What is glass fiber reinforced plastic?

Time：2022-03-23 08:53:22 / Popularity： / Source：

What is glass fiber reinforced plastic?

Glass fiber reinforced plastic is a composite material with a wide range of varieties, different properties, and a wide range of uses. It is a new functional material made of synthetic resin and glass fiber through a composite process.

Characteristics of glass fiber reinforced plastics:

(1) Good corrosion resistance: FRP is a good corrosion-resistant material. It has good resistance to atmosphere, water, acid and alkali of general concentration, salt, various oils and solvents. It has been widely used in all aspects of chemical corrosion protection. It is replacing carbon steel, stainless steel, wood, non-ferrous metals and other materials.
(2) Lightweight and high strength: Relative density of FRP is between 1.5 and 2.0, which is only 1/4 to 1/5 of that of carbon steel, but its tensile strength is close to or even surpassing that of carbon steel, its strength is comparable to that of high-grade alloy steel. Is widely used in aerospace, high-pressure vessels and other products that need to reduce their own weight.
(3) Good electrical performance: FRP is an excellent insulating material, used to make insulators, and it can still maintain good performance at high frequencies.
(4) Good thermal performance: FRP has low electrical conductivity, 1.25~1.67KJ at room temperature, only 1/100~1/1000 of metal is an excellent thermal insulation material. It is an ideal thermal protection and ablation resistant material in the case of instantaneous superheat.
(5) Excellent process performance: Molding process can be selected according to shape of product, process is simple and can be molded at one time.
(6) Good designability: materials can be fully selected according to requirements to meet product performance and structure requirements.
(7) Low modulus of elasticity: Modulus of elasticity of FRP is 2 times larger than that of wood but only 10 times smaller than that of steel. Therefore, product structure often feels insufficient rigidity and is easy to deform. Solution can be made into a thin shell structure or a sandwich structure; it can also be made up by high modulus fibers or reinforcing ribs.
(8) Poor long-term temperature resistance: Generally, FRP cannot be used for a long time at high temperatures, strength of general-purpose polyester resin FRP will decrease significantly above 50 degrees.
(9) Aging phenomenon: Under action of ultraviolet rays, wind, sand, rain and snow, chemical media, mechanical stress, etc., it is easy to cause performance degradation.
(10) Low interlaminar shear strength: Interlaminar shear strength is borne by resin, so it is low. Interlayer adhesion can be improved by selecting process, using coupling agents and other methods, try to avoid shearing between layers during product design.

Advantages of glass fiber reinforced plastic:

Heat-resistant temperature of glass fiber reinforced plastic is much higher than that of no glass fiber, especially nylon plastics.
Glass fiber reinforced plastics have low shrinkage and high rigidity.
Glass fiber reinforced plastic will not stress crack, and at the same time, impact resistance of glass fiber reinforced plastic is much improved.
Strength of glass fiber reinforced plastics is high, such as tensile strength, compressive strength, and bending strength.
Due to addition of other additives, glass fiber reinforced plastics have greatly reduced combustion performance of glass fiber reinforced plastics. Most of materials cannot be ignited and are flame retardant materials.

Disadvantages of glass fiber reinforced plastic:

Glass fiber reinforced plastic becomes opaque due to addition of glass fiber, and it is transparent before adding glass fiber.
Plastic glass fiber reinforced plastic has lower toughness and increased brittleness than plastic without glass fiber;
Due to addition of glass fiber, melt viscosity of all materials increases, and fluidity of plastic glass fiber reinforced plastics is increased. Injection pressure is much higher than that without glass fiber. For normal injection molding, injection temperature of all reinforced plastics should be increased by 10℃-30℃ than before without glass fiber.
Due to addition of glass fiber and additives, moisture absorption performance of glass fiber reinforced plastic is greatly enhanced. Original pure plastic that does not absorb water will also become water absorbing. Therefore, it must be dried during injection molding.
In injection molding process of glass fiber reinforced plastic, glass fiber can enter surface of plastic product, making surface of product rough and spotty. In order to obtain a higher surface quality, it is best to use a mold temperature machine to heat mold during injection molding, so that plastic polymer enters surface of product, but appearance quality of pure plastic cannot be achieved.
After glass fiber is reinforced, glass fiber is a material with high hardness. After additives are volatilized at high temperature, it is a very corrosive gas, which greatly wears and corrodes screw and injection mold of injection molding machine. Therefore, when producing molds and injection molding machines using such materials, attention should be paid to surface anti-corrosion treatment and surface hardness treatment of equipment.

Gud Mould Industry Co., Ltd