Primary aluminum billets of 7” and 8” in diameter and 225” in length are imported or locally bought to produce FISA’s extruded products.
The standard alloys extruded in FISA are AA 6063, AA 6061 and AA 6005.
The die through which the aluminum billet is forced is the element that gives the desired shape. FISA imports its dies from Europe and the United States of America. Likewise, FISA counts with specialty software and CNC equipment that enables designing and even fabricating some dies. Dies can be either available for the different customers or exclusive of a single customer.
Among the services provided, free of charge by FISA, are the design and development of the dies with the consulting of the extrusion feasibility.
When designing an aluminum extrusion, it is important to consider the size, complexity and thickness of the walls of the desired shape. The circumscribed circle is the method used to determine the size of the extrusion.
FISA counts with four hydraulic aluminum extrusion presses. This results in an annual extrusion capacity of 52 million pounds. Extrusions of up to 10.25” of circumscribed circle can be produced in our presses.
Aluminum extrusion is a semi-continuous process in which a preheated billet is forced through a die opening. The result is a product with uniform cross section given by the geometry of the die. An extensive variety of solid or hollow cross-sections can be produced by extrusion. Through extrusion, the mechanical properties of aluminum are improved since it is converted from a casted material to a forged material.
After the metal is extruded at high temperatures that increase its plasticity, it is moved onto a table where it is cooled with air or water depending on its size, shape, the alloy and the properties required. The material is then stretched in order to get straight extrusions and eliminate any residual stresses. After cooling and stretching, the extrusions are cut into the desired lengths. Finally, they are placed in trays that go into an oven at about 190°C for 6 to 8 hours, depending on the desired temper. This is called the ageing process and is carried out to give the material the correct strength and surface hardening.
Electrostatic liquid Coating
FISA has one vertical liquid coating line with an annual capacity of 16 million pounds. FISA has been qualified as a certified applicator of PPG’s Kynar 500. This coating applied in two layers provides the highest resistance to chemical products and the environment.
Liquid coating is the process of electrostatically applying liquid paint composed of pigment, resin and solvent onto the part to be coated. Before powder coating takes place, a chrome-based pretreatment is carried out to improve the adherence and resistance of the coating. After coating takes places, aluminum extrusions are cured at high temperatures. FISA guarantees a product with excellent corrosion resistance and a uniform, durable and low friction surface.
Electrostatic Powder Coating
FISA has two independent horizontal powder coating lines that together result in an annual capacity of 16 million pounds. Three application cabins provide flexibility to paint three different colors simultaneously. Moreover, FISA can paint the aluminum extrusions with virtually any color. The maximum length of aluminum extrusions that can be treated in this process is 9.1 meters.
Powder coating of aluminum extrusions is a dry finishing process that uses finely ground particles of pigment and resin electrostatically charged and sprayed onto a part to be coated. Before powder coating takes place, a chrome-based pretreatment is carried out to improve the adherence and resistance of the coating. After coating takes places, aluminum extrusions are cured at high temperatures. FISA guarantees a coating thickness between 60 and 80 µm that provides excellent corrosion resistance and a uniform, durable and low friction surface.
The annual anodizing capacity at FISA is 13.2 million pounds of extruded aluminum of a length up to 7.3 meters.
Anodizing is an electrochemical process that thickens the oxide film of the aluminum extrusion. The process consists of immersing the extrusion into a solution of pH acid or alkaline while DC current flows through the extrusion. Anodizing improves resistance to corrosion, durability and electrically insulates the surface of the metal.
While the natural oxide film of aluminum is only 0.02 µm, oxide layers between 5 and 25 µm can be obtained through anodizing. FISA guarantees an oxide film between 10 and 25 µm based on the requirements of the product. The corrosive resistance of aluminum increases as the oxide film increases. The anodized layer can be stained in many colors, meaning that aluminum’s natural color can be maintained or a color from a wide range of options can be selected. Some of these colors are different tones of bronze, champagne, gold and black. FISA has all of these colors in mate and polished finishes.
In order to ensure that aluminum extrusions from FISA are not damaged throughout the distribution and storage processes, the packaging used is divided in two parts. First, a layer of paper interleaved is placed around the extrusions. Then spiral plastic wrap is used on top of the paper. Bar coding with all the relevant product information is used to label the packages.
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