Name: Architectural glass film
Features: Durable and strong
Method: Visual observation - Observation of clarity
Measurement standard: 560NM
1. The most basic composition
Architectural glass film is made of a polyester substrate (PET), one side of which is coated with an anti-scratch layer (SR), and the other side is a composite of an installation adhesive layer and a protective film. During construction and installation, the protective film is peeled off and the side of the exposed adhesive layer is affixed to the inner surface of the glass (if it is a film specially designed for external application, it is affixed to the outer surface of the glass).
PET is a durable, strong, high-toughness, moisture-resistant, high-temperature and low-temperature resistant material. It is clear and transparent, and has been processed by dyeing, metallization coating, magnetron sputtering, interlayer synthesis and other processes to become a film with different physical properties to meet the needs of different places such as commercial buildings, residences, shop windows, bank counters, cars or ships.
Architectural glass films are mainly divided into two series: building energy-saving films and safety films. The main varieties are: body dyed film, heat reflective insulation film, low reflective insulation film, high light transmittance magnetron sputtering film, low-radiation (LOW-E) film, special film for museums and archives, frosted and translucent decorative film, gradient decorative film, transparent safety film, etc.
Four basic characteristics: heat insulation and energy saving, UV resistance, beautiful and comfortable, safe and explosion-proof. Glass film can be called an "amphibious" product in the construction industry. It can be used for both renovation of old buildings and new buildings.
2. The principle of heat insulation
To explore this issue, we must start with the source of life-the sun. Almost all heat comes from sunlight. As a part of electromagnetic waves, the solar spectrum is divided into three parts: ultraviolet rays (210NM-380NM), visible light (380NM-780NM), and infrared rays (780NM-2800NM).These three rays carry 3%, 44%, and 53% of solar energy respectively. Among them, ultraviolet rays are the most lethal, and infrared rays generate the main heat. The purpose of architectural glass film is to block almost all ultraviolet rays (sun protection), block infrared rays to the maximum extent (heat insulation), and for safety reasons, allow enough visible light to pass through.
Scientists have created such spectral selection technology, mainly using the principle of different reflectivity of metal particles to light of different wavelengths. Through single-layer or multi-layer metal sputtering technology, multiple layers of precious metal particles are coated on a thin PVC substrate, which reflects almost all ultraviolet rays and reflects infrared rays to the maximum extent while maintaining light transmission, achieving incredible heat insulation effect. The key technology of architectural glass film is only in the hands of several large American manufacturers with the highest global production, and the most advanced multi-layer metal spectrum selection technology is simultaneously used in American aviation programs.
3. Distinguish the pros and cons
Architectural glass film has gone through several generations, from dyed film to today's magnetron sputtering multi-layer metal film, with a wide variety of types and different performances. Then, the performance of architectural glass film is divided into several indicators: light transmittance, ultraviolet blocking rate, and infrared reflectivity (heat insulation rate). Ultraviolet rays have the strongest lethality, but due to the shortest wavelength, most architectural glass films can achieve a blocking rate of more than 98%; the naked eye can feel whether the visible light is transparent, but the actual data needs to be measured by instruments. The most widely used one is the light transmittance meter of the Ministry of Public Security, and its measurement standard is 560NM (visible light range 380NM-780NM).
Since the main purpose of installing architectural glass film is heat insulation, how to measure the heat insulation index is undoubtedly the most important. The common practice in the market is sensory measurement, that is, using glass with architectural glass film in front of the sun lamp to compare the heat blocking effect. Its advantage is that the intuitive feeling is strong, and the disadvantage is also obvious. The human body feels large errors and is easy to falsify.
At this time, it is particularly important to use instruments to measure. The international single-band standards for testing the light transmittance and infrared blocking rate (heat insulation rate) of architectural glass films are 560NM and 1100NM. Using this standard instrument for measurement can objectively reflect and compare the performance of architectural glass films. Even if it is not absolutely accurate, it is a world of difference from the behavior of deceiving consumers by only publishing data or even arbitrarily exaggerating data!
In the absence of instrumental measurement, you can choose to use a simpler method for measurement:
See with your eyes - observe the clarity
The clarity of architectural glass film is an important indicator to ensure the field of vision. Regardless of the color depth of the film, please pay attention to whether the outer contour of the object is clear through the film glass. Inferior films will feel foggy and even cause the outer contour of the object to deform, while high-quality films will have very high clarity regardless of the color depth, and will never have a foggy phenomenon with unclear vision;
Smell - tear open the lining and smell the odor
Inferior architectural glass film usually uses pressure-sensitive adhesive, which is not stable enough, of poor quality, contains a large amount of benzaldehyde molecules, and will evaporate and produce odor under sunlight, while the special insulation film glue has almost no smell;
Touch with your hands - feel
High-quality architectural glass film feels thick and smooth, while inferior architectural glass film is very soft and thin, lacks sufficient toughness, and is easy to wrinkle;
See with your eyes - color
High-quality architectural glass film has high clarity, and the pigment of high-quality film is evenly integrated into the film, which is durable and not easy to change color. It will not fade after being scraped by a scraper during the pasting process. The color of inferior film is in the adhesive, and the color will fall off after tearing off the inner lining of the film and scraping it with fingernails;
Wipe with chemical reagents such as alcohol, gasoline, and asphalt cleaner.
Wipe with chemical reagents such as alcohol, gasoline, and asphalt cleaner.
Because inferior architectural glass film is only dyed by the glue layer, or only coated with UV blocking agent on the glue layer, fading can be seen after removing the protective layer of the film and wiping the glue layer, or testing with instruments can find that the ultraviolet rays are greatly reduced;
Anti-scratch
The surface of high-quality and high-end films has an anti-scratch layer, which can protect the film surface from being scratched under normal use; if there is no anti-scratch layer, scratches will be scratched by tools when the film is applied, which will reduce the clarity of the film and seriously affect the service life of the film. You can use your fingernails to scrape the glass film (not the inner lining) back and forth a few times. If scratches can be easily made, it is definitely not a high-quality architectural glass film;
Warranty period
The warranty period of architectural glass film is 10 years or more, and the warranty period of automotive glass film is 8 years or lifetime. There will be differences depending on the specific product, but the difference should not be too large.
