Pultrusion requires complex, technical equipment such as engineered mats, rubber rollers (rovings), a resin injection system and pulling mechanism. The entire process requires a lot of power and a large amount of space. Therefore, the initial start-up costs are very high, which puts off willing investors. This also means that the ongoing costs remain relatively high. Unfortunately, without any one of the parts, pultrusion would not be possible and so the costs cannot be cut.
Owing to the nature of pultrusion, only simple products can be produced. In other words, the pulling mechanism which draws out the molten plastic into the desired size and shape cannot be changed easily to create more complex cross-section profiles -- such as hexagons. Therefore only simple formations can be manufactured, namely objects with a circular cross section such as rods and pipes.
Pultrusion primarily makes circular tubes. One major disadvantage of the manufacturing process of this is the inability to vary the size of the tube to give a tapered shape. When the plastic is squeezed through the rovings and pulling mechanism, the cross-section has to remain at a constant width. It can only be varied after each process has finished.