FRP（Fiber Reinforced Plastics）

Advantage

1. Light weight and high strength

The relative density is between 1.5 and 2.0, which is only 1/4 to 1/5 of that of carbon steel, but the tensile strength is close to or even higher than that of carbon steel, and the specific strength is comparable to that of high-grade alloy steel. Therefore, it has excellent results in aviation, rockets, space vehicles, high-pressure vessels, and other products that need to reduce their own weight.

2.Preservative

FRP is a good corrosion-resistant material, and has good resistance to atmosphere, water and general concentrations of acids, alkalis, 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, etc.

3.Good electrical insulating performance

It is an excellent insulating material, used to make insulators. It can still protect good dielectric properties under high frequency. It has good microwave permeability and has been widely used in radomes.

4.Good thermal performance

FRP has low thermal conductivity, 1.25~1.67kJ/(m·h·K) at room temperature, which is only 1/100~1/1000 of that of metal. It is an excellent thermal insulation material. It is an ideal thermal protection and ablation resistant material in the instantaneous ultra-high temperature situation, and can protect the spacecraft from the erosion of high-speed airflow above 2000 ℃.

5.Good designability

(1) A variety of structural products can be flexibly designed according to needs to meet the requirements of use, and the product can have a good integrity.

(2) Materials can be fully selected to meet the performance of the product, such as: corrosion resistance, instantaneous high temperature resistance, special high strength in a certain direction of the product, and good dielectric properties can be designed.

6.Excellent workmanship

(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, it can be formed at one time, and the economic effect is outstanding, especially for products with complex shapes and small quantities that are not easy to form. Its process superiority is more prominent.

Disadvantage

1.Low modulus of elasticity

The elastic modulus of FRP is two times larger than that of wood, but 10 times smaller than that of steel (E=2.1×105). Therefore, the product structure often feels insufficient rigidity and is easy to deform. It can be made into a thin shell structure, a sandwich structure, or made up of high modulus fibers or reinforcement ribs.

2.Poor long-term temperature resistance

Generally, FRP cannot be used for a long time at high temperature. The strength of general-purpose polyester FRP decreases significantly above 50°C, and generally only used below 100°C; general-purpose epoxy FRP has a significant decrease in strength above 60°C. But you can choose high temperature resistant resin, so that the long-term working temperature is 200~300℃ is possible.

3.Aging phenomenon

Aging phenomenon is a common defect of plastics, and FRP is no exception. Under the action of ultraviolet rays, wind, sand, rain, snow, chemical media, and mechanical stress, it is easy to cause performance degradation.

4.Low shear strength

The interlaminar shear strength is borne by the resin, so it is very low. The bonding force between layers can be improved by selecting processes and using coupling agents. The most important thing is to avoid shearing between layers as much as possible during product design.