Office Chairs
Vinobrew
Reconditioned Sander Drums
Lithographs

thomas jefferson, one of america's founding fathers, came up with the first swiveling mechanism for office chairs.

Decades later, charles darwin added small wheels, called casters, to his chair to roll it around the study as he worked on the theory of evolution.

Today, office chairs still swivel and roll.

The office chair has become a status symbol.

Executive versions have kingly dimensions.

They're extremely plush and have serious lumbar support.

Using a hydraulically powered machine, a worker bends 14-gauge steel tubing to form the bottom cushion frame.

He joins the ends and welds steel bars to the middle.

The bars will support the mechanism for adjusting the position of the seat.

He hooks s-shaped steel springs from the front to the back of the seat frame.

These sinuous springs will eventually provide a flexible web of suspension in the seat.

He positions the rods laterally and clips them to the springs for additional stability and support.

The office chair seat frame is now complete.

Next, a worker builds the chair's back frame.

The frame includes a spine lumbar support, armrest attachments, and other parts.

He grinds burrs and other rough spots from the steel.

In the upholstery department, another worker smoothes a leather hide so that it sits evenly on the cutting table.

He cuts out the patterns following cardboard templates.

As he cuts, he works around the natural flaws in the hide, making calculated decisions to minimize waste.

By cutting carefully, he'll be able to get all the leather he needs for one chair from this large hide.

That's important because color and grain can vary from hide to hide.

Using pieces from the same one will give the chair a consistent look and texture.

Once all the leather pattern pieces have been accumulated, another worker cuts foam cushioning for backing.

The density of the foam in the chair varies.

He uses more rigid foam for the chair's contoured cushioning so it will hold its shape.

Another worker selects softer foam for the part of the chair that the occupant's back will rest against.

He cuts slits into this softer back padding.

This creates channels that will ultimately become a design feature.

Using chalk, he draws lines onto the corresponding leather that match up with the slits in the foam.

A worker aligns the chalk lines in the leather with the slits and puckers the leather as he sews the backing to it.

This forms a ribbed pattern in the upper half of the chair upholstery.

He stitches the padding flat to many of the other pattern pieces.

This particular part is a side panel for the back of the chair.

Returning to the upholstery with the ribbing now, he sews contoured casings to each side.

To complete the back of the chair, workers add a chipboard panel and encase the structure with foam, then cover it with the leather upholstery.

Once the chair seat has been upholstered, an employee installs a plastic cover to enclose the back.

He screws a sliding plate to the base.

This mechanism will work in conjunction with the plate to slide the seat forward and backward, depending on legroom needs.

It also has features for adjusting the tilt and height of the seat.

The hydraulic cylinder for adjusting the seat height is next.

The cylinder also doubles as the chair's stem, and it swivels to allow the seat to rotate 360 degrees.

He attaches the aluminum base to the cylinder.

He snaps the casters into slots in the aluminum base.

He equips the back of the office chair with an automobile-style headrest.

The prongs fit into the brackets in the chair frame.

Finally, he locks the armrests into the frame.

This office chair is now ready to make someone's desk job a lot more comfortable.

Vinobrew is just what the name implies-- vino, meaning wine, and brew, referring to beer.

This hybrid beverage is part of a fledgling trend by some adventurous breweries and wineries to merge their two otherwise separate worlds of alcohol and create a unique drink.

This vinobrew is made from port-style sweet wine, dark strong beer known as stout, and another ingredient that's brewed-- coffee.

This concoction is the collaborative creation of a winery, microbrewery, and coffee producer.

The microbrewery grows some 20 different varieties of hop plants whose flowers contain the resins and essential oils that give beer its bitter and aromatic characteristics.

To begin the beer-making process, the brewmaster fills a tank, called a mash tun, with water, then ignites a burner.

When the water heats to around 150 degrees fahrenheit, he pours in a blend of different types of malts.

Malts are cereal grains such as barley or corn which have been soaked to kick-start germination, then, once sprouted, dried with hot air to halt germination.

Stirring the malt into the hot water activates enzymes that convert the starches in the grain into fermentable sugars.

After an hour or so, he transfers just the liquid, called wort, to the boil kettle and gradually adds different varieties of hops.

He brings the wort to a boil to kill off bacteria and sterilize it.

Next, he cools the wort and transfers it to the fermentation tank.

Then he adds yeast.

Over the next 10 to 14 days, the yeast consumes the fermentable sugars in the wort, converting them into alcohol and producing carbon dioxide gas, which creates bubbles.

This process transforms the wort into beer.

At the coffee company, the hot coffee beans must be cooled quickly after coming out of the roaster so that they don't overcook.

This perforated cooling pan stirs the beans to help dissipate the heat, then a commercial coffee grinder grinds the beans into coarse-ground coffee.

To prepare coffee for the vinobrew, a worker puts grounds into a filter bag, saturates the bag with cold water, then submerges the bag in water, letting the grounds soak for about 16 hours.

Then he pours the coffee into a large jar.

At the winery, winemakers harvest and press the grapes, add yeast and ferment them, then age the port wine for at least 2 years in oak barrels.

To prepare to make vinobrew, the winemakers test samples from different barrels for acidity and sweetness to help decide which wines to potentially use.

The winemaker and the coffeemaker then experiment with amounts of those wines and different cold-brew coffees made from various types of beans.

The brewmaster also joins in, measuring out beer.

This process is as much art as science.

For each batch of vinobrew, the respective makers play with a selection of ingredients and with the proportions, tasting and smelling the samples to evaluate aroma, sweetness, bitterness, and acidity.

What they try to create is a harmonious blend of the three elements, a new flavor without the taste of any one element dominating the others.

Once they pin down the winning formula, they replicate it on a large scale for production.

The winery pumps the selected wine from storage tanks into barrels for transport to the brewery.

At the brewery, the brewmaster pumps the required amount of wine from those barrels into a blending tank.

He pours the required amount of cold-brewed coffee into the blending tank.

Then he pumps the required volume of beer into the tank.

Beer makes up the largest proportion of the recipe, followed by wine, then coffee.

After blending the ingredients in the tank, the brewmaster pumps the vinobrew into a beer keg.

Then he injects carbon dioxide gas to add more carbonation.

When you pour a glass of vinobrew, the bubbles rise to the top, producing foam known as beer head.

But while this might look and feel like regular beer, one sip tells you that vinobrew is uniquely different.

To refinish a hardwood floor, one has to sand it with a floor-sanding machine.

After a few thousand hours of operation, the machine's drum, which drives the sandpaper, wears out.

The contractor can either replace it with a new one or send the worn one out to be reconditioned.

This company specializes in reconditioning worn sander drums, that means restoring them to like-new condition.

A drum can be reconditioned as many as eight times before it has to be replaced.

The first step is to grind off what's left of the aluminum drum's worn rubber surface.

It gets worn down due to the drum rotation speed of up to 2,600 revolutions per minute and often gets damaged by running over protruding nails or carpet tacks.

A worn drum doesn't hold the belt of sandpaper taut, which causes the machine to slip to the left and right, rather than sand smoothly in a straight line.

A worker places the drum on a press to detach the arbor shaft, which attaches the drum to the sanding machine.

When the drum was new, its aluminum sides were freshly painted.

That paint is now mostly worn away.

Sawdust and rubber residue fill the drum's nooks and crannies, so a worker places the drum inside a sandblast cabinet and puts his hands through gloves that reach inside.

He holds the drum in one hand, a sandblasting nozzle in the other, and in a few minutes, the drum is pristine.

But it still has an ever-so-thin layer of rubber remaining, so another worker mounts the drum on a lathe and shears off the rubber with a knife.

Then he passes the knife again, removing a mere tenth of a millimeter of aluminum.

This exposes a new smooth aluminum surface.

Then a worker cuts a sheet of brand-new rubber to the exact length needed to cover the circumference of the drum.

The rubber is nearly two-thirds of an inch think, roughly twice the thickness of the worn layer they grinded off.

After clamping it down flat, the worker applies an adhesive designed for rubber.

Then he sprays an accelerant onto the drum's primed surface to strengthen its bond with the rubber.

He lets the accelerant dry for 6 hours, then spreads a second coat of adhesive on the rubber and wraps it around the drum.

Twenty-four hours later, with the adhesive cured, another worker mounts the drum on a lathe and trims off the excess rubber from both sides.

He then sands the trimmed edges to make them perfectly flush with the sides of the drum.

The drum goes back on the grinder now to finalize the overall diameter of the drum.

Using a ruler, a worker adjusts a measuring instrument, called a caliper, to the diameter measurement.

He then grinds down the rubber a bit at a time, spot-checking with the caliper regularly.

The worker stops grinding once the caliper check tells them the drum diameter is correct.

If a sanding drum isn't perfectly balanced, it vibrates and disfigures the floor, so a worker mounts the drum on a balancing machine.

He applies a band of masking tape and draws a black line on the tape to give the machine a reference point from which to start measuring.

As the machine rotates the drum, a sensor measures velocity on both sides simultaneously.

If the velocity is inconsistent on either side, he balances the drum by adding or reducing weight on the problem side.

To reduce weight, a worker drills a hole to remove aluminum.

To add weight, he fills the drilled hole with tin, a metal that's far heavier than the aluminum he removed.

The final step is to repaint the sides.

A worker masks the rubber with a template then sprays the aluminum with rust-inhibiting metal paint.

Now this main component of a floor sander is as good as new, ready to bring a worn wood floor back to life.

Lithography was discovered when german playwright alois senefelder had no paper handy for writing a laundry list.

So he wrote it down on a stone using a grease pencil and stumbled onto a new method of printing, one that relies on the chemical aversion of grease and water.

Lithographs can rival paintings for detail and mood.

They have a unique visual quality, and that's why making them hasn't become a lost art.

A lithograph starts with a flat limestone slab.

The artist confirms the same thickness all the way around the slab.

She now resurfaces the stone using a grinding tool called a levigator.

She wets down the surface of the stone and the levigator to allow the levigator to move freely across the stone during grinding.

The artist sprinkles silicon carbide grit on the stone.

She spins the levigator across the stone and, together with the grit, it grinds off the top layer.

This process removes the previous drawing and preps the stone for the next one.

She finishes the grinding with a finer abrasive to give the limestone a smooth finish.

Once the residue has been rinsed off, the stone is ready for a fresh image.

She brushes a natural gum, called gum arabic, around the edges, creating a border that will be receptive to water but not the printing ink.

This process makes a non-image area.

The artist marks up a piece of paper with a crayon made of wax, charcoal, and clay.

She places the paper on the stone, crayon-side down, and sets a drawing upside down on top.

She tapes the drawing to the stone.

She now follows the lines of the figure on the paper with a pencil, pressing firmly.

This transfers the drawing to the stone and creates a reversed image on it.

The artist simulates specks of snow, with a technique called stippling, with gum arabic and a brush.

She fills in the drawing using a greasy crayon.

The stone picks up and holds the greasy substance.

These crayons come in varying degrees of hardness.

Once the artwork is complete, she dusts the image with rosin which is a tree sap powder, followed by a talc powder.

This will ultimately protect the image during etching.

The artist then brushes gum arabic onto the art to protect the stone from the corrosive nature of the etching material, a mix of nitric acid and gum arabic.

This mixture alters the surface of the stone so that the image areas will attract ink, and the non-image areas will repel it.

She places a sheet of paper on the print stone and applies lubricant to the bottom of the scraper bar on the press.

She spreads more lubricant onto a tympan, a thin sheet of durable plastic, that she's placed on the paper-covered print stone.

This allows the stone to slide under the pressure of the press.

The artist moves the sliding press bed forward so that the lithography stone sits directly under the scraper bar.

She turns the mechanism to tighten the bar to the stone.

She moves the press bed forward to test the pressure of the scraper bar.

She confirms that the pressure is sufficient for printing but not too tight.

Satisfied, she removes the tympan.

She washes the crayon from the stone using highly refined mineral spirits.

What remains is a ghost of the image.

The artist then rubs a petroleum-based substance onto the stone that will serve as a base for the ink.

The substance attaches to the image on the stone.

Using a big leather roller, she picks up oil-based ink.

An assistant dampens the stone with a wet sponge.

The artist transfers the ink to the damp stone.

The greasy parts of the stone pick up the ink while the wet parts don't.

The assistant moistens the stone again.

The artist places a sheet of print paper cut to size over the image.

She covers the stone with clear plastic tympan.

The press bed rolls forward until the stone sits directly under the scraper bar.

The preset bar applies the exact pressure needed to print the image onto the paper.

The artist carefully lifts the paper, revealing a perfect mirror image of the art.

Using the same stone, she can make hundreds more, each one a work of art.


Giant Valves
Sardines
Barographs
Disposable Diapers

Valves control the flow of liquids and gases through pipes and tubes.

They're so much part of our lives, we hardly think twice about them.

But a faulty valve in an airplane or chemical plant could be catastrophic.

Valves must be precision-made and trouble-free, whether it's small enough to fit inside the human body or as big as a car.

Many gate valves use handwheels to control the flow.

Turning this wheel opens or closes a gate or wedge inside the valve body.

This giant 11-ton gate valve works the same way.

It will receive an internal gate or wedge that starts and stops the flow of liquids or gases.

First, an automated horizontal boring mill prepares the valve body for assembly and for a controlling mechanism.

It takes a controlling mechanism or motor, not a handwheel, to open and close a wedge that weighs about 3,300 pounds.

An automated drill pilot drills the flange of the valve body.

This centers the holes used for the bolts that will connect the valve cover.

A technician double-checks to make sure the holes are in the right place.

Then an automated spade drill starts penetrating the flange.

Coolant prevents the steel from heating up and removes steel chips from inside the perfectly centered holes.

Meanwhile, the wedge is ready.

A propane torch preheats the wedge for the plasma-arc welding machine.

This machine hard-faces the sealing surface of the wedge, a process that ensures minimal wear.

Hard-facing creates three rows of weld beads, which will be machined smooth.

Before installing the wedge, a technician inserts a seat ring into the valve body.

A seat ring helps ensure precision fit with the wedge.

The ring fits into the grooved body cavity.

Then the technician sets another seat ring into place.

Before the wedge goes in, a semiautomatic welding machine welds the two seat rings into place using a rotating positioner.

Then a lapping machine inserted into the valve body polishes each seat ring to guarantee their finish is flat and smooth.

Next, a crane lowers the machined wedge into the body cavity.

Using a gauge, a technician verifies the gap.

He repeatedly checks to see what adjustments the wedge may need to ensure a tight shutoff.

Another technician installs a sealer gasket to prepare the valve body for the cover or bonnet.

Now he begins final assembly.

A fully adjusted wedge with the stem attached fits perfectly in between the two seat rings.

This stem will connect to the controlling mechanism that opens and closes the valve.

A crane lowers the bonnet with attached yoke assembly onto the body.

Its studs fit exactly into the holes that were drilled into the valve's flange at the start.

A technician readies all the bolts for machine tightening.

Then he greases the top part of the stem.

He lowers the controlling mechanism onto the stem, and he screws it into place until it's flush with the yoke, the top part of the bonnet.

A technician then bolts the controlling mechanism onto the yoke.

Finally, another technician spray-paints the fully assembled gate valve with a protective coat of corrosion-resistant paint.

Precision-made gate valves are expertly crafted.

They come in all shapes and sizes and are equipped with controlling mechanisms or handwheels.

From refineries and nuclear power plants to submarines and aircraft carriers, gate valves are helping our world run safely.

The health benefits of eating fish are always under study.

Today, it's said that most fish, like sardines, are a good source of vitamins, minerals, and omega-3 fatty acids.

If you want to make healthy eating choices, you need to stay informed, so seeing how these little guys end up on your kitchen table is a good way to start.

Sardines from the pacific coastal waters off of costa rica are freshly packaged in a variety of tasty flavors.

It starts when sardines are put into a vat of icy water to keep them fresh.

The temperature of the fish must be kept below 41 degrees fahrenheit to avoid spoiling.

The fresh sardines then go through a machine that deposits the fish onto sorting lanes.

Each lane allows a certain sized fish to fall through the gap onto a chute below.

Sorted as small, medium, or large, the fish drop into the proper container.

Then workers load a specific size of sardine into a machine that removes the scales.

Removing the scales takes 3 to 11 minutes, depending on the size of the fish.

Once done, there is no mistaking a sardine with or without scales.

Workers then place descaled sardines onto trays that take them into a cutting machine.

They arrange the sardines on the trays in such a way that blades inside the machine will cut off the heads and tails.

A look inside the cutting machine shows how it removes the heads and tails and sends them on their separate ways.

It also cuts open and cleans out the bodies of the sardines and readies them for packaging.

The packing cans travel by conveyor to a work station, with their bottom side up and open.

They fill the cans manually to decrease the possibility of introducing foreign matter into them.

The worker draws on his experience to estimate the required weight, then stuffs and trims the fish to fill the cans one by one.

To be sure each can is exactly the right weight, he weighs and adjusts the amount in each tin.

In only a matter of minutes, he completes a set of cans.

Then another worker turns the set over and sends the open-bottom cans into an oven that cooks the sardines at about 212 degrees fahrenheit.

After cooking for about 25 minutes, a worker turns the set of cans over again and transfers them onto a conveyor system.

All the cooked sardines gradually funnel into a single file, and depending on the product, a filling machine treats them to oil or a specific flavor of tomato sauce.

The filling machine overfills the cans with sauce, but a flute hidden inside the machine removes just enough sauce to put the lids on properly.

The machine pressure-seals the lids onto the cans so that when they exit the machine, they're airtight.

The traveling cans then enter a machine that washes them in about 194-degree water and makes them spotless.

Pallets of cans then go into a chamber that sterilizes the product to keep it fresh.

Then the cans go into a labeling machine that applies a thin coating of glue and precut paper labels onto each one.

The finished product comes out of the machine with an attractive full-color label, ready to ship to the customer.

Sardines come in a variety of flavors with easy-to-open packages that maintain the freshness of the fish.

Ancient civilizations tried to forecast the weather by observing cloud patterns or even using astrology.

Today, we rely on instruments like the barometer or the barograph, which automatically records on paper the variations in atmospheric pressure.

High pressure indicates good weather.

Low pressure means bad weather is likely.

This barograph has three main parts-- the recording arm, the cells that react to atmospheric pressure, and a rotating drum.

To make the drum's lid, a die-press operator stamps out a 3½-inch disk from a long strip of brass.

He cleans off the grease from the die press and places the disk on another press to form an edge.

To make the drum, he cuts a 4-inch-long cylinder from a brass tube.

Next, he places the drum on an arm that rotates at high speed.

He etches fine lines into the brass using steel wool.

Thanks to a handy rotating device, all the drums get an even coating of protective lacquer so the brass doesn't corrode.

The barograph's mechanism rests on a solid brass plate that's 8½ inches long by 5 inches wide.

A worker greases each one and then places them on a press that punches out the holes for the fastening screws.

Next, he places the plate in a metal holder and buffs it with a rotating polishing brush.

He applies wax to the brush to help achieve a perfect mirror finish.

Now workers use a fine grade of sandpaper to polish the solid brass arms that will hold the working parts in place.

Then they line them up on a board and buff them with a polishing brush.

How do they get those parts so shiny?

By washing off any machine grease before polishing them.

Putting the barograph together is precision work.

Laid out before the assembler are all the working parts she will need.

She begins with an arm, inserts a brass screw, then sets in a second arm and attaches them to the baseplate.

These hollow metal cells are the key to the mechanism.

Air pressure makes them expand and contract.

The barograph records this movement to measure high and low pressure systems.

The cell stack is put in place on the baseplate.

Then they add the lever system that connects the recording arm to the paper.

This lever system connects to the arm, raising and lowering it so the felt pen at the tip can record changing air-pressure levels on the drum's rotating chart.

The assembler inserts tiny pins to hold it together.

Inside the drum's base is a battery-driven quartz clock, which maintains a steady rate of rotation.

Now she wraps the chart around the drum and attaches a brass clip to hold it in place.

The drum rotates once over a seven-day period, so slowly that the movement is invisible to the naked eye.

There's a gear system inside the drum, which rotates it once it's set on the axle.

A brass screw holds it in place.

Now the worker puts the mechanism on a mahogany base.

She screws it into place, then covers it with a glass and mahogany housing.

Brass hinges and a closing mechanism hold the housing firmly in place and provides easy access.

A quality controller places the barograph into a pressure-sealed chamber to check its accuracy.

He compares the barograph's recordings to gauges outside the chamber that measure the changes in air pressure that he applies inside the chamber.

This weekly chart shows hour-by-hour recordings of air-pressure variations measured in hectopascals, a unit of atmospheric pressure.

Barographs are available in a variety of designs, from modern to traditional brass and mahogany models that any sailor would be proud to own.

Parenthood has many joys, but a dirty diaper isn't one of them.

And that's why we have disposable diapers.

They were first introduced in the 1940s for travel use.

It took several years for the idea to catch on.

But when it did, diaper duty was never the same.

Many would say disposable diapers represent a change for the better, helping parents make the best of a messy business.

They start with superabsorbent polymer particles, which drop into a forming chamber.

Pulp unwinds into the same chamber.

A spray of water helps suppress any static electricity that could interfere with processing.

Inside, the pulp mixes with the polymer particles.

The result is this fluffy absorbent material that will be the diaper core.

This rotating drum has a vacuum that shapes the fluffy material into padding.

Another vacuum drum then merges the padding to a moving web of fabric.

Guides fold the fabric around the padding, and a hot adhesive seals it.

At this debulking station, rollers compress the padding, making the diaper core slim enough to comfortably fit a baby.

A cylindrical cutter slices the diaper core to size.

At another station, plastic film winds around guides and merges with another stream of fabric.

Machinery glues the layers together to form the diaper's back side.

Next, equipment pulls elastic bands into other layers of fabric to make leg cuffs and outer gathers on the top portion of the diaper.

The elastic will ensure the diaper fits snuggly, preventing leaks.

Each diaper will be equipped with a set of these front tabs punched out by this rotating die.

This cylinder applies stretch side panels to the top part of the diaper, which has the leg cuffs and gathers.

The absorbent core now meets up with the back side of the diaper.

And then the other layers come together and adhere.

A computerized system monitors the assembly.

Incredibly, it takes less than a quarter of a second for all the layers of the disposable diaper to be assembled.

The diapers now travel past guides that fold down the tabs and side panels.

The diapers are then cut into individual units.

Again, belted rollers compress the completed diapers.

Paddles then fold them in half.

Conveyor belts relay the folded diapers to a carousel.

Finger paddles separate them and position them for packaging.

Sensors count the diapers as they move toward compression arms that squeeze the required number together.

A pusher swoops in to slide the diapers into a bag.

Vacuum arms open the bags right on cue.

Hot bars seal the package full of diapers.

It then moves down the line to be packed into boxes for shipping.

Each disposable diaper has a phenomenal capacity to absorb liquid, and the key is those polymer particles.

They act as tiny gel sponges, expanding to hold many times their weight in fluid.

Cut open a wet diaper, and you'll discover the liquid has turned the solid particles into gel.

The proof is in the weighing.

For example, this dry diaper comes in at about an ounce and a half.

When wet, it weighs over 18 ounces.

And that's the bottom line.


Sawhorses & Toolboxes
Sorbet Pops
School Buses

When it comes to construction, renovation, or simply repairs, whether you're a seasoned pro or a do-it-yourselfer, having the right tools makes the job easier.

Sawhorses support the piece of wood you're cutting, and a toolbox keeps your implements organized and portable.

Sawhorses are always sold in pairs because you need two under a piece of wood to stabilize it for cutting.

By pulling the hinged tray upward, the sawhorse collapses flat for transport and storage.

This model is made from pellets of an exceptionally strong type of polypropylene plastic.

A vacuum system draws the pellets into an injection-molding machine.

The machine melts them then shoots the liquid into a mold.

It takes about a minute for the liquid to solidify, at which point the mold automatically opens, and an articulated robotic arm removes the parts-- for each sawhorse, two halves, the legs, and two panels which form the collapsible hinged tray that holds those legs open.

The robot drops those parts at the first assembly station, where a worker joins each panel to a sawhorse half and applies non-slip footpads.

These pads help keep the sawhorse stable and protect the floor from scratches.

The worker lays out the parts for both sides of the sawhorse in a positioning fixture then activates the press a couple of times to snap the parts together.

At the next station, a worker inserts ribbed rubber pads into molded holes on top of each sawhorse half.

These anti-slip pads help hold large pieces of wood steady on the sawhorse.

Next, he lays both sawhorse halves on the work table and with a tool called a stamping arm, snaps the two panels together.

This forms a strong hinge, which opens and collapses the tray.

The sawhorse is now finished and heads to the packaging station.

There, a worker stacks two sawhorses, then, with a foot pedal, activates a machine which binds them with a plastic strap.

Then she tapes on a wrap-around label.

Have tools, will travel.

This two-piece toolbox consists of a large storage tub on the bottom and a spacious toolbox on top.

Like a rolling suitcase, it has two large polypropylene wheels with molded-on rubber treads and a collapsible pull handle.

A toolbox doesn't have to withstand pressure bearing down on it, so it's made of standard, rather than high-strength, polypropylene.

The injection-molding process is the same.

The storage tub, the toolbox bottom, and the toolbox lid are each molded separately.

In the assembly area, workers apply an adhesive label on the front of the toolbox then install the latches for locking the lid.

The latches slide into molded slots.

After inserting a removable tray, workers install the lid with a few strikes of a non-marring urethane hammer.

Both lid and latches snap in easily because the polypropylene is still hot and flexible.

Once it cools and becomes rigid, the lid and latches can't dislodge.

To assemble each wheel, workers position a star nut and steel axle into the wheel, then, with an assembly ram, press the axle into the star nut to lock the parts together.

They snap a wheel onto each side of the tub portion of the toolbox, then, with a press, force the wheels into their final locked position.

Once the toolbox and tub portions are each separately assembled, workers hang a parts tray on the rim of the tub then sit the toolbox on the tray and lock it in place with two large side hinges.

And that completes construction of this workshop on wheels.

Traditionally, sorbets have been dished up between courses to refresh the palate, but served in a squeezed-up pop, a sorbet becomes a snack you can grab anytime-- no need for scoops, spoons, or dishes.

Just squeeze the sorbet out of the paper sleeve.

Now that's refreshing.

A long favorite of foodies, fruit sorbet has gone mainstream with these squeeze-up pops.

More fun than a few scoops in a dish, sorbet pops are also lower in calories than a lot of other snacks.

They start with freeze-dried rice syrup.

They pour it into a mixing vat that's a mega version of a home blender.

They add strawberry puree.

This is the main ingredient of the sorbet pops.

The berries were pulped within 12 hours of harvest.

The next ingredient is cane sugar.

It's followed by strawberry essence-- compounds extracted from the berries for more intense flavor.

They turn on the tap for the final ingredient-- water.

It's time to close the lid and power up this industrial blender.

The mixer has four blades that turn at a high velocity.

They whip up the sorbet ingredients to the consistency of a fruit smoothie.

The sorbet mixture then flows into refrigerated pipes that chill the mixture to 40 degrees fahrenheit.

The pipes wind around the factory and finally deliver it to holding tanks.

Inside, an agitator swirls the chilled mixture to maintain the smoothie-like consistency.

Once a tank is full, a technician tests the acidity and the level of suspended sugars in the mixture.

If the levels are right, they transfer the mixture into a continuous freezer.

It pumps air into the sorbet mix, and it churns and scraps it against the freezing-cold walls of the machine.

Cool water runs through the motor to keep it from overheating as it freezes the sorbet.

This is only a partial freezing to keep the sorbet soft enough to be pumped into the paper squeeze tubes.

A device with little robotic fingers pries the papers tubes from a stack and deposits them in slots in a moving tray.

The tubes are in position to receive the partially frozen sorbet, and because the sorbet is only partially frozen, it is able to now flow through conduits.

Frozen solid, it couldn't make the journey to the squeeze tubes.

As the sorbet is pumped into the paper sleeves, its temperature is critical.

It is precisely 37.8 degrees fahrenheit.

One degree cooler and it would be too thick to pump.

A degree warmer, and ice crystals would form during the final freezing.

The next machine collects foil lids from a pack, using rubber heads with tiny magnets in the center.

It deposits the lids onto the sorbet-filled tubes.

The foil lids stick to the glue-coated rims.

This line fills 280 paper sleeves with fruit sorbet per minute.

That's just under 17,000 per hour.

An iron applies heat to the lids to further melt the glue and provide a water-tight seal.

It happens fast so the sorbet doesn't have time to start melting.

Sealed and partially frozen, the sorbet pops cascade into crates.

Each one holds about 100 pops, so they don't need to keep count.

And then it's into the blast freezer, also know as the shock freezer.

Fans circulate the cold air to rapidly lower the temperature of the sorbet pops, bringing it down to -24 degrees fahrenheit.

This fast freezing prevents the formation of large ice crystals that would damage the consistency and flavor of the sorbet pops.

Out of the freezer, a mechanized arm grabs and opens cardboard boxes.

A pusher shoves the sorbet pops into the boxes.

And they're ready to grab and squeeze.

The big yellow school bus puts millions of children on the road to an education.

It all started in the 19th century with horse-drawn trucks known as kid hacks.

The word "hack" was short for hackney carriage.

In the 20th century, they were motorized and became known as school buses.

Every school day, children across north america wait for the school bus.

Appearance-wise, it's hard to miss.

Big and yellow, it is deliberately conspicuous, designed to stand out in traffic so other drivers slow down and take notice.

Manufacturing starts with a support structure-- the steel underframe.

They arrange several short rails down the top of two long frame rails.

These cross rails will link the long rails and provide strategic support.

Using the lift, they raise the long rails, and the cross rails slide into position just under the rims of the long ones.

Now, in a fixture that pins the rails together, workers bolt them together.

With the school-bus underframe assembled, they roll in two enormous wheel axles complete with brakes.

Overhead cables lift the bus frame and workers guide it into place on the axles.

They attach the axles to the frame with metal brackets, shackles, and spacers where needed.

The chassis is ready for the engine.

They lower it onto the front of the frame and secure it with bolts.

The school-bus engine packs a lot of power.

It's diesel-fueled with six cylinders.

Next up is the front cal assembly, which includes the instrument panel and steering column.

A workers wires the steering wheel to the controls in the column and slides it into place.

They mount the tires and rims-- four on the back axle to handle the heavier passenger load and two on the front.

Using a multi-pronged tool, the worker tightens numerous nuts to fasten the wheels to the axles.

They now encase the engine with a fiberglass hood.

The hood has been pre-painted and equipped with cross-view mirrors and headlights.

They bolt it to the vehicle frame, and after adding antifreeze and coolant, the bus is technically drivable.

They roll it over to a test station to check the brakes.

The wheels turn on rollers so the bus runs in one spot.

A computer monitors the performance of both the front and back brakes as a driver applies them.

They now move on to build the school-bus body.

The body starts with the floor.

They unwind double-sided galvanized steel into a machine that slices it into panels.

It also cuts holes to be used for assembly.

A forming machine folds the sides to create support beams.

Two more steel beams will really stiffen the floor panel.

A worker positions those beams on the panel, and an automated machine welds them to it.

It feeds the floor panel to the welder incrementally so it can spot weld down the length of the beams.

It takes dozens of welds to solidly secure the steel supports.

And with those reinforcements, the floor panel is complete.

It's ready for assembly.

Workers arrange several panels upside down in a precise configuration.

Then it's into a second automated welder that joins them to make one school-bus floor.

After manually welding pockets for wheels, a machine called the floor flip picks up the bus floor and turns it rightside up.

They're now ready to build the passenger compartment, so stay tuned.

A school bus transports precious cargo-- children.

To hold the average bus together, they use an incredible 6,100 rivets, bolts, and screws and make a total of 840 welds.

For the maker of school buses, there's strength in those numbers.

To build the frame for the school-bus walls and ceiling, they bend steel beams into bow shapes.

A hydraulic machine with pushers does the job in seconds, achieving an exact radius.

The bows will serve as ribs for the school-bus body.

They make several bows for each bus.

The precise number depends on the bus size and capacity.

Workers plug the ends of the bows into holes in steel rails and secure them with bolts.

They weld lateral supports higher up, and the cage-like skeleton of the school bus takes shape.

They're now ready to build on this framework.

They attach the metal windshield surround.

The team then moves the steel side sheets and skirting into place.

They secure these panels with super-strong adhesive and numerous rivets.

Using cables and nylon straps, they pull steel sheets to the roof structure to make them conform to the contours.

The steel is 20-gage-- a grade that's flexible enough to be easily bent.

The cables hold the steel panels tightly to the roof structure while the workers rivet them to it.

The number of rivets and the strength of the joints are among many government safety standards the school bus must meet.

Working from the inside, they glue fiberglass insulation into the pockets of the cage to keep the bus warm in winter and cool in summer.

The insulation will also muffle road noise and absorb some of the student chatter for a quieter ride.

The team installs steel panels on the ceiling.

These panels have tiny perforations to allow sound to escape into the insulation.

They tape up the windows and doors and sand some areas as they now prepare to paint the exterior of the bus.

The paint, national bus yellow, takes the metal from dull to bold.

This shade was developed specifically for school buses and can be noticed even with peripheral vision.

With the paint now dry, they open the doors and lay a plywood subfloor inside.

It too will absorb noise.

An employee drives the chassis over to the school-bus-body production line, and parks it.

Using cables, they lift the bus body over to the chassis.

At over three and a half tons, it's hefty.

They gently lower it onto the frame rails and mate the front to the hood.

They tie the body to the frame with heavy-duty clips.

They arrange the seating to surround the passengers with cushioning.

This creates compartments around the occupants to protect them in a collision.

Outside, a worker applies school-bus lettering.

Another worker presses an adhesive-backed manufacturer's emblem to the hood.

They equip the bus with the flashing lights and stop signs to get the attention of other drivers when children are loading and unloading.

They also install a crossing gate to keep children within the bus driver's sight line.

They test all of the warning lights and safety devices.

And satisfied that everything is operational, the bus rolls off the production line.

It's taken a day and a half to build it, and when it comes to an education, it's ready to deliver.


Compact Discs
Mozzarella Cheese
Pantyhose
Fluorescent Tubes

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

Compact discs...

Mozzarella cheese...

Pantyhose...

And fluorescent tubes.

Today there's virtually no limit to the information we can store on compact discs.

Millions of bits of data representing words, numbers, music, graphics, or even video can be stored on the discs.

Let's take a "spin" through a cd factory.

Compact discs are copies made from an original glass master disc.

A thin plate of glass is first placed in this unit, which brushes the surface clean.

Cleaning is done with de-ionized water and a small goat-hair brush.

The excess water is eliminated by the rapid rotation of the disc.

The disc then goes into this surface analyzer, where a laser beam inspects the cleanliness of the surface.

At this stage, two chemicals are applied-- a primer and a photoresistant coating.

This operation is done at a temperature of 70 degrees fahrenheit and lasts three minutes.

The disc is carefully retrieved from the apparatus.

Then the photoresistant coating dries in an oven for 30 minutes.

This developer has two spouts.

One applies a de-ionized water, and the other sprays a solution to develop the data etched on the glass.

The information is now engraved on the disc.

Then the disc is placed in this metal-coating equipment.

The next step consists of applying a thin coating of nickel and vanadium.

This electroforming process results in the master from which discs will be made.

The etched glass is immersed in a chemical solution for 70 minutes.

Then the plated piece is removed, thus obtaining a die.

The die is sent off for finishing.

It is stamped out into the desired shape.

The excess material is recycled.

Next, the compact discs will be fabricated from this master unit.

Here we clearly see the stamping-out technique.

The master is taken out.

A technician peels off the film which protected the data etched onto the die.

After a visual inspection, the die is sent to the pressing department.

The die is delicately installed in the mold, which will form compact discs.

Discs are made from a very special plastic called "polycarbonate".

The mold is closed, and liquid polycarbonate is injected into the die.

It comes out as a small, hard, translucent disc.

It is now ready to be metal-coated so it can be read by a compact-disc reader.

A robotic arm lifts the disc from the mold and places it on these supports.

This metallizing process is extremely short and very simple, taking but a second.

It consists of covering the plastic disc with a very thin coating of aluminum.

Here we see the inside of the mold, where the aluminum coating is applied.

In this facility, almost everything is automated, helping them produce over 100,000 compact discs per day.

Protecting the surface of the disc is essential, so a coat of varnish is applied.

This also helps silk screening stick to the surface.

Ultraviolet lamps quickly dry the varnish.

And here in the pressing room, they apply the label.

This step is also very fast since the machine prints 70 discs in 60 seconds.

Once the silk-screening is completed, the finished discs leave for packaging.

In a sandwich, as a topping, or all by itself, cheese has always been a popular food.

This dairy product goes back thousands of years, and it's always started with three basic ingredients-- milk, curds, and whey.

Just ask little miss muffet.

Like all cheeses, mozzarella starts from milk.

To assure good milk quality, the interior and exterior of milk-transport trucks must be washed after being emptied.

A tank such as this one can carry an average of 8,000 gallons of raw milk at temperatures between 37 and 39 degrees fahrenheit.

Raw milk destined for cheesemaking contains 3.8% fats and 3.3% proteins.

They store the milk and whey, a milk by-product, in these immense silos, each with a capacity of 59,000 gallons.

This milk separator extracts surplus cream to adjust the percentage of fat according to the type of cheese to be made.

Fabrication begins with this tank, which feeds the pasteurizer.

Pasteurization sterilizes beverages which can easily ferment.

Milk samples are drawn off to accurately determine their milk-fat and protein content.

Tests are carried out in this laboratory, where they impose controls.

These test tubes contain milk samples which will undergo microbiological analysis.

Milk quality must be impeccable.

This is a curdler with a capacity of 6,600 gallons.

Here milk and other essential ingredients are introduced, such as the enzyme, rennet, that curdles the milk.

This mix must be well-stirred and cooked.

The agitators are used to cut the whey into little lumps.

This step takes about 30 minutes.

The temperature of the tanks depends on the type of cheese they're making.

Agitators continue stirring the milk.

Once cooking is done, the whey is pumped onto tables to be drained.

It stays there for about 25 minutes.

The solid and the liquid are now well-separated.

The liquid we see draining is called the "lactoserum".

The lactoserum will be concentrated and transformed into milk by-products.

The water has been almost entirely extracted, and the cheese particles are now sufficiently dry.

This large automated blade then moves cheese particles towards the next step-- the molder.

In the molder, the cheese is cut up before being carried to the cooker-- the final processing step.

It appears that this mozzarella has just the right texture.

The cheese finally arrives at the molder, which will give it the proper shape.

Each mold has a 5 1/2-pound capacity and is rectangular.

Brine, a salt solution, cools and salts the cheese blocks.

The blocks are unmolded and fall into a brine tank.

The cheese blocks will remain in another brine solution for a while.

Then they're carried by a conveyor towards another tank, where they will be immersed for 4 to 10 hours at a temperature of 36 degrees fahrenheit.

Sprays of brine remove the foam which forms at the surface of the tank.

The 8,000 gallons of milk we saw coming in by truck at the beginning have enabled the factory to produce 1,400 blocks of cheese in 8 to 12 hours.

Finally, the cheese blocks are vacuum-packed and ready for shipment.

There was a time when women wore silk stockings.

Then came the invention of pantyhose, a cheaper, more convenient alternative.

Pantyhose are knitted from strands of raw nylon.

It's no "stretch" of the imagination to say that when they go on sale, there's usually a "run" on them.

Making a nylon stocking takes only a few minutes.

However, it's a complex operation that involves the knitting of five to eight threads as fine as a hair.

The threads, usually nylon and spandex, are used along with elastic.

Sometimes polyester or cotton are added.

The knitting machine goes into action.

This one fashions a tube for sheer stockings in 90 seconds.

In three minutes, it makes a tube for tights.

Its speed is adjusted according to the product being made, varying between 750 and 1,200 revolutions per minute.

Once the tube is knitted, it is sucked up and lands in a bag, where it will be inspected.

More than 500 machines share the work, each making a specific model.

The two ends must now be joined.

This automated machine assembles the two tubes together to form the pantyhose.

Then scissors cut the pantyhose, a necessary step in production of a pair.

This opening is enlarged to allow for sewing, which will join the two tubes at the top of the leg.

The label with the size or brand name is sewn in place in 10 seconds by this robotic machine.

At this pace, it sews on 4,800 labels in 8 hours.

Installing a gusset requires some preparation.

Scissors makes a hole at the joining point.

Then the stocking is turned inside out by suction so certain stitching can be done on the inside.

Thus, these stitches will be less visible.

Now the foot must be sewn.

This robotic machine places the foot in position.

Then a sewing machine makes stitches at the same time it cuts away excess material.

This step takes only 10 seconds.

Then the pantyhose is turned right side out, again using suction.

Everything is ready for installation of the gusset.

The pantyhose is placed in a tub and taken to this department.

The stocking is again suctioned and placed on a gusset machine by the operator.

This method assures that the gusset will be well-centered without a pleat.

Putting in the gusset is the final operation in the process.

A precut piece of cotton is slid into the space reserved for the gusset and automatically sewn in.

Only aesthetic touches remain, such as adding a little color to the pantyhose.

They're placed in this machine, which has a large drum with four compartments and a 99-pound capacity.

The pantyhose are washed in soapy water, then immersed in dye.

Temperature climbs gradually to 200 degrees fahrenheit.

After a 5-minute rinsing cycle, a softener is added.

This process takes 2 1/2 hours.

Once dried, they proceed to inspection.

The pantyhose is placed onto a form which stretches it to allow inspection for any imperfections.

If all is well, the pantyhose is transferred onto another metal form, where it will be pressed.

The pantyhose's position is guided by a magic eye.

The pantyhose is then carried toward a steam room, where it will stay for 2 1/2 seconds before being dried in 7 1/2 seconds at 280 degrees.

They fold and pack 420 pantyhose per hour and make 180,000 pairs per day.

Throughout the ages, artificial light has let people extend the convenience of daylight long after the sun goes down.

Fluorescent tubes are more energy-efficient than light bulbs.

That's probably why they've become a "fixture," so to speak, in stores, factories, and offices.

Once, the only source of light was the flame of fire in the forms of torch, candle, and oil lamps.

It remained so right up until the 19th century, when gaslight made its first appearance around 1840.

Almost 40 years later, thomas edison invented his famous incandescent light bulb.

In 1909, the frenchman georges claude developed the fluorescent tube, a light that remains unaltered to this very day.

Did you know that mercury allows us to see in the dark?

The production of fluorescent lamps is highly complex.

The fabrication process starts with glass tubes that have been meticulously cleaned with warm water to remove dirt and impurities.

Then the tubes have to be specifically shaped with a folder-shaper.

They're heated for 30 seconds, then quickly curved using a template.

This automated machine can bend 14 tubes a minute.

The bent tubes go into the coating chamber, where a thin coat of phosphorus is applied to their inner surfaces.

Phosphorus produces light by transforming ultraviolet photons generated by the ionization of mercury.

The surplus phosphorus is removed from the ends of the tube to facilitate sealing.

They now move to the electrical components.

The cathode mount is made in this auto mount.

Here, they make the wire that will carry the current from the mount.

The wire carrying the current is shaped.

And here, the wire is heated.

This prepares it for the next step.

It's essential to prevent the cathode coating from spreading to the prongs.

The filaments are inserted into their mounts.

The emissive substance plays a crucial role.

When heated, it emits electrons, which participate in producing light.

The emissive substance is actually this liquid.

The wiring mount is transferred from the auto mount to the sealing machine.

At this stage, the wiring mount and the glass tube are joined.

Sealing is done at a very high temperature.

One important step remains.

This is where the glass tube is emptied of air and filled with gas.

This machine also decarbonizes the tube and introduces the drop of mercury essential for producing light.

Once the very tiny drop of mercury is injected into the tube, the fluorescent lamp is almost completed.

But one step remains.

This threader positions the wires for insertion of the tube cap, which establishes electrical contact.

The tube cap is placed into position in preparation for sealing.

The cap must be securely attached and installed in a watertight manner to eliminate any risk of leaking.

The capper permanently seals the cap onto the tube, and it's all finished.

Each lamp is tested on a large testing wheel to verify its quality and performance.

Once the meticulous inspection is over, the fluorescent lamps are carried to the packaging department.

A robotic machine handles the lamps and places them into the packages.

The glass tubes have now become fluorescent lamps.


Air Boats
Onions
3D Metal Printing
Curved Cabinet Doors

An airboat is a flat-bottomed vessel with a huge propeller at the back.

All of the boat's mechanics are above the water line, and just a bit of the hull rests below.

This makes the airboat the preferred mode of transport through shallow water, particularly marshes and swamps.

to steer an airboat, large vertical rudders direct the propellers' airflow.

At full speed, an airboat can hit 62 miles per hour.

The boat's hull is made of aluminum that's about 2/10 of an inch thick.

Workers stiffen the hull's bottom plate with aluminum "t" bars positioned 7 inches apart.

After they clamp the "t" bars, a jig descends to hold everything steady as workers weld on the strips.

Next, they weld on aluminum sheets to form the sides of the hull.

At the front, they push the bottom up for welding, giving the boat a curved bow.

They complete the hull by welding on a sheet across the back to form the transom.

To that, they weld a splash plate that prevents water from coming over the edge into the back of the boat.

Next, they weld various parts to the front of the boat to reinforce it structurally and to create a covered storage area.

Once that's done, they screw a thick sheet of high-resistance polymer to the bottom of the hull.

Should the boat scrape against a rock, this layer will shield the hull from damage.

Once that's secured, they paint the inside of the boat with a blend of epoxy and paint.

This forms a layer of what they call "webbing".

On the outside of the boat, they apply a coat of primer followed by two coats of durable marine paint.

Meanwhile, others have constructed and painted the boat's above-water structure out of steel or aluminum tubes.

The rigging, as the structure's called, supports the mechanics, two fiberglass seats, and the instrument panel.

They mount a belt-driven reduction unit to the boat's gasoline engine.

This unit reduces the propeller speed in conjunction with a preassembled set of gears.

Without it, the propeller would turn at the same rate as the engine.

This would exceed the propeller's operating limits and destroy it.

The engine is now ready to take its place at the rear of the rigging.

Heavy-duty bolts secure it.

Under the engine goes a 50-gallon fuel tank-- at the very back, an aluminum radiator.

Then they bolt the rigging to the hull's "t" bars.

Next comes a floor panel and a 3-passenger bench seat with a storage compartment underneath.

The boat's exhaust system consists of stainless-steel pipe, which attaches with band clamps to a header coming off the engine.

The other end leads to a stainless-steel muffler.

From that, an exhaust pipe runs out the rear of the boat.

Next, they mount the propeller guard, a stainless-steel safety cage that surrounds the engine and propeller.

The three propeller blades are made of carbon fiber.

Aluminum rudders steer the boat by directing the propellers' airflow.

Cables or rods connect the rudders to a control stick.

Smaller airboats, like this one, are ideal for hunting and fishing.

There are also much larger pleasure models that can carry 18 or more passengers on excursions.

Historians believe consumption of this common vegetable dates back to prehistoric times, when it grew in the wild.

Man eventually learned to cultivate onions, and this strong-tasting plant bulb became a food staple of many ancient civilizations throughout the world.

In ancient egypt, the onion was an object of worship, the inner structure of concentric rings symbolizing the eternal circle of life.

Today mechanical harvesters pull the bulbs out of the ground and lay them out in rows.

After drying for a day or two, a tractor collects them into large baskets for storage.

To prevent spoilage, the onions are stored at between 34 and 36 degrees fahrenheit.

When they arrive from the field, their first stop is a cooling tunnel from which powerful fans remove the heat.

The vegetables take about five hours to cool down to the storage temperature.

The grower separates the onions according to variety and size, then either bags them for sale whole or sells them to a processing plant.

At the processing plant, workers load the onions on a conveyer that leads to the peeling and cutting stations.

A cutter chops off each bulb's top and tail simultaneously.

It also scores the skin to prep it for peeling.

The onions then move into a custom-designed peeling machine.

It uses a combination of air and water pressure to blow off the skin.

The onions then roll off the peeler and pass before quality-control workers who swiftly cut away bruises and any other imperfections as well as anything the cutter and peeler might have missed.

The next machine rinses the onions with cold, ozonated water that kills bacteria.

Then the onions pass through a metal detector, just as a precautionary measure.

At this point, there's a fork in the processing road.

One direction leads to slicing, the other to dicing.

On the slicing line, workers load the onions into tubes that feed slicing blades.

These blades are adjustable to output slices anywhere from 1 1/2 to 25 millimeters thick.

Workers gather up the complete slices and fill 5-pound plastic trays.

A conveyer moves the trays through a machine that seals them with plastic film.

The film has microperforations designed to allow in just the right amount of oxygen to keep the onions fresh.

On the dicing line, meanwhile, the onions collide head-on with a rotary blade that chops them to bits ranging from 3 to 25 millimeters in diameter.

The diced onions then go for a bath in cold water.

Chopping an onion releases juice from its tissue, paving the way for bacteria to grow.

This cold-water treatment reverses the damage, restoring shelf life.

Next, an escalator transports them from a spin dryer to the packaging department.

There an automatic scale portions out the specific weight they're packaging in this production run.

When the target weight is reached, a trapdoor swings open, dropping the portion into the waiting package.

Restaurants buy their diced onions in jumbo-sized bags.

The filling machine automatically forms plastic into a bag, adds a zipper closure, then seals the bag.

For grocery stores, the factory packages smaller quantities of both diced and sliced onions in plastic containers.

Kept in the fridge, they remain fresh for at least a couple of weeks.

For busy cooks, it's a convenient, no-tears time-saver.

Building complex shapes out of metal typically requires weeks of manufacturing, using tailor-made casts or precise machining techniques.

But 3-d metal printers are faster and cheaper.

They build objects from successive layers of metal powder, which are then fused together at high temperatures.

3-d metal printing makes it easy to manufacture complex metal shapes using a fully automated process.

Every item starts with a computer model of the object.

This is the build box in which the object will be created.

A technician plugs in electric heaters and pours superfine stainless-steel powder into the box.

The heat will keep the metal powder from clumping.

He pushes the box into the machine, then fills the feed box with more stainless-steel powder, which will be needed later in the process.

The machine spreads the first layer of stainless-steel powder in the build box.

Tubes carry a binding substance to the machine's printhead.

This binder acts like a weak glue and is injected in very narrow jets by the printhead.

As the printhead moves back and forth over the stainless-steel powder bed, it deposits binder at the exact locations specified by the computer.

As soon as the printhead has finished printing a full slice of the object, powerful overhead heaters ensure the layer is completely dry.

A roller applies a new layer of powder a fraction of a millimeter thick.

Then the printhead adds a new layer of binder.

This builds the object from the bottom up.

The printing process takes several hours.

Once the layering is done, they put the build box in a curing oven heated to 350 degrees fahrenheit for 24 hours.

This will evaporate all the moisture and harden the binder.

They vacuum out the loose powder, and the piece emerges, its stainless-steel particles lightly held together by the binder.

They gently blow air to dislodge any excess powder.

At this point, the object is very porous and contains about 40% air.

It is so fragile that it can easily be crushed with bare hands.

Using more stainless-steel powder, they prepare another box in which the piece will be infused with bronze.

They're making a support structure on which to rest the pieces during the next phase of the process.

They carefully fill the box with alumina oxide grit, which will support the pieces during the infusion process.

This dam prevents the grit from leaking out.

Now they pour in bronze powder.

The piece is then heated in a furnace at more than 2,000 degrees fahrenheit for 24 hours.

This melts the bronze, which then gets sucked up into the piece like water by a sponge.

Infused with bronze, the piece is now solid metal.

They knock off the base with a hammer.

It's taken just a few days to build this intricately designed piece of hardware.

It can now be polished, gold-plated, or painted to match any decor.

Whether they build sophisticated door handles or fancy sculptures, 3-d metal printers work faster than conventional methods at just a fraction of the cost.

To create classic, elegant style in a kitchen or bathroom, decorators typically use traditional materials such as wood and marble.

Curved cabinets can heighten that effect.

But their unique style comes at a higher price because, for the most part, these elegant doors must be custom-ordered and handmade.

Most cabinet doors produced by this factory are custom-made.

They typically start out as a sketch, which the factory transforms into a technical drawing.

They then use that drawing to program the automated woodworking machines.

After cutting all the pieces of wood they'll need, they run each one through a planer.

It simultaneously smoothes both the top and bottom surfaces.

A cabinet door consists of a center panel surrounded by a frame.

This machine, called a molder, carves the frame's two vertical pieces and cuts a groove on one edge into which the center panel will fit.

To construct that center panel, a worker feeds planks through a wood shaper that bevels their edges.

The angle of the bevel is such that when the pieces line up side by side, they'll form a curve.

After trimming the pieces to the length of the center panel, another worker runs them through a glue applicator, which coats the beveled edges in adhesive.

Then she lines up the pieces in an assembly fixture that's been adjusted to the center panel's width and radius.

Once everything's positioned, she applies clamps which force the pieces tightly together.

The glue sets in 20 minutes.

Once the glue cures to full strength, the piece goes onto a computer-guided router.

It rounds both sides of the panel for a smooth, seamless look.

This particular door has a concave curve.

Others can have a convex curve or a crossbow curve, which is "s"-shaped.

The same router now automatically switches to a different type of tool and profiles the panel's edges.

It also carves a tongue that fits into the groove in the frame pieces.

The same machine can then load another tool to engrave a custom motif or monogram if the customer desires.

Next, a computer-guided sander smoothes out the panel, preparing the wood for stain or paint later on.

Making the frame's horizontal pieces is more complex than making the vertical ones because the top and bottom have to curve just like the center panel.

Workers coat thin slices of wood with heat-activated glue, then stack them over a curved form in a press.

The press squeezes the slices tightly together.

Then a high-frequency electrical current generates intense heat, triggering the adhesive.

The bonded slices exit the press looking like a solid, curved piece of wood.

Once the glue has set, a computer-guided router carves it to the same decorative style as the vertical pieces.

It also miters the corners so the horizontal and vertical frame pieces will fit together seamlessly.

All that's left to do is glue the frame to the panel.

The tongue running along the panel's perimeter fits neatly into the groove of each frame piece.

Workers now clamp everything together and let the glue set for a half-hour.

Then the cabinet door goes off for painting or staining.

This factory produces curved cabinets in 10 different types of wood and dozens of colors and finishes, opening the door to endless design possibilities.


Plastic Cups and Cutlery
Special Effects Makeup
Gold
Harps

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

Plastic cups and cutlery...

Special-effects makeup...

Gold...

And harps.

The industry calls it single-usage plasticware, but that's just a fancy way to say throwaway plastic dishes.

Plastic plates, bowls, drinkware, and cutlery come in many styles and colors.

So for your next party, you can go disposable for everything from champagne flutes to parfait glasses.

Factories make cutlery by injecting plastic into molds.

They make cups, plates, and bowls using a different process called thermoforming.

Before the forming phase can begin, an automated system loads polystyrene pellets into a machine called an extruder, adding pigments for colored plastic.

The extruder heats the pellets until they melt.

Then it forces the molten plastic through a die to shape a hard-plastic sheet about 8/100ths of an inch thick.

They use molds to form this continuous sheet into plastic cups.

First, the sheet passes through an oven that's 10 feet long.

It heats the hard plastic until it becomes malleable.

Then it enters the thermoforming machine, which simultaneously pushes and vacuums the sheets into the mold cavities...

Forming row after row of cups.

The entire process takes just three seconds.

The cups then travel to the trimmer, which uses a die to cut them off the sheet.

The machine grinds up the leftover plastic and remelts it into new sheets, so there's no loss of material whatsoever.

The trimmer feeds the cups directly to a machine that stacks them...

Then feeds them to a conveyor belt in one long line.

The conveyor transports them to a machine called the lip roller.

It reheats the cups just enough to make the plastic flexible.

Then, as we see here in slow-motion, it folds the rim over, forming a rounded lip.

They also make cutlery from melted polystyrene pellets, as well as from polypropylene-- a lighter, more flexible, and less expensive type of plastic.

The cutlery molds consist of two halves.

You can see the difference in this fork mold.

In one half, the utensil cavities are right-side up-- the fork prongs indented.

In the other half, the cavities are upside down-- the fork prongs raised.

A plastic-injection machine melts the pellets and injects the molten plastic into the mold.

A built-in cooling system solidifies the form in about 10 seconds.

The extracted cutlery drops to a conveyor belt that leads directly to the automated-packaging equipment.

For certain customers such as fast-food restaurants, the factory packages utensils individually.

The automated wrapping machine cuts polyethylene film to size, heat-sealing the ends.

This factory also uses polypropylene pellets to make straws.

The black beads are pigments to color the plastic.

An extruder--  a different one this time-- melts the pellets, then forces the molten plastic through a circle-shaped die.

As the long, continuous straw exits the extruder, it cools and hardens in a tank of chilled water.

As it leaves the tank, a knife chops it into individual straws.

They fall onto a conveyor belt which transports them to the packaging line.

Just like the forks, these straws will also be individually wrapped-- but in paper, not plastic film.

The wrapper machine feeds them one-by-one into a paper sleeve.

Gears mesh the edges together, creating a crimped seal.

The dies on this machine turn ordinary straws into flexible ones by forming a corrugated section that lets you bend the top of the straw toward your mouth.

The machine compresses the corrugation to preserve the shape.

Back to the plastic cups now.

This factory can print customized designs in up to six colors applied simultaneously.

Ultraviolet lamps built right into the printing press dry the ink instantly.

Polystyrene is naturally transparent.

Combining two grades of polystyrene creates plasticware that's semiopaque and also highly flexible.

On "how it's made," we usually stick to the show's title and show you how products are manufactured.

But this next segment is about special-effects makeup-- the kind that makeup artists use on theater and movie actors.

So in this case, we'll show you how it's made, but we'll also show you how it's applied.

Watch as this special-effects-makeup artist works his magic to transform this 28-year-old woman into a senior citizen.

After gelling her hair flat, he glued on a bald cap using a theatrical adhesive called spirit gum.

He protects her eyebrows and eyelashes with petroleum jelly, then covers her face in alginate, a material generally used to take dental impressions.

Then he applies wet plaster bandages.

After 25 minutes, the materials harden into a mask.

Now he lines it with plaster.

In a half-hour, the plaster hardens into a perfect replica of the woman's face.

Like putting non-stick spray on a baking pan, he coats the model in a release agent.

Then, using professional-grade plasticine, he begins to sculpt an elderly face.

He smoothes out the wrinkles with strong rubbing alcohol so they'll look realistic.

He uses a bumpy rubber pad to give the skin an aged orange-peel texture.

The finished sculpture sits in water for 2 to 3 hours.

This activates the release agent, detaching the plasticine from the plaster underneath.

The artist carefully cuts the sculpture into sections.

The number of pieces varies with the size and complexity of the mask.

Now he can start producing the mold he'll use to cast the elderly woman's face mask.

First, he takes a thin plaster impression of each piece.

Then he coats the impression in plaster to make the positive half of the mold.

Once it hardens, he applies the plasticine piece to space the depth of the mold cavity.

Then he coats that in plaster to create the negative half of the mold.

When it hardens, he applies release agent to both mold cavities, pours in hot gelatin, then closes the mold.

In a half-hour, the gelatin hardens into a flexible replica of that particular piece of the plasticine sculpture.

He implants synthetic hairs to create eyebrows.

Now, using surgical glue, he begins to apply the pieces, called prosthetics.

He starts with the largest facepiece first.

It includes the nose, cheeks, neck, and upper lip.

He cuts a hole in the chin area so that he can apply the chinpiece.

Now the lower lip.

He cuts off the excess, then glues the edges of the chinpiece to the large facepiece.

Now for the forehead-- again, he applies glue along the edges to connect it to the rest.

To age the eyes, he uses contact lenses.

They create a ring around the iris-- a typical feature of elderly eyes.

Using tweezers, he applies eye bags, again gluing the edges to the rest of the mask.

And finally, some wrinkly eyelids.

With the mask fully assembled, it's makeup time.

Using a toothbrush, the artist sprays it unevenly over the mask, then smudges it with his fingers.

This technique creates a realistic look because the human face--  aged skin especially-- has color variations.

Using a very thin brush, he accentuates some wrinkles by creating depth with a darker color.

Now some freckles and age spots...

And a gray wig.

And finally, just a bit of lip color because lips dull with age.

All this takes an experienced makeup artist about a month of work.

And such expertise doesn't come cheap.

A major transformation like this for stage or screen can cost up to $10,000.

Gold is the softest and most malleable metal.

It can be pressed extremely thin, crafted into various shapes, even drawn out to form a fine wire, and all without breaking.

Gold isn't affected by water or oxygen, as many metals are, so it doesn't rust or tarnish.

Most gold comes from lode deposits, also called vein deposits-- concentrations of gold and other metals in the cracks of rocks.

Lode deposits require hard-rock mining, using drilling and blasting to remove gold-bearing rock called ore.

Miners descend more than 1,600 feet underground.

There they drill holes for explosives using what's called a long hole air drill.

They drill in a specific pattern set out in a plan prepared by the mine's engineers.

The engineers know exactly where those veins of gold are thanks to the mining company's geologists, who've studied ore samples.

The company collects these samples by drilling deep into the rock at 50-foot intervals.

These diamond-drill cores, as they're called, are up to 330 feet long and measure 1.5 inches in diameter.

Gold in its natural state isn't pure.

It's usually intertwined with silver or other metals.

So the mined ore has to be processed afterward to isolate and extract the gold.

A ton of ore yields only about 2/10ths of an ounce of gold.

After blasting the rock apart with explosives, miners use what's called a muck machine to transfer the ore to cars headed to the main shaft and then aboveground to the mill.

There, a crusher reduces the large chunks into smaller rocks about the size of road gravel.

A mill then pulverizes them to the texture of beach sand.

The factory adds a water and cyanide solution, then another mill grinds it further into a mud-like pulp.

The pulp flows into large settling tanks.

The wet solids are heavier and sink to the bottom.

The water at the top drains to another area.

They transfer the wet solids to an agitation tank and blow in air.

The oxygen sets off a chemical reaction between the cyanide and the gold trapped in the ore, triggering the gold to dissolve and leach into the surrounding water.

Drum filters then separate the water from the solids.

This water now joins the water that was separated earlier.

They pour in zinc powder to solidify the dissolved gold and form pieces containing both zinc and gold.

To smelt it into bars, they first have to mix several chemicals-- manganese dioxide...

Fluoride...

Silica flour...

Borax...

And sodium nitrate.

This chemical mix, called flux, will separate the gold from the impurities.

They pour it into the smelter, whose temperature is a fiery 2,910 degrees fahrenheit.

They rotate the smelter so that the contents heat evenly over 2 1/2 hours.

The heavier gold eventually sinks to the bottom, while the impurities, called slag, float to the surface.

They pour out the slag, taking a sample to make sure it contains no gold.

If it does, it goes back in until it's gold-free.

By now, the gold has cooled slightly, so they reheat it to 2,910 degrees fahrenheit, then cast it into bar-shaped molds.

The gold takes about four minutes to solidify.

It's put in a basin of cold water, where it will cool completely after an hour.

They extract the gold bars from the molds and clean off any slag residue.

Gold bars are also called ingots.

At this stage, the gold is 80% pure.

The united states mint will refine it to 99.9%-- the international gold standard.

Harps come in many sizes.

The type that classical musicians play is known as the orchestral, or concert, harp.

It produces more tones than any other stringed instrument.

The player plucks the harp with the thumb and first three fingers of each hand, while at the same time operating foot pedals.

The harp is one of the oldest string instruments, originating in the middle east as early as 3000 b.c. harps begin appearing in europe in the 700s.

They initially had a curved pillar.

By about 1500, this evolved into a sturdier straight pillar that could support more tension.

As music became more sophisticated, they added a second row of strings as well as pitch-raising mechanisms, enabling the orchestral harp to produce more notes.

This harp is a cross between a classical harp and a celtic harp.

There's the pillar in the front, the sound box in the back, and the neck running across the top.

The sides of the sound box are called the ribs.

They're made from pieces of solid poplar, 3/10ths of an inch thick.

The instrument maker traces a rib-shaped template on the wood and then cuts out the shape using a band saw.

He clamps them onto his worktable and, with a plane, makes them symmetrical.

Now he draws three lines across each rib to mark where he'll cut slots.

You'll see what those slots are for later on.

Next he glues on a notched strip of wood called a lining to the curved side of the rib.

The lining enlarges the glueable surface, making it easier to assemble the side to the back of the sound box.

The notches enable the lining to bend to the curved shape.

Now he glues on the lining that will connect the straight side of the rib to the front of the sound box.

He shaves off some wood with a small plane, then rounds off a corner.

He planes the back lining as well, removing a corner to flatten it.

Trimming the linings reduces the final weight of the instrument.

Now he cuts off the ends of the linings on both sides to be able to slide into place the adjoining parts, the bottom plate, and the top plate.

They're made of russian plywood, which is a piece of plywood sandwiched between sheets of birchwood 1/10th of an inch thick.

He glues the top plate into place, then clamps it.

He does the same with the bottom plate.

He closes the back of the sound box with what's called the back plate.

It's also cut from russian plywood.

He glues it onto the lining, applying pressure with tight rubber strapping.

When the glue dries after about an hour and the strapping comes off, he marks the location of the sound holes, the holes from which sound exits the instrument.

He constructs the top plate on the front of the sound box from solid spruce.

He lays the pieces down from widest to narrowest, then glues on a reinforcement strip made of solid maple.

The strings pass through the strip and another on the inside.

They prevent the tension from rupturing the top plate.

He attaches a solid poplar frame to strengthen where the top plate and the ribs join.

After sanding with fine sandpaper, he coats the sound box in varnish.

Remember those slots in the ribs?

They now hold bracings to prevent the ribs from bowing under the tension of the strings.

Using a band saw, the instrument maker cuts the neck from a board of russian plywood about an inch thick.

He makes a slot for gluing the pillar, also made of russian plywood.

Once the varnish on the neck and pillar are dry, he hammers in pins for the strings.

This type of harp has 34 strings.

Brass bridge pins space them evenly apart.

Steel zither pins adjust the tension for tuning.

He uses a wooden guide to hammer the pins to a uniform depth.

The three finished pieces fit together with dowels and slots.

He secures the joints with glue and a long screw through the pillar.

Strength is critical.

This harp has to withstand 790 pounds of string tension.

Reaching through the sound holes, he threads the strings through the reinforcement strips to the pins outside.

These are nylon strings.

Harps can also have steel strings.

He winds them around the zither pins with a special key.

The last step is to tune the harp with the help of an electronic tuner.


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

Horse-drawn carriages...

Artificial eyes...

Dog and cat food...

And mirrors.

Nothing takes you back to the past quite like a ride in a horse-drawn carriage, a timeless vehicle in both appearance and construction.

Building one today still requires the expertise of several traditional craftspeople, from ironworkers to wheelwrights.

The carriage's turning mechanism is a fifth wheel that is positioned horizontally above the two front wheels.

Workers weld the fifth wheel to the carriage's steel frame then weld the boarding steps to the frame.

Until now the frame has been positioned upside down.

Now they turn it right side up to install the driver's seat.

First they measure carefully to ensure it's perfectly centered.

Then they weld it in place.

Once the frame is complete, it goes through an acid wash to remove any residue.

Then they buff the welded joints to smooth out their surface.

The carriage has drum brakes.

Workers install them onto the axle then assemble the steel springs that make up the suspension and bolt them onto the axle as well.

Next, they connect the brake line.

Then they install the whole assembly under the carriage's frame.

Like in the olden days, they make the wheels out of wood.

Metal isn't flexible enough to withstand bumps in the road.

They use ash because it's a very hard wood that doesn't rot easily.

Workers position 16 spokes around a steel hub.

They clamp the spokes in place, compressing them against the hub.

Then they secure them with nuts and bolts.

Next, they mark the spokes in two places.

The first line shows how long to cut each spoke, the second line how far to dowel the end.

To form the dowel, they first shape the end into a cone.

Then the cone into a dowel.

Those doweled spokes will fit into corresponding holes they now drill into two semicircular strips of wood.

The strips form what's called the fellow, the round part of the wheel.

Workers tighten the hub then press a steel band called a channel against the fellow.

They cut the channel to size.

Then weld the ends together.

Finally, they buff the joint smooth.

Next, they drill eight holes through the channel then, using a tapering tool, thread the holes to fit the bolts that bind the channel to the fellow.

Finally, they tighten the bolts with a special gun.

The tires are made of rubber.

They contain two steel wires to hold them in place over the wheel.

Workers grease the channel of the now-painted wheel so that the tire will slip on easily.

Then they mount the wheel on the automated tire-installation machine, which pulls on the wires, installing the tire tightly over the wheel.

They solder the wire ends together using bronze solder for a stronger joint.

Then-- here comes the high-tech part-- they bang the wheel on the ground four or five times until the distance between the tire ends closes, covering the soldered wires inside.

A tap of the hammer followed by a final bang ensures the tire joint is secure.

Now they can mount the wheels onto the axles and install the axles under the body of the carriage.

After testing the fifth wheel and the brakes...

It's time to apply the finishing artistic touches.

All they need now is a little horsepower.

The ancient romans and egyptians fashioned artificial eyes out of painted clay.

By the 1500s, europeans started making them out of enameled gold and soon out of glass, which remained the norm for hundreds of years.

Today most artificial eyes are made of acrylic.

If you've lost an eye in an accident or to a disease, a specialist known as an ocularist can fit you with an artificial eye.

You can get a ready-made model or a custom-made prosthesis, like the one for which this patient is being fitted.

No two people's eye sockets are the same, so the first step is to take an impression.

After inserting an impression tray, they inject a material called alginate, filling the entire socket cavity.

After 90 seconds, the alginate sets, and they can remove the hardened impression.

They place the impression in a mold.

And pour in a type of plaster.

When the plaster has hardened, they remove the impression tray and then the impression itself.

What's left in the mold is a plaster replica of the socket.

Now they put a wad of acrylic plastic dough into the mold...

Lock the mold into a press, and submerge it in a high-pressure curing unit for 25 minutes.

Then they cool the mold in cold water.

Here's the original impression compared to the acrylic model they've just cast.

This model is called the fitting shape because they use it to fit and mark the positioning of the fake iris.

They accentuate the markings, then attach a peg with a drop of wax.

The peg indicates the natural angle of the iris when the patient is looking forward.

Next, they add wax around the perimeter to enlarge the fitting shape.

This excess will give the ocularist some room to work with for the final sizing.

Now they take this marked and enlarged fitting shape and make a plaster mold.

They will later use that mold to cast the actual artificial eye.

But first they have to make the iris.

They take a curved, black acrylic disc and paint it as realistically as possible with high-quality artist oils.

The patient has to be present so they can match the real eye.

Next, they glue an acrylic cornea with an appropriate-sized pupil onto the painted iris.

At this point, the artificial iris is half an inch in diameter.

If the patient's real iris is smaller, they trim down the replica to match.

The iris then goes into the plaster mold covered with white acrylic dough.

After the same high-pressure curing process as before, out comes the artificial eye covered with excess white acrylic.

They trim off that excess and the peg using a grinding tool and a cutter.

This refines the shape and exposes the iris buried underneath.

They smooth the surface against a grinding stone and verify the measurements.

Then, using hard coloring pencils, they add finishing touches to the iris and draw blood vessels.

They label the eye with the patient's initials and then apply an acrylic coating to seal the pencil marks.

To create veins with some dimension, they use the same acrylic coating to stick on some delicate silk threads.

Once they're satisfied the artificial eye is a perfect match, they seal the artwork with another acrylic coating.

Once that cures, they polish the eye to a shine with a cotton wheel.

The shapes and colors of artificial eyes are endless because patients' eye sockets and irises vary greatly, as do their scleras, the white of the eye.

This artificial eye, or ocular prosthesis, is ready.

The final step is to ensure that the fit is perfect.

The patient's ocular muscles attach to the implant, enabling his artificial eye to move in unison with his real eye.

So much for feeding fido scraps from the table.

Today's pet food is the stuff of sophisticated nutritional science.

It's about protein, carbohydrates, vitamins, minerals--  a well-balanced diet.

Want to bet some dogs and cats eat healthier than their owners?

The formulas for dog and cat food differ because dogs and cats have different nutritional requirements.

Cats, for instance, need more fat and protein in their diet than dogs do.

But the basic ingredients that factories grind up to make dog and cat food are similar.

First, corn kernels.

Then cereals, such as barley...

Wheat...

And rice.

Workers weigh the ingredients, grind them in a mill, then combine everything in a mixer until they have an even and well-blended powder.

A machine called the extruder transforms that powder into bite-sized pieces of pet food.

It steam-coats the mixture, then forces it through dies at high pressure.

The dies shape it, the way the tip of a pastry bag shapes icing into swirls or roses.

Check out this dog-bone die.

As the continuous stream of shaped mixture exits the die, a spinning knife cuts it into pieces.

The company has different dies to produce different shapes.

This is a batch of round pieces.

Next stop, a hot-air dryer for 25 minutes.

It heats the pieces to 300 degrees fahrenheit to draw out the moisture, then cools them at room temperature.

Once the pieces exit the dryer, they enter a revolving drum, where they're sprayed with fat and flavoring.

The fat is designed to add food energy while the flavoring gives the bland pieces an appetizing odor and taste-- appetizing for pets, that is.

The rotation ensures the pieces get coated evenly.

From here, the pieces go into storage silos.

When they leave the silos for bagging, the machinery screens out any crumbs.

The pet-food industry has made some interesting observations about the likes and dislikes of its four-legged clientele.

Apparently, cats and dogs aren't crazy about food that's too dry, too hard to chew, or too mushy.

If the pieces are too small, they'll swallow them whole without chewing and not digest them properly.

But if the pieces are too big, they'll gag and get turned off to the food altogether.

In the packaging department, automated scales weigh the exact quantity per package.

This batch is destined for bags weighing about 6 1/2 pounds.

The package sizes range from just under one pound all the way up to 44 pounds.

Shelf life is from 12 to 16 months, depending on the formula.

Pet-food experts say dogs and cats prefer food with a fattier content and a combined meat-and-cereal formula over just cereal alone, but too much meat flavoring can turn them off.

Cats, as a rule, are more particular.

They favor more acidic food, while dogs tend to have a sweeter tooth.

And you thought kids were fussy eaters.

No bathroom is complete without one.

And any parent will tell you that no teenager can survive without one.

Mirror, mirror on the wall, how do they make you, after all?

Well, "how it's made" is about to show you.

But first, let's reflect on the history of mirrors.

The earliest mirrors were curved pieces of highly polished metal, such as brass or bronze.

They're even mentioned in the bible.

Then, in the 14th century, the venetians invented very crude glass mirrors that reflected off a metallic backing.

They later perfected this technique using an amalgam of tin and mercury.

Eventually, the secret of mirror-making spread to other cities.

By 1835, a german chemist developed the silver-backed mirror that we know today.

A mirror starts out as clear glass.

A robot lays each panel horizontally on a conveyor belt, which transports it to the washing station.

There, sprayers blast the glass with water and cerium oxide, a powder derived from a type of soil.

Rotating brushes scrub and polish both the top and bottom surfaces, removing oils and other contaminants.

This washing process takes about a minute per panel.

Next, sprayers rinse the glass with piping-hot demineralized water, demineralized because the minerals in plain tap water would damage the metals they apply next.

The first metal is liquefied tin, which goes on what will be the back of the mirror.

It allows the second metal, silver, to adhere because silver won't stick directly to glass.

The silver is also in liquid form mixed with a chemical activator.

Within seconds of interacting with the tin, it hardens.

And as it does, you begin to see a reflection.

It's this silver backing that transforms clear glass into a mirror.

Sprayers rinse off the excess silver, which gets recycled back into the system.

The factory will seal the silver backing with two coats of paint.

Paint by itself, however, isn't enough to protect the silver in the long term.

So they first spray on a layer of copper.

Sprayers rinse off the excess copper.

Then the panel passes through a dryer at almost 160 degrees fahrenheit.

This evaporates the moisture on the surface in just 75 seconds.

Now the panel passes, copper side up, through what is called the curtain coater, a machine that runs a continuous curtain of paint across the conveyor belt.

With its fresh coat of paint, the mirror then passes through an oven heated to 210 degrees fahrenheit.

After a minute and 45 seconds, the paint is cured.

Now the second coat of paint.

There's no reason for the different color other than to differentiate the coats.

This time, the curing period is twice as long and at a higher temperature, close to 245 degrees fahrenheit.

After an acid wash to remove any metal residues, they stand the panel upright to inspect it.

If they find a fault, such as a bubble in the glass, they cut that portion out.

The factory now cuts these large panels into whatever size and shape the customer has ordered using a special mirror-cutting machine that's precision-guided by computer software.

It scores the mirror using a carbide wheel.

Carbide is a strong metal.

To make round mirrors, the machine first scores the panel into squares.

Then, in each square, it scores a circle.

Using special tools, workers separate the squares, then the circles.

To make beveled mirrors, they use what's called the shape-bevel machine.

First, it carves out the edge.

Then polishes it to a shine using concentrated cerium oxide, a stronger version of what they used earlier to clean the glass surface before plating it with metals.

Mirror factories also ship whole panels to shops that do the cutting themselves, a fragile feat that's certainly not for the superstitious.