FRP ，FRP Products

Glass Fiber Reinforced Plastics (GFRP), academically named Fiber Reinforced Plastics, commonly referred to as FRP, is a type of fiber-reinforced composite plastic. According to different reinforcing fibers, it is classified into Glass Fiber Reinforced Plastics (GFRP), Carbon Fiber Reinforced Plastics (CFRP), boron fiber reinforced plastics and other categories.

It is a composite material that uses glass fiber and its products (glass cloth, tape, mat, yarn, etc.) as reinforcement materials and synthetic resin as the matrix. Fiber-reinforced composites consist of reinforcing fibers and a matrix.

Fibers (or whiskers) have a tiny diameter, generally below 10μm, with few and minor internal defects. Their fracture strain is within approximately 0.03, belonging to brittle materials that are prone to damage, fracture and corrosion.

Compared with fibers, the matrix has much lower strength and modulus, but can withstand large strain. It usually exhibits viscoelasticity and elastoplasticity, and is a tough material.

Part One: FRP Products

FRP products refer to items manufactured using FRP as the raw material. Due to its physical properties, FRP has distinct advantages and disadvantages as follows:

I. Advantages

Light Weight & High Strength

Its relative density ranges from 1.5 to 2.0, only 1/4~1/5 of carbon steel, while its tensile strength is close to or even higher than carbon steel. Its specific strength is comparable to high-grade alloy steel.

Therefore, it delivers excellent performance in aerospace vehicles, rockets, spacecraft, high-pressure vessels and other products requiring weight reduction. The tensile, bending and compressive strength of certain epoxy FRP can exceed 400Mpa.

Corrosion Resistance

FRP is an excellent anti-corrosion material with good resistance to atmosphere, water, common concentrations of acid, alkali, salt, as well as various oils and solvents. It has been widely applied in all aspects of chemical anti-corrosion engineering, gradually replacing carbon steel, stainless steel, wood and non-ferrous metals.

Excellent Electrical Performance

It is a superior insulating material for making insulation components, maintaining good dielectric properties even under high frequency. With good microwave permeability, it is widely used for radar radomes.

Good Thermal Performance

FRP features low thermal conductivity of 1.25~1.67 kJ/(m·h·K) at room temperature, merely 1/100~1/1000 of metals, making it an ideal thermal insulation material.

Under instantaneous ultra-high temperature conditions, it serves as an ideal thermal protection and ablation-resistant material, protecting spacecraft from high-speed airflow erosion above 2000℃.

Superior Designability

(1) Various structural products can be flexibly designed according to actual needs to meet application requirements and achieve good overall integrity.

(2) Materials can be optimally selected to customize product performances, such as corrosion resistance, instantaneous high-temperature resistance, ultra-high strength in specific directions, and excellent dielectric properties.

Excellent Processability

(1) Molding processes can be flexibly selected according to product shape, technical requirements, usage and production quantity.

(2) The process is simple and allows one-step integral molding with outstanding economic benefits. It shows particular superiority for small-batch products with complex shapes that are difficult to form by other methods.

II. Disadvantages

Low Elastic Modulus

The elastic modulus of FRP is twice that of wood, but about 10 times lower than steel (E=2.1×10⁵). It often suffers from insufficient rigidity and easy deformation in structural design.

This can be compensated by adopting thin-shell structures, sandwich structures, high-modulus fibers or reinforcing ribs.

Poor Long-term Temperature Resistance

Ordinary FRP cannot be used long-term at high temperatures. The strength of general polyester FRP drops significantly above 50℃, usually limited to below 100℃; general epoxy FRP experiences obvious strength decline above 60℃.

By selecting high-temperature resistant resin, the long-term service temperature can reach 200~300℃.

Aging Tendency

Aging is a common defect of plastics, and FRP is no exception. Its performance tends to degrade under the effects of ultraviolet rays, wind, sand, rain, snow, chemical media and mechanical stress.

Low Shear Strength

Interlaminar shear strength is mainly borne by the resin matrix, resulting in relatively low values. It can be improved by optimizing molding processes and using coupling agents. Most importantly, product design should avoid interlaminar shear stress as much as possible.

Part Two: Industry Applications of FRP Products

Construction Industry

Cooling towers, FRP doors and windows, building structures, enclosure structures, indoor equipment and decorative parts, FRP flat sheets, corrugated tiles, decorative panels, FRP cover plates, sanitary ware and integrated bathrooms, sauna rooms, surfing bathrooms, construction formwork, storage silo structures, concrete formwork, reinforcement materials, solar energy utilization devices, etc.

Chemical & Petrochemical Industry

Anti-corrosion pipelines, storage tanks, anti-corrosion delivery pumps and accessories, anti-corrosion valves, gratings, ventilation facilities, sewage and wastewater treatment equipment and supporting parts.

Automotive & Railway Transportation Industry

Automotive housings and components, all-plastic mini cars, coach body shells, doors, inner panels, main pillars, floors, bottom beams, bumpers, instrument panels, light trucks, fire tankers, refrigerated trucks, tractor cabs and engine hoods.

Railway Transportation

Train window frames, interior ceiling bent plates, roof water tanks, toilet floors, baggage car doors, roof ventilators, refrigerated car doors, water storage tanks, and certain railway communication facilities.

Highway Construction & Marine Transportation

Traffic signs, isolation piers, sign piles, marker boards, highway guardrails; inland passenger and cargo ships, fishing boats, hovercrafts, yachts, racing boats, high-speed boats, lifeboats, patrol boats, as well as FRP navigation buoys and mooring buoys.

Electrical Industry & Communication Engineering

Arc extinguishing equipment, cable protection pipes, generator stator coils, support rings, conical shells, insulating pipes and rods, motor retaining rings, high-voltage insulators, standard capacitor housings, motor cooling bushings, generator wind deflectors and other power equipment; distribution boxes and panels, insulating shafts, FRP enclosures and other electrical appliances; printed circuit boards, antennas, radar radomes and other electronic engineering applications.

With the development of science and technology and the improvement of living standards, a large number of civil FRP products have been developed and widely applied, including urban sculptures, craft art shapes, fast food tables and chairs, motorcycle parts, FRP flower pots, safety helmets, amusement equipment, and household appliance shells.