The film in the end there is no use? Car film evaluation

Introduction: When I was young, I used to put all my valuables on a protective film, a cover cloth on the TV, and a school textbook "swrap book cover." And now this habit continues, remote control protection, mobile phone film, mobile phone protection cover, TV cover, computer film, car film.

Many times, the main purpose of filming a car is not to protect the window, but to protect it from the sun and privacy. How much role can the film have in the end, can it really be "heat-insulated, sun-blocked, and opaque" as many businesses are promoting? Here, many people will also talk about how foreign cars do not have a film. Isn't the film actually useless?

In fact, this is not the case. Compared with many countries abroad, our people are generally more introverted and do not like to expose the interior environment. Secondly, we mostly believe that white is beautiful, while foreign friends mostly prefer sun drying to “skinning wheat”. In addition, in light of regulatory issues, the transmittance of glass abroad is extremely demanding. In some states of the United States, in order to allow police to observe the situation at a glance, glass film is simply prohibited. In fact, many foreign cars are also foiled, but the light colors make people unable to notice.

Experiment preparation:
We have found two cars with the same appearance and interior color, one car window film (front and rear windscreen, side windows) with full car membrane, and one car without film. The two cars were directly exposed to the open air, and thermometers were placed at the same location of the two vehicles for actual measurement, and temperature changes were recorded in real time for comparison. In order to ensure the rigorous experiment, before the experiment, we first stopped the two cars in a dark place for 2 hours in order to achieve the approximate starting temperature of the two cars. The test instruments were a convenient thermometer, a USB thermometer with an error of only 0.5°C, and an infrared thermometer for measuring the temperature.

The experiment was conducted:
The temperature of the day was 34°C. The experimental site was selected to be exposed in an open, unoccupied parking lot for 60 minutes to simulate the interior temperature after short-term parking. The front of the two vehicles is facing the sunlight. The initial temperatures in the vehicle are: uncoated car 27.1°C; foil car 24.2°C. After 60 minutes of exposure, the interior temperature of the unmounted car increased from the initial 27.1°C to 48.3°C, an increase of 21.2°C. The car's interior temperature increased from the initial 24.2 °C to 38.6 °C, only an increase of 14.4 °C, the temperature difference between the two from 2.9 °C to 9.7 °C.

End of experiment:
After opening the door, the temperature of the steering wheel and the main driving seat of the vehicle was quickly measured. The temperature of the unstucked vehicle was higher than that of the vehicle on both the steering wheel and the leather seat, and the temperature difference on the leather seat reached about 9°C. Therefore, it can be seen from this experiment that the window film can indeed play a role in blocking the temperature in a short time.