Sun Control Film

what is the function of the sun control film pasted on the windscreen glasses of an automobile

You have answered your own question.

what is its life?

Greater than or equal to the expected life of the windscreen glass and/or vehicle itself.

I have never seen a film outlast a vehicle or even windscreen. Now if we could make the cars out of the same stuff we would solve a number of the worlds problems!

reason being - I have a car which is about 6 years old...and now I find that it is hotter inside the car than outside even with the airconditioning on....

Your aircon is not working correctly. get it regassed

Turn the heat off or it possibly needs the control that switches it from heat to cold looked at.

It is likely your air conditioner that is the problem. Think of the sun control film as a pair of sun glasses for your windscreen, they block some wavelengths of light to reduce driver glare, but its ability to reduce the sun heating the inside of the car is negligible.

How can the sun control film reduce the temperate in the car. i don't think it works. Better refill the gas in the air conditioner.

Drug and alcohol test

the sun control screen is there to reduce not stop some of the heat getting into the vehicle, the air con does the rest