This is what climate protection looks like.

A good climate pays off.

Intelligent Shading Devices

Transparent blinds made from PLEXIGLAS? molding compound protect against sunlight and heat without making rooms dark. That cuts energy costs for air conditioning and heating.
Temperatures in Germany are on the rise: Since 1901, the average temperature in Germany has gone up by about one degree, reports the German Weather Service. The climate has changed. It is getting warmer and warmer and climate zones are shifting.

Hot temperatures make it difficult to concentrate, especially at work. So various methods are employed to make rooms cooler, as can be seen by the strong demand for air conditioning units. European Union studies have shown that cooling requirements will increase fourfold by 2020. Living rooms and workplaces heat up very quickly especially due to sunlight shining on windows and glass fa?ades.

To prevent heat buildup, rooms are usually cooled with cold morning air and windows and blinds are closed later on to keep out the heat. At the same time, the closed blinds prevent glare from the sun or prevent it from shining on computer monitors. But that also has its downside. When the sun is shining outside and the beautiful weather makes us long to be outdoors, blinds obstruct the view and make it dark inside, which means the light has to be switched on. That results in additional power costs.

Shutting out sunrays without making rooms dark  

In cooperation with Evonik, Prismaplex has developed a solution that protects against direct sunlight  and heat, without making rooms dark: blinds made of transparent PLEXIGLAS? molding compound. The blinds reflect direct sunlight via small linear structures on their surface.

“Only lateral sunrays are let into the room. Unlike directly incident rays, these transport less heat, which reduces heat buildup. The blinds provide uniform lighting so no-one suffers from glare,’ says Peter Battenhausen, Business Development Manager at Evonik’s Acrylic Polymers Business Line. Since the PLEXIGLAS? blinds are transparent, they provide a clear view of the sky and only let diffuse daylight into the room. Daylight is indispensable for some activities, such as those that involve color, because its individual shades can only be distinguished in daylight.
The blinds are also worthwhile from a financial perspective, since they substantially reduce air conditioning and lighting costs. Whereas a conventional air conditioning system pushes up electricity costs for every day in use, the blinds counteract heat buildup in rooms by re-flecting sunlight and reduce cooling costs. In addition, there is no need to switch on electric lights because the blinds let enough light in even when they are closed.
The 90-degree prismatic surface structure enables the transparent PLEXIGLAS? strips to provide total reflection. “These are structures with pits and crests of less than a millimeter, so-called optical microstructures,” Battenhausen explains.

New manufacturing process for reproducing the structures

In close cooperation with Evonik, Prismaplex has developed a production process that creates the structures with the highest precision. For this, the company requires a special grade of PLEXIGLAS? molding compound and the corresponding technology. Prismaplex uses special molds that create the precise crests and pits on the surface. The right temperatures during production are essential.  Certain sections of the embossing drum are heated to over 200 degrees and cooled down to 70 degrees within half a revolution. The high temperature melts the PLEXIGLAS? quickly and easily, and the cool temperature hardens the structures in the desired shape. Only in this way can prisms be uniformly and accurately reproduced.

Not every molding compound is suitable for this kind of processing. The right material must have low melt viscosity and special flow properties. “So we developed a molding compound that meets these requirements. The PLEXIGLAS? molding compound also offers high opti-cal transparency and weather resistance,” Battenhausen says. The strips can be supplied in any length, which is new. Previous processes only allowed them to be produced in limited lengths, which was much more expensive as well. The standard Prismaplex products are two to three millimeters thick. The PMMA strips are up to 1,000 millimeters wide.

“The microstructured blinds simply shut out direct sunlight and heat without darkening the room. That makes for a better working environment,” says Battenhausen. It certainly does, and in two ways: room temperatures are reduced and it is more pleasant to work with daylight than with electric light. In the long term, effective sun shields of this type are indispen-sable against the backdrop of constantly rising energy costs. And the next heat wave is sure to come soon.