What You Should Know about Tinting Films
It seems ironic but the rays of sunshine that help life to flourish on our planet can also cause skin diseases. It’s not only the heat (infra-red rays) from that ball of fire 150 million kilometres away but also ultraviolet (UV) rays that cause body cells to become cancerous.
Motorists may imagine that sitting inside the car means they are protected from excessive exposure to sunshine so they need not worry. However this is not entirely true because a great deal of sunlight comes through the glass windows, especially the windscreen which, in many modern cars, is at a shallow angle. Thus even while driving around town, it is likely that the skin will be exposed to sunshine for some time. So you are also running the risk of having cancer in the long-term!
In earlier days, automotive glass was untinted but from the 1970s onwards, many manufacturers began to add a slight amount of tinting to the glass. The amount of tinting varies and some models may have as much as 11% tinting while customers may have an option of installing very darkly tinted glass (in some countries) which is often called ‘Privacy Glass’.
Early tinting of glass focussed on simply reducing glare with the belief that darker also meant that less heat would get through. However, this is not necessarily the case as the infrared (IR) rays and UV rays are actually invisible because they are at other wavelengths. Thus, there may not be real protection for the skin nor significant heat reduction.
These days, manufacturers have begun to provide glass that is specially made to cut the invisible rays but it is costly so only the more luxurious models have them as standard. Some types of glass are so effective that they can cut IR transmission to zero, which causes problems for those using electronic tags to pay tolls. In many of the toll plazas, the electronic system uses an IR scanner to communicate with the tags on the dashboard and if IR beams cannot pass through the glass, then the tag cannot be read. Apparently, in Singapore, Audi had to modify the windscreen glass of its flagship A8 model which has a superior glass tinting that prevented the Electronic Road Pricing (ERP) tag from being read.
While owners of lower-priced models may not have the benefits of such high-tech glass, they can still add tinting films to their glass to achieve the same thing. However, in countries like Malaysia, there are regulations concerning the minimum amount of light that is transmitted through the glass – 70% for the front windscreen and 50% for the side windows and rear glass – more for security reasons than for safety. The authorities feel that excessively tinted glass will prevent law enforcement officers from being able to spot any illegal actions that may be taking place within the car or identify criminals easily.
The only exception is on the top of the windscreen where a dark tinted band can be applied for reducing sky glare. However, the height of this band, which is not subject to any minimum light transmission level, must not be more than 20% of the height of the windscreen.
There are many tinting films now available in the market and for a typical vehicle, it would cost upwards of RM400 to apply the film on all glass panels, depending on the quality of the product. Most of these are metallised films which are made using one of two processes – deposition or sputtering. This technology is the latest in use and is superior to the older method of just applying dyes which usually do not last long.
Deposition technology is a low-cost process but the coating is thick and the particles are fairly large. This results in a darker tint that will sometimes cut too much light transmission. Sputtering technology is a more advanced process and requires a vacuum chamber for the application of the metallic layer which is done at the atomic level. Sputtering allows the use of a wide variety of metals and each type of metal has the ability to block off specific rays in the solar spectrum. The reflective metallised layer is a very thin layer – about 1/100th the thickness of human hair so it does not reduce light transmission greatly.
According to a manager at EON, which distributes the EONTech Sunscreen film that uses sputtering technology, cancer-causing UV rays can be cut by up to 99.5%. Apart from the better protection for your skin, there is also less deterioration of the areas such as the dashboard which fade or crack after prolonged exposure to sunlight. This is because, in addition to the very high temperatures, UV rays can break the chemical bonds of a polymer, and much of a dashboard is made from this material.
As for the rejection of IR rays which bring heat into the cabin, EONTech Sunscreen is claimed to cut the level by up to 60% through the windscreen. This not only means a cooler environment but it also makes the air-conditioning system work less hard. And because the air-conditioning system’s compressor is powered by the engine, reduced effort translates into fuel savings in the long run. The moderate reduction of IR rays makes it less likely for problems to occur using electronic toll tags so owners don’t have to cut a hole in the film.
In the case of the EONTech product, EON has had it tested by JPJ using a Proton Wira and the official result was 71.5% of visible light through the windscreen and 55.2% of visible light to pass through the side windows. So in spite of its superior reduction of those nasty rays, it is still within legal limits.
A side benefit of installing tinting film is that it increases the strength of the glass. While many of the newer cars come with laminated windscreens that won’t shatter into a million sharp pieces when hit by a stone, virtually none have laminated glass for the other windows. The addition of a film gives the glass better resistance against breakage, a benefit that will be welcome during an accident or even to make it more difficult for a thief to break in.
