The manufacturing process can be seen as another important parameter. There are essentially two different ways to manufacture pipes from glass and resin.
Centrifugal casting process
The centrifugally cast pipe represents the optimum in terms of chemical resistance and abrasion resistance.
Centrifugal pipes are manufactured in a process in which blanks corresponding to the circumference and the length of the mould are manufactured from various types of glassfibre and glass mat. These blanks are placed on a mould; this mould is rotated (centrifugal casting). Resin is subsequently injected from inside.
This process offers the following benefits:
- The highest thermal resistance because of the optimum impregnation of the glassfibre with resin.
- The highest chemical resistance as there is only resistant resin in the inner chemical protective layer.
- The lowest flow losses as there is a "completely" smooth internal and outer wall.
As the production of centrifugally cast pipes over a nominal width of DN 350 is no longer economically interesting, the so-called winding process has been perfected as a further production method. Filament-wound pipes are manufactured in a process in which endless long filaments (roving) are fed to a mould via a wide comb. Here either the mould or the filaments are impregnated with resin and superimposed on the mould (winding). This technology can be improved by varying the winding angle and adjusting this to the requirements (e.g. in the case of internal pressure a winding angle of 54º to the tubular axle). In the case of this production method, we also strive to achieve a highest percentage of resin in the inside of the pipe. For this purpose, a non-woven fabric or mat is applied as a bearing for the resin at the start of production of the pipe.
- The lowest wall thickness as optimum arrangement of the fibres for loading.
- High chemical resistance as the strength of the internal chemical protective layer is variable.
- Economic alternative to other materials such as rubberised steel.
Wall mounting of Fiberpipe filament-wound pipes made from epoxy resin or vinyl ester resin.