missile casings and masts for ocean-going yachts.
How Do They Work?
Two-axis machines are the simplest filament winding machines – the first axis is the mandrel, and the second axis is the delivery carriage. The machines can be more complex, however – four- and six-axis machines are used in different industries.
The mandrel is usually removed from the cylinder once the winding process itself is finished, thus creating an open-ended cylinder. At other times, the mandrel is left inside the finished vessel to act as a lining or inner container.
Manufacturers use a variety of different resins to coat the fibres as they are wound. Epoxy resin or polyurethane resin are used for the aerospace industry, but other industries can use cheaper resins such as polyester. Once the winding process is completed, the vessel is treated, usually with heat, to “cure” the resin. The combination of the resin coating and the high proportion of glass in the fibres which are used will result in a very light, strong and rigid product.
What Are the Benefits?
Filament winding machines can be calibrated to deliver a very precise thickness, resulting in a consistent product and a highly reliable outcome. The actual machine process is very simple and can be almost totally automated, meaning that your staff don’t need to spend a lot of time supervising the process. The finished product is light, strong and stiff. And although the product is very versatile and used in diverse industries, the machines themselves are quite straightforward and don’t require complex maintenance. This means that costs can be kept down.