Harrodsburg, Kentucky is Corning's oldest glass

factory. This facility was built for ophthalmic

glass pressing in the early 1950s.

And then in the 1980s, we transitioned into the

fusion forming process to make LCD glass. That

grew into an enormous business for us within Corning.

But about six months before the first iPhone was

released in 2007, Steve Jobs made a call to the

CEO of Corning and asked the company to create

glass that could withstand scratches and breakage

for a new Apple product. Before that phones were

typically covered in plastic.

Corning quickly developed Gorilla Glass and this

factory went through a complete transformation.

We leverage the fusion forming technology to make

Gorilla Glass and to make the first composition

of Gorilla Glass here in Harrodsburg. Since 2007,

I could say that the Harrodsburg plant has

undergone a number of innovations to support all

of the new Gorilla Glasses as they transition to

stronger and more scratch resistant and more durable glass.

The same company that developed the glass for the

Edison bulb in 1879 is now making the glass that

covers 6 billion smartphones, tablets, screens

and wearables worldwide. We got a rare look

inside Corning's flagship Gorilla Glass factory

to find out how it's made.

Robots and massive machines are continuously

making glass 24/7 here. It starts with a mix

materials that are sourced from all over the world.

Here we are in the mix house. This is really where

the heart and the start of the Gorilla Glass

composition begins.

Some people may think the glass is just sand but

it really isn't. There's a lot of complex science

that goes into Gorilla Glass specifically.

It is extremely important that we have a strong

and robust recipe. So as you think about how you

make your cake at home similar to that we have

fine tuned and evolved the process for making

glass over decades. What you can see in the

facility are screw feeders and feeding systems

that will take that material and transition it

into a large bowl where it will be mixed so that

we ensure that the mixture is homogeneous and can

create the best glass possible.

One bag, as you see here, once it's filled will

actually turn into thousands of sheets of Gorilla

Glass. The raw material then travels up seven

stories to the top of the factory. Where it

enters a giant oven turned up to more than 1,800

degrees Fahrenheit. Corning did not allow us to

film the oven for fear that competitors would

figure out its secret sauce and take a chunk of

its $11.4 billion in sales in 2018. But it was an

impressive giant machine that melts the raw

material to hot molten glass over the course of

days. The lava-like glass then flows down several

stories while it cools and strengthens in a

process called fusion forming. So to describe our

fusion forming process, if you imagine a trough

and the glass comes into the top of that trough

and then flows over the edges of the trough down

to the point where it fuses together.

It's really fusing together in air and nothing

touches that pristine surface so both sides of

the glass are pristine as it transitions down

multiple stories to the bottom of our process

where it's then scored and separated into

discrete sheets. Fusion forming process is

capable of making thicknesses of glass over two

millimeters down to 100 microns or dot one

millimeter, which is just larger than the size of a strand of hair.

The glass comes out of the fusion process in

sheets that are cut as big as 9 feet by 10 feet.

Only robots touch the glass throughout the

process. And sometimes the robots make mistakes.

So as the glass transitions to this final step

before it gets shipped and packed realize that

the glass has never been touched by human hands.

When it gets to this final step, we laminate the

glass to protect it both for shipping and to

allow our customers to handle the glass as they

pull the sheets out of the crates. The sheets are

then transitioned into crates where they're

further packed and ensured that they're in

pristine condition as they ship.

Early on in fusion glass development there were

some manual steps but we found that those manual

steps could impose safety concerns. And so the

robots were really developed to enhance our

manufacturing process and to eliminate the safety

involved in handling glass.

We can create glass from extremely thin to 100

microns to two millimeters thick.

Depending on the thickness of glass, it really

determines how many sheets of glass we pack in a crate.

But crates in general can have hundreds of sheets

within one crate. We really have limited breakage.

Once it's loaded into crates the glass is then

shipped off for finishing, which is done all over

the world depending on the preference of the

device manufacturer. Gorilla Glass is one of the

toughest glasses out there. And what makes it

tough is not only what you see here because it

actually hasn't obtained all of its strength at

this point. After it's packed and shipped it goes

through a chemical strengthening process called

an ion exchange process. The composition that

we've set up allows us to then take a finished

sheet of glass put it into a bath of hot salt and

in that bath of hot salt sodium ions are

exchanged for a larger potassium ions in the glass.

And if you imagine those larger potassium ions

pack into that glass causing a much tighter and

stronger compressive area on the glass. And

that's really what gives the glass its strength.

Corning employs 400 people at this factory, many

of whom are focused on quality control and

research as device manufacturers demand thinner and sleeker phones.

Corning is constantly having to update and improve

Gorilla Glass to try to keep this from happening.

What makes Gorilla Glass so strong is the unique

composition and glass science behind the glass.

That allows us to create this compressive layer

that, when it is ion exchanged, creates really a

layer of armor and an extra strength that other

glasses are not capable of doing.