Original subtitles

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-- www.Vitac.Com

captions paid for by discovery communications, inc.

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