Mechanical Technology

Mechanical Technology — April 2016

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Structural engineering materials, metals and non-metals

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Bandra Ohm will be a residential tower block, shaped like the Greek letter

omega and inspired by the fluidity and movement of water.

Photo: James Law

Cybertecture International.

This is what a city street might look like with a combination of different dis-

play elements on the solar roadways of the future.

Photo: Scott and Julie Brusaw.

SCHOTT makes ultra-thin glass using a down-draw process, where the glass

is continually drawn directly from the smelter through a nozzle, forming a

glass ribbon. This ribbon is then coiled for further processing.

Photo: SCHOTT.

can be made powerful enough so that the

absorbed energy can be used to increase

the range of an electric vehicle.

Display screen glass technology

Everyone has display screen glass at their

fingertips on a daily basis, whenever they

use their smartphones. In Germany alone

it is used by 44 million citizens – and the

trend is still upward.

It seems that wherever we go we are

continually accompanied by ultra-thin

display glass. And, of course, it needs to

be particularly impact-proof and scratch-

resistant, so that it can withstand normal

stress. We also want it to feel good and

be easy to clean – and it needs to weigh

as little as possible. This creates a rather

difficult balancing act for the producers.

Glass continues to be an unrivalled

material for touch screens. But we are

seeing more and more power and func-

tionality having to be accommodated in

fewer and fewer square centimetres of

space. This means that the heat pro-

duced by our devices is increasing due to

ever more powerful, yet smaller electronic

components. The solution to the problem

is ultra-thin display glass, glass being an

ideal material for retaining its stability

and shape despite rising temperatures.

The secret of thin glass is in the ma-

terial composition. The constituent that

has gained ground in the glass industry

is aluminium silicate, which is highly re-

silient and reduces reflection. Multi-touch

screens are produced from float glass that

has been chemically pre-stressed via ion

exchange. A semiconductor film is then

attached to the glass to add optical and

capacitive properties.

Production gets even more delicate

when we look at ongoing developments

in ultra-thin glass. Operating under the

name KONFEKT, three major companies

in the industry – SCHOTT AG, tesa SE

and Von Ardenne GmbH – are currently

working on a project to develop ultra-thin

glass for use in organic electronics and

OLED applications. The project is sup-

ported by the German Federal Ministry

for Education and Research.

The aims are ambitious, researching

all the various manufacturing and finish-

ing processes in connection with ‘glass

from the roll’, and indeed in such a way

that glass can be used for functions

in organic electronics, such as OLED

technology. Users particularly appreci-

ate the basic properties of glass, i.e, it

is impermeable to gas and water and

can protect sensitive componentry from

moisture and oxygen ingress.

The underlying process has been de-

veloped by the German glass manufactur-

er, SCHOTT, which is using a down-draw

process, whereby a glass sheet is drawn

down through a cooling section. Accurate

process control is applied to achieve the

tightest of manufacturing tolerances with

respect to uniformity of thickness for

large yet very thin surfaces. The process

makes it possible to produce glass to a

thickness of 25

m – half the thickness

of a human hair (50

m). Applications

are already being found in biotechnology

and sensor applications and the material

is now available in sheets, wafers or rolls.

Innovations and further developments

of ideas such as these we will be show-

cased at glasstec 2016 in Düsseldorf

from 20 to 23 September, with selected

outstanding innovations being high-

lighted at a symposium called Glass

Technology Live on 21 September, being

held under the auspices of the VDMA

Glass Technology Forum.

The glass can react to sunlight to

automatically produce shade, to light

up or to transform the incoming light

into electric power. BMW is seeking a

transparent and flexible carrier mate-

rial that will make it superfluous to

scrape ice off their cars.