Pultrusion is a manufacturing technique that is used to create compound materials made up of many fibers. Fibers are pulled through the pultrusion machine, where they are bathed in a resin. The resin then hardens, which binds all of the fibers together. This process is used to make composite materials with a number of uses. Material made by pultrusion is used in the aerospace field, used in floor construction, and in devices that require high strength but must be light weight, like some sporting equipment.
Designing a pultrusion system requires knowledge of the fibers that will be used to create the finished product. In addition, the number of fibers that make up a given length of material must be known. Since many fibers are bundled up simultaneously, the pultrusion system must be capable of feeding all of the fibers to the machine simultaneously. Each fiber must therefore reside on its own spindle, and have its own feeding mechanism. For example, a material that requires six fibers per length of material will require six spindles and six fiber feeding mechanisms. It doesn’t matter if these fibers are the same material or not. Since they must all be fed into the system to form one piece of pultrusion material, they each require their own spindle.
The resin used by the material must also be known. The resin feeding mechanism must be capable of handling the resin in its liquid phase. Depending on the exact resin and its setting time, this liquid phase may not last long, and the resin may be very thick. This requires a special apparatus to encourage liquid flow and discourage premature resin settling. Some techniques such apparatus use are heating coils that keep the resin warm. So long as it is warm, the resin will flow easily and it will not harden. Taken together, all of these factors form a good starting point for a solid pultrusion machine design. A pultrusion machine can produce very strong, high quality material. However, none of this is possible without a great design. By considering these factors, a great design can be achieved.