Introduction to Pultrusion
Pultrusion is a manufacturing process used for production of fiber reinforced plastic (FRP) composites. This process effectively combines many elements, which offer a mix of properties and characteristics that can boost efficiency of the final product. Some features of the innovative process include choice of reinforcements and resin, positioning of reinforcements, plus complex shape and length capability.
Pultrusion is a controlled, continuous process that produces consistent quality and materials with these basic steps:
- Fiber reinforcements are precisely set-up and connected to mechanical pulling equipment. (Figure 1.1)
- Polymer resin in liquid form is pumped into a bath staged after the fiber reinforcement set-up. (Figure 1.3)
- Process begins with reinforcing fibers being mechanically pulled through the resin bath where fibers are thoroughly saturated and impregnated with polymer resin. (Figure 1.1-4)
- The saturated fibers are then pulled through a machined-precision die with entry portal and internal cavity in the shape of the final product. The composite is formed and cured within the heated, steel die. (Figure 1.5)
- Upon exiting the die, the thermoset composite is cut to the desired length and is a finished part. (Figure 1.6-7)
- The process continues until production requirements are met.
Reinforcing fibers are mechanically pulled into a resin bath where fibers are thoroughly saturated and impregnated with polymer resin.
Saturated fibers are pulled through a machined-precision die with entry portal and internal cavity in the shape of the final product. The composite is formed and cured within the heated, steel die.
Upon exit from the die, the thermoset composite is cut to the desired length and is a finished part.
Why is Pultrusion Used for Structural Composites?
Strength of an FRP composite is controlled by type, content, and alignment of its reinforcements. Glass fibers with high tensile strength are excellent reinforcing materials for FRP structural materials. The pultrusion process enables high content of glass fiber reinforcements to be incorporated within the material to produce parts with high strength to weight.
Pultrusion dies can produce shapes that increase structural properties and offer installation benefits.
For structural composites, it is essential that premium quality resins are used. Pultrusion utilizes resins like isophthalic polyester, vinyl ester, or phenolic. The process enables resin content to be accurately controlled as well as the reinforcing constituent.
As a result, the pultrusion process can produce FRP structural composites that are durable, have high strength to weight, and offer long service life with huge life-cycle cost savings. FRP structural composites manufactured by pultrusion process include:
- Beams, channels, angles, tubes, rods, and plate
- Wall, roof, and decking panels
- Cable and instrumentation tray
- Strut support systems
- Ladder and handrail
Applications for Pultruded FRP Composites
Effectively designed pultruded composites have long and successful track records in applications with highly corrosive and challenging environments such as:
- Chemical and petrochemical
- Metal processing
- Oil and gas
- Waste and water treatment
- Agri-chem and fertilizer
- Food processing
- Mass transit
- Mining and minerals
- Pulp and paper
Each of these applications present unique and challenging conditions that require reliable materials and performance. For additional information and assistance, please contact Enduro Composites, Inc. Our full list of product solutions plus informative case studies are included on our website.
Pultruded FRP Composites in Construction – 8F6 Purlins & Girts
Designed for use as roof purlins and wall girts, 8F6 beams have provided outstanding service and huge, life-cycle cost savings for many clients. This includes metal treatment, salt plants, fertilizer, chemical and food processors, mining, and others.
The continued growth of 8F6 usage is a result of proven performance and efficient design, which incorporates four (4) key factors, which optimize properties and cost efficiency.
- Process Selection. By using pultrusion, higher reinforcing content can be achieved compared to other manufacturing methods such as Contact Molding or Spray-Up. As a result, higher structural properties are achieved for the 8F6 beam. In addition, the pultrusion process ensures consistent properties and quality.
- Material Selection. The resin component in 8F6 beams is either premium grade, Isophthalic Polyester or Vinyl Ester dependent upon the application. Both resins deliver outstanding corrosion resistance and ability to withstand attack from tough chemical exposures. Having high tensile strength, glass fibers are excellent reinforcing materials for the composite.
- Quantity and Alignment of Reinforcements. 8F6 beams utilize continuous glass fiber rovings placed in length or longitudinal direction as the primary reinforcing material. For load reaction in cross-width direction, most pultruded composites use a continuous strand mat placed in cross-width direction. The 8F6 design goes beyond this by utilizing continuous weft rovings (not in mat form) in the cross-width direction. This enables higher glass content, over 60% of its weight compared to 55% approximate content for typical pultrusions. Strength and Stiffness properties increase as content of glass fiber reinforcements increases.
- Product Shape. The 8F6 Flanged Tube Shape increases structural properties and contributes to easy installation.
As a result of efficient design, 8F6 Beams, at lower weight, carry more load than heavier FRP I-Beams and WF-Beams! As noted in this chart, 8F6 Flanged Tube, at 15% and 30% less weight, has greater load capacity than heavier FRP I-beams and WF Beams for single span conditions. For two span conditions, the 8F6 capacity is even greater.
The 8F6 shape enables easy installation. This video shows 8F6 girts at a steel treatment facility being bolted to primary framing through shop-drilled access holes.
FRP Siding and 8F6 Beam Finished Installation
Other Pultruded FRP Structural Composites
In addition to 8F6, Enduro Composites offers Flanged Tube Beams in 12” and 18” depths for long span and high load conditions that also require corrosion resistance. As with 8F6, the design for the 12” (12F12) and 18” (18F17) sections optimizes structural properties and cost through innovative use of shape, glass fiber reinforcing, and manufacturing process.
The material’s Isophthalic Polyester or Vinyl Ester resin system provides outstanding corrosion protection and fire-retardant materials with flame spread rating of 25 or less. The combination of corrosion resistance and strength delivers significant end user benefits and life cost savings.
Applications include primary frames for building structures, baffle wall columns, and tank cover support beams. For complete systems, Enduro provides pultruded baffle wall panels and tank cover decking panels.
Enduro Composites also manufactures by pultrusion a complete line of FRP Standard Shapes including beams, channel, angle, tube, rod, and flat plate.
For additional information and assistance, please contact Enduro Composites, Inc. Our full list of product solutions plus informative case studies are included on our website. If the product needed is not shown, please consult our team for the custom product you need.