All language subtitles for S21E10 - Customized Knee Replacements; Leaf Springs; Lavender; Rivets and Rivet Tools (1080p AMZN WEB-DL x265 Garshasp)_track3_[eng]

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Narrator: the typical candidate
For a knee replacement

Has osteoarthritis,

Where the cartilage in the knee
Has worn away.

Knee replacement surgery

Restores the worn areas
With an implant.

To help place
The implant properly,

The surgeon can use
An instrument custom-designed

For the patient's
Damaged anatomy.

A successful knee replacement

Depends on its alignment
With the femur and tibia,

The upper and lower leg bones
That connect at the knee.

That's a challenge because
Knee implants are standard,

While every patient's bones
Are unique.

So starting with an mri scan
Of the patient's knee,

This medical device company

Produces custom-made
Surgical templates,

Plastic devices the surgeon uses

To sculpt the surface
The patient's bones

To align the knee implant
Accurately.

The surgeon no longer has to
Visually calculate the bone cuts

On the spot
In the operating room,

Which takes more time
And is more invasive.

An engineer uses the mri scan

To create 3-d models of
The patient's femur and tibia.

The patient's cartilage has
Worn out in between these bones,

Causing painful rubbing
That erodes the bone surface.

The implant effectively replaces
The damaged bone and cartilage.

Once each bone model is ready,

Another engineer
Applies a 3-d model

Of the correct-size implant,

Then, following directions
The surgeon has provided,

Performs virtual surgery
On the bone model.

This will properly align
The implant

To the patient's
Specific anatomy

And fit it to the angle at which
That particular knee moves.

During the surgery simulation,

The computer records
Every bone cut.

The surgeon reviews
And approves this surgical plan

Only once
Before manufacturing begins.

The computer,
Which recorded the bone cuts,

Guides a 3-d printer
To produce plastic templates

For both the femur and tibia.

The surgeon will use these

To repeat the same exact cuts
In real life.

The 3-d printer applies a layer
Of powdered plastic,

Then following
The computer model,

Solidifies select areas
With a laser.

This process keeps repeating,

Building up the shape
Of these surgical templates

Layer by layer.

One printer run produces
Personalized templates

For up to 50 patients at a time,

So the laser inscribes
The patient's name

And identification code
On each part.

Once the printing's done,
It's just a matter

Of breaking up the unsolidified
Powdered plastic...

...And fishing out
The templates.

They brush off the bulk
Of the remaining powder.

The posts on the bottom

Are the points at which pins
Affix the template to the bone

During surgery.

Next, the templates go
Into a tumbler

Containing plastic balls
And air jets.

As the drum rotates
For 20 minutes,

The balls knock off
And the air jets blows off

Most of the remaining powder.

The templates exit the tumbler
90% clean.

They go through two wash cycles

To remove the last remnants
Of powder.

Before packaging,
They'll be sterilized.

But first,
Every template must pass

A quality-control inspection.

Using a laser,
A technician scans it

To make sure
The manufacturing process

Produced an exact match
To the patient's bone.

This model shows how the femur
And tibia form the knee joint

And how the surgeon secures
The customized template

Onto each of these bones.

Thanks to these devices,

The surgeon doesn't have to
Figure out the bone cuts

On the fly
In the operating room.

They're all pre-calculated
By the computer model.

This method eliminates
Several steps required

In standard surgery.

The operation takes less time

And requires
Half as many instruments

To set up and clean up.

And because the surgeon

No longer has to drill a hole
In the bone

To check the knee implant's
Alignment,

The patient experiences
Less pain and bleeding

And a smaller chance
Of developing complications.

Narrator: the earliest version
Of leaf springs

Were likely
Flexible wooden poles

Used in carriages
In ancient rome.

In the early 19th century,

Metal leaf springs
Were developed.

Today the journey continues,

And it's fairly smooth thanks
To these suspension springs.

A leaf spring is a stack
Of curved plates or leaves,

Or sometimes even just one.

This spring has the flex

To absorb bumps and dips
In the road,

But it's strong enough
To provide serious support.

Today these super-strong
Suspension springs

Are generally used for trucks
And other heavy vehicles

More than cars.

Production starts
With spring steel.

It's an alloy
That has elasticity.

Big shears cut the steel
To various lengths

For a multi-leaf spring.

It's one of the two kinds
Of leaf springs.

Using a band saw,

They cut steel for the other
Kind of leaf spring,

Known as a full taper spring.

It's made of one to four leaves

That are approximately the same
Length but various thicknesses.

After cutting,
They rapidly heat the ends.

Computerized machinery
Rolls and stretches the piece

To a tapered profile.

This achieves
The same flex effect

As the progressively shorter
Leaves on the multi-leaf spring,

But the end product will be
Lighter and not as stiff.

Next, it's into a press
That trims the stretched ends

And punches holes
For various components.

It takes about an hour

For the steel to cool down
For the next operation.

Meanwhile,
Other members of the team

Are hard at work
On the multi-leaf spring.

They feed the heated tip
Of the main leaf

To a machine that wraps it
Around a die form.

This creates an eye mount

For attaching the spring
To the vehicle.

They create an eye mount
On the other end, as well.

Next they curl the ends
Of a slightly longer steel bar

Into a loose "C" shape.

This piece will serve
As an outer protective wrap

For the main leaf
And protect the eye mounts.

Back to the taper spring,

Hydraulic machinery bends it
To the final "Z" shape

So it will fit around
A vehicle axle.

They soak both the taper
And multi-leaf springs in oil

And temper them in a furnace
To strengthen the steel.

Then it's time for a process
Known as peening.

Machinery clamps
The steel leaf onto a carriage,

Which takes it through a chamber

For blasting
With tiny steel pellets.

The blasting
Changes the surface tension,

Further strengthening the metal.

A worker now assembles
The multi-leaf spring.

He inserts a pin through
The center of the main leaf

And wrap to align them.

Each of the next leaves
Is shorter than the last.

They're known
As graduated leaves.

It's a design that will make
The spring more flexible.

He transfers the stack
To a hydraulic station...

...And inserts a different pin
For more precise alignment.

He activates
The hydraulic mechanism,

And it squeezes
The leaves together.

The mechanism maintains
The leaves under tension

As he removes the pin
And now bolts them together.

He pounds clips installed at
Specific locations on the spring

To close them
Around the leaves.

The clips tighten the stack
All the way across

And will stop the leaves
From twisting or turning.

Next, another hydraulic device
Applies pressure,

This time to simulate the load
The spring will carry.

This sets the spring
To a specific height

And compresses it to stiffen
The overall performance.

The worker measures the spring

To confirm that it meets
The specifications.

The assembled leaf springs

Now take a quick dip
In a tank of black paint.

The paint coats the leaves,
Clips, and fasteners

To give these suspension springs
A uniform finish.

Painted black,
They should blend in

With all the other components
On the vehicle's undercarriage.

Now complete, these leaf springs
Can be depended on for support

When the going gets rough.

Narrator:
Lavandula angustifolia

Might sound like a name
Of an ancient roman emperor,

But it's actually the scientific
Name for the lavender plant.

The leaves
And striking blue petals

Of this aromatic flowering shrub

Are used to make
Lavender essential oil,

An ingredient in many health
And beauty products.

Lavender essential oil
Has antiviral, antibacterial,

And anti-inflammatory
Properties.

No wonder it's long been
A natural remedy

For many ailments.

And with its flowery fragrance
And relaxing effects,

It's a common ingredient in
Lotions, soaps, and bath oils.

Lavender is a perennial plant

That begins flowering
In its second year.

Harvest time at this
Canadian farm is in july,

At the peak of the first bloom.

There's a second bloom
Afterward,

But not significant enough
To warrant another harvest.

Weeds like to grow at the base
Of lavender plants,

Siphoning off water
And important soil nutrients.

So between may and september,

Killing those weeds
Is a vital daily ritual.

The weeding machine

Lifts the lavender stems
Out of the way,

Then blasts the weeds
Around the base with hot steam.

To determine
The right time to harvest,

The producer looks
At the quantity of blooms

And the color of the flowers.

They should be purple-blue,

On the verge
Of turning grayish-brown.

The producer
Also crushes a few petals

To see how much oil comes out.

The harvester is specially
Designed for cutting lavender.

Like a stylist cutting hair,

It pulls the stem straight up,
Then snips near the base.

The cut stems,
About 15 inches long,

Fall onto a conveyer belt,
Which moves them into a tray.

From there, workers manually
Transfer the lavender

To the harvester's trailer.

When the trailer is full,

The harvester delivers its load
To the on-site distillery.

Workers load the lavender
Into a still,

A large stainless-steel vessel

Typically used to produce
Alcoholic spirits.

They compact as much lavender
As possible into the still

To prevent the formation
Of air pockets.

The less air,
The greater the oil yield.

Once the still is stuffed
To compacted capacity,

They close it tightly

And start up
An oil-fired boiler.

The boiler
Heats water into steam,

Which they then inject
Into the bottom of the still

At very low pressure.

Over the course
Of about 15 minutes,

The steam slowly rises
To the top of the still,

Heating the lavender
Along the way.

They continue the steam
For another half-hour or so.

This bursts the glands
Located primarily in the petals,

Releasing the oil.

To collect that extracted oil,

They feed cold water
Into a coiled pipe

Running through the still.

When the hot steam
Hits that cold pipe,

It condenses,
Transforming back into water.

Only now, the water contains
Lavender oil.

They open the still's tap

And let the water flow
Into a holding tank.

On average,
The proportions are

One part lavender oil
To 40 parts water.

In the holding tank
Over the next hour or so,

The oil naturally separates
And rises to the surface.

At that point,

They begin pumping the water
To another container,

Stopping
At the first sign of oil.

What remains in the tank
Is the final product --

Pure lavender essential oil.

The pumped-out water

Is a secondary product
Called lavender flower water.

The producer sends both products
To a laboratory to be filtered.

Producers primarily sell
Lavender oil and floral water

As ingredients to manufacturers
Of health and beauty products,

But they also often design

Their own lines
Of lavender creations

For pampering the body and soul.

Narrator: rivets hold
A lot of things together.

Product fabricated with rivets

Include aircraft,
Cars, computers,

And household appliances.

Installed with a rivet tool,

These fasteners create
Strong and permanent joints.

Without rivets, a lot of things
Might fall apart.

Whether the job
Is large or small,

Chances are
There's a rivet for it.

And using a special rivet tool,

It's possible to form strong
Attachments quickly and easily.

The two together
Make a perfect match.

The rivet tool starts
With a precast aluminum handle.

A technician
Inserts a steel sleeve.

It will serve as a chamber
For hydraulic fluid.

The spring for
The tool's trigger is next.

She screws an aluminum plate
To the base

To enclose the two parts
And the handle.

This is
The pulling-head assembly.

It has tiny jaws
To grab the rivet stem.

She lubricates it

And presses it into the main
Bore of the rivet tool.

She installs a fill screw
In the top of the handle casting

For top-offs of hydraulic fluid
During servicing.

But the initial supply
Of hydraulic fluid

Is added through
The steel sleeve at the bottom.

She inserts
An air-piston assembly

Into the fluid-filled chamber.

She threads a screw into
The nose of the rivet tool.

This keeps the internal workings
In the correct position

For the next step.

She places the base of the tool
Into an air chamber,

Then hooks up an air hose

And secures it
With steel clamps.

She plugs the tool
Into an air supply

And pulls the trigger.

The air puts pressure
On the hydraulic fluid inside

To activate
The riveting mechanism.

And now the test --

She places a rivet
In the nose of the tool,

Then inserts
The other end of the rivet

Into a hole on the test plate

And presses the trigger.

The tool efficiently installs
The rivet in the hole.

It's time to stock up on rivets.
They make them from round wire.

A machine
Cuts the wire to length

And then punches it
Into a die twice

To form a rivet stem blank.

Here's the cutting and forming
Action in slow motion.

The machine operates in a blur,

Producing 200
Rivet stem blanks a minute.

The stem blanks move
Between serrated rolling dies.

The dies form grooves

To allow the stem to be gripped
By a rivet tool.

They also make ridges that
Will serve as a breaking point

During rivet installation.

This is a slow-motion close-up

Of the serrated rolling dies
In action.

Here's the rivet stem
Before and after forming.

The next machine
Creates the rivet body.

It cuts wire
To the correct length

And forces it into dies.

It takes five punches
To transform the solid wire

Into a hollow rivet body.

These machines can produce
Up to 300 parts a minute.

Next, the rivet bodies go for
A tumble in a cleaning solution

To remove oily residue
Left by the forming.

The rivet stems also undergo
This thorough washing.

The rivet bodies
Then travel through a furnace.

The intense heat
Followed by a gradual cooling

Hardens the metal to free it
From internal stresses.

After zinc-plating,

The rivet bodies
Head towards the next station.

The rivet stems
Are also on the move.

They travel through a channel
That gradually widens

To sort out stems
That are too big or small.

The undersized stems
Fall through at the beginning,

And oversized ones
Fall off the end.

A magnet loader collects
The correctly sized stems,

And rejects are discarded.

The rivet stems
Cling to the loader,

Which is stopped at the moment.

The rivet bodies
Now ride a carrousel.

It pauses briefly

To allow a stem
To be inserted into a body.

These are slow-motion shots,
And back in real time.

These machines work fast.

They pump out
Millions of rivets a day.

The rivets are now ready to
Leave this factory for another,

Where they could be used
To make almost anything.

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