Smart windows by LC-glass

Facilities for the LCD Industry

Machines for the Production of Smart Windows - Innovative LC Glass Technology

Production of Smart Windows - Basics

Smart Windows are switchable sun protection windows or privacy windows but also switchable building windows or glazings, manufactured through innovative LC glass technology. They offer flexible adjustment options between transparency and opacity, brightness and dimming. Smart Windows represent a groundbreaking innovation in the world of glazing technologies. Through the smart application of liquid crystal technology or electrochromic materials (EC type), these windows can be switched not only clear or opaque but also milky. This flexibility allows individual control over light transmission and privacy, making Smart Windows an intelligent and practical solution for modern architecture, smart glasses, plant cultivation, or military applications. The liquid crystal display (LCD), consisting of only one or a few pixels, allows the entire window or parts of it to be switched to the desired state via electric control. Similar to a conventional LCD, various grayscale levels and even color effects can be set. The EC type also changes its thermal and light transmission properties in response to an applied voltage. These intelligent windows are manufactured using proven LCD technology, but without the need for the high resolution required for smartphone or TV displays. However, with large glass surfaces or other substrates, precise and error-free processing is essential.

Where Innovation Begins: Our Production Equipment for Smart Windows

Fertigungstechniken

The production of smart windows presents a unique challenge for equipment manufacturers, as the glass is much larger, thicker, and heavier than the substrates typically used in the LCD sector. In addition, constantly changing glass sizes and shapes are required for buildings. Our partner Shindo has specifically addressed this issue and, due to its many years of experience in the LCD sector, can offer all the equipment for a complete production line. These are individually adapted to your specifications, substrate sizes, materials, shapes, and throughput to find the best possible solution for your process.

The state-of-the-art production equipment of our Korean partner Shindo utilizes cutting-edge technology, especially liquid crystal technology, to produce smart windows, but also production lines for EC type smart windows are available. An overview of the machines required for both technologies, their advantages and disadvantages, and details of the machines required can be found further down the page.

Smart Windows Comparison: LC Type (Liquid Crystal) and EC Type (Electrochromic Materials)

Liquid Crystal Type

Electrochromic Crystal Type

Operating Principle:

Use of liquid crystals that change orientation when an electric field is applied, thereby altering light transmission and scattering

Operating Principle:

Color change through electrochemical redox reaction, which alters light absorption

Substrate:

Glass on glass
Film on film

Substrate:

Film on film

Advantages:

Very fast switching
Larger switching range between light and dark or opacity
Excellent privacy protection
Very high durability
Generally lower acquisition costs

Advantages:

Power is only required for switching
Good control of solar heat and IR absorption

Disadvantages:

Continuous power consumption in transparent state
Minimal effect on heat radiation and UV light

Disadvantages:

Slow switching
Slightly shorter life expectancy
Lower dimming range

Ultrasound Cleaning (USC) System

USC Dry Surface Cleaning with Ultrasound

Precise Cleaning Without Wetness

DDry surface cleaning of glass or other substrates using ultrasound (US) prior to the actual manufacturing process ensures thorough cleaning of the glass surface without the use of liquids. This helps prevent any degradation in the performance of LC glasses due to moisture absorption.

Preservation of Structural Integrity

USC removes dirt particles and contaminants gently, without compromising the structural integrity of the glass.

Environmentally Friendly

Since USC is a dry cleaning method, it does not require additional cleaning agents or water compared to wet cleaning methods. This contributes to environmentally friendly production practices.

Efficient Cleaning of Large Surfaces

The process is suitable for mass production of large glass surfaces, minimizing production costs.

TCO Coating System

Transparent Conductive Oxide Coating (TCO Coating)

Transparent Conductivity

In the second step, a transparent, conductive oxide layer is applied. Typically, this is an ITO coating (Indium Tin Oxide). This ITO coating provides transparent conductivity, electrical controllability, and a homogeneous coating with low resistance.

Electrical Controllability

With an indium tin oxide coating, transparent electrodes can be generated. This means that by applying an electrical voltage to the ITO coating, changes in the optical properties of the switchable window can be induced. This electro-optical controllability is crucial for the window's ability to switch between different states, such as transparent and opaque.

Polyimide Coater

Polyimide Coating (PI)

Compatibility of polyimide

Polyimide (PI) is applied as a transparent protective layer on the glass surface. It is compatible with the materials in switchable windows and provides flexibility for various glass shapes.

Alternatives to Polyimide

It should be noted that there are also alternatives to liquid crystal, such as electrochromic materials, electro-optic polymers, PDLC (Polymer Dispersed Liquid Crystal), and electroactive polymers, which can be used in some smart window processes without polyimide coating.

Kalandar, Rollen-Presse fÃ¼r vollautomatische Produktionslinie

Rubbing Machine

Molecule Alignment by Rubbing

Der The rubbing process allows for the alignment of polyimide molecules. This influences the alignment of liquid crystal molecules and enables a uniformly pre-defined transparency or opacity. The contact pressure and the angle of the rubbing roller can be freely chosen.

Spacer Spray Coating System

Application of Spacers

Zweck der Spacer

The Spacer Spray System is used to spray microscopically small spacer particles (balls) with a defined size onto the surface of the glass layer. These spacers act as spacers between the upper and lower glass layers, ensuring a uniform gap. Both regular spacers in various sizes and adhesive spacers (sticky) can be used. For high-resolution displays and applications such as smartphones or TV devices, spacer spray technology has been replaced by lithographically produced photo spacers. However, for smart windows, spacer spray technology is more suitable and cost-effective due to the very large glass surfaces.

Curing to Fix the Spacers

Depending on the specific process, after applying the spacers, a curing process is integrated to ensure that the spacers adhere firmly to the surface. This step is crucial for the stability and precision of the distance between the glass layers, which in turn has an impact on the uniformity of the tinting of the switchable windows.

ODF Dispenser Machine

ODF Dispenser System for LC filling (Liquid Crystal)

The precise and homogeneous application of sealant and liquid crystal (LC) is crucial for the flawless functionality of the window. The dispenser system plays a decisive role in this.

ODF Technology (One Drop Filling Technology)

This process step is of central importance for the production of smart windows and has a significant impact on the final result. Our systems rely on ODF Technology (One Drop Filling), which allows extremely precise dosing. Before the glass plates are joined under vacuum, the exact amount of liquid crystal is dosed onto the lower glass plate.

High-Precision Dosing

This method requires high-precision dosing, as an excessive amount may overflow during assembly and compression, while too little dosing could leave bubbles.

Homogeneous Distribution

The single-drop method ensures not only accurate dosing but also a homogeneous distribution of the material across the entire glass surface. This is crucial to ensure that switchable windows exhibit uniform performance and optical quality. Thus, the dispenser system significantly contributes to perfecting smart window manufacturing.

Vacuum Laminating Machine

Avoidance of Gas Inclusions

The vacuum laminator presses the upper and lower glass layers under vacuum, where precise pressure distribution and accurate operation are crucial to prevent the formation of gas bubbles.

Vakuum Laminierung

Final curing Machine

Curing through UV Radiation or Thermal Curing

Finally, the curing of the entire window takes place. During this process, the sealant and any other materials used in the window are activated and cured through supplied heat or UV light. Simultaneously, uniform pressure is applied to adjust the layer thickness of the liquid crystal. Both thermal and UV curing methods contribute to improving the end product properties of switchable windows. They ensure a stable structure, good adhesion between different layers, and increased resistance to environmental influences. The choice between thermal and UV curing depends on the specific requirements of the materials used and the manufacturing process.

Our manufacturing facilities stand for efficiency, quality, and state-of-the-art technology. Contact us to learn more about how we produce innovative smart windows.