Seeking information on the temperature resistance, pressure resistance, and corrosion resistance of fiberglass-reinforced plastic

What does your company do? Our company uses fiberglass-reinforced plastic

I work in chemical engineering design. For a recent project, we want to use fiberglass-reinforced plastic materials for the equipment that will be used in media containing hydrochloric acid and HCl. I would like to learn more about the temperature tolerance, pressure resistance, corrosion resistance, and other aspects of fiberglass-reinforced plastic, but I don’t know much about it

It’s absolutely fine to use it as an acid tank!

I know that Daqing Hanwei Changyuan High-Pressure Fiberglass Pipe Co., Ltd. and Shashi Steel Pipe Factory produce high-pressure fiberglass pipes. The operating temperature of the medium can reach 115 degrees, and the pressure can reach 25 MPa. The maximum pipe diameter I’m aware of is DN200; you can check this information online.

Glass fiber reinforced plastic is actually a composite material, typically composed of resin, glass fibers, and a small amount of curing agent; therefore, its temperature resistance depends on the type of resin used (such as unsaturated polyester resin, epoxy resin, and phenolic resin) as well as the curing agent. It should be noted that the glass fiber reinforced plastic we commonly see is one that is made using epoxy resin. It usually cannot withstand high temperatures and is generally used in environments below 80 degrees. As for the acid resistance of fiberglass, it is generally not a problem. Of course, when it comes to concentrated sulfuric acid and concentrated nitric acid, we don’t need to use fiberglass in actual production, as it’s easy to select materials that provide sufficient passivation. As for withstanding pressure, the epoxy resin fiberglass used in general applications is designed for use at normal pressure; however, if pressure resistance is required, it can be customized to withstand extremely high pressures. You can search for the manufacturers directly, as this material technology is quite mature. Below are some basic facts about fiberglass: Fiberglass, commonly known as FRP (Fiber Reinforced Plastics), refers to fiber-reinforced plastics, and generally denotes materials in which glass fibers are used to reinforce unsaturated polyester, epoxy resin, or phenolic resin matrices. Reinforced plastics that use glass fibers or their products as reinforcing materials are known as glass fiber reinforced plastics, or fiberglass. Due to the different types of resins used, it is known as polyester fiberglass, epoxy fiberglass, and phenolic fiberglass. Physical and chemical properties: Glass is hard and fragile, yet it possesses excellent transparency as well as resistance to high temperatures and corrosion ； At the same time, steel is very hard and not easy to break, and it also has the ability to withstand high temperatures. So people began to think that if a material could be created that possessed the hardness of glass, resistance to high temperatures and corrosion, as well as the strength and indestructibility of steel, it would surely have many useful applications. Through research and experimentation, people have finally developed such a composite material. It is fiberglass, which can stand shoulder to shoulder with steel. Let’s first take a look at a test to see whether its performance is good or not. In a valley surrounded by mountains and shaded by green trees, an experiment is underway. People hiding behind bunkers over 200 meters away were all staring at an oxygen tank placed in the center of the valley. The air compressor rotates rhythmically, continuously filling the oxygen tank through alloy steel pipes. The pointer on the pressure gauge tugs at everyone’s heart. The reading gradually increased from 100 to 200, then to 400 and 500, until it reached 700 kilograms per square centimeter. At that moment, there was a loud explosion – the oxygen tank had blown up! The people around cheered and jumped up: “It worked! ” An oxygen cylinder is a pressure-resistant container. The working pressure it can withstand is 150 kilograms per square centimeter. For safety purposes, it is required to withstand three times the normal operating pressure during manufacturing, namely 450 kilograms per square centimeter. It is only considered qualified if it does not burst. The oxygen cylinder used in the above experiment far exceeds the design requirements. What kind of steel is this made from? It is fiberglass; more precisely, it is made by combining glass and plastic together. Glass is a hard and brittle material that shatters upon being dropped; can fiberglass, which has its name derived from glass, withstand being dropped? So new experiments were conducted. Inflate the other fiberglass oxygen tank to 150 kilograms per square centimeter, and then roll it down the valley from the mountaintop. It collided with the jagged rocks and kept rolling down to the bottom of the valley without exploding. The fiberglass oxygen cylinders have passed the quality assessment test. The tensile strength of ordinary glass is only one-eighth that of regular steel. The glass is melted and drawn into glass fibers that are only a fraction of the diameter of a hair; the originally hard and fragile glass thus turns into soft and highly ductile glass fibers, whose tensile strength can increase by more than ten times. As we all know, cement blocks are resistant to compression, while steel is resistant to tension. Using steel as the framework and cement, sand, and gravel as the ‘muscles’, combining them into one entity so that they can complement each other and become extremely strong – this is reinforced concrete. Similarly, by using glass fibers as the reinforcement and synthetic resins (phenolic plastics, epoxy resins, and polyester resins) as the \"muscles,\" and combining them together, the material produced can achieve tensile strength comparable to that of steel—hence the name fiberglass. Uses: Glass fiber reinforced plastic is a composite material that has seen rapid development over the past fifty years or so. 70% of the production of glass fiber is used to manufacture fiberglass-reinforced plastic. Fiberglass has high ancient hardness and is much lighter than steel. It is used as fuel tanks and pipelines in jet planes, helping to reduce the aircraft’s weight. The miniature oxygen tanks carried by the astronauts who went to the moon were also made of fiberglass. FRP is easy to process, does not rust or decay, and requires no painting. Our country has widely adopted fiberglass in the manufacture of various small motorboats, lifeboats, yachts, as well as in the automotive industry, thereby saving a significant amount of steel. The art world also uses fiberglass to create sculptures, while the film industry employs it for props – it is both convenient and cost-effective, and allows for the replication of various material effects. As a result, it is very popular. Chemical plants likewise use fiberglass made from phenolic resin instead of stainless steel for various corrosion-resistant devices, which helps to extend the lifespan of these devices. FRP is non-magnetic and does not block the passage of electromagnetic waves. Using it as a radar shield for missiles is like putting protective glasses on the missiles; it does not block the radar’s ‘line of sight’ while still providing protection. Now, the radomes of many missiles and ground radar stations are made of fiberglass-reinforced plastic. Entering the 21st century, thanks to the excellent wave-transmitting properties of fiberglass, this material has been widely used in the manufacture of covers for 2G and 3G antennas, as mobile communications have become increasingly popular. Its good formability and ability to enhance the appearance of structures have made it useful for beautifying residential areas; examples of such products include square post covers, artificial stones, and decorative trees for outdoor use. Fiberglass has also played a significant role in improving the standards of sports. Since the invention of the pole vault sport, the highest record achieved by athletes using wooden poles is 3.05 meters. Bamboo poles were used later. By 1942, the record was raised to 4.77 meters. The advantage of bamboo poles is that they are light and elastic, but their drawback is that they are thicker at the bottom and thinner at the top, making it difficult to improve their performance for recording purposes. As a result, people began using aluminum alloy poles instead of bamboo poles; although these are light and strong, they lack elasticity. Thus, from 1942 to 1957, over a period of 15 years, the highest record in pole vaulting improved by only 1 centimeter. But since the advent of the new fiberglass pole, thanks to its light weight and elasticity, records have risen rapidly; today’s high jump records have already exceeded the 6-meter mark. Today, fiberglass is also widely used in people’s daily lives. People affectionately call it “fiberglass.” Since certain types of it retain many of the advantages of glass, such as transparency, it is used as window glass – allowing it to block ultraviolet rays from the sun while also keeping rooms bright. It is also used to make various sturdy and durable daily household items. Such as bath items, kitchen utensils, toiletries, etc. The meaning of fiberglass: The scientific name for fiberglass is glass fiber reinforced plastic. It is a composite material that uses glass fibers and their products (such as glass cloth, tape, mat, yarn, etc.) as reinforcing materials, and synthetic resin as the matrix material. The concept of composite materials refers to a situation where a single material does not meet the required specifications; in such cases, two or more materials are combined to create another material that can fulfill those requirements – and this is what constitutes a composite material. For example, single glass fiber, although highly strong, has loose fibers between them; it can only withstand tensile forces, not bending, shear, or compressive stresses, and it is also difficult to shape into a fixed geometry, making it a soft material. If bonded together with synthetic resin, they can be made into various rigid products with fixed shapes that can withstand tensile stress as well as bending, compressive, and shear stress. This constitutes a glass fiber-reinforced plastic matrix composite. Due to its strength, which is comparable to that of steel, and because it contains glass components, it possesses properties such as the color, shape, corrosion resistance, electrical insulation, and heat insulation characteristic of glass. For this reason, the easy-to-understand term “fiber glass” came into use over time. This term was coined in 1958 by Comrade Lai Jifa, who was then Minister of the Building Materials Industry; it spread from the building materials sector throughout the country and is still widely used today. It can be seen that fiberglass reinforced plastic refers to a reinforced plastic in which glass fibers are used as reinforcing materials and synthetic resins as binders; abroad, it is known as glass fiber reinforced plastic. With the development of the fiberglass industry in our country, the reinforcing materials based on plastics have expanded from glass fibers to carbon fibers, boron fibers, aramid fibers, alumina fibers, and silicon carbide fibers. Undoubtedly, the reinforced plastics made from these new types of fibers are high-performance fiber-reinforced composites, and the term \"fiberglass\" can no longer be used to describe them. Given its historical origins and development, fiberglass-reinforced plastic composite materials are commonly used, so such a name is quite comprehensive. What are the advantages, disadvantages, and characteristics of FRP materials? I. FRP has the following characteristics. (1) Light weight and high strength: Its relative density ranges from 1.5 to 2.0, which is only 1/4 to 1/5 that of carbon steel; however, its tensile strength is close to, or even exceeds, that of carbon steel, while its specific strength can compare with that of high-grade alloy steels. Therefore, it exhibits excellent performance in applications such as aviation, rockets, spacecraft, high-pressure containers, and other products where reducing weight is necessary. The tensile, bending, and compressive strengths of certain epoxy FRPs can exceed 400 Mpa. The density, strength, and specific strength of some materials are shown in Table 1-1. (2) Good corrosion resistance: FRP is an excellent material resistant to corrosion; it has strong resistance to the atmosphere, water, acids, alkalis, and salts at normal concentrations, as well as various oils and solvents. It has been applied in various aspects of chemical industry corrosion protection, and is replacing carbon steel, stainless steel, wood, non-ferrous metals, etc. (3) It has good electrical properties and is an excellent insulating material used for manufacturing insulators. It maintains good dielectric properties at high frequencies. Microwaves pass through it well, and it is widely used in radar radomes. (4) Good thermal properties: FRP has a low thermal conductivity, ranging from 1.25 to 1.67 kJ/(m·h·K) at room temperature; this is only 1/100 to 1/1000 of that of metals, making it an excellent insulating material. Under instantaneous ultra-high temperatures, it is an ideal thermal protection and ablation-resistant material that can protect spacecraft from the impact of high-speed airflow at temperatures above 2000°C. (5) Good designability: ① Various structural products can be flexibly designed as needed to meet usage requirements, enabling the products to have excellent integrity. ②Materials can be carefully selected to meet the performance requirements of the product; for example, it is possible to create products that are resistant to corrosion, capable of withstanding sudden high temperatures, having extremely high strength in certain directions, or possessing good dielectric properties, among other things. (6) Excellent processability: ① The molding process can be flexibly selected based on the product’s shape, technical requirements, application, and quantity. ②The manufacturing process is simple, allowing for one-time molding; it offers excellent economic benefits. Its advantages in terms of manufacturing process are particularly evident for products with complex shapes that are difficult to mold in small quantities. II. It is not possible to expect a single type of FRP to meet all requirements; FRP is not omnipotent, and it has the following shortcomings as well. (1) Low elastic modulus: The elastic modulus of FRP is twice that of wood, but 10 times lower than that of steel (E=2.1×106); therefore, it often lacks rigidity in product structures and is prone to deformation. It can be designed as a thin-shell structure or a sandwich structure, and reinforcement can also be provided using high-modulus fibers or reinforcing ribs. (2) Poor long-term heat resistance: Generally, FRP cannot be used for extended periods at high temperatures. The strength of conventional polyester FRP decreases significantly above 50°C, and it is usually only suitable for use below 100°C ； The strength of general-purpose epoxy FRP decreases significantly above 60°C. However, high-temperature resistant resins can be chosen, making it possible to operate at temperatures of 200–300°C over the long term. (3) Aging phenomenon: The aging phenomenon is a common defect of plastics, and FRP is no exception; it is prone to a decline in performance under the influence of ultraviolet rays, wind, sand, rain, snow, chemical agents, mechanical stress, etc. (4) Low interlayer shear strength: The interlayer shear strength is supported by the resin, which is why it is quite low. The interlayer adhesion can be improved by selecting appropriate processes and using coupling agents, etc. The most important thing is to avoid shear forces between the layers as much as possible during product design. III. What are the production methods for FRP? Answer: Basically, there are two main categories, namely wet contact type and dry pressure molding. Classified by manufacturing characteristics, there are hand lay-up molding, laminating, RTM, pultrusion, compression molding, winding molding, etc. Hand lay-up molding includes the hand lay-up method, bag pressing method, spray method, wet paste low-pressure method, and moldless hand lay-up method. The four most commonly used molding methods in the world today are as follows. ①Hand lay-up method: Mainly used in **Norway, Japan, the UK, Denmark, etc. ②Spray method: Mainly used in **Sweden, the United States, Norway, etc. ③Molding method: Mainly uses **from Germany and other countries. ④FTM method: Mainly used in **Europe, the United States, Japan. In our country, over 90% of FRP products are manufactured using the hand-laying method; other methods include compression molding, winding, and laminating (see Chapter 11). The hand-laying method in Japan still accounts for 50%. Around the world, the hand-laying method still accounts for a significant proportion, indicating that it remains viable. The characteristic of the hand lay-up method is that it uses wet resin for molding; it requires simple equipment and low costs, and can produce integral products over 10 meters in length in a single operation. The disadvantages are low mechanization level, long production cycle, and unstable quality. In recent years, China has introduced foreign-made equipment for processes such as extrusion, spraying, and winding. With the development of the FRP industry, new processing methods will continue to emerge

By the way, I searched this forum again and found a thread that discusses the corrosion resistance of fiberglass-reinforced plastic pipes; you might want to take a look – it should be helpful to you! Address: http://bbs.hcbbs.com/viewthread.php?tid=412082