1. Fiberglass, when you say the word. The first words that pop up in the minds of people around you must be two words: glass and steel. In their consciousness, they either think that this is a new type of glass, or they think it is some kind of special steel. At this time, you must first explain to him the concept of FRP.
FRP is a word with Chinese characteristics. On the surface, it seems to be composed of two materials: glass and steel, but it is not as simple as it sounds. Glass, which refers to glass fibers, exists as a reinforcement. And steel has nothing to do with its composition, which means that it behaves like steel and has super high strength.
The scientific name of FRP should be called glass fiber reinforced plastic (FRP for short). From the scientific name, we can see their composition, glass fiber and plastic. And this plastic generally refers to thermosetting resins such as unsaturated resins, vinyl resins, epoxy resins, and phenolic resins.
At this time, the problem came again. For them, plastics are heard and seen a lot. What is the concept of thermosetting? The so-called thermosetting is another classification relative to thermoplastic. Thermoplastics are plastic stools, washbasins, mouthwash cups, mineral water bottles, plastic bags, feeding bottles, electrical casings, etc. that are seen every day in daily life. One of the biggest characteristics of this type of plastic is that it can flow and deform when heated, and it can maintain a certain shape after cooling. The simple understanding is that it can be formed repeatedly by heating. Thermosetting resin is just the opposite. Once it is molded, it shows the characteristics of infusibility and insolubility. It cannot be softened and molded repeatedly when heated, and it is also insoluble in common solvents.
2. After listening to what you said, everyone thought about it and had a general idea of FRP. At this time, a studious baby raised his hand and asked: Just now you mentioned that glass fiber is used as a reinforcing material, so what kind of material is plastic used as?
If you want to study FRP products in detail, it actually includes three types of materials: glass fiber, resin, and additives. Among them, glass fiber is used as a reinforcing material, while resin is used as a matrix material, and additives mainly play some auxiliary functions.
It seems a bit difficult to understand, so let's give an example.
An example of this is the house we live in every day. Today's houses basically use reinforced concrete structures (if not, don't argue). Among them, reinforced concrete is a typical composite material. As a reinforcing material, steel bars mainly play a role in conducting force. A simple understanding is that when it is subjected to force, the steel bar can transfer the force to better protect the concrete. (It sounds very powerful, a bit like Zhang Wuji's Great Teleportation!) The cement mainly plays a bonding role and protects the steel bars from oxidation and corrosion, as a matrix material. Others such as sand, water and the like are used as auxiliary materials.
Now it is relatively clear that the fiber in FRP corresponds to the steel bar. As a reinforcing material, it has high strength and modulus. Resin mainly plays a bonding role, has a certain toughness, can protect fibers, and has a similar effect to cement, and is a matrix material for fibers. And various additives are a bit similar to sand and stone, to meet some special needs, such as aesthetics, flame retardancy and so on.
At this time, everyone suddenly realized that your job is the same as that of a plasterer. (Whoever said that, stand up for me)
3. The stunned student asked weakly: I often hear people talk about carbon fiber, what kind of material is this?
This is another good question. (It seems that you say every question is a good question)
Carbon fiber is a new type of fiber with high strength and high modulus with a carbon content of more than 95%. Its strength is much higher than that of glass fiber, so it can form products with lighter weight and better strength. With the rapid development of materials, the reinforcing materials in FRP have been developed from glass fiber to carbon fiber, aramid fiber, ultra-high molecular weight polyethylene fiber, basalt fiber and so on. Therefore, FRP is not limited to glass fiber reinforced plastics, but should be fiber reinforced plastics in a broad sense.
4. At this time, more and more people raised their hands to ask questions. The aramid fibers and ultra-high molecular weight polyethylene fibers you mentioned...what are they all? We all know what the materials are, so what method is used to make the finished product? Is it really the same job as a plasterer? (Hey, this classmate, I remember you. Just now you said that my work is like a plasterer. But in fact, a plasterer is also very good. If you want to build a good house, you must have excellent skills. This is very similar to us.)