A vacuum flask, also known as a thermos or insulated bottle, is a highly efficient container designed to maintain the temperature of its contents for extended periods, whether it’s keeping liquids hot or cold. This ability is achieved through a unique construction that minimizes heat transfer by utilizing a vacuum-sealed, double-walled design. Vacuum flasks are widely used for storing beverages like water, coffee, tea, and soups, and are especially popular for outdoor activities, travel, and daily use at work or school.
Key features:
• Double-Walled Structure: A vacuum flask consists of two walls, usually made from stainless steel for durability and insulation. The space between these walls is where the insulation magic happens.
• Vacuum Insulation: The space between the two walls is a vacuum, which means it contains no air. Since air is a medium for heat transfer (via conduction and convection), the absence of air greatly reduces heat loss from the inside to the outside. This insulation works in both directions—preventing heat from escaping hot liquids and stopping heat from entering to keep cold liquids chilled.
• Reflective Coating: In some high-end vacuum flasks, the inner wall is coated with a reflective material (such as aluminum) that helps reflect radiant heat back into the liquid, further enhancing heat retention. Click and read more: How Do Insulated Bottles Cups Work?