Orthophthalate Resins
Ortho resins comprise the most common type of UPR, and many are known as general purpose resins. FRP composites utilizing ortho resins are found in such application as boat hulls, bath ware, and bowling ball cores.
Ortho resins benefit with good mechanical properties and Adequate resistance to weathering and ageing. It can be a thixotropic polyester resin, moderately reactive for general usage, with good mechanical properties. It contains special additives which significantly improve the working environment during and after application, thanks to the considerable reduction in styrene emissions.
Isophthalate Resins
Isophthalic Resin is a medium viscosity, medium reactive polyester resin based on Isophthalic acid and superior glycols. It exhibits good mechanical and electrical properties together with good chemical resistance compared to general-purpose resins. ISO Resin rapidly wets the surface of glass reinforcements resulting in fast curing and a tack-free surface. It is recommended for moderate chemical resistance applications. At moderate temperatures, the resin has good resistance to water, acids (dilute to medium concentrations), weak bases, and good resistance to petroleum solvents like vessels, tank linings, ducting fume hoods, and many other applications requiring good chemical resistance and superior mechanical strength compared to Orthophthalate.