How It's Made (2001) s01e13 Episode Script

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Narrator: Today
on "how it's made"
Bicycle helmets -- letting
safety go to your head
Aluminum -- probably the
most versatile metal around
Car brakes -- we bring
you breaking news
about how they're
manufactured
And lithium batteries --
you'll get a charge
out of this one.
If you're serious
about bike-riding,
you should also be
serious about safety,
and it all starts
with your head.
Today's bike helmets meet
all the required safety standards
and come in a wide
range of colors and styles,
which means you
can protect your head
and look great doing it.
A bicycle helmet is
constructed of an exterior shell
and an interior one
of polystyrene foam
designed to absorb shocks.
Some designs for bicycle
helmets are drawn by hand
and with
computer-aided graphics.
The design has
to take into account
that it is not on
a flat surface,
but on a rounded one.
This creates optical deformities
that have to be corrected.
Fabrication begins
with the exterior shell.
This polymer sheet is
heated in a heat former
at a temperature of
65 degrees centigrade.
The mold lifts the sheet
and suctions it to fill all
the cavities of the mold.
This operation lasts
about one minute
and produces four shells.
Then, when cooled
down and hardened,
the four shells are cut by hand.
Ventilation openings are cut
with a heated wire apparatus.
These openings
have been preformed
during molding of the shell.
The heated wire easily
and neatly cuts the polymer.
Next up, trimming the helmet
to eliminate excess polymer.
The circumference is
manually cut using a router.
The edges are then
sanded to even them.
It is also possible to cut
the circumference of the shell
with a heated wire.
This operation takes more time,
but is more precise because
of the resulting cleaner cut.
Now they're going to
fabricate the foam interior
that will be placed
inside the shell.
It's made of polystyrene beads
that will expand
and bond together.
This expander increases
the volume of the granules
that fall into it.
Steam and an agitator
let the polystyrene
beads expand uniformly.
The granules are now ready.
The contents of this bin
will be able to produce
about 20 foam pieces,
which will take
shape on these molds.
The press closes up for
the six minutes that it takes
to mold four foam pieces.
The particles fuse with steam
before being cooled with water.
The foam is removed
from the mold.
Forms are produced
for different helmets.
Fusing of the particles
has welded the
granules to one another.
Depending on the helmet model,
openings have to be
made with this heat iron
to allow for installation
of an air-vent accessory.
All that remains is to
make the adjustment pads,
cut with this
press-powered stamper.
The adjustment pads
are held in with velcro
to allow easy
adjustment of the helmet.
This allows the cyclist
to change the foam pads
for greater comfort.
Inserting the straps calls
for good manual dexterity
and takes only a minute.
The shell and the polystyrene
foam liner have to be joined.
They're adjusted
one inside the other,
then solidly secured
with adhesive tape.
The helmet is now completed.
And now it's ready
for packaging.
The safety helmets
have to be certified,
guaranteeing their safety,
and conformity tests are done.
At least one helmet in 500
will undergo this destructive test.
Here, it drops vertically
onto a piece of steel.
This facility can produce
up to 4,000 helmets daily
in hundreds of models
and over 500 variations.
Narrator: Take a look around,
and you'll find this
wonder metal everywhere,
in everything from
screen doors to jet planes.
Aluminum has so
many applications
because it's light and strong,
and it's corrosion-
and crack-resistant.
Producing aluminum is costly,
but it saves money over time.
Aluminum -- so
widely used today,
and the world's most
abundant metallic element,
does not occur
in a natural state.
The most available source of
aluminum is actually bauxite.
Bauxite is mainly mined
in tropical countries.
The aluminum atom in bauxite
is bonded to oxygen molecules.
These bonds have to
be broken by electrolysis
to produce pure aluminum.
Bauxite is carried
by rail to the plant,
where it will be crushed.
Then, through a
chemical transformation
called the bayer process,
alumina is extracted.
This is then
roasted in calciners
to eliminate all moisture.
This is the reduction facility.
This plant has 432 pots
through which a powerful
electric current will be passed
to produce electrolysis.
An overhead crane
dumps alumina into the pots.
Then the electric
current from the anode
passes through the alumina
that we see here at
the bottom of the pot.
Via the process of alumina
reduction at 1,742 degrees,
the anodes lose volume
and will have to be replaced.
It's a continuous operation.
Each anode has a
life-span of about 20 days.
Spent anodes are recovered from
the pot with this overhead crane
and carried off to be recycled.
They clean the aluminum
rods, which will then be reused.
Here we see the crust
formed atop the anode.
When the anodes are replaced,
the accumulated impurities
have to be recovered
from the top of the pots.
This is accomplished
with these pincers.
Then a new anode is
inserted into the alumina,
and electrolysis continues.
The electric current
breaks the molecular bonds.
The heavier aluminum
collects at the bottom of the pot,
while the oxygen bound to
fluorine is released as a gas,
which is drawn off and treated.
The liquefied aluminum
remains at the bottom of the pot.
It has to be recovered in
this huge crucible with a tube.
The tube is dipped into
the bottom of the pot,
and a vacuum system
draws the molten aluminum
from the crucible.
The aluminum is
recovered in a short time.
Air is vacuumed
from the crucible
by a flexible pipe
held by an operator.
The tube is finally withdrawn,
and the overhead crane dumps
another quantity of alumina
into the pot.
Thus, the aluminum-fabrication
process continues uninterrupted.
The crucibles filled
with molten aluminum
are transported to
the casting house.
Their contents are poured
into holding furnaces,
that have a capacity of 60 tons.
In these very hot furnaces,
the molten aluminum is
stored to await casting.
Finally, casting begins.
The aluminum can
be semicontinuously
vertically cast, producing
ingots, sheets, or billets,
or it can be directly cast
into semifinished products.
The cooling of aluminum pieces
is accelerated by water sprays.
The large, rectangular ingots,
which can weigh up to 25 tons,
will head for hot-rolling,
and eventually will be
fabricated into products
like aluminum foil.
From four to five
tons of bauxite
have produced
two tons of alumina,
which in turn produces
one ton of aluminum.
This particular plant produces
200,000 tons of
aluminum annually.
Some other facilities
can turn out as much
as 400,000 tons.
Narrator: If you've ever
had to stop suddenly
while driving at high speed,
you know that once
you hit the brakes,
they can easily lock
up, making you skid.
But with the sophisticated
computer technology
behind today's antilock brakes,
skidding is becoming
a thing of the past.
Brakes are absolutely
essential equipment
for every vehicle to
slow down and stop.
And brakes have remained
practically unchanged
for the past 40 years.
Conventional disk
brakes have pads
that press against the brake
disk attached to the wheel.
These pads grip the disk
on only 15 to 30 degrees
of its circumference.
This develops high
heat, wheel skidding,
and results in premature wear.
The new floating disk brakes
have two pads
of friction material
on 360 degrees of the disk.
When the brake is applied,
hydraulic pressure
activates the diaphragm,
which applies pressure
on the inboard pad,
which is then pressed
against the disk.
In this animation, the diaphragm
movement is exaggerated.
However simple, the
design of this brake
calls for some complex
development steps.
It all starts on
the monitor screen
with computer-aided design.
This powerful software creates
objects in three dimensions,
which can be
virtually manipulated.
They then proceed
to digital analysis.
Here, digital models are
submitted to repeated braking
to verify that the parts
conform to design objectives.
The software verifies
changes in heat,
the effects of vibration,
and resistance to breakage.
The right choice of
materials is critical.
The electrical components
also have to be created.
Here, we see the delicate
construction of tiny sensors,
that measure the force
exerted by the braking system.
The sensor is the main component
of the intelligent
A.B.S. Braking system,
which functions more efficiently
than traditional
antiskid systems
and reduces braking distance.
Next, it's the fabrication
stage of prototype parts,
which will be tested.
The machining of these
parts must take into account
the requirements
of mass production.
This high-precision,
robotized machining
is done by computer-controlled
digital machines.
A liquid sprinkled
on the machine part
cools it during the process.
The finished parts are
precisely measured,
then fitted and assembled to
form the total braking system,
which will be first
tested in the laboratory.
Brakes in full contact
have a friction surface
six times superior
to traditional brakes.
The use of aluminum
and composite materials
allow for a weight savings
of 5.5 pounds per wheel.
This affects roadholding
and reduces fuel consumption
by .05 gallons per 100 miles.
They proceed to power
and endurance tests
on this dynamometer, in which
a brake and wheel assembly
act against a
large rotating drum.
These lab tests are critical,
since they can detect any
defect in a braking system
before it's installed
on an actual vehicle.
In order to evaluate the power
and endurance of the brakes
in full application under
extreme conditions,
they were installed on
this Porsche 911 turbo
entered in the motorola cup.
They proved
completely satisfactory,
and the Porsche went
on to record many wins.
Once all validation
tests are done,
we move on to the next step.
Brakes are installed on a
production-model vehicle.
With data systems,
engineers can observe
the performance of brakes
under all conditions
thousands of times a second.
Finally, engineers proceed
with actual braking trials
with test vehicles.
All that remains is to produce
brakes on a large scale
to supply auto manufacturers'
production lines.
And that's the story of brakes,
from original idea
to final product.
Narrator: There's nothing like
the sound of a car engine starting,
especially when it's 15
below on a winter morning.
Today's automotive batteries
are smaller, more powerful,
and more efficient, even
at extreme temperatures.
It's all thanks to the power
of lithium-ion-cell technology.
While dissecting a frog in 1786,
the Italian researcher Galvani
noted that when his
scalpel touched a leg muscle,
it contracted from an
electric current produced.
Later, volta believed
the current was produced
by the metal instruments,
the animal being
only a conductor.
To prove it, he stacked
disks of zinc and copper
connected by conductors
and fabric impregnated
with an acid solution.
And so, in 1800, the
electric battery was born.
Batteries power all
kinds of electric motors.
A new lithium-metal-polymer
battery pack such as this one
could soon power
an electric automobile,
as well as a hybrid vehicle.
This battery will be made
up of four components.
It all starts with
this lithium ingot,
which weighs about 11 pounds.
It's transformed
into a thin sheet
by this extrusion press that
applies 440 tons of pressure.
The press creates a sheet
that's only about
1/100 of an inch thick.
The whole extrusion sequence
is closely computer-controlled.
Extrusion is now completed.
The metallic lithium sheet
is the required 1/100
inch in thickness,
or 1/4 of a millimeter.
The sheet has to
be further thinned.
Placed on a roller, it is
carried to the laminator.
At room temperature,
it's thinned once again.
In just 20 minutes,
the 11-pound ingot
will have been transformed
into a thin sheet .01 inches wide
and some 655 feet in length.
This laminator completes
the thinning of the sheet.
The resulting 1
1/4 mile-long sheet
will allow for the fabrication
of 210 battery units.
Lithium is a soft, sticky metal.
For this reason, a
polypropylene film
has to be fixed onto
the lithium sheet.
Without this protection,
the sheet would adhere to
itself and become unusable.
The sheet will be used to
make individual battery cells.
Then these cells
will be assembled,
in series and in parallel,
and inserted into modules
of different shapes.
To make an
individual battery cell,
the sheet has to be rolled up.
This automated spooling machine
winds up the lithium
film in 26 revolutions.
The wound-up sheet is
put into a vacuum oven,
where the various layers
adhere firmly to one another.
This step lasts for
about 90 minutes
at 176 degrees.
Here, a test is made.
Using a voltmeter, the
battery is checked to see
that it produces the
required 3.56 volts.
Any problem can be
detected here and corrected.
A final quality check is
made with this caliper.
It precisely measures the
thickness of the battery cell.
The battery cells
are then stored.
Metallic plates are
placed between them
for the entire storage period.
One more step remains,
and that's the
metallizing of the contacts.
The battery cells are sent
off to a fabrication facility
in this container.
The container is
robotically handled.
First, it's put into
a protective tank.
Then the metallizing
of the contacts is done
by spraying on molten metal.
This takes just a few seconds,
since the metal
cools very quickly.
The battery is now finished.
It comprises four elements --
lithium, which
acts as the anode,
a metallic oxide cathode,
a dry solid polymer electrolyte,
and a metallic
current collector.
All that remains to be done
is the assembling of
the individual battery cells
into a module.
It begins with the
placing of individual cells
onto one another and
isolating them with foam
so that they do not
touch each other.
These red sheets are
actually heating elements,
since the lithium-metal-polymer
cells function
at temperatures of between
104 and 176 degrees.
Here, we see these
modules of a battery pack
for a hybrid vehicle,
an automobile that works
with a gasoline-powered motor
and an electric motor.
This prototype battery
was created for a
totally electric vehicle.
It surpasses heavy
traditional lead-acid batteries
that can't develop the same
amount of electrical energy
and have much
shorter life-spans.
--Captions by vitac--
captions paid for by
discovery communications, inc.
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