Glassfiber Reinforced Plastic (GRP) is a combination of two or more materials
(reinforcing agents & matrix), differing in form or composition on a macro
scale. In (glass) fibre - reinforced composites, fibres are intended to carry
the load, while the surrounding resin matrix sets the fibres in the required
orientation. When the materials are compatible, the matrix also acts as a load
transfer medium between the fibres, and protects them from environmental
damages due to temperature changes, humidity and corrosion.
The term GRP implies glass reinforcement and not any other fibre such as
aramid, carbon or polyester. There are hundreds of plastic types available
(such as thermoplastics, thermosets, and elastomers), and also many variants
of glass reinforcement (such as chopped strand matt, woven rovings and
combination mats) - which also differ between manufacturers.
Therefore, GRP is a description representing an extensive family of composites
with an extremely variable range of properties. The type of GRP usually
specified for tanks and pipes is a composite of glass fibres with more
chemically resistant resin types like vinyl ester, isophthalic polyester or
epoxy.
