DFHB Centrifugal Casting GRP pipe is a composite material consisting of three components and can be classified as a thermosetting plastic. Base materials for manufacture are unsaturated polyester resins as bonding agent, chopped glass fibers as reinforcement and quartz sand as aggregate.
During the fully automated centrifugal casting process, components are fed into the mold using special programmes to electronically control the timing and dosing of the materials to produce the desired wall structure. The pipe wall structure is built up from its exterior surface. When all the materials have been positioned in the mold, the rotation speed is increased.
Due to the centrifugal forces the materials are pressed against the wall of the mould under enormous pressure (in the order of 40G) and the compound materials are compacted and de-aerated completely. This manufacturing technology assures the production of pipes with high density walls free of voids and evenly smooth surface all over their length. The curing of the pipes proceeds in the rotating mould, so that an exact roundness with constant wall thickness over the whole length of the pipe is guaranteed.
Upon completion of the polymerization process, the finished pipe is extracted from the mould. The outside surface of the pipe is completely smooth and has the same outside diameter all over its length.
