Artificial smoke and fog provides a special effect for music artists performing on stage. Most artists make use of this effect and complement it with lighting while they are on tour.
Whats the difference between smoke and fog?
People in the film business often do not differentiate between what smoke and fog is. Yet from a chemistry point of view, each is defined differently. Smoke is a gas that has solid particulate matter dispersed in it. On the other hand, fog is a liquid phase dispersed in gas.
How do fog machines work?
Though there are many ways to make artificial fog, one of the most common approaches is using a propylene glycol and water-based fog fluid. A machine pumps this liquid into a heater that vaporises the fluid and creates instant fog. In other words, the fog is created by dispersing small liquid particles in a gas form. This is possible because the water vaporises at 100ºC while the other ingredients of the mixture have higher boiling points, thus they remain in their particulate form.
Creating different types of fog
By varying the ratio of propylene glycol and triethylene glycol a person can create different types of fog. These range from a fine mist used for laser shows to the thick dense white fog that is necessary to simulate real fog in the movies. Laser shows use special fog machines called haze machines. Depending on the ventilation of the venue of the laser show, the fog created by these machines can last for hours, ensuring that they are cost effective. Artificial fog has a drying effect compared to the damp effect of real fog. So if you spent a lot of time in glycol based fog; your eyes, nose and throat are likely to dry up.