Fiber Reinforced Polyester Composites

The composite material is in fact a uniform solid structure. Each of the various components retains its identity and characteristic structure within the composite. In general, the structure of a composite consists of two phases, a matrix and a reinforcing component. Matrix continuous phase and reinforcement is discontinuous. The task of the reinforcement is the strengthening of the composite. And the matrix has a bonding responsibility. There are recognizable interfaces between matrix materials and reinforcements. However, composite materials are generally components such as hardness, strength, weight, high temperature performance, corrosion resistance, hardness and conductivity.

In fact, composites are produced in a process. Composite materials, particularly fiber-reinforced polyester (FRP), emphasize how different sub-materials work in a synergy.
Analyzing the analysis of the good properties of the composite material indicates that they all depend on the properties of the individual components.
Among the factors affecting the efficiency of the composite material are the relative amount of phases forming the different materials; routing various other components; The degree of bonding between the matrix and the reinforcements and the size, shape and distribution of the discontinuous phase can be considered. The material contained in the composite may be organic, metal or ceramic. Therefore, there is a wide range of freedom. Therefore, the composite materials can be designed to meet the desired and required engineering properties and characteristics.

There are many types of composite materials and various methods of classifying them. One method is based on matrix materials including polymers, metals and ceramics.
The other method is based on the reinforcing step in the form of fibers, particles and filaments (whiskers). These filaments are shorter lengths than fibers. Therefore, the link between particles, fibers or fibrils and matrix is ​​very important.

In structural composites, polymeric molecules are known as coupling agents. These molecules form bonds with the dispersed phase and are integrated into the continuous matrix phase.
The most popular composite material type is fiber-reinforced polyester composites in which a material is embedded in a polyester matrix where the continuous thin fibers are glass, carbon or natural fibers.
These composites are also referred to as glass fiber reinforced polyester (GRP), carbon fiber reinforced polyester and natural fiber reinforced polyester.
Examples of fiber-reinforced polyester (FTP) are used in a wide range of applications, including industrial structures, aerospace, aircraft, electronic components, automotive industry, railways and wagon systems, and even sports equipment.

In addition to the desired mechanical properties of fiber reinforced polyester composite materials, corrosion resistance is also an attractive factor for use in different areas.
They are used very efficiently with good care against UV light, heat and moisture.

Different Stages of FRP Composites

Fiber Supplements

Fibers are an important component in fiber-reinforced FRP composites. There have been a lot of research and development on fibers, types, volume fractions and their effects on architecture.
The fiber can generally cover 30 to 70% of the matrix volume in the composites.
Fibers can be uncut, woven, stitched or braided. Usually, they are extruded to improve the bond and to improve the bonding by using starch, gelatin, oil or wax layering materials. Binders are also used to improve the process.
The most common fiber types used in advanced composites for structural applications are glass fiber, aramid and carbon.
Carbon fiber composites are the most expensive among fiber-reinforced polyester composites.
The cost of aramid fibers is approximately the same as those of low grade carbon fibers.
There are also fiber types used. These include high strength and high modulus fibers such as boron. However, fibers of this type are currently considered to be not economically efficient.

Fiberglass Types

Although there are different classifications, glass fibers are divided into three main classes in the general literature, namely E glass fiber, S glass fiber and C glass fiber.
E glass fiber is designed for electrical use and S glass fiber is designed for high strength.
C glass fiber is for high corrosion resistance. It is rare for civil engineering applications.
Three-fiber E glass fiber is the most common reinforcement material used in civil and industrial areas.
It is produced from lime-alumina-borosilicate which is abundant as raw material such as sand.
The fibers are drawn into very fine filaments if necessary. The strength and modulus of the glass fiber may be impaired by increasing temperature. Although the glass material is broken down under a constant load, it can be designed for satisfactory operation.
The fiber is considered to be an isotropic material and has a lower thermal expansion coefficient than steel.

There are also other fiber glass fibers used for fiber reinforced polyester reinforcement;
• A glass fiber containing sodium silicate for areas where the strength, strength and good electrical resistance of the E-glass fiber is not needed.
• D-glass, borosilicate glasses with low dielectric constant for electrical applications.
• The maximum alkali content of ECR glass fiber is 2% by weight. Calcium alumino-silicate glass fibers.
• AR glass fiber is alkali-resistant glass fibers composed of alkali zirconium silicates used in cement surfaces and concrete.
• R glass fiber is used where additional strength and acid corrosion resistance are required for calcium alumino-silicate-containing reinforcement.
• S-2 type glass fibers are high strength in extreme temperature and corrosive media, composite structural applications requiring modulus and stability, and textile fibers containing magnesium alumino-silicate.
The following table shows the mechanical properties of different glass fibers.