29x04 - Thermoplastic Fire Helmets, Basketry Sculptures, Coffee Roasters

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Narrator: thermoplastic
fire helmets are lightweight,

But that doesn't mean
they aren't tough.

Because of
their chemical composition,

These plastic helmets

Remain sturdy, even
when exposed to temperatures

Of over 500 degrees fahrenheit.

Developed in the 1970s,

The helmets
have become standard issue

At many fire stations.

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There are few situations
more dangerous than entering

A burning building.

Thermoplastic fire helmets
weigh substantially less

Than other alternatives.

These helmets
are one piece of equipment

That won't slow down
the rescue mission.

Production starts with a special
blend of thermoplastic pellets.

A vacuum pulls the pellets
into a hopper.

The pellets then flow into
an injection-molding machine.

It melts and molds the pellets
into the shape of a fire helmet.

A robot retrieves the helmet

And transfers it
to a cooling station.

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A worker then clips off
plastic that solidified

As it flowed through a channel
and into the mold.

This unwanted bit
is called sprue.

She wipes off fingerprints
and inspects the condition

Of the helmet shell.

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The next worker trims the brim
to remove excess plastic

That formed
when the mold closed.

For this process, he uses
a blade with a curved edge.

Next, he applies
reflective strips

That will allow the firefighter
to be seen in the dark.

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He drills holes for attaching
either goggles or face shields.

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And the worker adds
a last reflective strip.

He screws a support plate
for the i.d. Shield

To the front
of the helmet shell.

He uses plastic screws
rather than metal

Because metal
is electrically conductive

And would put the firefighter
at risk

In the event of electrical
sparking during a fire.

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Another worker
now applies labels

To the inside
of the helmet shell.

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The labels indicate
that this model of fire helmet

Is in compliance
with the safety requirements.

The worker inserts
high-density foam padding

In the helmet shell.

The padded cap
will cushion the wearer

From the force of an impact.

This web of straps will serve
as a suspension liner

And will also support the helmet
on the wearer's head.

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Another worker installs
a ratchet system for adjusting

The fit of the liner
to the firefighter's head.

Positioned at the nape
of the neck,

The firefighter
can turn the knob

To pull the suspension web
tighter.

Attachments on the suspension
liner fit into sockets

On the helmet
to lock it in place.

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He fastens the chin strap
to the helmet

By wrapping the ends
around molded struts

On both sides of the shell.

The chin strap
has a quick-release button

In the event
that the firefighter

Has to remove the helmet fast.

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Another worker now folds up
flame-resistant earflaps.

The flaps are equipped
with hooked

And looped fastening strips
that fit to the helmet.

He sets the earflaps aside
while he inserts snaps

For goggles
into brackets on the helmet.

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He screws the snaps
snugly to the helmet.

The worker then wraps the
fire-and-fog-resistant goggles

Around the helmet
and snaps them to it.

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He tucks the maintenance
instructions into the helmet,

Followed by the folded earflaps.

This thermoplastic fire helmet
is now complete,

But there's still one last bit
of official business.

The worker screws
the large leather i.d. Shield

To the support plate.

The shield bears the name
of the fire department

And a symbol that denotes rank.

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This fire helmet
is now ready for duty.

It will be one of
the first things the firefighter

Reaches for when he or she
gets an emergency call.

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Narrator: contemporary artists
are challenging

Our perception of basketry.

Focusing on form
rather than function,

Artisans are weaving grasses

And other fibers
into sculptural art.

These basketry sculptures

Usually aren't meant
to contain anything.

Instead, they're meant to
capture and hold our attention.

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Is it art, or is it a basket?

A basketry sculpture is both.

It celebrates the tradition
of the craft

While elevating basketry
to an art form.

Materials
for a basketry sculpture

Can include a mix of thing,
from natural fibers,

To metallic pieces,
wire, and beads.

Soaking fibers
like palm-tree strands

In hot water will soften them

And make the fibers
flexible enough for weaving,

But they won't lose their
interesting crinkly texture.

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About two hours in,
the artist checks the suppleness

Of the fibers.

They can now be bent
without breaking,

But they need
a bit more softening up.

So she covers the fibers
with plastic and leaves them

To soak a little longer.

She turns her attention
to the sculpture's centerpiece,

Which will be made of copper.

She draws a design

Onto the copper's
protective plastic liner.

Using metal shears,
she cuts out the shape.

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The artist peels off
the plastic liner

That has protected the copper,

Revealing the glossy,
untarnished surface.

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She now places the copper above
a bag full of small pellets

And pounds it
using a nylon mallet.

This process gives the copper
an aged, hammered texture.

She gives some areas on the
other side the same treatment.

The hammering also bowls out
the profile of the piece.

Using a marker,
the artist draws a line

About 1/3 of an inch in
from the edge.

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She marks dots
onto this newly defined border,

Spacing them evenly apart.

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She then punches holes
through all the dots,

Using a lever-operated
drill press.

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She cuts out the space
between the holes,

And this process creates
separate tabs for each hole.

The artisan
now bends back the tabs,

Following the marked line.

The application of a clear
powder coat prevents tarnishing.

After a few hours,
the palm strands

Are now sufficiently softened.

She retrieves the strands
from the hot-water soak

And sets them aside.

The artist returns
to the copper centerpiece

And begins to weave,
starting with rattan reeds

That have also soaked
to make them more pliable.

She pulls the reeds through
the tabs and intercrosses them

So that they fan out
in two directions.

She then braids cotton string
against the centerpiece.

This creates a neat and sturdy
border all the way around.

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She clips clothespins
to the rattan

To hold the braided border

In place
against the centerpiece.

She then trims
the ends of the strings.

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Next, the artist
weaves rattan reeds

Parallel to the cotton braid,

Entwining them with the reeds
that extend outward.

She creates one row of these
rigid fibers for structure.

She's now ready
for the palm strands.

After the soaking, the strands

Remain soft and pliable
for many hours,

So she doesn't have
to rush the work.

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As she continues,
she alternates rows of palm

And rattan fibers.

The different textures
add visual interest

To the basketry sculpture.

It will take two months
to complete this work.

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When the basketry work is done,

The artist
takes the piece outside

And airbrushes them
with acrylic paint.

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She sometimes relies
on a metal template

To more evenly define
the paint border.

It's the finishing touch
to the basketry sculpture,

And now it's up to the public
to understand the story

That the artist has woven.

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Narrator: the earliest tools for
roasting coffee beans were pans

You would hold over hot coals
or an open fire,

But, today, coffee roasting

Is a far more
sophisticated process,

Using large, often fully
automated machines

With built-in gas burners

That heat air
to roast the beans.

This coffee roaster
is both programmable

And manually adjustable
by touch panel.

The roast master can tailor
the temperature

And roasting time
to influence flavor,

Acidity, and other
characteristics of coffee.

To shape the roast chamber,
workers feed a sheet

Of stainless steel
through a sheet-metal roll.

The roast chamber is the drum
in which the beans roast

By convection heat.

The next step is to weld the
rolled sheet into a cylinder.

Then workers grind and polish
the welds until they're flat,

Smooth, and shiny.

Another worker makes the cooling
tray in a similar way,

But with a support band
welded to the top.

The cooling tray is the drum
into which the hot beans drop

When they exit
the roast chamber.

Stirring arms circulate
the beans as a fan draws air

Through the tray
to cool the hot beans.

Certain parts of the roaster

Are cut
from a stainless-steel sheet.

Stainless steel
is the ideal material

Not only because it's stylish,

But also because it's durable
and corrosion-resistant.

This computer-guided
laser cutter

Is slicing out
a safety component

Called the heat shield,
which prevents the roast master

From accidentally
touching a hot surface.

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The heat shield,
like many other parts

Cut from stainless-steel sheets,

Has to be formed
to a very precise shape.

A worker bends angles
and curves into the metal

With a press brake.

Another component, the trier,
lets you draw a sample

Of beans during roasting.

A craftsman constructs the trier
by welding various smaller parts

To a piece
of stainless-steel tube,

Then meticulously grinding

And polishing the welds
until they're smooth.

This high-pressure water-jet
cutter also cuts parts

From stainless-steel sheets.

This component is one
of six flights,

Which is part
of the paddle that lifts

And mixes the beans
inside the roast chamber

So that they roast evenly.

To form the flights
to the required shape,

A worker curves them
one at a time in a press.

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Next, the welder places
all the paddle components

Into a specialized fixture,

Which positions them correctly.

First, he aligns the spokes
to the paddle shaft.

Then he welds
the parts in place.

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He positions the flights,
clamps them securely,

And welds them on.

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The combination
of inner and outer flights

Lifts the beans
into the airflow,

Ensuring the beans roast evenly.

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A custom-designed
grinding machine hones

The flights to produce
a small clearance

Of around 1/10 of an inch
between the edge of the paddle

And the wall
of the roast chamber.

This design ensures the paddle
is wide enough to pick up

Every last coffee bean

Without touching the wall
while rotating.

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Once they install the paddle,
a worker closes up

The roast chamber
with a faceplate.

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Alignment pins
ensure the faceplate

Is properly positioned.

The paddle shaft protrudes

Through a bearing
in the faceplate.

The assembly team uses a hoist
to lift the heavy chamber

And position it
on top of the coffee roaster's

Stainless-steel support frame.

They install the heat shield
that was cut by the laser cutter

And bent to shape
in the press brake.

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On top, the assembly team mounts

The machine's
funnel-shaped hopper.

The hopper feeds
the unroasted coffee beans

To the roast chamber below.

The hopper's lid has a tube,

Which connects
to a vacuum system

That draws the coffee beans
up through a plastic hose.

On the front
of the roasting chamber,

An assembler hangs
a hinged discharge door

That has a viewing window.

He plugs in a sensor
that measures the temperature

Of the beans
in the roasting chamber

And sends that information
to the machine's computer.

More to come
after this coffee break.

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Narrator:
this coffee-roasting machine

Has three additional
temperature sensors

That send data to the computer.

These sensors measure
the temperature of the air

Entering and exiting
the roast chamber

And the temperature
of the clean air

Exhausting from the machine

After the burner incinerates
the smoke generated

By the roasting process.

Workers continue assembly
by installing the cooling tray

Beneath the discharge door
of the roasting chamber.

The cooling tray
sits on a support frame,

Which contains a motor

That turns the stirring arms
inside the tray.

At the back of the machine,

A worker installs
the tray's cooling fan

And the motor that drives it.

This gauge measures
the pressure of the air

That mixes with the gas
going into the machine's burner.

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Next, they install
the circulation fan.

The fan is designed
to withstand high heat

And move air efficiently
throughout the coffee roaster.

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The bottom end
of this stainless-steel tube

Connects to a vacuum motor.

The top end connects
to the tube protruding

From the feed hopper's lid.

To fill the roasting chamber,

The vacuum motor sucks
the raw green coffee beans

Up into the hopper,

Which drops the beans
into the chamber,

Where, as they roast,
their papery skin,

Called the chaff, breaks off.

This separating device,
known as a cyclone,

Connects to the circulation fan.

The fan blows hot air returning
from the roasting chamber

Into the cyclone
at high velocity.

The air circulates in a downward
spiral past the burner

At the base of the cyclone,
incinerating the smoke.

This also draws the chaff
out of the air into a barrel.

Nozzles spray water on the chaff
to prevent it

From catching fire,

Which is a common hazard

With traditional
coffee roasters.

The circulation fan then forces
the clean, hot air

Up and out the top
of the cyclone,

Through this "s"-shaped,
insulated air duct,

Back into the roasting chamber.

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A technician in the factory's
electrical department assembles

The machine's control panel.

Among other components,

The circuitry
runs control systems

And the machine's
six electric motors,

Which operate moving parts,

Such as the bean-drawing
vacuum motor,

The circulation fan,

The cooling-tray fan,
the roasting-chamber paddle,

And cooling-tray
stirring arms.

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Workers then install
the control panel in a cabinet

On the side of the machine.

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They connect all the wires.

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They mount
the machine's computer

Adjacent
to the control-panel cabinet.

Next, a worker assembles
the cooling-tray system.

A motor under the tray
drives the stirring arms.

The hot roasted coffee beans
sit on top

Of the stainless-steel screen.

The cooling fan pulls
ambient air through the beans,

Down through the openings
of the screen,

Then out an exhaust pipe
to the outdoors.

The stirring arms
move the beans around

So that they cool quickly
and evenly,

Which prevents the beans
from continuing to roast.

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The factory runs
every finished coffee roaster

Through multiple test roasts.

After heating the roast chamber
to a specific temperature,

The operator uses
the touch screen to release

The beans into the chamber.

The hot air travels from the
cyclone to the roast chamber,

Then through a return pipe
back to the cyclone,

Where it's cleaned
and sent back to the chamber.

To know when to manually
end the roast cycle,

The operator views,

Smells, and listens
to the beans.

That's because coffee beans make
crackling noises as they expand

And shed their chaff.

The machine
can also be set to end

The roast cycle automatically

When the beans reach
their target temperature.

A trapdoor opens
to draw in ambient air.

This cooler air pushes smoke
in the roasting chamber

Up to the cyclone
for incineration.

The computer
can automatically open

The roast chamber's
discharge door,

Or the operator
can do so manually.

As soon
as the roasted coffee beans

Drop into the cooling tray,

The stirring arms and cooling
fan automatically start up.

If the beans
are perfectly roasted,

The machine is ready
to be shipped

To a coffee-roasting business.