How To Choose Extruded Composite Materials? Briefly Describe Their Advantages, Disadvantages, And Main Applications.

          Extruded composite materials are high-performance fiber-reinforced polymer (FRP) composites manufactured using a continuous process called extrusion. In this process, continuous fibers (such as glass or carbon) are pulled through a bath of thermosetting resin (such as epoxy, polyester, or vinyl ester), and then shaped using molds to achieve the desired form. The resin is then cured to create a strong, lightweight, and durable composite product.

          The choice of matrix resin is crucial in extruded composites. Common matrix resins for extrusion include epoxy, polyurethane, phenolic, vinyl ester, and more recently thermoplastic resin systems which have gained significant attention. Due to the characteristics of extruded composites, the matrix resin needs to have low viscosity for easy mixing and fast reaction rate at high temperatures. When selecting a matrix resin for extrusion applications it is important not only to consider its reaction rate but also its viscosity since higher viscosity can affect lubrication during product manufacturing.

           Epoxy Resin: Extruded composites made with epoxy matrix resins exhibit high strength and can be used under high temperature conditions due to their fast curing speed. Epoxy-based fiber-reinforced composites are commonly used in wind turbine blades and blade roots; however they suffer from brittleness issues along with short applicability period due to poor permeability properties and high curing temperatures which increase processing difficulties leading to resource waste and increased manufacturing costs.

Polyurethane: Polyurethane resins have lower viscosity compared to polyester or vinyl ester resins allowing for higher fiberglass content in polyurethane-based extrusions resulting in bending modulus similar to aluminum properties. They offer excellent processing performance compared with other resins.

          Translation: "Phenolic resin has become a hot topic in recent years due to its outstanding advantages such as low toxic release, low smoke generation, and flame retardancy. Its extrusion molding composite materials have gradually gained popularity in fields such as rail transportation, offshore oil drilling platforms, chemical anti-corrosion workshops, and pipelines. However, traditional phenolic resins have slow curing reaction speed and long molding cycles. Especially during the curing process, a large amount of condensation water and volatile organic compounds are produced. This easily leads to the formation of bubbles and pores in fast continuous production of extruded products, severely affecting product performance. Acid catalytic systems are commonly used. Vinyl ester resin and vinyl alcohol resin possess excellent mechanical properties, heat resistance, corrosion resistance, and rapid curing characteristics. Around 2000s they were one of the preferred resins for extrusion products. Thermoplastic composites avoid the drawbacks of thermosetting composites such as poor environmental friendliness, long processing cycles,and difficulty in recycling. They also exhibit strong flexibility and impact resistance along with good damage resistance ability and damping performance.Thermoplastic composites have strong resistance against chemical corrosion and environmental factors without undergoing any chemical reactions during the curing process,enabling rapid processing.They can be reused without compromising their performance.Common thermoplastic resins include polypropylene,nylon,polysulfide,polyether ether ketone,polyethylene,and polyamide. Compared to traditional materials like metal,c eramics,and non-reinforced plastics,glass fiber reinforced plastic (GRP) extrusion molding offers various advantages.It possesses unique custom design capabilities that can meet specific product requirements."