FRP materials have a wide range of applications in our lives, involving many industries. The so-called FRP is omnipotent. We have a general understanding of what FRP materials are. Today we are going to talk about the characteristics of glass tube materials.
Glass Reinforced Plastics (FRP) is also known as GRP, that is, fiber reinforced plastic, generally refers to the use of glass fiber reinforced unsaturated polyester resin, epoxy resin and phenolic resin matrix. Reinforced plastics that use glass fiber or its products as reinforcing materials are called glass fiber reinforced plastics, or glass steel. Due to the different types of resins used, it is called polyester fiberglass, epoxy fiberglass, and phenolic fiberglass. Lightweight and hard, non-conductive, high mechanical strength, less recycling and corrosion resistance. It can replace steel to manufacture machine parts, automobile and ship shells, etc. Lightweight 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. The tensile, flexural and compressive strengths of some epoxy FRP can reach more than 400Mpa. Good corrosion resistance.
FRP materials are good corrosion-resistant materials, and have good resistance to atmosphere, water and general concentrations of acids, alkalis, salts, and various 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. It has good electrical properties and 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. Good thermal performance.
FRP has low thermal conductivity, 1.25~1.67kJ/(m·h·K) at room temperature, only 1/100~1/1000 of metal, and 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 ℃. Good designability
(1) Various 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, high strength in a certain direction, and good dielectric properties can be designed. 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 molded at one time, and the economic effect is outstanding, especially for products with complex shapes and small quantities that are difficult to form, and its process superiority is more prominent. Disadvantages and deficiencies, low modulus of elasticity.
The elastic modulus of FRP materials is twice that of wood, but 10 times smaller than steel (E=2.1E5), so 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 reinforced ribs. The long-term temperature resistance is poor. 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 it is possible to choose high temperature resistant resin, so that the long-term working temperature is 200~300℃. Aging phenomenon
Aging phenomenon is a common defect of plastics, and FRP materials are no exception. Under the action of ultraviolet rays, wind, sand, rain, snow, chemical media, and mechanical stress, it is easy to cause performance degradation. The interlayer shear strength is low, and the interlayer 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 when designing the product.