27x02 - Chemical Tank Pressure Vents, Candy Wafers, Food Trucks, Traditional Ropes

[bunniefuu]

♪♪

Narrator:
today, on "how it's made"...

It's common for pressure
to build up

Inside chemical tanker trucks
during transport.

Special vents
regulate that pressure,

Preventing
any unwanted gas build-up,

Which could lead
to an expl*si*n.

♪♪

Pressure relief vents
are standard equipment

On chemical tanker trucks.

They ensure tanks can hold up

To the pressures
inherent to this industry.

Production starts with a bin
of wax pellets.

They use pellets to make models
of the vent's parts

In a process
called lost-wax casting.

Pellets are fed
into an injection machine.

The wax melts into a mold
of the vent's lower housing.

Four wax models are fused
to a single wax tree stand.

The tree stand is left to cure
for a couple of hours.

Once cured, a worker
dips the wax tree

Into a slurry of ceramic.

He removes the stand
of wax models,

Then twirls it to drain
any excess ceramic.

This is the first
of several ceramic coatings.

Between coatings,
he applies silica sand

To the wet ceramic.

The sand rains
down onto the ceramic,

Creating a stucco effect.

The first layer of stucco
is finally granulated.

The next few layers
will be coarse.

By building up progressively
coarser layers of stucco,

He creates a ceramic shell

With the desired thickness
and strength.

The final layer of sand
is very coarse.

Air pumps through the sand
as the worker dumps the models.

This process ensures uniform
coverage of the heavier sand.

They bake the forms next,
melting out the wax

And hardening the ceramic
into shells.

Next, a team pours blazing
liquid steel into a ladle.

The ceramic shells
have been heated

To around 3,000 degrees
in an oven.

Workers pour hot, liquid steel
into the hollow tree.

They add a chemical sealer,
then top the molten metal

With a piece
of ceramic-fiber insulation.

After about 3 hours in an oven,

The steel castings are solid.

A worker shatters the ceramic,

Revealing
the vent-housing parts.

A powerful circular saw slices
the parts off the tree.

Workers clean off
any ceramic residue.

Computer-guided tools calibrate
the pressure-vent housing part

To precise specifications.

After cleaning and polishing,
the part is complete.

It's time for assembly.

The worker starts with the top
of the pressure vent.

A large spring is inserted
to aid pressure relief.

A metal plate is added
to seal the top of the vent

To the lower part.

The lower vent housing is then
seated on the metal plate.

He moves the assembly
under a hydraulic ram.

The ram presses
the lower housing,

The sealer plate, and the spring
to a specific tension.

He then screws the lower housing
to the top of the vent.

A metal ring inscribed
with the vent's model

And flow rate
is attached at the top.

This chemical tank pressure vent
is now ready for testing.

The technician screws it
to the test stand.

He activates a system

That forces compressed air
into the vent.

This confirms whether the vent
works at the desired setting.

Once approved,
he attaches a cover

To shield the vent
from rain and snow.

The trackable serial number

Is etched into the top
using a laser.

This vent is now ready
to prevent hazardous situations.

♪♪

Narrator: the candy wafer
is a classic american treat.

Invented in 1847,

It's a thin, lightweight disk
of sugary candy.

It's softer and dissolves
faster than hard candy.

You can bite into it right away

Or let it melt in your mouth.

These candy wafers
come in eight different flavors.

The original roll
has a random assortment

Of 38 pieces.

Part of the fun is seeing how
many of your favorite flavors

You get.

This factory makes one flavor
at a time.

The first step
is to add food coloring

And flavoring
to pulverized sugar.

This pink color

And mint flavoring
produces a wintergreen taste.

Corn syrup comes next,

Along with a binding solution
of vegetable gums

And gelatin dissolved in water.

After mixing
for about 8 minutes,

The candy dough's
consistency is checked.

If it isn't thick,
elastic, or sticky enough,

More binding solution is added
until the dough is just right.

Workers divide the dough
into chunks,

Then feed them
into a dough sh**ter.

This is the first station
on the wafer-forming line.

The black dough
is licorice flavor.

A conveyor
returns leftover dough

From the end of the line

To be reused
for making new wafers.

They're pushed through a slot,
forming the dough sheet

That's 20 inches wide
by about an inch thick.

This yellow dough
is lemon flavored.

A steady sprinkle of cornstarch

Prevents the sheet
from sticking to the equipment.

Rollers compress
and stretch the dough forward,

Fl*ttening the sheet
to an inch thick.

The next station stamps

On the company logo,
then cuts out the wafers.

The cutter moves up and down


The wafers fall through a gap

To a moving conveyor belt below.

The conveyor belt
moves the wafers

To a multilevel tunnel dryer.

They pass through the dryer


Over the course of an hour.

These green wafers
are lime flavored.

The dryer temperature
is about 150 degrees fahrenheit,

Warm enough to remove
half of the moisture

Without melting the sugar.

These brown wafers
are chocolate flavor.

Once out of the dryer,
the wafers

Pile up in trays
without sticking.

Workers stack the trays
in a drying room.

It's heated
and humidified with steam.

The candy wafers stay here
until their moisture level

Drops to between 0.75% and 1%.

The factory tests a few samples

Using a device
called a penetrometer.

It measures the force required
to penetrate the candy wafer

To the point of breaking it.

This ensures the candies
are the correct consistency.

When the trays come
out of the drying room,

Workers send the candies
to the packaging line.

The colors are mixed together,

Ensuring every roll of candy has
a random assortment of flavors.

The wafers flow into channels,

Which stand them on their sides.

Workers grab
about two rolls' worth,

Then fill two channels
of a feeder

That takes them
to the wrapping station.

Another worker
fills in the gaps,

Ensuring each roll
has 38 pieces.

The wrapping machine
cuts printed,

Translucent paper wrapping

And applies a bead of glue
to one edge.

In a matter of seconds,
the machine lifts the roll

Into the wrapper,
seals the edges,

And twists the ends closed.

As the sealed rolls move
on a conveyor belt,

Heated blocks iron
the twisted ends flat.

Each candy wafer roll
weighs 2 ounces.

Workers pack 24 rolls
per retail box,

Then pack the boxes
in shipping cases.

In addition to a traditional
roll with assorted flavors,

The factory also
produces chocolate-only rolls.

Production has modernized
over the years,

But the recipe
itself hasn't changed much

Since the first candy wafer

Rolled off
the production line in 1847.

♪♪

Narrator: food trucks used to
only sell sandwiches

And other prepackaged food.
Not anymore.

The modern food truck
is a mobile restaurant

With a full kitchen inside.

Food is cooked fresh

And sold to customers
through a service window.

Most food trucks
are standard panel trucks.

Their cargo area is a fully
equipped commercial kitchen

With a service window
on one side.

They're usually customized
by boutique companies,

So there's no standard method.

However, certain modifications
to the panel trucks are common,

Like enhancing
the truck's suspension system

Or reinforcing
the flooring and walls

To support the kitchen's weight.

The lighten the load,
this company

Builds the kitchen's
structural components

Out of aluminum bars
rather than heavy steel.

Once the pieces are cut,

A worker assembles,
then welds them together.

This structure will support
a stainless-steel countertop.

Workers cut the countertops
and cabinets

From thick sheets
of stainless steel.

They bend the sheets using
a machine called a press break.

For this countertop,

They bend a 90-degree angle
on the front end

To form a 1.5-inch square edge.

To construct walls and ceilings,

They rivet thin sheets
of stainless steel or aluminum

To panels of wood.

Fire-retardant plywood
is used for the kitchens.

The boards are installed
over styrofoam insulation.

They leave the truck's
aluminum floor as is.

Once the walls, ceiling,
and flooring are complete,

It's time to install the
kitchen's cabinets and counters.

Workers screw
each counter support

To the wooden structure
of the wall,

Then fasten the countertop
with rivets.

They peel off the film

That was protecting
the stainless-steel surface.

Next, they install
the major appliances,

Which include
a commercial refrigerator,

Freezer, and cooking equipment.

Then the electrical box
is installed.

They connect wiring
for the outlets,

Lighting, water heater,
water pump,

And air-conditioning system.

The generator is installed
underneath the nearest counter.

It supplies the truck
with electricity.

Next to the electrical box is
the power-transfer box.

It contains a switch

That enables the truck
to use an outdoor power source.

The switches for the interior
and exterior lighting

Are underneath
the electrical box.

Workers install
the light fixtures,

Cabinetry, sink,
and serving window.

They also install the gas lines

That power the commercial
cooking equipment.

This truck has
several gas appliances --

A six-burner gas range
with large oven,

A deep fryer, a charcoal grill,
and a flattop cooking surface.

The kitchen is equipped
with a ventilation hood

Over the cooking area.

Its powerful fan gathers smoke

And sends it out a vent
on top of the truck.

It's time
to outfit the exterior.

Some food trucks are painted,
but most use graphics

That are digitally printed
on adhesive vinyl.

After positioning each panel
of the design,

They apply heat with a torch.

This removes trapped air,

Stretching the vinyl over rivets
and other protrusions.

This mobile eatery
is ready to roll with a kitchen

That meets fire-code
and food-service regulations.

It may not provide the ambiance
of a sit-down restaurant,

But when a food truck pulls up,
you never need a reservation.

♪♪

Narrator: rope has been made out
of plant fibers for centuries.

Stronger synthetic
and steel cords are available,

But there's still a market
for traditional twine.

They have their own
unique strengths,

And that's why we are still
bound by their ties.

Woven from manila, sisal,
or flax fibers,

Traditional ropes are
a binding element in our world.

They're easier to grip

And stretch
less than synthetics.

At this deep
and narrow building,

They've been
twisting fibers into rope

For more than two centuries.

They're still producing rope
the old-fashioned way.

The process starts with racks
of natural-fiber yarns.

The yarns are funneled
through separators,

Which configure them
to twist evenly together.

The fibers
then travel through tubes

That squeeze them into bundles.

Workers tie the ends
of the bundles

Onto a wheeled vehicle
called the forming machine.

They roll the machine back

Until there's no slack
in the bundles.

The machine is then sent
to the opposite end

Of the factory,
over 1,000 feet away.

As the machine
travels backwards, its gears

Turn hooks, twisting the yarns
into a tight configuration.

The formation of the twists

Ensure an even distribution
of tension.

This is what makes rope
so strong.

This long, indoor space
is called a ropewalk.

There aren't many of them
left in the world.

Halfway down,
a worker places a trestle

Underneath the twisting yarns.

This keeps them off the floor
and prevents tangling.

When the machine
reaches the back wall, it stops,

And workers cut both ends
of the strands.

They tie them to posts

To maintain tension
and prevent unraveling.

The twisted fibers stretch

From one end of the building
to the other.

On one side,
they tie three of the strands

To a machine that will
transform them into a rope.

Halfway down,
they bring in a cart

That holds a piece
of grooved wood known as a top.

They tuck the twisted strands
into the grooves of the top.

They then roll the cart

Down to face
the rope-making machine.

A worker ties rope
around the strands in the top.

This holds them in place
as the rope-making machine

Twists the three strands
into one.

The cart rolls along rails
propelled by twisting action.

It leaves newly formed rope
in its wake.

The rope machine
with twisting hooks

Remains in the same place.

When the cart arrives
at the opposite side

Of the building,
the rope is formed.

A worker removes
the ties around the top.

They now have a piece of rope

That's over 700 feet long

And almost 5 inches in diameter.

They slice the rope
at both ends.

Then they wind it
onto a big spool,

Packing it into a tight coil.

This traditional rope
is almost ready to be shipped.

The customer
requested looped ends

For securing the rope
with a shackle.

So, the rope-maker
unravels the ends

And pierces the rope
with a hollow tool called a fid.

He makes a loop

And slides the unraveled strands
through the fid.

He finishes the job
by weaving the strands

Into the rope.

They're ready to test
a segment of the rope.

Two hydraulic jaws
pull it until it breaks.

The rope must be able
to handle 55 tons of force.

Traditional ropes have
the strength to carry on,

As they have done
for a very long time.