Pultrusion Process - With Stainless Steel

 

Pultrusion is made from the words “pull” and “extrusion” as it involves pulling the composite material from a die. Fiber Reinforced Plastic (FRP) pultrusions are used in many different applications throughout many different industries. The pultrusion process allows AIMS Composites to produce continuous lengths of fiber reinforced polymer profiled shapes. Pultrusion material holds a lot of value over other types of materials that you may be considering for your next construction project or application.

 

Pultrusion Material Advantages

• It is fire-retardant
• It is non-conductive
• It is corrosion resistant
• It is stronger, more durable and lightweight
• It is cost-effective
• High Strength
• Electromagnetic Transparency
• High Stability
• Lightweight

Pultruded products have been used in many structures from the Bellagio Fountains in Las Vegas to pedestrian bridges in the heart of New York City, materials formed through pultrusion can be found across the country and the world. Pultruded composite profiles have seen an increase in demand in recent years due to their high durability and non-corrosive character. Before pultrusion at inspection sites, each employee, contractor, and sub-contractors, and TIP shall be adhering to safety procedures and will be monitored.

FIBERGLASS REINFORCEMENT
The starting base of the pultrusion is the material (filament or fabric) fed into the machinery to begin.

PREFORMING GUIDES
The material spools and reinforcements are threaded into a machine known as the tension roller. This roller shapes the pultrusions towards the finished product.

IMPREGNATION
The glass is met with resin which will soak and permeate the unfinished product. This is known as the impregnating stage and may utilize different types of resin. This step is important because it protects the final product from corrosion, UV rays and impact.

HEAT
With the resin base attached, the product enters a hot, steel-forming die. This hot die is pivotal to the pultrusion process as it creates the hard shape of the material.

CUTTING
The product is now cut into appropriate lengths and shapes. The finished product is a fiberglass reinforced polymer.

Pre-Process

• We configure the arrangement of roving, mat, and veil to enter the die efficiently.

• We arrange the roving into the general shape of the rail to properly enter the die during the pultrusion.

• We run a quick check on the pultrusion pulling system to ensure it is functioning in operating condition.

• All storage should be at room temperature and should be below 75 degrees Fahrenheit.

• Resin should be warmed to at least 65 degrees Fahrenheit prior to use in order to assure proper curing and handling.

• The temperature of the die must reach the set temperature of 270 degrees and then the pultrusion process may begin.

 
Process

 

pultrusion with steel

 

8.1 - Arrange the single end roving in the glass feed racks based on the matrix configuration called out in AIMS Technical Specification.

8.2 - Configure the roving to allow the ends to enter into the first carding plate.

8.3 - The following carding plates will consolidate the roving into thicker ends which will form the shape of the rail cross-section.

8.4 - Glass mat placed on the pylons are configured to allow the fabric to enter the impregnator on the outside of the cross section and around the rectangular floating mandrel and stainless steel tube. The stainless steel tube will act like a floating mandrel as it is being inserted during the pultrusion process.

8.5 - The rectangular floating mandrel allows the rail cross section to have the proper void area to fit the FRP splices.

8.6 - Synthetic veil is also placed on pylons and enters the impregnator as the outermost layer and it is only used on the outer perimeter of the shape.

8.7 - The glass roving, mat, and synthetic veil is then impregnated with the resin mix which is pumped into the impregnator with a pressure between 80 psi (± 10 psi).

8.8 - Some companies may recycle the excess resin that is pumped into the impregnator, if so; ensure that the excess resin is filtered for debris before being reused.

8.9 - The glass, veil, and resin continue to move through the die which is heated to a temperature of 270°F (± 10°F) to allow the resin to cure.

8.10 - Pullers provide the required rate of pull based on the volume of the shape. The pullers will need to be adjusted to ensure the resin is cured before it leaves the die. The pull rate for the rail is 6” per minute
(± 1” per minute). Adjustments to the pull rate can be made to maintain product quality.

8.11 - As the shape comes out of the die, it is now cured and it continues down the length of the pultrusion machine until it reaches 56’-0” (± 1/8”) at the cut-off saw.

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