Brief Introduction to the Advantages, Disadvantages and Applications of Pultruded Composites

 

Pultruded composites are a type of high-performance fiber-reinforced polymer (FRP) composite material manufactured using a continuous process called pultrusion.

 

Here, continuous fibers (such as glass or carbon) are pulled through a bath of thermosetting resin (such as epoxy, polyester or vinyl ester) and then formed into the desired shape using a mold. The resin then cures to form a strong, lightweight and durable composite product.

 

 

Pultrusion Resin

The matrix resin is an important component of pultruded composite materials. Common pultrusion resins include epoxy, polyurethane, phenolic, vinyl, and the recently widely concerned thermoplastic resin system. Due to the characteristics of pultruded composite materials, the matrix resin needs to have low mixed viscosity and fast reaction speed under high temperature conditions. When selecting the matrix resin, not only the pultrusion reaction rate but also the viscosity of the pultrusion resin should be considered. If the viscosity is relatively high, it will affect the lubrication effect during product production.

 

 

Epoxy Resin

Polyurethane

The lower viscosity of polyurethane resin allows for higher glass fiber content than polyester or vinyl ester resins, which makes the flexural modulus of pultruded polyurethane composites close to the properties of aluminum. It has excellent processing properties compared to other resins.

 

Phenolic Resin

Vinyl Ester Resin

Vinyl alcohol resin has excellent mechanical properties, heat resistance, corrosion resistance and fast curing characteristics. It is one of the preferred resins for pultruded products around 2000.

 

Thermoplastic Resin

Compared with traditional materials such as metals, ceramics and non-reinforced plastics, FRP pultrusion has many advantages. They have unique custom design capabilities to meet specific product needs.

 

 

Advantages of Incorporating Pultruded Composites Include:

 

• Manufacturing efficiency: Pultrusion is a continuous process that offers advantages such as high production volumes, lower costs, and faster lead times over alternative composite manufacturing methods.
• High strength and stiffness-to-weight ratio: Pultruded composites are strong and stiff, yet lightweight. Carbon fiber pultrusions are significantly lighter than metals and other materials. This makes them ideal for applications where weight reduction is a priority, such as aerospace, automotive, and transportation.
• Corrosion resistance: FRP composites are highly resistant to corrosion, making them ideal for applications in industries such as chemical processing, marine, and oil and gas.
• Electrical insulation: Fiberglass pultrusions can be designed to be non-conductive, making them ideal for electrical applications that require dielectric properties.
• Dimensional stability: Pultruded composites will not deform or crack over time*. This is important for applications that require precise tolerances.
• Custom designs: Pultrusions can be manufactured in a variety of shapes and sizes, including rods, tubes, and beams, as well as more complex profiles. They are also highly customizable. Materials and processes such as fiber type, fiber volume, resin type, and surface yarns and treatments can be engineered to meet specific performance and application requirements.

Disadvantages of Using Pultruded Composites Include:

• Limited geometries: Pultruded composites are limited to parts with constant or near-constant cross-sections. This is because the fiber reinforcement is pulled through a continuous manufacturing process of a forming die.
• Higher cost to manufacture parts: The dies used in pultrusion can be expensive. This is because the dies must be made of higher quality materials, must be able to withstand the heat and pressure of the pultrusion process, and are produced to tight processing tolerances.
• Low transverse strength: Pultruded composites have lower transverse strength than longitudinal strength. This means that they are weaker in the direction perpendicular to the fibers. However, this problem can be overcome by incorporating multiaxial fabrics or fibers into the pultrusion process.
• If a pultruded composite is damaged, it can be difficult to repair. The entire assembly may need to be replaced, which can be expensive and time-consuming.

It is important to weigh the advantages and disadvantages of pultruded composites before deciding if they are right for your application. If you need a material with high strength, high stiffness to weight ratio, corrosion resistance and constant cross-section, then pultruded composites are a good choice. However, if you need a composite with high lateral strength or complex geometry, then you may want to consider other options.

 

 

How to Choose the Right Pultruded Composite

When choosing a pultruded component or profile for your application, it is important to consider the following factors:

o Mechanical property requirements: What are the strength, stiffness, and shear requirements of the application?

o Environmental requirements: Will the composite be exposed to harsh environmental conditions, such as chemicals, salt water, or extreme temperatures?

o Weight requirements: Is weight reduction important for the application?

o Cost requirements: What is the budget for the application?

An experienced pultrusion manufacturer can provide design and formulation expertise and work with you to develop the right pultruded composite for your application.

 

Applications of Pultruded Composites

 

Pultruded Composites have a Wide Range of Applications, including:

 

• Aerospace: Aircraft and spacecraft components, such as control surfaces, landing gear, and structural supports.
• Automotive: Automotive components, such as drive shafts, bumpers, and suspension components.
• Infrastructure: Infrastructure reinforcement and components, such as sleepers, bridge decks, concrete repair and reinforcement, utility poles, electrical insulators, and crossarms.
• Chemical processing: Chemical processing equipment, such as pipes and floor gratings.
• Medical: Stent stiffeners and endoscope dissection poles.
• Marine: Marine applications such as masts, battens, pier whips, retaining wall piles, anchor pins and docks.
• Oil and Gas: Oil and Gas applications such as wellheads, pipelines, pump rods and platforms.
• Wind Energy: Wind turbine blade components such as blade reinforcements, spar caps and root stiffeners.
• Sporting Goods: Parts that require a constant cross section such as skis, ski poles, golf equipment, paddle shafts, archery components and tent poles

 

The FRTP anti-collision beam developed by CQFD together with Plastic Omnium and Hyundai Motor uses an in-situ pultrusion process to form the main body of continuous glass fiber reinforced PA6

 

Pultruded composites have many advantages over traditional metals and plastics. If you are a design material engineer looking for high-performance composites for your application, pultruded composites are a good choice.