Manufacturing Process of Smart glass
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What is Smart Switchable Film?
Switchable Film, (also referred as Smart Film, Smart Tint or PDLC Film) is a switchable technology that can manipulate light transmission between transparent and private opaque, through the use of an AC power. With the improvement in moisture resistance, our 4th generation of the switchable film can directly installed on existing window glass with its self-adhesive feature or special tape. Multiple functions are available with the switchable film which include, light adjustment, Harmful rays block (UV and IR), advertising and security.
How switchable film is made?
The main component in Switchable Film (PDLC – Polymer Dispersed Liquid Crystal) consists of two layers PET sheets with ITO conductive coating and liquid crystal microdroplets coated in the middle of ITO film which is suspended in the polymer.
The natural state of the smart film appears the PDLC is randomly arranged, in a way that causes light wave is scattered, and reflected away from the surface, distorting the state of the glass to presented as opaque. When electricity is applied through the PDLC layer, the liquid crystal molecules lined up, allowing light to pass through, which creates a transparent surface.
Most of the smart film is operated under certain voltage (48/60vac) which require a transformer to supply the appropriate voltage.
Standards PDLC film is composed of multiple layers-
The two outer layers protective film which is a kind of PET film to protect the smart film from scratch.
Two-layer ITO film, which is full named as Indium Tin Oxide film, – on which the conductive material is coated, enabling electrical current to pass through the PDLC material, allowing optical clarity.
PDLC core, the main material is composed of liquid crystal droplets that are suspended in polymer and then coated in the ITO film to allow for the electrical current to pass through it.
Under the state of power off, the smart film appears with its natural state as a private opaque. The PDLC core is randomly arranged. Such a way, it makes the glass appears with the frosted state, And the benefit is it still allows a small part of the light to penetrate the layers.
When the PDLC film is turned on, the surface is transparent, while due to the nature of the technology, the switchable glass may present with a slight haze, which is not optically clear as standard glass.
The smart switchable film can be used for existing window. And type of lamination(Non-adhesive) PDLC smart film is mostly used for the production of switchable glass, which includes the following forms as below:
Laminated switchable glass
It’s the most common type of smart glass with a switchable layer laminated between 2 pieces of toughened glass.
Toughened switchable glass
The switchable layer is pre-coated on any thickness glass in the factory.
Double glazed switchable glass
Double glazed units are integrated with the PDLC film layer, which is an energy-efficient solution for buildings.
Two main classifications of the switchable film: self-adhesive smart film and lamination/non-adhesive smart film
Self-Adhesive Switchable Film
It a kind of switchable film with a surface treated with special glue, which can be applied for any existing windows. The benefit is there is no need to replace the glass, just a simple stick, the film will be bonded on the glass.
Lamination/Non-adhesive switchable film.
Non-adhesive smart film is mainly applied to produce switchable glass. It can also be bonded on the glass with special glue.
What is Switchable Glass?
Smart Glass is a kind of opto-electrical laminated glass, which is also called as switchable glass. It is an innovative building material that allows the transparent window to be switched on-demand, from clear to completely private opaque.
The laminated smart glass is composed of two layers toughened glass on the outer side, PDLC smart film in the middle integrated with EVA/PVB film to form a sandwich-like structure. All the materials are bonded together through an autoclave machine. The smart glass is opaque when switched off, and turns transparent when switched on. It’s a kind of safety glass, sometimes is used a projection screen. A wide range of glass can be chosen such as laminated glass, insulating glass/double glazed panel, fire rated glass, sound-insulating glass, curved glass, etc. it is widely used indoors, windows, partitions, curtain walls, skylights, furniture and other transparent surfaces in various sectors including automotive, architecture, residential space, interior design, retail window, and consumer electronics.
The frosting level of smart privacy glass can be easily controlled by applying the appropriate voltage, such the same with heat or light. Your window glass can change from transparent to translucent by applying switchable glass. It can block UV and IR rays which is harmful to people and let others pass through.
There is also a kind of smart glass which is called solar smart glass. It doesn’t need electrical powered on, and the con is that it needs a long time to switch the glass. As per its requiring electrical power or not, the smart glass is classified with active and passive. Today what we mainly talk is about active technology smart glass.
Synonyms for smart glass include:
Switchable glass | Smart Film | Smart Tint | Adjustable Glass | Dynamic Glass | Intelligent glass | Privacy Glass | Switchable Film | PDLC Film | Tintable Glass | Electric Glass
Smart Glass is particularly poplar for space with a glass walls, and partitions, with that, can replace traditional curtains and blinds which can ruin design aesthetics.
How Smart Glass Works?
The Switchable glass technology allows the control of various forms of light (Visible, IR, UV). With applied electrical power, the glass is switched from frosted to transparent, allowing for dynamic light control.
Using PDLC technology, that makes up the smart glass with a laminated interlayer or retrofitted film onto the glass
Two forms that smart glass is finally reached, using PDLC interlayer film that is laminated or retrofitted onto the glass.
The interlayer film consists of two PET transparent sheet, firstly with PDLC coated in the middle, then have ITO conductive coated on the surface. The ITO conductive coating force the PDLC layer to align, creating transparency when electrical power is applied.
As voltage decreases and the film starts turning to opaque, it allows a varying levels of opacity for dynamic shading and privacy, That is we called dimming effect. By controlling the voltage applied to the film, it is reached.
Smart glass generally uses a transformer or power controller to manipulate power. It is switchable, dimmable and WIFI enable. Transformer needs to be turned off at least once per day.
How is Switchable smart glass made?
Smart glass is manufactured by laminating with PDLC polymer interlayers integrated with PVB or EVA films. All steps are requested to be done in a high-quality environment (Dust-free and constant temperature and humidity) to ensure the durable quality of the glass.
There are two steps for smart glass production-
Step 1: Glass process
- Glass Cutting: all glass is cut into ordered measures.
2. Drilling: Holes can be drilled in the glass substances we offer. All toughened smart glass can be treated with large holes, cut-outs, notches, AC fan holes, etc.
3. Edgework.
Edgework is the term applied to grind, smoothing and polishing the edges of glass panels. Such a step makes the glass much safer to handle and gives the final products an attractive appearance with either ground or polished finished edges.
4. Glass toughened treatment.
After step 1, Toughened glass panels are ready for next step lamination.
Step 2: Lamination
1. Clean the Glass
Before producing the smart glass, all glass should be cleaned ensuring no stains or dust on the glass panels.
2. EVA film Coating
Cover the glass with one layer of EVA film.
3. PDLC Film Coating
Prepare the lamination PDLC film with busbar and wires installed with the same size as toughened glass. Peel the protection film on both sides of the PDLC smart film. Cover the EVA film with PDLC Switchable FILM.
4. EVA film Coating
Cover the PDLC film with another layer of EVA film.
5. The 2nd glass coating
Cover another cleaned glass on the top.
Note. All the steps should be handled in a dust-free room.
Trim the extra EVA film edges, to reach the same size as toughened glass.
7. Seal the edges with heat resistant PET double-sided tape.
8. Fix wires
Fix the wires with Heat Resistant PET double-sided tape.
Trim the extra EVA film edges, to reach the same size as toughened glass.
7. Seal the edges with heat resistant PET double-sided tape.
8. Fix wires
Fix the wires with Heat Resistant PET double-sided tape.
10. Wrap the whole glass with PET bag
Wrap the laminated glass in a PET bag with side heat-sealed, then evacuate the bag.
11. Ready for Lamination in an autoclave
Put all the glass in an autoclave for lamination.
12. The lamination process in the autoclave is finished in about 5 hours.
