Flaws and shortcomings
Low modulus of elasticity The elastic modulus of FRP is twice as large as that of wood, but 10 times smaller than steel (E=2.1E5). Therefore, it is often insufficient in rigidity and easily deformed in the product structure. It can be made into a thin shell structure or a sandwich structure, and can also be compensated by high modulus fibers or reinforcing ribs. Poor long-term temperature resistance Generally, FRP can not be used for a long time at high temperature. The strength of general-purpose polyester FRP is obviously lower than 50 °C, generally only below 100 °C; general-purpose epoxy FRP is above 60 °C, the strength is obviously decreased. However, it is possible to select a high temperature resistant resin so that a long-term operating temperature of 200 to 300 ° C is possible. Aging phenomenon Aging is a common defect of plastics. FRP is no exception. It is easy to cause performance degradation under the influence of ultraviolet light, sand, rain, snow, chemical medium and mechanical stress. Low interlaminar shear strength The interlaminar shear strength is borne by the resin and is therefore very low. The adhesion between layers can be improved by selecting a process, using a coupling agent, etc., and most importantly, avoiding shearing between layers during product design. Organic Fertilizers,Granular Npk Fertilizer,Water Soluble Fertilizer Well Chemical Co., Limited , http://www.chemistryr.com