1. Lightweight and strong
The relative density is between 1.5 and 2.0, only 1/4~1/5 of carbon steel, but the tensile strength is close to or even higher than that of carbon steel, and the specific strength can be compared with high-grade alloy steel. As a result, it has achieved excellent results in aerospace, rockets, spacecraft, high-pressure vessels, and other applications that require reduced weight. Some epoxy FRPs have tensile, bending and compressive strengths of more than 400 MPa. The density, strength and specific strength of some materials.
2. Good corrosion resistance
FRP is a good anti-corrosive material with good resistance to atmospheric, water and general concentrations of acids, bases, salts and a variety of oils and solvents. It has been applied to all aspects of chemical corrosion protection and is replacing carbon steel, stainless steel, wood, non-ferrous metals and so on.
3. Good electrical performance
It is an excellent insulating material used to make insulators. Good dielectric properties are still protected at high frequencies. It has good microwave permeability and has been widely used in radomes.
4. Good thermal performance
FRP has a low thermal conductivity, which is 1.25~1.67kJ/(m·h·K) at room temperature, and only 1/100~1/1000 of metal. It is an excellent thermal insulation material. In the case of instantaneous ultra-high temperature, it is an ideal thermal protection and ablation resistant material, which can protect the spacecraft from high-speed airflow at 2000 °C.
5. Good designability
(1) According to the needs, flexible design of various structural products to meet the requirements of use, can make the product has a good integrity.
(2) Can fully select the material to meet the performance of the product, such as: can be designed to resist corrosion, resistance to transient high temperature, the product has a particularly high strength in a certain direction, good dielectric properties, and so on.
6.Excellent craftsmanship
(1) The molding process can be flexibly selected according to the shape, technical requirements, use and quantity of the product.
(2)The process is simple, can be formed at one time, and the economic effect is outstanding, especially for a product with a complicated shape and a small amount of molding, and the process superiority is further emphasized.
7.Insufficient FRP
(1) Low modulus of elasticity
The elastic modulus of FRP is twice as large as that of wood, but 10 times smaller than steel (E = 2.1 × 106). Therefore, it is often insufficient in rigidity and easily deformed in the product structure.
It can be made into a thin shell structure, a sandwich structure, or it can be compensated by high modulus fibers or reinforcing ribs.
(2)Long-term temperature resistance is poor
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, and it is generally only used below 100 °C; the general-purpose epoxy FRP is above 60 °C, and 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.
(3) Aging phenomenon
Aging is a common defect of plastics, and 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.
(4)Low interlaminar shear strength
The interlaminar shear strength is borne by the resin, so it is 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.
