The function and relation of three elements of FRP

Glass fiber is the primary bearing part of FRP, which can not only improve the strength and elastic modulus of FRP, but also reduce shrinkage deformation, progressive thermal deformation temperature and low temperature impact strength. For example, after taking part in 50% glass fabric, the polyester resin casting of 306# can be improved from 50MPa to 200MPa, and the tensile modulus can be improved from 3.9GPa to 14GPa.

The effect and connection of three elements of FRP

Glass fiber

Glass fiber is the primary bearing part of glass fiber reinforced plastic, it can not only advance the strength of the glass fiber reinforced plastic and elastic modulus, and the ability to cut contraction deformation, progress heat distortion temperature and low temperature impact strength, etc. Such as 306 # polyester resin casting body, in 50% of the glass cloth. After tensile strength can be improved by 50 mpa to 200 mpa, tensile modulus can be improved from 3.9 GPa to 14 GPa.

(2) synthetic resin

Synthetic resins are the matrix of GFRP and the loose glass fibers are glued together into a whole.

Resin is the primary stress transfer effect, so the resin plays an important role in the strength of GFRP, especially in compression, torsion, change and shear strength.

As the resin is the matrix material, it has effects on the elastic modulus, heat resistance, electrical insulation, electromagnetic wave, chemical corrosion resistance, weather resistance and aging resistance of GFRP. Chemical resistance to liquid corrosion and water resistance, such as FRP, depends primarily on the function of the resin matrix. Generally unsaturated polyester resin 197# is good at chemical corrosion resistance, while 1289# is good at water resistance. Different types and brands of resin have different functions.

The resin content also affects the function of GFRP. Generally, the resin content is 20%-35%, which is related to the molding method and data type of zeng qiang. For example, encircling and moulding, the content of resin is relatively low, while the content of hand paste and resin is relatively high. The resin content of the strength layer is slightly lower, generally between 25% and 40%. The resin content of corrosion-resistant and impermeable layer is higher than that of glass cloth, and the resin content is lower than that of glass felt. When reinforcing data with glass fiber blanket. Up to 85% of resin - rich content.

(iii) interface

The interface is the interface between any two phases.

The function of FRP is not only related to the reinforcement data and synthetic resins used, but also, to a large extent, to the quality and durability of interfacial adhesion between fibers and resins.

As we all know, glass fiber is a kind of cylindrical glass, the appearance is also as smooth as glass, and the appearance is often strongly attached to a thin film of water, which of course affects the glass fiber and resin adhesion function. In particular, in the process of drawing and weaving of glass fiber, in order to reach the purpose of cluster, lubrication and elimination of static electricity, a layer of infiltrating agent is often applied. Most of the infiltrating agent is paraffin, which remains on the appearance of glass fiber, blocking the synthetic resin and glass fiber and preventing them from sticking together. Visible bound faces the function of FRP very big effect.

If there is a problem with the interface, you need to deal with it. As in the glass fiber exterior covering a surface treatment agent, so that glass fiber and resin can be firmly bonded together. This method is a very useful way to improve the fundamental function of FRP. It has been proved in practice that the glass fiber and its fabric not only improved the function of wear-resisting, water-resisting and electric insulation of the glass fiber after being treated with external treatment agent, but also improved the strength of GFRP, especially in the case of humidity.

In addition, FRP has interface problems with other materials or FRP itself is repeatedly laminated. For example, if the glass fiber reinforced plastics anti-corrosion lining is made on the inner layer of the metal tank, it is necessary to clean the outer surface of the metal tank, such as removing dirt, oil, water and rust layer, etc. If the metal surface treatment is not good, the FRP lining will fail. Sometimes, there will be solidified FRP layer, and then bonded FRP, there will also be interface problems. If choosing laminated solidification process or repairing FRP damage, the outer surface of FRP should be treated. In addition to removing dirt, oil and water, the surface sandpaper should be roughened to increase the Posting area. Otherwise, there will be lamination defect.

It can be seen that the factors affecting the quality of GFRP and its products, besides the two major components of glass fiber and resin, are also very important at the interface. These three elements, one cannot, they are closely related, inseparable. So we call them the three elements, and this is a summary of long term practice.

The experience tells us that fiber, resin and interface are the three elements of success or failure of FRP products. It can be said that whenever there is an accident, people can find the reason from three factors. For example, the fermenter of reinforced concrete of a brewery, the original series of asphalt lining, fell after short-term use failure. The GFRP lining is selected. As the surface of the original concrete pool is not cleaned, the paste will fall and fail, resulting in huge economic losses. Some glass mills, seeking higher profits for lower costs, chose the fiberglass from clay crucibles, and the corrugated fiberglass fell off in less than half a year. As the fiber surface drawn out by the ceramic crucible is untreated, the glass fiber surface has a layer of wax film, which makes the resin unable to stick. When we examine the edge of the corrugated tile, we can see that there are exposed glass threads. This kind of untreated glass cloth is resolute cannot use the son on glass steel, if want to use must pass high temperature dewaxing processing.