| |
|
|
Wood |
Vinyl
(Polyvinyl Chloride)
|
| Strength
(Tensile) |
Very
good mechanical properties. |
Wide
variation in properties from .08 to .8 tensile strength of aluminum
extrusions for glass filled compounds. |
Good
compressive properties, variable with the species of wood and moisture
content. |
Low
mechanical properties. |
| Density |
Lightweight;
about 1/3 that of copper or steel. |
Very
lightweight; about 60% the weight of aluminum. |
Very
lightweight. about 1/3 the density of aluminum. |
Very
lightweight about 60% the density of aluminum. |
| Strength
to Weight Ratio |
Very
Good. |
Low-good.
|
Low-good. |
Low-good. |
| Corrosion
Resistance |
Excellent;
it can be further increased, along with enhanced appearance, through
anodizing or other coatings. |
Excellent;
choice of compound and color important for weatherability (UV). |
Not
directly applicable; decomposes in the presence of some acids. |
Excellent;
high resistance to aikalis and salts but is attacked by organic solvents
and strong acids. |
| Formability |
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. |
Easily
formed or molded into complex shapes. |
Poor;
cannot be routinely formed. |
Easily
formed or molded into complex shapes. |
| Electrical
Conductivity |
Excellent;
on a pound for pound basis, twice as efficient as copper, used in
bus bar and electric connector applications. |
Poor;
used as an insulator, high dielectric capability. |
Poor;
cannot be used as an electrical conductor Usually cannot be employed
as an insulator. |
Poor;
electrical and thermal insulating characteristics. |
| Thermal
Conductivity |
Excellent;
ideal for heat exchanger applications. |
Poor;
low coefficient of thermal (heat) transfer. |
Poor. |
Poor. |
Finishing
|
A
near limitless array of finishes can be applied including mechanical
and chemical prefinishes, anodic coatings, paints and electroplated
finishes. |
Color
can be integral with material as well as plated, painted, and hot
stamped. |
Paint
and stain coatings can be employed. |
Color
can be integral with material. |
| Recyclability |
High
scrap value; routinely reprocessed to generate new extrusions. |
Routinely
reprocessed but loses properties; reprocessed material is added to
new stock. |
Low
scrap value. |
Low
scrap value routinely reprocessed. |
| Tooling
Economics |
Extrusion
tooling is relatively inexpensive. Generally, a simple shape will
cost only a few hundred dollars. Short lead times for tooling construction.
|
Tooling
is expensive; generally in the thousands of dollars. Long lead times
required. |
Very
inexpensive. |
Relatively
inexpensive. |
| Energy
Savings |
Lightweight
aluminum extrusions can offer energy savings for transportation vehicles. |
Savings
for vehicles, processing, insulation. |
In
certain applications. |
Can
offer energy savings in appropriate transportation applications. |
| Combustibility |
Noncombustible;
does not emit any toxic fumes when exposed to high temperatures. |
Combustible;
may emit toxic fumes when exposed to high temperatures. |
Combustible;
emits toxic fumes while burning. |
Combustible.
May emit toxic fumes when exposed to high temperatures. |
