Pultruded fiberglass grating is unidirectional in strength, provides increased load capacity and has high levels of corrosion resistance. The bearing bars and cross bars which are pulled by machine, provide a higher glass to resin ratio content giving it superior load capacity.
The pultrusion process used in the manufacturing of pultruded fibreglass grating and structural shapes starts with racks or creels holding rolls of fiber mat or doffs of fiber roving. For most applications,the reinforcement is fiberglass, but it can also be processed using carbon fibers, aramid fibers, or a mixture to provide additional strength. This raw fiber configuration is pulled off the racks and guided through a resin bath or resin impregnation system. The resin can also be injected directly into the die with some pultrusion systems.
The raw resin is almost always a thermosetting resin, and is sometimes combined with fillers, catalysts, and pigments. The fiber reinforcement becomes fully impregnated (wetted-out) with the resin so that all the fiber filaments are thoroughly saturated with the resin mixture.
This high density of glass core layer makes the structure very tough and rigid. The modulus of flexural strength and impact strength lengthwise exceeds normal steel. Fiberglass mats increase the transverse strength of the profiles and form a rich-resin layer on the surface, giving it a better finish with better characteristics of anti corrosion and anti fragmentation.