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ALUMINUM EXTRUSIONS
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ROLL FORMED STEEL
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COPPER EXTRUSIONS
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MOLDED PLASTIC
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WOOD
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VINYL
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Strength (Tensile)
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Very good mechanical properties.
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Very high mechanical properties.
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Average to low mechanical properties.
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Wide variation in properties from .08 to .8 tensile
strength of aluminum extrusions for glass filled compounds.
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Good compressive properties; variable with the species
of wood and moisture content.
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Low mechanical properties
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Density
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Lightweight: about 1/3 that of copper or steel.
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High density; high pounds per cubic foot.
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About three times heavier than aluminum
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Very lightweight; about 60% the weight of aluminum.
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Very lightweight; about 1/3 the density of aluminum.
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Very lightweight; about 60% the density of aluminum.
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Strength-to-Weight Ratio
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Very Good.
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Good.
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Low.
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Low-good.
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Low-good.
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Low-good.
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Corrosion Resistance
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Excellent; it can be further increased, along with
enhanced appearance, through anodizing or other coatings.
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Poor; usually requires protective coatings for
corrosion service.
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Excellent.
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Excellent; choice of compound and color important for
weatherability (UV).
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Not directly applicable; decomposes in the presence of
some acids.
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Excellent; high resistance to alkalis and salts but is
attacked by organic solvents and strong acids.
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Formability
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Easily formable and extruded in a wide variety of
complex shapes including multi-void hollows. Formable to net shapes, and
extrusions provide for the placement of metal where it's needed
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Readily formable; thinner cross-sections than aluminum
extrusions; metal cannot always be located where best used in design.
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Excellent formability and easily extrudable. Formable
to net shapes.
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Easily formed or molded into complex shapes.
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Poor; cannot be routinely formed.
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Easily formed or molded into complex shapes.
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Electrical Conductivity
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Excellent; on a pound for pound basis, twice as
efficient as copper, used in bus and electric connector applications.
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Poor; cannot usually be used as an electrical
conductor.
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Excellent thermal conductivity.
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Poor; used as an insulator, high dielectric capability.
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Poor; cannot be used as an electrical conductor.
Usually cannot be employed as an insulator.
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Poor; electrical and thermal insulating
characteristics.
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Thermal Conductivity
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Excellent; ideal for heat exchanger applications.
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Poor; cannot usually be used as a heat exchanger
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Excellent thermal conductivity; second only to silver
in industrial applications.
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Poor; low coefficient of thermal (heat) transfer.
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Poor.
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Poor.
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Finishing
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A near limitless array of finishes can be applied
including mechanical and chemical prefinishes, anodic coatings, paints and
electroplated finishes.
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Protective coatings such as paint finishes are employed
along with electroplated finishes.
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A variety of coatings and platings can be employed.
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Color can be integral with material as well as plated,
painted, and hot stamped.
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Paint and stain coatings can be employed.
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Color can be integral with material.
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Recyclability
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High scrap value; routinely reprocessed to generate new
extrusions.
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Low scrap value.
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Very high scrap value.
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Routinely reprocessed but loses properties; reprocessed
material is added to new stock.
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Low scrap value
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Low scrap value; routinely reprocessed.
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Tooling Economics
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Extrusion tooling is relatively inexpensive. Generally,
a simple shape will cost only a few hundred dollars. Short lead times for
tooling construction
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Typical tooling cost are thousands of dollars. Long
lead times are required.
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Inexpensive tooling costs for extrusions.
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Tooling is expensive; generally in the thousands of
dollars. Long lead times required.
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Very inexpensive.
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Relatively inexpensive.
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Energy Savings
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Lightweight aluminum extrusions can offer energy
savings for transportation vehicles.
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Life time energy requirements for wrought steel vehicle
components are twice those for aluminum components.
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In transportation vehicles, copper is less
energy-efficient than aluminum.
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Savings for vehicles, processing, insulation.
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In certain applications.
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Can offer energy savings in appropriate transportation
applications.
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Combustibility
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Non-combustible; does not emit any toxic fumes when
exposed to high temperatures.
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Non-combustible; does not emit any toxic fumes when
exposed to high temperatures.
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Non-combustible; does not emit toxic fumes when exposed
to high temperatures.
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Combustible; may emit toxic fumes when exposed to high
temperatures.
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Combustible; emits toxic fumes while burning.
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Combustible. May emit toxic fumes when exposed to high
temperatures.
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