“Frame with glass that the car carries in its front part to protect passengers from the air when the vehicle is moving” , is how the Royal Spanish Academy (RAE) defines what a windshield is. Just to protect us from the wind? This front window is no longer just another element, it has undergone a great technological evolution: the windscreen can save your life . We explain why.
The first windshields were dangerous
With a simple sheet of glass. These were the first windshields that appeared on cars in 1903. They began to be used mainly to protect the driver from wind, rain, insects, small stones… but the remedy could be worse than the disease due to serious injuries to the face and body that the occupants could suffer from the simple impact of a stone.
A solution had to be found and it was the French chemist Edouard Benedictus who, in 1910, invented the laminated windshield . He discovered it by chance when a glass that had contained cellulose nitrate fell to the ground and surprise! It didn’t break into a thousand pieces, they stuck together. This type of windshield – made up of two layers of glass and one of cellulose between them – did protect the driver and other occupants in the event of an impact because the glass did not shatter.into sharp flying pieces but the crystals formed a kind of spider web. It began to be marketed in series from 1920 under the name of Triplex, initially only reserved for the most luxurious models due to its high cost. Henry Ford offered it as an option on his models from 1921 onwards. The rest of the cars had to settle for ordinary glass that could cause cuts. It was called Trempé and was marketed until 1944. That same year the Swedish manufacturer Volvo began to mount the PV 444 safety windscreen on its models.
The second half of the 20th century marked a before and after in the evolution of windshields. They began to be considered an important security element and research was promoted, always using laminated glass as a base. In the 1960s, the first regulations on the manufacture of windshields would also arrive from the United States and would become mandatory in Europe. In 1972 the American Geral Keinath patented the resin windshield, more resistant and avoiding the danger of breaking. Then came bulletproof, armored windshields; anti-fog; windscreens with cameras, radars and sensors, panoramic, sensitive to light… Did you know that in recent years the glass surface of cars has increased by 15% and that at the same time the thickness of the glass has been reduced by 10%? Today’s windshield is safer, lighter, thinner and stronger. Gone are those aviator-type glasses that the first drivers used to protect themselves from dusty roads or inclement weather.
10 windshield features
The invention of the laminated windshield was a milestone in the history of safety along with the seat belt. Despite being an element quite unknown to the public, its function is fundamental due to its effectiveness in saving lives and injuries. What advantages does the windshield provide?
1. Protects from the wind but also from dust, the impact of insects or small stones, rain, snow… Can you imagine driving without a windshield to protect you? Your concentration on driving would not be total and would lead to an increase in distractions and the risk of suffering an accident. A recent guide of tips for driving in winter carried out by the Foundation for Road Safety (Fesvial) together with the General Directorate of Traffic (DGT) indicates that poor visibility on board the vehicle is the cause of more than 15% of the traffic accidents, a situation that is accentuated in winter conditions or with adverse weather: the risk of having an accident when it rains is 70% higher, with reduced visibility, and not less grip, being the main culprit in this accident rate .
2. Improve your visibility to the outside of the vehicle. We must remember that 90% of the information that reaches us while driving comes from sight. The windshield helps make this visibility the best it can be. In this case, the human factor plays an important role in keeping the moon clean and without cracks or bumps that reduce visibility. At this point we remind you that wearing the broken or dirty window, with stickers, curtains (as long as they hinder the correct visibility for driving) entails a penalty of up to 200 euros .
3. Prevents the driver or occupants from being thrown from the vehicle in the event of a collision . It is achieved thanks to the laminated glass and the resistance achieved by this kind of spider web that is formed preventing the pieces of glass from falling off. I take this opportunity to influence the use of the seat belt , a key and easy-to-use element that can save your life and/or prevent serious injuries.
4. Provides up to 30% of the vehicle’s structural resistance , thus, in the event of a rollover, it prevents the immediate crushing of the roof.
5. It complements the airbag in case of deployment because the windshield resists the great pressure of this airbag. If the glass were to break, the airbag would not be effective.
6. The windscreen plays an important role in the aerodynamics of the vehicle , essential both to reduce fuel consumption and to improve performance.
7. Improves the acoustic comfort of a car due to its insulating function , which leads to greater concentration at the wheel. A more comfortable and safe driving is achieved. Some modern windshields have a laminate that can reduce the noise level by up to 30%, because it reduces aerodynamic hum, as well as rain noise, according to specialists from Carglass, a leading company in Spain in repair and replacement of vehicle windows and their calibration.
8. The windscreen film blocks more than 90% of UV rays : it protects the eyes and skin of the occupants in the front seats. UV exposure is cumulative and is associated with 90% of all skin cancers. Some windshields also offer thermal protection by incorporating a transparent sheet of metal oxides, which reflects infrared radiation and transfers less heat to the passenger compartment. “This results in less use of air conditioning and, therefore, in a reduction in polluting emissions,” they say from Carglass.
9. The windshield serves as a support for installing cameras and sensors used by various driver assistance systems (ADAS), for example, lane departure warning systems or automatic emergency braking systems . In order for them to work effectively, the windshield must be kept clean and free of breakage. When a windshield is replaced, the cameras must be removed from the broken glass and mounted on the new one. Once installed, these systems need to be recalibrated to ensure that they work with maximum accuracy and provide the correct information. Only in this way will they avoid a collision or reduce its consequences. As of July 6, newly approved vehicles in Europe will be required to equip various ADAS systems as standard .
10. Information from the Head-up display is projected on the windshield , a driving assistance system that prevents you from taking your eyes off the road. In this link we tell you how it works and how the Head-up display will evolve .
As a curiosity and to celebrate the 100 years of history of the laminated windshield, the television program ‘El Hormiguero’ subjected it to an experiment that simulated the fall of the volcanic ava on top of a car . The windshield cracked, but it withstood the incandescent aluminum at 660º C and did not allow it to enter the passenger compartment.
Windshield Maintenance Tips
According to a study by Carglass and Fesvial, 60% of drivers do not check that their windshield allows good vision; 75% acknowledge having driven with the wiper blades in poor condition and more than 70% do not replace them with the recommended frequency. To improve safety when we travel by car, they give us these tips:
• Performs good maintenance and cleaning of the windshield surface.
• Check the condition of the wiper blades . If they do not work correctly you can get a fine of 80 euros .
• To remove ice from the windshield , it is best to use a suitable scraper (never metallic so that it does not scratch the glass). A quick solution, if necessary, is to spray it with sanitary alcohol or hydroalcoholic gel, which melts the ice.
• Never throw hot water or apply hot air directly on the frozen glass , since the thermal shock can cause it to break (something that is accentuated if the windscreen suffers impacts or small cracks). It is also not recommended to use water in the windscreen washer reservoir, but rather a specific liquid with antifreeze properties.
• If the vehicle is parked somewhere where temperatures are likely to drop below 0°C , it is a good idea to keep the wiper blades away from the windshield so that they do not stick to the glass, as they can damage the wiper motor and break the wiper rubber. .
• Keep in mind that if the windshield is sprayed with water or with windshield washer fluid while driving and the outside temperature is very low, it can freeze immediately and form an opaque film that will prevent us from seeing.
• In bad weather, car windows tend to mist up more. The windscreen must be demisted using the specific ventilation system function for this ; and connect the heated window to the rear window, which in many cars also defogs the mirrors. It is recommended to clean the dust from the grids and make sure that there are no objects that obstruct the passage of air so that the demisting is more effective. The inner glasses can be cleaned with anti-fog liquids.
• Evaluate carrying out an anti-rain treatment on the windshield of your car. It significantly increases visibility in the rain, as water droplets do not adhere to the windshield, they slide down it quickly and hardly leave trails of water in their path. In addition, it makes us use the windshield wipers less.
The advantages of repairing a windshield
If your windshield is damaged by a stone hit or has a crack, the solution may be simpler and cheaper than you expected. Possibly it can be repaired and you avoid replacing the entire window: the repair is faster (only 30 minutes compared to the hour and a half it takes to replace a windscreen), there is no need to recalibrate the driving assistance systems, ten times less CO2 is emitted than in a replacement (a windshield repair represents a carbon footprint of 4 kilos of CO2 and waste of 0.002 kilos; while in a replacement these figures shoot up to 39.1 kilos of CO2 and 13.9 kilos of waste, according to data from Carglass), less raw material is consumed.
It cannot be repaired in these cases :
• The impact is less than 2.5 cm from the edge of the windshield.
• The diameter of the impact is greater than 2.5 cm (like a €2 coin).
• The impact is in the driver’s viewing angle.
When an impact occurs, it is important to repair it as soon as possible , otherwise it is easy for it to increase in size. In addition to being dangerous for driving, it will mean a higher cost for your pocket.
