tyhjiöpulloon

A tyhjiöpullo, often referred to as a vacuum flask or thermos, is an insulating container designed to keep its contents at a stable temperature for extended periods. It achieves this by minimizing heat transfer through conduction, convection, and radiation. The primary component of a tyhjiöpullo is a double-walled vessel, typically made of glass or stainless steel. The space between these two walls is evacuated, creating a vacuum. This vacuum is a poor conductor of heat, significantly reducing heat transfer by conduction and convection.

To further enhance insulation, the inner and outer surfaces of the double walls are often coated with a reflective material, such as silver. This coating reflects radiant heat, preventing heat from escaping when the contents are hot and preventing heat from entering when the contents are cold. The opening of the tyhjiöpullo is usually sealed with a stopper, often made of plastic or cork, which also acts as an insulator and minimizes heat exchange through the neck of the container.

Tyhjiöpullot are widely used for storing hot beverages like coffee and tea, as well as cold drinks and food. They are common in households, outdoor activities, and travel. The effectiveness of a tyhjiöpullo depends on the quality of its vacuum and the design of its stopper and overall construction. While highly effective, they are not perfect insulators and some gradual temperature change will eventually occur.