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How Windscreens Are Made

To make a windscreen they start with a plane sheet of glass an automated plotter with the cutting wheel runs over it and the wheel scores the glass.

Now a robotic arm brandishes a torch it moves along the score line and the thermal shock completes the cut. This is the best way to cleanly cut through glass.

Next a robot suctions off the piece of glass and transfers it to the next station where it pushes the glass against the series of sanding belts to take off the sharp edges. This process is called seaming.

Now a conveyer belt takes the glass through some soapy water to clean it up then nozzle spray the glass with a mix of talcum powder and water, this will prevent the glass from sticking to a second sheet of glass.

A robot now sets that second piece of glass on top of the freshly sprayed one. This is a temporary arrangement.

The two sheets of Glass are layered for processing but will be pulled apart later.

Next they silk screen black paint around the border of the glass that will eventually be the inner part of the windscreen.

Then automated arms carry the glass to a station where samples are inspected visually.

After that rollers transfer the glass to automatic squaring packs to line up the two sheets of glass and then a robot lifts the sheets of glass and carries them to four metal pins.

The pins recede and the glass falls onto a bending iron. The iron is shaped like a specific windscreen. The conveyer takes the bending iron with the two glass sheets in to an oven called a bending Lear. The glass heats to 750 degrees causing the glass to sink into the shape of the bending iron then glass goes through a slow cooling cycle to anneal or toughen the new shaped.

Next a robot picks up a sheet of  PVB vinyl cut in the shape of a windscreen and it takes to one of the two pieces of glass just separated from the other piece. Then another robot lowers the other identical piece of glass onto the vinyl. And that’s the formula for glass lamination. Two layers of glass with a piece of vinyl between them.  In the event of an accident the windscreen will fracture but not totally shatter because the vinyl will hold most of the Broken Glass together.

At this point there’s no Clearview through that milky white vinyl that’s why the windscreen is headed to a machine called a nipper. The Nipper presses the windscreen through rubber rollers squeezing the air pockets in it. As the air is removed the view through the vinyl gets a bit clearer.

Now squaring Parkes position the windscreen and a robot fits brackets for the rear view mirror on it. This big blue chamber is an autoclave. It’s like a pressure cooker. After about an hour in there any remaining air pockets in the windscreen are removed.

A rail system transports the tub full of windscreens to the inspection station.

Here each windscreen goes through a close-up inspection by human.

He searches for surface scratches chips or any contamination between the glass and vinyl layer.

Now they placed a 2 and a quarter kg steel ball in to a pulley system that rises at 4 metres high yes this is a crash test for sample windscreen. The ball represents a driver head. The ball hits the glass but doesn’t go through which means the windscreen has passed the safety test.

Now they view each windscreen through polarised light to reveal stress defects in which only a trained eye can spot them.

Ones it’s decided that everything looks good the windscreen is ready for the road.

And now the view from the driver seat is clear as glass

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