Plastic Bags
Solar Panels
Plastic Gasoline Containers
Hockey Sticks

Today, on "how it's made"...

Plastic bags--  it's trash and carry.

Solar panels--  reflecting on energy efficiency.

Plastic gas containers--  fuel to go.

And hockey sticks-- mind if we take a shot at this one?

You can use them for groceries, for shopping, for taking out the trash.

Chances are there's a growing pile of them somewhere in your kitchen.

With so many everyday uses, it's easy to see how people can get "carried away" with plastic bags.

The plastic bags we use every day are made from granules of linear polyethylene resin that will be melted.

They combine the linear polyethylene with another low-density one in this mixer.

The granules are perfectly blended into a homogenous material.

Granules melt in the extruder, which heats them to a temperature varying between 356 and 465 degrees.

This produces a film of polyethylene in the form of a tube.

It is several hundred feet long, has a minimum thickness of .

0002 of an inch and a circumference of 20 inches.

The plastic tube gradually cools down.

Rollers then flatten out the plastic tube.

The polyethylene film is now easy to work.

And now they cut the tube on two sides to obtain different rolls.

This knife then cuts the film to the required width.

The excess strip is salvaged in this tube.

Several hundred of feet of film are produced and rolled up.

This particular roll contains the required quantity of film.

When the roll is full, the film is cut.

This roll moves forward and can be transported to another department.

An empty roll begins to fill up automatically.

A full roll weighs 348 pounds and can produce 35,000 bags.

The next step--  printing on the bags.

This alcohol-based ink circulates continuously to retain its viscosity.

Impressions are made by inking rollers.

Here another color is being applied on the bags.

Once printing is over, the plastic film is rolled up again.

The roll is now full, and the cutting of bags can get started.

This machine makes 150 bags per minute.

A sealer bonds the edges of the bag together with heat.

The wheel picks up the bag and puts them on 2 spindles that can hold 250 each.

Here, they're making bags with a hermetic zipper.

The zipper is made from a plastic pad which inserts into a slot.

The zipper is made in advance and is unrolled progressively.

The zipper strip is cut and heat-bonded to the bag at 356 degrees.

And here's the zippered bag, all finished.

In this other department of the plant, they make plastic bags with handles.

Printed bags circulate on these rollers.

The machine that welds the sides gives the bags the desired shape.

Then another machine, with a punch, cuts the handle holes.

Bags are heat-sealed and cut at 302 degrees.

Here, they fabricate another product-- packaging bags.

One end of the bag is heat-sealed.

This machine makes holes that let air out of the bag when it is being filled, to allow them to be generously filled with items.

At this stage, a stamper cuts the handle holes.

Bags are cut to the required size, automatically sealing the other side of it.

This plant makes eight types of bags, for an overall total of over one million a day.

Not so long ago, solar energy was a concept that seemed to be torn from the pages of a science-fiction novel.

But the time has come for this non-polluting energy source to step into the limelight--  or should we say the sunlight?

The future of solar panels is bright.

The sun is able to produce electricity.

Panels covered with photovoltaic cells convert sunlight into electricity.

This blue plate is a module made of crystalline silicon.

The grooves are the conductors, and the silicon crystals glisten at its surface.

To make a solar panel, several modules have to be connected together.

Then they apply a soldering flux on each module.

The soldering wire is heated with an iron.

The modules are placed on a special support.

Once the soldering is done, the modules are cleaned by ultrasound, in water, at 140 degrees.

When dried, the perfectly clean modules are ready to be assembled.

Now they can proceed with soldering the modules by groups.

First, a flux is applied which improves the quality of the soldering.

With great dexterity, they assemble four groups composed of nine modules each.

In this way, 36 modules are soldered and connected in series.

Modules are assembled end to end.

They have to be handled with great care.

Using a voltmeter, the voltage of each module is verified.

At this stage, it's easy to remake a solder connection if there's a problem.

If the voltage is adequate, they use suction grips to make handling of the nine rows of modules easier and to keep them clean.

The modules are placed into position.

Then this metallic strip is inserted.

It is a conductor that will link the four groups of nine modules.

Solder connections are made to link the modules to the metallic strip.

Then they put on this transparent sheet of layered glass.

It serves as a rigid transparent form which will support the modules.

The superposing of parts forms a laminate, that increases the rigidity and solidity of the panel.

Finally, a sealing film is applied to protect the module.

To laminate and stiffen the solar panel, it's placed in a heated oven from which air has been vacuumed out.

The panel will cook at 176 degrees for 15 minutes.

The oven hermetically reseals to proceed with the vacuuming out of air.

And here's the finished panel.

All the components are bonded together.

They now proceed with a test.

The panel is placed in a solar simulator.

Negative and positive contacts of the solar panel are connected to a voltmeter.

The panel is inserted into the simulator, and a powerful lamp will illuminate it.

The voltmeter is read to make sure that panels supply the electric current required.

Here now is the assembly of another kind of solar panel called the amorphous silicon type.

Its components were made in europe and asia.

These are the positive and negative connecting wires of the solar panel.

The panel is placed into a plastic frame and glued in place.

Then the frame is screwed tight so that it won't move.

The solar panel, made up of crystalline silicon modules, is put onto an a.b.s. plastic frame.

It is now finished.

Fabricating this panel will have required about one hour of work.

Six of them are made here every day.

Your needle's dipping past empty, but you're gambling you'll have enough gas in the tank to make it just a little further.

Well, when you're on that long walk to the nearest gas station, you'll be glad someone had the bright idea of manufacturing these handy plastic gas containers.

Plastic gas containers are made from these granules composed of a concentrated colorant and a u.v.-resistant additive.

They're mixed with white granules, which is the primary material, called high-density polyethylene, and recycled plastic, which has been ground up on a granulator.

It's all dumped into this milling machine.

These granules are all mixed together and melted.

The melted plastic will be blown in and will take shape within this mold, made of very high-quality dense aluminum, called aviation type.

Blow-molding continues and produces a soft plastic tube.

This is cut and placed in the mold.

Then this nozzle pumps the plastic into the mold shell.

The container is unmolded and moves along on a conveyor.

There's another way to mold plastic-- by rotation.

This previously colored powder has a 35 mesh size, which is just a little larger than flour.

Low-density linear polyethylene is poured into the bottom of the mold.

The mold has a cover that will be closed, then placed on a steel support.

This support is articulated by an arm on two rotation axes simultaneously.

This action allows the plastic powder to distribute itself thoroughly throughout the mold.

The mold is placed in an oven which generates a temperature of 590 degrees.

About 15 minutes is needed for the polyethylene powder to melt and another 15 minutes to allow the piece to adequately cool before unmolding it.

The mold cover is lifted off, and the plastic piece is unmolded.

Gloves must be worn, since the piece and the mold are still very hot.

Here they fabricate a mechanism cover for a stationary bicycle.

It's held in place by a cutting pattern, and openings are cut with a pneumatic tool.

Holes are made with a drill.

The casing is now completed.

Now we get back to the previous blow-molding process.

This type of molding produces residues that have to be eliminated.

These surplus pieces are cut with this small saw.

The now-hardened scraps are sent to the granulator to be reduced into granules, which will be newly added into the mixer to make other plastic containers.

This small pneumatic drill pierces the container's vent hole.

The container circulates from one step to another on the conveyor.

The next steps will be accomplished by robotic arms.

And then the final elements are attached, such as the pouring spout.

Then a sealing stopper, equipped with a rubber washer, prevents leaks.

And finally, the cap of the neck is automatically screwed into place.

Depending on the thickness of the mold, the blowing procedure allows the production of between 30 and 120 containers an hour.

The rotation process takes between 45 and 60 minutes to make a unit.

Finished containers are now ready for packing and delivery.

Few things are as elegant as curved, polished wood...

Especially at 100 miles an hour and driving a slap shot right past the goalie.

A lot of engineering goes into packing that punch.

Call it the science behind "he shoots, he scores".

The irish, some 1,200 years ago, were playing hurling, a form of hockey on grass with simple goal zones.

In the 17th century, american indians used curved sticks in a game they called "battagaway".

The sport we play today was developed by british soldiers in 1855 in ontario, canada, as a pastime during long northern winters.

Making a hockey stick requires the assembly of several pieces of wood and fiberglass.

These sticks are all replicas of those of great hockey professionals.

The shaft is made of a piece of poplar onto which they glue two thin strips of birch.

This is placed on a circular conveyor equipped with a press that holds the pieces together while the glue dries.

Then this multibladed saw cuts the wood into three identical stick-shaft pieces.

The shafts are moved to a precision sander.

The shaft has to be reinforced with fiberglass.

With a roller, they apply a coat of epoxy resin, a kind of glue, onto which they place carbon-reinforced fiberglass.

The resin has to dry and harden.

The stick shaft is placed in an individual mold and cooked in this press, heated to 176 degrees for 12 minutes.

The shaft then goes to a milling machine equipped with diamond-headed knives that round the edges.

A finish is applied to the shaft for a second sanding, which brings out the grain of the wood.

Now they glue small blocks to the end of the shaft in order to attach the blade.

Urethane glue is used.

It resists water and humidity and is specially made for hockey sticks.

This glue dries in 15 minutes at 100 degrees.

This slitter cuts the shaft and wood blocks in order to slide in the blade.

This machine inserts the glue and the blade into the stick shaft.

The stick is placed on a conveyor leading it to the next step and giving the glue a chance to dry well.

Then both sides of the blade are sanded to thin them.

The sticks are replicas of those used by hockey professionals.

This computer-controlled digital lathe cuts the blade.

Data on all the cuts are in the computer's memory.

The blade now has to be curved.

It's steamed for a minute, allowing humidity to penetrate the wood and make it flexible.

Then the blade is placed in this curved mold, where it is heated for 50 seconds at 131 degrees.

The blade is then worked by hand.

The new blade is compared with the pattern of a hockey player's stick to obtain precisely the same curvature.

This is why the company keeps 6,000 blades on hand.

Now the blade is sanded down to the desired thickness.

The blade must also be reinforced.

Fiberglass cloth is soaked with epoxy resin.

Then they place the cloth on the blade and leave a good margin around it.

They get rid of air bubbles, then put it into an oven to dry at 90 degrees over 24 hours.

The surplus fiberglass hardens and is cut with a band saw.

This step requires quite a degree of manual dexterity.

Finishing is done with this circular sander.

Finally, the blade is dipped into this epoxy resin to give it a nice luster.

All that remains is to paint the stick.

Here, the company logos are applied via silk-screening.

Besides the 6,000 personal models of professional hockey players, this company produces 65 other models of hockey sticks.

Each week, they make about 40,000 sticks, for an annual total of 1,600,000.


Boomerangs
Barbeques
Pinball Machines
Strobe Lights

Today on "how it's made," boomerangs...

Barbecues...

Pinball machines...

And strobe lights.

Boomerang is a throwback to primitive times.

Back then, people threw sticks to hunt and that's likely how they discovered that certain bent sticks would circle back.

Boomerangs have come a long way since then and are now finely crafted works of art.

Boomerangs come in many shapes, but fundamentally, they are all single-wing aircraft.

Construction begins with a solid piece of wood.

This tree's growth rings have been highlighted to demonstrate how compressed the outer rings become.

Because the wood from this section is denser than the inner rings, it's easier to work with.

A woodworker takes 16 strips of that dense wood and places them in a steam box for 20 minutes.

The steam makes the strips much more flexible.

In fact, they're so elastic, they can be bent by hand.

Watch how he arcs all 16 layers at once with little effort.

The basic form of a boomerang has taken shape.

To improve the contour, the strips into a boomerang-shaped mold.

They'll stay in this mold for a day or two, long enough to dry and harden into the bent form.

Now it's time to laminate the wood.

Glue is spread onto each bent strip.

Then the strips are clamped together again back into the mold.

This time, the mold has been coated with wax to prevent the glue from sticking to it.

The strips are left to set overnight.

The next day, the laminated piece of wood is removed.

It's solid but far too chunky to take flight.

A woodworker slices it into pieces 8 to 12 millimeters thick.

One piece of laminated wood yields about six thinner pieces, each of which will become a boomerang in its own right.

But it needs more form, and those rough edges have to go.

So a more refined design is traced onto the wood and cut out.

But there's an easier way to make a boomerang-- with sturdy aircraft plywood.

With plywood, there's no need to laminate and then physically bend the wood.

A woodworker simply cuts out the pattern...

Then sculpts the tops of the wings with a drum sander.

He's made the tops of the wings curve upwards but in opposite directions.

It's this contouring that will make the boomerang fly in a circle.

On some models, embedded lead weights are added for improved balance.

That laminated boomerang gets the same contouring but files are used instead of a drum sander.

Laminated wood responds better to this technique, but it's much more labor intensive and requires specialized skill.

One mistake in the shape and size and the boomerang's aerodynamics will be thrown off kilter.

But our woodworker has the job down to a fine art.

To fine-tune the boomerang, he first softens it over a steaming kettle while twisting the wings into an upward flip.

This blower dries the wood to ensure it stays flipped.

Then the woodworker sets it on a flat surface to check the curve.

A sealant is sprayed onto the boomerang, and finally, it gets several coats of lacquer for a high-gloss finish.

And now these boomerangs are ready to fly.

Up next, it's time to get grilling.

The barbecue's origins are clouded in a bit of a smoky haze, but it's believed that native caribbeans were the first to cook this way.

Of course, back then, they didn't have charcoal grills.

They roasted meat over a smoky pit.

Today, people still love a good cookout, but now we have better equipment.

Basic charcoal grills begin with big steel disks.

Rollers coat each one with soapy lubricant.

Then they're fed into a press that shapes each one into a big bowl.

Molding steel can be tricky.

If it's not lubricated enough, it could tear instead of bend, so workers need to make sure each disk gets a generous application of the soapy solution before it goes into the press.

This is a back view of the press.

With each powerful thrust, the ram delivers 500 tons of pressure.

A similar type of press makes the barbecues' lids.

An operator inspects each part for splits and cracks.

Then it's over to a press that trims the rim.

The scrap is tossed into a bin for recycling.

Next, the barbecue bowl spins around while an automated roller flanges the rim.

After that, holes are punched into the bowl for ventilation.

Now it's time to bring in the welding guns.

The guns fuse metal couplings to the bowls to serve as attachments for the barbecue's legs.

Here handles are lowed into an assembly machine.

Below, a turntable swings the barbecue bowls into position, then the handles are welded to each side.

At another station, the barbecue lids get a handle of their own.

No chef can check the progress of a burger without this essential part.

This one will allow the chef to lower the lid, to control the cooking temperature, and then lift it again when it's time to flip the burgers.

The barbecue parts now travel on an overhead rail to the wash station.

They're hosed down with soapy water, then rinsed clean.

Once they're dry, it's off to the finishing department.

Here the parts are dusted with a glass powder.

Then it's into a red-hot furnace set to 1,500 degrees.

The furnace bakes the glass dust into an enamel finish that protects the barbecue from rust and stains so they'll last for years.

Next, they go under intense lights that expose any defects in what should be a mirror-like finish.

An inspector examines each part inside and out.

A punch machine now makes dampers from aluminum.

It simultaneously cuts the shapes and embosses the company's logo onto them.

This handy attachment enables the chef to control the flow of air to the grill.

Nylon grips go onto the handle.

And the damper is installed over the lid's ventilation holes.

It's up to the consumer to complete the final assembly, and in just a few minutes, the burgers could be grilling.

Coming up, a high wire at a pinball factory.

Before video games, the pinball machine reigned supreme.

You pull a plunger to get the ball rolling, and as your flippers send the silver sphere flying, the machine comes to life with flashing lights and clanging bells.

No wonder it's not yet game over for pinball.

The game of pinball is unprogrammed and unpredictable.

It all starts with reams of wiring for the game's electronic system.

There's almost half a mile of wiring in one machine alone.

The color-coded wire is wound around pins and attached to connectors on the circuit board.

Technicians follow a detailed set of instructions, and an engineering diagram keeps things from getting in a tangle.

Once the wires are all laid out, they're removed in loosely tied bunches and dipped into a hot metal soup to solder them together.

But not all wires are soldered.

Some get attachments called lugs.

These connectors are crimped onto the ends of the wires with a hydraulic machine.

Eventually, the lugs will be used to connect wires to attachments on the play field.

But first, the cable is hooked up to a testing board where technicians check every circuit.

Meanwhile, the play field is placed on a bed of nails and foam strips.

As the nail bed rises and presses against the header, the nails prick the back of the play board, but the foam strips stop them from going all the way through.

These nail holes will serve as markers for installing pinball targets and tactical features on the play field.

Technicians drill a few holes, then cover the play field with a metal template and drill some more.

These holes will be used to mount the pinball gadgetry onto the play field.

Next, anchors are hammered into place.

They'll secure the metal railings that keep the silver balls from rolling off the play field.

A lamppost is fitted into place...

Followed by some plastic bumpers and 115 flashing lights.

Now it's time to permanently attach all that wiring.

Some are soldered directly onto the board.

Others are attached to switches.

A speaker is bolted into the cabinet for some major sound effects.

Then it's time for that essential tool-- the spring-powered plunger.

Workers attach a toy villain...

And add a ramp in the shape of a sword, along with a few other characters.

Finally, it's time for the inaugural run.

The pinball is rolled into every target and mechanism to test the game's electronic switches.

There can be 70 switches in a game.

As technicians press all the buttons, a computerized system diagnoses any malfunctions.

They rigorously test all of the game's features.

If everything works, the play field is inserted into its console.

A shatterproof window slides into place to protect the play field from overenthusiastic gamers.

A metal bar locks the window into place.

Finally, the header is attached, and this pinball machine is wired and ready for action.

Coming up, little lights with lots of flash.

Strobe lights often conjure up images of '70s discos.

But you'll also find strobe lamps-- the proper term, by the way-- on aircraft wings, in police lights, and on towers and tall buildings to warn low-flying aircraft.

Strobe lights even play a role in photography and on factory production lines.

A strobe lamp emits repeated flashes of high-intensity light.

At this factory, production begins with glass blowers.

Using a ribbon burner, they heat glass tubes to almost 3,000 degrees.

This softens the glass for bending.

But if it's too soft, the tubes will collapse, so the glassworkers blow air into it through a rubber hose to build counterpressure.

The size and shape of the glass tubes varies by model, but its job is always the same-- to house a strobe lamp's essential components-- electrodes, lead wires, and xenon gas.

The electrodes conduct the current, which charges the gas with electricity, making it illuminate.

This factory makes several strobe-lamp models, some in large quantities for the mass market, others in small quantities, custom-designed for specific clients.

With mass-produced models, automated machines take over after the glassblowing.

Custom orders are handmade from start to finish.

Workers even make the electrodes manually.

They weigh a precise amount of metal powder and pour it into the cavity of a press similar to what pharmaceutical factories use to make pills.

This powder is a blend of several different materials, but the company won't divulge the ingredients.

The press applies 4 tons of pressure, compressing the powder into a pellet.

The factory inspects every pellet to ensure it meets quality standards.

The pellets then undergo a hardening process called centering.

They bake for nine minutes in a hydrogen-fueled oven.

Hydrogen is one of the hottest types of fuel, and the 3,000-degree heat fuses the powder particles into a solid mass that won't crumble apart.

Next, workers weld a lead wire to each electrode.

Then they insert two electrodes, one for the positive current, one for the negative, into each glass tube.

Then they melt the end of the tube closed.

Then they attach a wire called a trigger lead.

It prompts a transformer to send a high-voltage electric pulse to the electrodes, illuminating the gas.

This automated machine assembles the factory's mass-produced models.

Before starting it up, workers load the components-- a pair of electrodes followed by a glass tube on top.

Now the machine takes over.

It vacuums out the air in the tube, injects xenon gas, melts the tube closed, then cuts off the excess glass.

The tube's interior must be completely free of contaminants for the gas to illuminate.

So, just before the vacuum fill-and-seal operation, a hot coil encircles each tube to burn away any impurities.

On custom-made models, all of these steps are done manually.

With the strobe lamp complete, it's installation time.

This model is for the warning lights you see on tow trucks and road-construction vehicles.

It goes into a glass reflector lined with metallic film.

A transformer regulates the voltage.

Its three wires connect to the positive, negative, and trigger leads protruding from the lamp.

A glass lens covers seals and protects the lamp within the reflector, and then this product is good to go.

Strobe lamps are also used in stroboscopes-- industrial devices that help factories perform quality-control inspections on high-speed production lines.

Calibrate the light pulses to the right interval and they appear to stop the action so that cameras or workers can examine the goods.

It's the size, shape, and configuration of a strobe lamp's components, along with voltage and other electrical specs, that determines how long, how often, and how quickly the light flashes.


Paving Asphalt
Marshmallow Cookies
Loudspeakers
Electronic Door Locks

Today on "how it's made"...

Paving asphalt...

Marshmallow cookies...

Loudspeakers...

And electronic door locks.

Asphalt is a black, liquid substance that's a by-product of processing crude petroleum.

Asphalt is a key component of waterproofing and insulation materials and roofing shingles.

But its best-known use is for paving roads.

Asphalt cement is a by-product of crude oil-- the key ingredient they mix with crushed rocks and other minerals to make paving asphalt.

So, production begins at the paving plant's quarry, where some 50 feet below ground, workers driving heavy machinery collect boulders of granite that have been blasted off the rock walls.

Trucks transport the rocks to the paving plant, which is right on the quarry site.

They dump their cargo into the primary crusher-- a machine whose steel jaws crush these big rocks into pieces smaller than 8 inches.

It takes mammoth force to crush solid rock.

The fly wheels that amplify the motor's energy weigh more than 6 tons.

The primary crusher empties onto a mobile conveyor belt, which transports the crushed rocks to an outdoor storage area.

When it's time to make the asphalt, the rocks travel, via conveyer belt, from the storage area to a screening building to be classified by size.

There, the rocks tumble downward over a series of inclined screens whose largest holes are 4 inches wide.

What's too large to drop through goes to a secondary crusher, that reduces the rocks to 4 inches or smaller, then sends them to a third, or tertiary, crusher that further reduces them to 1 inch or smaller.

What's small enough to pass through the screens bypasses the secondary crusher and goes directly to the tertiary crusher.

After this last crushing stage, the largest stones are 1 inch in size.

Everything smaller than 1/4 inch goes in one pile-- that includes stone dust created by the crushing process.

Stones that are 1/2 to 3/4 of an inch go into another pile...

Stones 1/4 to 1/2 inch into another.

Trucks transfer material from each pile to separate compartments called feed bins.

Exactly what goes into the paving asphalt depends on what's being paved.

But, generally, these are the four ingredients...

Sand...

Stone dust...

1/4- to 1/2-inch stone...

And 1/2 to 3/4 of an inch stone.

The ingredient proportions vary according to what the paving asphalt will be used for.

Stones, along with sand and stone dust as fillers, usually make up about 95% of the mix.

The remainder, added later, will be liquid asphalt cement.

Each bin releases a specific amount of material onto a conveyor belt running under it.

The belts lead to a main collecting belt that dumps the ingredients, combined, onto yet another belt that leads to a drier.

The drying process, which takes about a minute, removes all traces of humidity.

This will enable the materials to bond better with the asphalt cement.

Screening equipment then reseparates the dried ingredients, making it possible to precisely weigh out the required amount of each one.

Everything then goes into a mixer.

As this demonstration shows, the mixer blends everything thoroughly.

Then it's time to pump in hot asphalt cement.

Oil refineries make asphalt cement from what's left over after they've processed crude oil.

The paving mix contains about 5% asphalt cement.

This is what happens inside the mixer.

The hot asphalt cement binds the ingredients in about 30 seconds.

The result is ready-to-lay paving asphalt.

The mixer empties directly into trucks destined for the paving site.

There, a paving machine will spread the hot asphalt on the road bed.

Then a compactor roller will pack it down.

The asphalt cools and hardens in about one hour, depending on the weather.

The next time you bite into a marshmallow cookie, you can thank the ancient egyptians.

They invented marshmallow candy by thickening honey with sap from the root of the marshmallow plant-- a herb that grows in salt marshes and along large bodies of water.

Modern marshmallow contains gelatin instead of sap from the mallow root.

The snap test-- to make sure the coating is hard and thick enough.

Then, the taste test.

If you've got a sweet tooth, doing quality control in the marshmallow cookie factory is your dream job.

To make a batch of dough for the cookie base, they mix wheat flour, salt, baking soda and powder, cornstarch, whey powder, and potassium sorbate.

Then they add several liquid ingredients.

This one causes a chemical reaction, making the biscuit lighter.

This cream-colored liquid is vegetable oil shortening.

This transparent liquid is glucose fructose, a sweetener.

The ingredient proportions are also a company secret.

From the mixer, the dough goes into a machine called the chipper.

It shreds the big blob into pieces about the size of the cap on a highlighter pen.

This makes the dough more manageable for the next machine, called a rotary mold.

Inside that machine, a large roller flattens the dough pieces, forming them into a dense sheet about 1/2 inch thick.

It then presses the sheet against another roller whose surface is a cookie mold.

The factory uses the rotary mold machine for many different types of cookies.

It simply installs the appropriate roller for the cookie in production.

For marshmallow cookie bases, the mold cavities are round.

The bases exit the rotary mold and make their way onto a moving baking sheet.

That transports them to an oven.

The baking time and temperature are, once again, top secret.

The baked cookie bases exit the oven and move onto a conveyer belt that transports them to a cooling area.

Once they cool to room temperature, the bases go into a machine called the base feeder.

It lines them up like marching soldiers to receive their marshmallow filling and chocolate coating.

The process does require military precision.

Factory technicians have to adjust this machine daily to ensure accuracy to 1/32 of an inch.

A portion of filling has to land perfectly centered on each base, finishing off in a curled peak, this brand's trademark.

The company won't divulge how much marshmallow filling goes into each cookie, nor will it reveal its marshmallow recipe.

But marshmallow is usually made from either corn syrup or sugar and gelatin.

And now for the final layer-- the chocolate coating.

Not only are the marshmallow and base covered in hot, melted chocolate, the base floats in it, which coats the underside, as well.

Built-in air jets blow off the excess.

The chocolate hardens inside a cooling tunnel.

How long that takes in the tunnel temperature are-- you guessed it-- classified information.

As the cookies exit the cooling tunnel, a quality-control worker does spot-checks to ensure the coating is thorough, hard enough, and thick enough.

On the packaging line, the cookies go into plastic trays.

To keep up to speed, the workers have to grab four cookies in each hand without breaking the coating.

The trays pass through a machine that wraps them in plastic film.

This keeps the cookies fresh and also prevents them from falling out of the tray.

Meanwhile, another machine assembles the boxes-- first folding and gluing one end shut.

Once workers load the trays, the machine glues the open end closed, as well.

Then with the go-ahead from quality control, the box's next stop is the cookie aisle of your local supermarket.

Loudspeakers take an electrical signal and turn it into sound.

The key to it all is a magnetic wire voice coil and a permanent magnet that attract and repel each other.

As the coil moves back and forth, it rapidly vibrates a flexible cone.

This vibrates the air in front of the speaker, creating sound waves.

Loudspeakers contain at least two magnet-and-cone assemblies known as drivers.

They're typically housed in a box called a speaker enclosure.

To build the internal magnetic structure, the factory begins by cutting two plates of iron, each about 1/2 inch thick.

They go one at a time onto a lathe.

First, the machining tool smoothes and evens out the surfaces, getting rid of the marks the saw made.

Then it cuts out a small hole in the center of one plate and a larger hole in the center of the other.

Next, they cut a smaller and thicker round piece of iron called the core.

A reamer bores a large hole through it.

They apply superhigh-strength epoxy glue to the core and to the back plate-- the plate with the smaller hole.

They glue and screw the pieces together because the bond has to be strong enough to withstand intense magnetic pull.

They glue a foam filter in the hole to ensure the vibrating cone doesn't draw in dust and cause internal damage.

Now they spread the glue on the narrow end of what's called the metal basket, a die-cast aluminum frame that will hold the magnetic structure and cone.

They screw the front plate, the plate with the bigger hole, onto the glued surface.

Then they glue the underside of the front plate and one side of a ferrite, a ceramic ring made from the iron powder.

After adhering the ferrite to the front plate, they apply glue to the other side of the ferrite, then flip the basket over to attach the back plate.

The core fits through the large hole in the front plate.

They insert shims to center it while the glue dries.

After screwing terminals to the basket, they put the entire structure they've just assembled into a magnetizing machine with 600 volts of direct current.

The machine creates positive and negative poles, transforming the magnetic structure into a permanent magnet, meaning it has a constant magnetic field around it.

Now they wind the voice coil-- the electronic magnet that will interact with the permanent magnet.

An electromagnet is an object that generates a magnetic field only when there's a current running through it.

They wind enamel-insulated copper wire, gluing it to a rigid plastic sheet.

The positive pole of this voice coil will be attracted to the negative pole of the permanent magnet.

The negative poles will repel each other.

The key is that the voice coil's poles are constantly reversing position because the electrical current running to the speaker is an alternating current, meaning it switches between a positive and negative charge several times per second.

This makes the magnets attract and repel each other continuously, causing the voice coil to move back and forth rapidly.

This vibrates the cone, which creates sound waves.

After slipping the voice coil between the front plate and the core, they glue on the bottom suspension-- flexible fabric rings that move with the voice coil and prevent it from rubbing on the magnetic structure.

Next, they glue the cone.

It's usually made of cardboard, plastic, or metal.

Then solder the electrical connections.

The current coming from the amplifier travels by wire to the two terminals.

The terminal wires connect to the voice coil wires.

After making sure the cone moves freely without rubbing, they glue on a rigid cardboard cap to keep out dust.

The last step is to take the speaker for an audio test drive.

They connect it to a machine that transmits different frequencies.

They make sure the movement of the voice coil and cone isn't obstructed in any way.

Then a computer device analyzes the sound wave the driver sends out.

Two-way speaker systems have two drivers in each enclosure-- a woofer and tweeter.

A woofer has a large cone that vibrates more slowly for low frequencies.

A tweeter has a small cone that vibrates quickly for high frequencies.

Three-way systems have a third driver with a medium-sized cone for the midranges.

At most hotels, room keys are a thing of the past.

You're more likely these days to be given a key card.

When you arrive at the door to your room, you swipe or insert it to unlock the handle and get in.

Because the room number doesn't appear on the card, this system is far more secure than door locks with a keyhole.

The metal case that houses the door lock's mechanical and electronic components is called the housing.

To make it, they begin by melting zinc ingots.

To melt zinc, you have to heat it to about 734 degrees fahrenheit.

Die-cast machinery then injects the molten zinc into molds.

Between injections, sprayers coat the empty mold cavities with a release agent, the industrial equivalent of greasing a baking pan.

A built-in cooling system hardens the metal.

Then a trimming die cuts off excess zinc around each piece and in the openings.

Meanwhile, the electronic circuit board, the brain of the lock, takes shape.

They call this the "pick and place" machine.

It picks up the 60-odd electronic components and places them in the right position on each board.

This computer-guided machine installs 15,000 components per hour.

Next, the boards undergo what's called wave soldering.

A mix of molten lead and tin surges up from underneath, fusing components in place and creating electrical bonds.

Then, both sides of each circuit board get a coat of silicon-based sealant.

This protects the components against the elements.

Back to the housings now.

Workers lubricate them with grease and apply what's called a sleeve bearing-- a nylon bearing that enables the handle to turn smoothly.

Next comes the drive tube onto which the lever will be assembled on the other side.

There are several clutch components that link the lever to the latch.

Swipe the right card, and they permit the latch to retract.

After applying more lubricant, they install an override that enables the hotel to open the door with a key, if, for some reason, the electronics malfunction.

They install the circuit board and connect it to the various parts it controls, such as the clutch motor, which they install next.

Now they close up the completed housing with the steel back plate.

This protects the components inside from rusting.

The last step is to insert a battery pack.

It holds three standard double-a batteries.

The factory tests the lock using a test key card because the lock isn't yet programmed to work with a specific card.

That's done after installation.

Elsewhere in the factory, they assemble the mortise-- the part of the lock that goes inside the door.

When you lock up, the mortise's bolt comes out of the door's edge and fits into the hole of a receiving piece, called a strike plate, in the door frame.

They close up the mortise with the back plate.

This demonstration shows how they install the mortise in the door.

Once it's in, they screw a decorative plate on top.

This is what the finished electronic door looks like.

Key cards have instructions on one side, a magnetic data stripe on the other.

They use a generic card to test every lock that comes off the production line.

In the quality-control lab, they subject every new design to several rigorous tests.

They open and close 1 million times.

They subject the lever, latch, and lock to repeated impacts.

They also test lock function in extreme temperatures.

These electronic door locks come in several metal finishes plated over the zinc and even in a painted finish that simulates wood.


Pressure Cookers
Mechanical Singing Birds
Oceanographic Buoys
Tank Trailers

When the pressure is on, the juices start flowing for quick results.

The pressure cooker traps steam inside to raise the cooking temperature and produce a meal in minutes.

The technology has been around for centuries but was only adapted for household use in the 1930s, when the concept really picked up steam.

Modern pressure cookers have new lid-locking technology and safety features, keeping it on the front burner in the kitchen-gadget department.

A pressure cooker starts with a stainless-steel disk.

A dip of some lubricant will aid the forming process, as equipment pushes the disk over a pot-shaped die.

That flat disk is now a nicely rounded pot.

Next, this punch cutter moves in to make notches in the pot's rim.

These notches will interlock with the pressure-cooker lid, allowing it to hold up tight against steam pressure.

Next, they submerge aluminum disks in a liquid mix of aluminum and silicon to give them an even coating.

While the disk is still damp, they arrange it on the bottom of the pot, then set a stainless-steel disk on top of it.

A turntable delivers the pot to an element that's heated to more than 1,100 degrees fahrenheit.

This intense heat activates the aluminum and silicon solution to fuse the disk to the bottom of the pot.

Then it's into a cooling tank, where the pots float towards the next station.

There, two blades shave away the ragged edges of the fused layers on the bottom of the pot.

It creates a cosmetic beveled effect.

That layer of aluminum sandwiched between the steel will improve the pot's heat conductivity.

And now it's time for some grit and polish.

In this special chamber, sanding and buffing tools add luster to the pots.

The pressure-cooker pot then takes a trip through a washing station to clean off the sanding residue.

And now it's ready for the crowning touch-- the lid.

It takes six pressing operations to shape it completely.

The holes at the center are for the pressure cooker's two safety valves.

To install the main valve, they align a retaining ring with the lid's larger hole, then pop the spring valve into that hole.

An automated device underneath tightly screws it into place.

The backup valve goes in the smaller hole.

These two valves are crucial.

They'll release excess steam to avert an explosion.

A rubber ring creates an airtight seal with the pot.

They test the valves and check the sealing ring, along with the lid's closing mechanism.

This plastic cooking guide encircles the main safety valve, but doesn't impede its function.

They weld several bolts into the pot on either side.

They leave a bit of space between the bolt heads and the pot.

This allows them to install the brackets for the handles.

They torque the bolts to tightly secure the bracketed handles.

After all, a pressure cooker is one thing you don't want to lose your grip on.

And now this pressure cooker is in the home stretch.

There's one last test, which they perform on randomly selected pots.

They pump the pot full of air to simulate the effect of steam and confirm that this pot can handle the pressure.

Pressure cookers with double walls are another innovation.

They'll keep that stew warm longer to ease the pressure on the chef.

Mechanical singing birdsfirst appeared in 1780, adorning snuffboxes.

The swiss-made novelty soon became the rage among classy europeans.

A few decades later, a french watchmaker perfected the sound mechanism, making the birdsong virtually indiscernible from the real thing.

switzerland is home to the last remaining company making these singing automatons.

The workshop crafts large ones that go in birdcages and small ones that pop out of boxes and clock cases.

the first step is to adjust the bird's two spring-loaded steel rods.

One pivots the bird's head and the other its beak and tail.

Then it's time to dress the bird's body.

It's illegal to harvest real bird feathers, so the artist uses real antique feathers in a couple of key spots and realistic-looking synthetic feathers everywhere else.

To craft the tail, she glues feathers onto stiff paper, then folds it over and adheres it to the bird.

Then she adds more feathers, meticulously creating colorful layers.

The plumage alone takes about four hours' work.

No two birds are alike.

Each is a unique piece of art.

In the technical department, they screw the windup key to the mechanical movement that animates the birds.

The movement is made up of 250 brass and steel components assembled manually.

They connect leather bellows.

The movement pumps the bellows, which sends air through a tiny whistle, producing the birdsong.

Now for the birdie.

This one's the small pop-up kind that goes in a box or clock case.

They screw him to a lever in the movement, then, using a brass template, position him correctly.

This rack gear moves the bird from side to side while he's up and singing.

This pin attaches that gear to the movement.

This lever pops the bird out of his nest, moves the rack gear, and pumps the bellows.

A push button on the movement triggers the lever, setting all this in motion.

now they install the movement into its decorative box.

Birdcage models require an identical but larger movement.

The base of the cage sits on top of it.

The rods that manipulate the birds connect to the movement through tubes in brass perches.

workers construct the top of the cage over a curved form.

First, they slide on two brass rings and position a brass disk at the top.

Then, they feed thick brass wire through holes in the rings.

They lock each wire onto the disk temporarily, then, with a bit of acid to help the process, solder the wires to the disk permanently.

After making sure everything's well-positioned, they solder the wires to the rings, as well.

Once the structure is soldered, the cage can safely come off the form.

Decorative brass rings cover the structural ones.

They, too, have to be soldered in place.

This requires a light brush of acid...

Lead pellets...

And a torch to melt the lead, binding the outer and inner rings.

Every mechanical singing bird this company produces is a work of artistic and technical craftsmanship that delivers a performance on command.

oceanographic buoys enable scientists to study the sea, help meteorologists predict weather, and rescue teams better to find a search area.

The top part of the buoy houses instrumentation that tracks temperature, surface currents, and other conditions.

Its antenna transmits the data via satellite to a base station.

This model has a ball-shaped surface float with a tether cable connecting a long fabric tube called a drogue.

The drogue detects water movements several yards below the surface.

The component that connects the surface float to the cable is called the stress relief.

The factory makes this part in a mold, casting 10 at a time.

Workers inject liquid urethane into the mold cavities.

It's the same material from which in-line skate wheels are made.

After three hours, they extract the castings, which then cure for a full week.

The surface float contains a barometer sensor that collects air-pressure data, as well as a temperature sensor and a locating system.

A 13.5-volt battery pack powers all these instruments.

Workers build it by arranging 36 standard d-cell batteries.

Using nickel strips, they make pairs, linking the negative end to a positive end.

Then, they spot-weld the strips, creating circuit pathways along which electricity will flow.

Next, they immobilize the batteries by filling the spaces between them with hot glue.

Then, they weld the final connections and solder on the leads that will connect the battery pack to the instrumentation.

Now they apply special insulating paper to prevent the battery pack from shorting, should it come into contact with a metal object.

A wide band of electrical tape safely seals this 13-pound battery pack.

The nylon/polypropylene drogue is too lightweight to hang vertically in the water, so it needs something to weigh it down.

That something is a heavy, plastic hoop.

They make the hoop by blowing sand into a plastic garden hose.

The sand makes it heavy.

After capping the hose, they insert it in a pocket at the bottom of the drogue.

So now the drogue, all 26 feet of it, will dangle straight down into the water.

Now for that stress relief they molded earlier on.

It attaches underneath the bottom half of the surface float.

Inside the bottom half, they install the battery pack...

Then a control board...

A transmitter...

And an antenna.

The surface float is made of a.b.s. plastic, the top surface coated for u.v. protection, because it will be exposed to direct sunlight.

They attach one end of the tether cable to the stress relief and the other end to the drogue.

They reinforce the connection with epoxy.

This type of buoy is designed to monitor only the top yard of water, so it doesn't have a long vertical drogue like the other one.

What it doeshave is a parachute, because it's designed to be dropped by aircraft in a search-and-rescue operation, to mark the location of an incident.

As the demonstration shows, the buoy opens on impact.

All the components are spring-loaded-- floats made of foam, drogues around the central cylinder housing the instrumentation, and on top an antenna.

The buoy packaging is water-soluble and biodegradable, so, over time, it simply disintegrates.

No need to retrieve them.

Stainless-steel tank trailers carry all kinds of products, from milk, sugar, and animal feed to fertilizer, shampoo, or even wine.

Some tank trailers only haul chemicals like methanol.

Made of stainless steel inside and out, they keep all the products they're transporting contaminant-free.

Stainless-steel tank trailers carry as much as 12,000 gallons of product.

They start with a laser cutting machine which cuts pieces like this manhole opening from the stainless-steel sheet used to make the tank.

The laser that cuts the steel is as precise as the pen you use to sign your name.

Next, they make the larger pieces of the tank by putting two sheets of stainless steel into a machine called a plasma seam welder.

Using stainless-steel wire as a filler metal, the computer-controlled machine welds the two sheets of steel together.

A worker then uses a belt sander that rides on a track to smooth out the weld evenly and in a straight line.

The sheet then goes through a rolling machine that shapes it into a cylinder.

It takes two to four cylinders to make a tank, depending on the size.

Meanwhile, a ring-rolling machine makes what's called channel rings that will strengthen the cylinders and help them keep their round shape.

The rings are also made of corrosion-resistant stainless steel.

Some tanks need up to 12 of these reinforcement rings.

A worker then welds the channel rings onto the tank, stopping periodically to inspect the weld.

Next, they weld tank heads to the cylinder.

Welding parts on the outside of the tank causes heat discoloration to the steel on the inside.

That's why a worker then polishes the stainless steel, giving the full interior of the tank a noticeably clean and bright finish.

Then, they attach polyurethane spacer bands to the tank.

These create the sections they need to mount fiberglass insulation around the tank, which keeps the product either warm or cold.

Workers then install thin sections of stainless steel around the tank to protect the insulation.

This steel is shiny for cosmetic reasons only.

They hold the sections in place temporarily using leather belts.

They secure this entire outer wrapper so it fits properly.

Then, they weld each section of steel to the frame of the tank.

Next, they prepare the outer wrapper heads using what's called a lock-seam flanger.

That makes a lip in the edge of the heads.

They attach the front and rear heads to the outer wrapper by fitting the lip into the outer wrapper's grooved edge and crimping them together using a hammer.

Next, they install the aluminum fenders over the rear tires.

After that, they attach a stainless-steel tube ladder that gives access to the manhole at the top of the tank, where they load the product.

They put the mudguards on next, followed by the reflective conspicuity tape that goes on both sides of the tank and on the two rear bumpers.

They install the stoplights and taillights into a light box at the rear of the trailer.

After that, they install the turn indicators on the sides of the trailer and test them to ensure they function properly.

Finally, they check all the connections used to operate the tank trailer, so when it leaves the plant, it works perfectly and the customer can transport their product safely.


For this invention, the path to success has been bumpy and rocky, and that's the whole idea.

The all-terrain vehicle was developed for off-road driving back in the 1970s.

The first machines were three-wheelers, and then the safer four-wheelers came along, improving on a concept that was truly trailblazing.

If you're looking for adventure, an all-terrain vehicle will get you out of a rut.

All that bouncing around won't hurt a bit because the independent rear suspension takes some of the shock out of that bumpy ride.

To make an all-terrain vehicle, they clamp pieces of the steel framework to a worktable.

The table flips and lands in a precise position for welding robots to go to work.

These computerized robots do all the big welds.

Humans take over for the more intricate work.

Once the vehicle mainframe is complete, they hang it on an overhead rail, which takes it through a painting station.

When the paint is dry, they lock it onto rails that will move it down the assembly line.

They tie the radiator to it with hose.

It will be attached more securely later.

The steering axle for the front wheels goes in next.

At the next station, they bolt the steel handlebars to the front of the vehicle.

They hoist a 300cc engine into the chassis.

It's suitable for beginners or smaller riders.

They fit the carburetor into the engine manifold.

Moving down the line, they install the suspension system for the front wheels and run the brake lines to the brake disks.

They brace the suspension with a steel bracket.

The extra support will come in handy when this atv is on rough terrain.

They push the outer exhaust pipe onto one that extends from the engine and hook them together with springs.

They then slide the front and rear clutches onto grooved shafts and connect them with a rubber belt to transmit power from the engine to the transmission.

The radiator has been permanently mounted to the chassis, and they bolt the coolant tank to the framework above it.

The 4 1/2-gallon fuel tank goes between the handlebars and seat.

They insert the air-filter box in an opening behind the tank.

This much bigger lid goes on the storage box in the front.

And after a little trademark artwork, they push the instrumentation panel into place between the handlebars.

Footwells made of rigid plastic flank each side of the atv.

At the next station, they mount the front grille and headlights.

They screw a rack onto the back.

It can be used to tie down anything from camping gear to game.

Workers then press a comfy vinyl seat onto the center of the vehicle, snapping it into place.

Now this all-terrain vehicle is ready for its wheels.

The back ones are larger to provide that cushioning effect over the bumps, while the smaller wheels in the front provide traction and maneuverability.

They apply reflector decals to the sides and back, so the atv can be seen more easily when daylight dims.

The tank has been fueled, and this atv is ready to take a ride on the drum tester.

The operator parks the wheels on a set of drums.

He activates the computer, and those drums are ready to roll.

The gate closes, and the atv rides on the spinning drums, reaching high speeds without actually moving.

It's the perfect opportunity to test the gears, brakes, and exhaust system.

The operator then gives the brakes a workout because good brakes are critical in backwoods conditions.

And it passes.

From the three-wheel machine of the '70s to the flashy four-wheeler of today, the atv continues to be popular off the beaten track.

Thousands of years ago, scandinavians strapped wooden planks on their feet to glide across snow.

Those first skis enabled them to hunt and trap in the winter.

Essentially, they skied to live.

Today, however, some of us live to ski, and cutting-edge equipment is part of the appeal.

In the past century, downhill skis have become shorter and curvier for peak performance.

They start with a squared-off ash log.

A band saw slices it into several planks.

Ash is supple, but strong, which makes it the ideal wood for the core of a ski.

A second blade thins each plank at the end and widens it where the skier's foot sits.

Sanding establishes subtle angles on the edges.

Then the planks move along to a machine that cuts teeth into them.

A ridged applicator applies epoxy glue to the toothy ends of two boards.

Machinery presses them together for a tight fit.

As the glue dries, it creates a permanent bond.

The two planks are now one ski core.

It still needs some fine-tuning, so a robot positions it on a conveyor, which takes it under a sanding belt.

It smooths the interlocked section and grinds deep cuts into the core.

This defines the parabolic shape that helps skiers carve through powder in short, clean turns.

They silk-screen graphic artwork and logos onto plastic.

It's a bit of corporate p.r., but the flashy designs can also inspire the skier.

An operator then brushes a release agent into a mold, as she prepares to build and shape several skis at a time.

A little vacuuming gets rid of any dust that would sully the work.

Then she tucks pieces of graphite-fortified polyethylene into the mold.

It will form the base of the skis.

She places rubber on the ends to minimize vibrations while skiing.

Next come layers of special fiberglass that run the length of each ski.

This material is both flexible and durable.

It's been formulated specifically for skis.

The weave varies from layer to layer, depending on the type of ski.

Strips of rubber reinforce the back ends, followed by pieces of heavy-duty polyurethane.

The assembler places the curved wooden cores on top of the synthetic layers.

She installs melamine to build up the ski's sidewalls.

This improves gripping in hard snow.

To provide a firm base for bindings, she covers the narrow waist of the ski with more fiberglass, followed by an aluminum plate to hold the binding screws in the ski.

More layers of fiberglass follow, imbued with epoxy glue, which is about to be activated.

Once the colorful top sheet is secured, they close the mold.

Inside, the temperature reaches 212 degrees fahrenheit.

This causes the glue impregnated in the fiberglass to liquefy, while the mold squeezes the layers into the shape of the ski.

When the glue hardens, the many layers become one solid ski.

It's a fusion of synthetic, wood, and metal.

But it's still a bit rough around the edges, so this robot smooths the tip and tail of the ski against a sanding belt.

The ski then travels over several grinding wheels.

This cleans it up and creates angles for precision carving on the slopes.

Then, like a powerful fist, this machine tests its flexibility and strength.

Finally, a worker screws a rail system to the waist of the ski to make it easier for the ski shop to install bindings.

Then it's all downhill from here, which, of course, is the whole idea.

A laser cutter is a high-tech machine that factories use to cut parts out of metal.

The traditional way to cut metal is with a stamping press, a slower process that requires a separate tool for each type of cut.

A laser cutter's computer-guided beam can precision-cut virtually any shape.

A laser cutter is made up of a laser resonator, which produces the beam, and a mechanical system that moves the laser over the metal in a computer-controlled pattern.

To build the laser resonator, they mill two blocks of aluminum.

Each will hold a mirror on opposite ends of the resonator.

They will reflect light back and forth inside the chamber to form the laser beam.

All the parts go into a cleaning solution because any contaminants would shorten the laser's life.

Assembly takes place in a clean room.

After mounting the aluminum blocks onto separate aluminum tubes, they slide one tube inside the other.

This forms the resonator's main structure.

They install an electrical connector on one of the blocks.

Then they mount a mirror onto each aluminum block.

A generator pumps electrical energy into a pressurized mixture of gasses, producing particles of light called photons.

The mirrors at both ends of the resonator direct the photons back and forth, creating the laser beam.

They now fill the resonator with that pressurized gas.

It's a mixture of nitrogen, carbon dioxide, and helium.

For the laser beam to cut well, it has to be the right shape, but the beam is invisible.

So, to see its shape, they have to shoot it into a plastic cube and observe the formation it makes.

They gradually fine-tune the beam's shape by adjusting the mirrors on the resonator.

They keep at it until the laser cuts a cone formation in the plastic.

On top of the tubes, they install a square housing containing a series of mirrors, which further refine the beam.

Meanwhile, a robotic welder fuses sheets of steel to construct the laser resonator's housing.

On the main machine, these large suction cups move the sheet of metal to the cutting area.

The sheet remains stationary, while a motion unit moves the laser beam over it.

A rack-and-pinion system propels the motion unit.

The system's racks must be perfectly aligned for the machine to cut accurately, so a technician uses precision measuring equipment to check the racks, then various tools to make adjustments.

Once that's done, they set up the guide rails on which the motion unit rides, then mount the motion unit onto them.

They bolt the motion unit to the front of the machine and the housing that contains the laser resonator to the back of the machine.

The resonator creates the laser beam.

Mirrors deliver it to the motion unit's cutting head.

Lenses inside the head focus the beam on the metal that's underneath.

They run a series of tests to ensure the machine cuts with ultimate precision.

It all boils down to whether the motion unit moves accurately, which means the drive-system racks must be perfectly aligned.

After testing, they enclose the cutting head with a safety cover made of sheet metal and plexiglas.

The cutting head's copper-tipped nozzle emits the laser beam, while a curtain of brass pins confines that beam to a restricted area.

The motion unit moves in three axes, enabling the laser beam to cut different thicknesses in two dimensions.

A stamping machine leaves rough edges that workers must grind smooth afterward, but a laser cutter leaves a smooth edge that needs no further work.

This saves on time and labor cost, making this technology a cut above.

It was michelangelo who once said, "every block of stone has a statue inside it, and it is the task of the sculptor to discover it".

Centuries later, sculptors still chisel by those words, using techniques similar to those used by the brilliant michelangelo so many years ago.

A lifelike image emerges from stone, and that well-chiseled look is the result of a lot of planning and posing.

The artist first molds the subject in clay, which allows him to capture his impressions quickly.

His clay model is the sculpture equivalent of a painter's sketch.

Clay also allows him to make changes that would be impossible once carved in stone.

When the prototype is complete, the artist is ready to choose a stone.

The search leads to this quarry in the hills of northern italy, where they've been extracting white carrara marble for centuries.

A long saw on a track makes a horizontal incision in the bottom of the rock face.

Once this undercut is complete, the operation moves to the top of the stone.

A machine pulls a loop of diamond cable down through the rock to cut the back of the slab.

A constant spray of water cools the cable and flushes the cut.

When the two cuts intersect, this marble slab is ready to be extracted.

Equipment gently tips it onto a soft pile of dirt intact.

The supervisor gives the slab a production number and draws lines to indicate how it should be cut to prepare it for sculpting.

Once cut down to size, it's into the studio, where it's positioned beside a plaster version of a clay model.

With calipers, an artisan measures the proportions of the plaster cast and transfers them to the marble slab.

His pencil marks define the main mass and outer limits of the form that's to be sculpted.

This artist chips away big chunks of the stone to give the rough size and shape of the plaster model.

The penciled measurements ensure that he doesn't chip away too much and destroy the slab.

Once the general shape has been achieved, it's time for the detail work.

The sculptor measures the plaster prototype with a tool called a pointing machine.

He transfers the measurements to the marble sculpture, ensuring that all the details will be to the correct scale.

Of course, pointing tools can only show the artist whereto carve-- there's no substitute for skill.

With a pneumatic chisel, the artist shapes the foot of the figure.

Next, the artist switches to a series of rasps and files, so he can shape the smaller details and eliminate any chisel marks.

The fingers require a gentle approach.

They're delicate and could be broken easily.

It takes about four months for a sculpture to go from the rough form to the finished.

And now for the final touches-- he rubs oxalic acid into the marble.

This seals it and protects it from stains, but also gives the sculpture a polished look.

The result is a translucent effect that gives the sculpture visual depth.

Like ghosts in the attic, there's an incredible array of plaster casts on this studio's upper floor.

Many of them are replicas of famous classical works.

They're all on standby to serve as prototypes for sculptural reproductions.

And once these images are carved in stone, they should live on forever.


Bowling Balls
Barber Poles
Felt
Radar Guns

The bowling bowl has undergone a lot of changes over several centuries to become such a striking success.

From a crude stone to carved wood to rubber to molded polyester, it's been reinvented numerous times.

But the latest version has turned out to be a real winner.

Technological advances have reshaped the bowling ball at its very core.

No longer round, the nucleus is asymmetrical, which causes the ball to curve towards the pins as it rolls down the lane.

They make the cores from polyester resin, blending in minerals like barites, silica powder, and limestone.

The result looks like chocolate milk, or make that hot chocolate, because a catalyst triggers a chemical reaction that heats it up.

As they pipe it into the molds, it quickly starts to cure and solidify.

In just two minutes, it's ready to extract.

This core is oblong--  flat on one side with a knob.

There are different versions of this core design, each one carefully calculated to manipulate the bowling ball's performance at a specific skill level.

They now drill toward the center of the core to make a pinhole.

This allows the core to be suspended in just the right position in a second mold.

This asymmetrical core is about to be encased in a more uniform sphere.

They tamp the core into the bottom part of the mold and then lock down the top half.

After all, they don't want any leaks as they pump it full of plastic.

It's a liquid-polymer blend.

A special chemical in it causes the mix to solidify slowly.

It can take days for it to harden around the core, depending on the formulation and type of bowling ball being made.

When they knock it out of the mold, all is revealed.

That asymmetrical core is now sealed in a very symmetrical polymer shell.

Next, it's into a third mold.

This one will seal the bowling ball in an outer skin called the veneer.

This veneer has been scientifically formulated to enhance the ball's traction as it hooks towards the bowling pins.

It's made of colorant, plasticizer, a chemical called i.s.o., and urethane.

Blending these ingredients produces high-performance polyurethane.

As the mix flows into the molds, a chemical reaction causes it to heat up and solidify in just seconds.

Then it's into an oven to boost the chemical reaction.

Next, a spinning grinder shaves off the bump, which was formed by overflow at the mold's intake tube.

The removal of this bump rounds off the shape of the bowling ball.

With its three layers, this bowling ball looks a bit like a big bonbon when it's sliced in two.

And while it may look sweet, it needs a bit more work before it's ready to take on the competition.

A lift system delivers the bowling ball to a sanding operation, which roughs up the surface.

The coarseness of the sanding varies, depending on the performance goals of the particular ball.

This machine heat-stamps trademark information onto the ball.

They do one last sanding, as a constant flow of water removes the powdery residue.

The more polished the surface, the less pronounced the ball's hooking action will be.

Even this last sanding is geared to a certain performance standard.

Once they buff the surface, all that's left is to custom-drill the finger holes.

With this bowling ball in hand, success should be within striking distance.

Barber poles go back to a time when barbers also performed surgery, tooth extractions, and bloodletting.

Some believe that the idea for the red and white strips came about because of bloody and clean bandages that twisted together in the wind as the customer held onto a pole during a procedure.

Over time, barber poles have come to lose their gruesome connotation but not their place as an historic symbol.

There's only one company left in north america that makes them.

They begin by rolling a printed liner onto a wooden mandrel.

The mandrel they use depends on the size of the pole they're making.

Using a knife, they score the liner at both ends.

The liner is made of paper and vinyl treated with u.v. protection to prevent it from fading.

Scoring the liner helps guide the worker as he trims the familiar red-white-and-blue material to the required length.

Next, he rivets the company logo to a support frame.

Then with bolts, he attaches a top and bottom support casting.

The frame and castings are made of aluminum, so they're virtually rustproof, which is a big plus since barber poles have to weather the elements.

After ensuring the assembly is level, they install the glass cylinder, which can be made out of extruded or handblown glass.

After a final tightening, they double-check that everything fits snugly.

Next, they add water to a special caulking powder and mix it to a smooth consistency.

The caulking must be just the right thickness to properly fill the cavity between the aluminum casting and the glass cylinder.

Five minutes later when the caulking is dry, they carefully trim off the excess on both ends of the cylinder, leaving behind a smooth, watertight seal that helps secure the glass cylinder in place.

Cleaning the glass by hand is just another example of all the artisanal handiwork that goes into making these time-honored barber poles.

Next, they mount the assembly on a hook and paint the caulking with a colored sealer that matches the casting and makes the caulking waterproof.

After that, a worker puts in a motor mechanism.

The motor will rotate the printed liner inside the glass cylinder.

Once the motor is hooked up, he takes an inner cylinder, which has the printed liner mounted on it, and installs it on top of the mechanism that makes it rotate.

He then installs a two-socket light fixture with a bulb that illuminates the liner.

To keep the printed liner straight as it turns, he then attaches what's called a top-cylinder bushing.

All that's left to complete the pole is to attach a rustproof aluminum cover and the second light bulb that lights up the white glass globe.

Finally, he hooks up the pole to electricity and makes sure the motor, both lights, and the inner liner are working properly, creating the illusion of movement.

Modern barber poles come in various sizes and styles, with or without illuminating globes, but they always keep their link to the past.

When production hits a snarl at the felt factory, things are going well.

That's because felt is made by entangling fibers into a matted material.

Felt has actually been around for thousands of years and may be the first fabric ever produced.

These days, mechanization puts a new twist on felt.

Boot liners are an example of the way felt layers our lives.

They begin with bales of polyester fibers.

Sometimes they add wool or synthetic fiber.

This machine is about to sink its teeth into those fibers.

It's a rotating bed with hundreds of fierce-looking spikes protruding from it.

An operator loads the bales of fibers onto a feeder conveyor.

It shuffles the clumps toward that spiked conveyor, which snags the fibers and takes them up to another spiked rotating belt.

But this one moves in a different direction to grab and pull the short, springy fibers apart.

The process fluffs and blends the fibers, transforming the dense clumps into something that's the consistency of cotton wool.

Now that the fibers have been loosened up, it will be easier to extract any metal bits that may have contaminated the bales early on.

A magnet pulls out these contaminants, which would otherwise cause damage to equipment down the line.

With the metal bits removed, the fibers move into another machine.

This one has a series of pinned rollers that are close enough to almost touch.

They rotate in different directions to align the fibers.

This creates a uniform web of fluff.

Then it's over to the cross lapper-- a system of conveyors that move back and forth to neatly fold it up.

They then travel between rollers, which squeeze several layers down to a thickness of a little more than a centimeter.

10,000 long needles repeatedly stab the compressed web to entangle the fibers.

Each needle is equipped with nine barbs to snare the polyester fibers.

This process is how they become enmeshed.

It transforms the compacted fluff into felt.

Rollers pull the matted material out of the machine...

As they wind it onto a big roll.

You can see that the fibers are now a solid mass.

Next, they layer two piles of felt onto a metalized nylon film.

This shiny film will reflect the outside cold, and the three layers combined will provide extra thermal protection that will even insulate against arctic temperatures if need be.

More long needles punch into the three layers and entangle the fibers to create one sheet of material.

It's a form of laminating without glue.

The needles leave little holes in the reflective film that improve the breathability of the fabric.

Next, a worker uses a 25-ton press to punch boot-liner patterns out of the felt.

The press bears down on dyes that cut out various-sized insoles and boot-liner sidepieces.

This felt is now ready to add a little warmth to someone's life.

All they have to do is sew the parts together.

The seamstress stitches the two sidepieces, using an industrial machine with needles that easily penetrate the thick, stiff felt.

The top of the boot liner is finished.

But without its sole, it's incomplete.

They sew the felt sole onto it with a neat loop stitch-- the only stitch that would hold this configuration together.

From a pile of synthetic fibers to a rigid liner that's ready to protect you against the elements, it's been quite a journey, and it's far from over, as felt continues to keep its foothold in the world of layers and liners.

If you see one of these, it's likely connected to the long arm of the law.

Police have been using radar guns to nab speeders ever since the 1950s.

They bounce radar off your vehicle and analyze the returning signal to get a reading, and that's when sirens wail and the officer says, "do you know how fast you were going"?

If you're a speeder, the police have probably got your number, thanks to the radar gun.

When operated properly, radar guns boast an accuracy rate of plus or minus half a mile per hour.

But of course, you can always try arguing with the officer.

Making a radar gun starts with cable wire-- lots of it.

Rollers straighten it, then automated blades cut it to length and strip the plastic casing at both ends.

With the wires now exposed, they're ready for the metal contacts that will allow wiring interconnections.

A technician places the exposed wire in the contact, and a machine crimps them together.

They then assemble wires in various harnesses.

These connect to a power cable and communications port.

The technician inserts wires into a plastic connector to allow them to easily hook into a circuit board later.

This little gadget is a microwave transmitter and receiver.

It sends radio-frequency energy to moving vehicles and then receives it when it bounces back.

The red wires being soldered to its post will deliver power to it.

The white ones will return the radar signals.

This special plastic lens will focus the radar beam.

She attaches the transmitter-receiver unit to the funnel-shaped antenna at the back of the lens.

Next, she solders wires to a circuit board.

Some will carry power to it.

Others will deliver the returning radar signals for analysis.

This second smaller circuit board will process power from the police vehicle to operate the radar gun.

And an insulated metal plate shields the unit from interference from things like the police radio.

The technician secures it with cable ties, and this radar module is now complete.

She moves on to the display and control panel and snaps the keypad onto a little circuit board just below a light-diffusing display window.

She inserts the control-panel hardware into a plastic faceplate and secures it with screws.

As another safeguard against electrical interference, this plastic faceplate has been infused with metal.

He wires the control panel to the power board to run a test.

He checks all the digits and icons to confirm they display correctly.

This machine presses melted plastic into the shape of casing for the radar gun.

A static discharger worn on the wrist dissipates any static electricity from the technician's body.

This prevents damage to sensitive electrical components, so it's worn throughout the assembly process.

She links the two computer boards, ensuring a good connection, because one will power the other.

Then she installs the radar gun in the molded casing.

She plugs the display assembly into connectors on one of the computer boards.

Then she slides it into grooves in the casing.

Now she hooks up this radar gun to a power source for a trial run.

She taps the lens with a tuning fork.

The gun responds to it as it would to a moving vehicle.

If it functions properly, she installs the trigger switch.

She closes the radar gun, securing the two-part casing with screws.

A serial number and other identifying information goes on the side.

In a final test, she connects the radar gun to a computer and aims the lens into a chamber.

The chamber sends signals to simulate the effect of a moving vehicle, and the computer analyzes the gun's performance.

You only have to look at a 35-year-old radar gun to see that this technology has come a long way.

So it's ready if you try to pull a fast one.


Brushes and Push Brooms
Blackboards
Smoked Salmon
Zippers

Today on "how it's made"...

Brushes and push brooms...

Blackboards...

Smoked salmon...

And zippers.

Nothing scrubs or sweeps quite like a good, sturdy brush.

Cleaning brushes in north america date back to about the 1830s.

Their bristles were usually made of wire twisted into wood.

Today we have many different bristle materials, both natural and synthetic.

The first factory manufactures the brush block-- the hardwood base that holds the bristles.

It's usually made of maple, but sometimes oak or beech.

After cutting the planks to the required width, they use a special wax crayon to mark lines on both sides of any cracks or knots in the wood.

A laser then reads the marks, guiding a saw to cut out the faults.

At the same time, the saw chops the planks into block-size lengths.

The next step is called "molding".

A series of saws trims the blocks to the required thickness.

Now they contour the pieces, using a machine appropriately called a shaper.

The machine revolves, running the block's outside edge against a cutting head.

This profiles half the block.

Workers then turn it around and line it up for a second pass to profile the other half.

There's a different shaper machine for each model.

This type is known as a dauber-- a brush for waxing shoes.

For the cuts to be accurate and smooth, it's essential that the machine's cutting heads remain sharp despite repeated use.

That's why they're made of carbide, a material stronger than steel.

Workers run certain models against an extra cutting head to carve a groove in the block's edges.

The groove gives your hand a better grip on the brush.

These 2 1/2x24" blocks will become push brooms-- those wide, rectangular brooms janitors use to sweep floors.

The blocks go to an automated machine that drills a hole through the middle and carves two grooves in the underside.

These are for the steel adapter that will hold the broom's wooden handle.

Rounded push brooms sweep more easily in corners.

To produce those, workers take the rectangular push broom blocks and round the corners against a cutting head.

At another factory, the blocks go onto a machine that pierces holes for the bristles, using a computer-guided drill.

This particular model of push broom needs 240 holes.

It takes barely a minute to drill them all.

Next, the blocks go to the bristle-installation machine.

Bristles can be made of horsehair, vinyl, plants or tree leaves, or synthetics such as polypropylene.

The bristle-installation machine is fully automated, as we see here in slow motion.

It takes about 40 strands at a time, folds them in half, then inserts and staples them into a hole.

Here's what that bristling action looks like at actual speed.

The machine fills four holes per second.

The factory uses this same process regardless of the style of brush block or type of bristle.

Computer software guides the machinery to follow the correct pattern, making possible a sweeping array of brushes and brooms.

Chalk one up for the blackboard.

This trusted teaching tool goes back centuries, yet still remains the focal point of the classroom.

Today's blackboard-- or chalkboard, as it's also called-- hasn't changed that much in appearance, but the materials used to make it have changed.

Our lesson begins at the blackboard factory, with thin sheets of galvanized steel.

These will eventually form the front and back surfaces of the blackboard.

They arrive at the factory already precut to standard sizes-- 6, 8, 10, or 12 feet.

First stop is a machine that blasts the sheets with acid.

This removes any dirt that would prevent paint from adhering to the surface.

As the sheets exit the cleaner, powerful fans dry them off.

The paint is a type of acrylic enamel designed especially for blackboards.

The factory adds a powdered mineral formulation to make it dry to a rougher texture.

This helps chalk adhere better.

Traditional slate blackboards were naturally black.

Today's steel-surface boards come in several colors.

The most popular, though, are black and green.

Some companies use colored porcelain instead of paint.

Here, spray guns apply three coats of paint, one after another, with no drying time in between.

For the paint to harden properly, it has to be heat-set, so the sheets go into an oven at 420 degrees fahrenheit for 10 minutes.

A strong fan cools them off as they exit the oven.

Next, a worker sprays contact cement on the backs of two painted sheets.

One sheet will form the front of the board, the other, the back.

Sandwiched in between will be what's known as the blackboard's core.

It can be made of materials such as particleboard or, as we see here, 1/2-inch-thick fiberboard.

Workers feed the three assembled layers through a high-pressure roller.

It forces out any trapped air and bonds the layers tightly.

They make the blackboard's frame out of one long strip of aluminum molding.

It has a stainproof satin finish.

They make a series of 45-degree-angle cuts.

This enables them to bend the strip around the board's perimeter, creating neat corner seams.

Workers file down and polish any sharp edges left by the cutting.

After verifying that it's perfectly square, they fasten the frame, using either rivets or screws, depending on the model.

Then, they attach an aluminum rail along the bottom to hold the chalk and erasers.

This model happens to be a reversible mobile blackboard-- the type typically rolled into conference rooms.

It has a few extra components--  a pivot mechanism, enabling the board to be flipped to the other side...

And a latch system for tilting the board to different angles.

The blackboard stand is made of painted steel tubing.

It rolls on rubber- and chrome-plated steel castors.

The factory takes samples from the production line and subjects them to rigorous quality-control testing.

These tests ensure that the painted surface is glare-free and can withstand everything from chemical solvents and extreme humidity to heavy impact and hard scratches.

The company has even designed this special machine to conduct a killer durability test.

It applies 100,000 chalk and brush strokes, using the typical amount of pressure a person would use.

For the production batch to make it to market, surface wear on the sample has to amount to less than 1/100 of a millimeter.

And that's not all.

The paint finish must still be matte.

A writing test has to produce chalk lines that are clear and dark enough, and the writing has to erase cleanly and easily.

For thousands of years, smoked fish was a survival food.

People would cure their catches by salting them and hanging them to dry or by smoking them over an open fire.

This enabled people in cold climates to stockpile nutrient-rich fish for those long winter months.

Today we smoke fish primarily to enhance its flavor.

This is wild sockeye salmon that was gutted and frozen on board the fishing trawler to preserve maximum freshness.

The smokehouse defrosts the fish for over 15 hours in running water that's just 2 degrees above freezing.

This slow, cold water thaw helps prevent bacteria from forming.

Next step, filleting.

First, they slice off what's known as the collar-- the fish version of a neck.

Then, they cut each fish in half lengthwise, separating two fillets from what's called the control bone-- the fish equivalent of a spinal column.

The tail is attached to it.

They feed the control bones into a machine that strips off any remaining scraps of flesh.

The machine grinds these bits into minced salmon, which is used to make salmon pie.

They trim the fillets using a razor-sharp knife, slicing off the fins, any excess fat, and any control-bone fragments left behind.

After this, the fish will be ready for curing-- a preservation process that also enhances taste.

Workers coat the fillets in a mixture of salt and 26 spices, then let them sit for roughly an hour and a half.

This short cure time will limit the salmon's salt content to less than 1%.

To stop the curing process, they rinse off the coating with cold water, then glaze the fillets with maple syrup to neutralize any remaining salt residue.

Some companies use a less costly mix of boiled water and brown sugar.

The fillets go into a huge smoke oven.

Workers load its combustion chamber with sawdust-- maple-tree sawdust for the first 8 hours of smoking, cherry-tree sawdust for the next 8 hours, and apple-tree sawdust for the last 8 hours.

This particular sequence is a major factor in flavoring the fish.

They douse the fire with water to generate smoke.

This process is called "cold smoking," because the oven temperature is 50 degrees fahrenheit-- significantly lower than the industry norm of 77 degrees.

Smoking at this lower temperature takes at least 24 hours--  3 times longer than the norm-- but the company says it produces a moister product.

When the fillets come out of the smoke oven, they're thoroughly cooked but still have the consistency of raw fish.

Workers remove the fin bones--  40 fin bones per fillet-- located between the head and fin.

The fillets then go through a skinning machine, which neatly slices off the skin without removing any flesh.

Then, it's into a freezer at 27 degrees fahrenheit.

This firms up the fillets, making them easier to slice.

The manual slicing machines cut them into pieces about 1/10 of an inch thick.

Workers weigh out the amount they're packaging-- in this case, 2 1/2 ounces.

They place each portion on a tray made of aluminum-coated cardboard.

Aluminum blocks the fat from seeping through.

To kill off any remaining bacterial, they vacuum-pack the wrappers, then deep-freeze them for about an hour at negative-31 degrees fahrenheit.

They store and ship at a milder zero degrees-- the temperature of your home freezer-- where this preservative-free smoked salmon stays fresh for a full year.

Zippers can be found on clothing, on bags, even on footwear.

The zipper started out as a closure mechanism for boots and tobacco pouches.

The fashion industry didn't put them on clothing until the 1930s-- some 80 years after the invention of this fabulous fastener.

An american, elias howe, was the first to patent a zipperlike clothing fastener in 1851, but he never ended up marketing it.

It wasn't until 1893 that another american, whitcomb judson, designed a similar device, called a clasp locker.

He eventually hired a canadian engineer, gideon sundback, to simplify the original complex design, which had never really taken off.

In 1917, judson and sundback patented the modern zipper.

Zipper teeth are made of metal, plastic, or nylon.

The fabric part of the zipper is called the tape.

It's usually polyester, but sometimes cotton or fireproof fabric.

To make metal zippers, the factory feeds a long, continuous roll of tape into what's called the teeth machine, along with a long roll of metal ribbon known as "flat wire".

As we see here in slow motion, the machine cuts off a tiny piece of flat wire, forces it through a die that forms into a tooth shape, then clamps it onto the edge of one side of the tape.

The machine does all this at a rate of 45 teeth per second.

These zipper teeth are aluminum.

Sturdier zippers are made of stronger metals like brass and nickel.

Depending on the model, teeth can range in width from about 1/10 of an inch to 4/10 of an inch.

The wider the teeth, the thicker they have to be.

Workers now feed two tapes with metal teeth into what's called the joining machine.

The teeth interlock, meshing the two halves of what's now a continuous zipper.

From there, it's into a cleaning machine, which washes the zipper, removing any shards of metal left behind by the tooth-cutting process.

After drying the zipper, the machine applies a coat of hot wax.

This lubricates the teeth so the slider will glide over them smoothly.

Next stop is the gapping machine.

It removes a 2-inch-long section of teeth at regular intervals.

They'll later cut the tape at these gaps, dividing the continuous zipper into several shorter zippers.

There are two main types of zippers.

Closed-end zippers are the kind whose two halves don't separate at the bottom when opened-- purse zippers, for example.

These need a part called a bottom stop-- a thick piece of flat wire positioned at the base of the zipper.

When you unzip, it stops the slider and prevents the two halves from separating.

Open-end zippers are the kind whose two halves doseparate at the bottom when opened-- jacket zippers, for instance.

At the bottom of these zippers, a machine applies a clear reinforcement strip.

This stiffens the tape so that the next machine can apply the pin and box.

The pin is that vertical piece of metal on one half of the zipper that you have to align in the box on the other half before you can pull the slider to zip up.

The next machine installs the slider.

Watch in slow motion as it opens each gap and hooks a slider onto the track of teeth.

The next machine inserts what's called the top stop-- a thick piece of flat wire that stops the slider at the top of the track when you zip up all the way.

The machine then slices the tape at each gap, separating the finished zippers.

Plastic zippers are made quite differently than metal ones.

The tape is the same, but the teeth are made from plastic pellets.

A machine melts them, then injects the liquid plastic into a mold that's the shape of a strip of zipper teeth.

The mold cools almost instantly, hardening the plastic.

The machine then stamps the teeth onto the tape, automatically gapping the desired zipper length at the same time.

The excess plastic in the middle is remelted.

There's no joining machine to mesh the two halves of plastic zippers.

Workers do this manually so that they can inspect the plastic teeth to make sure they're well formed.

Then, automated machines install the remaining components.