What is keepDGREE technology?
The keepDGREE technology describes the insulation system of our stainless steel bottles.
The stainless steel outer walls of our insulated products are double-walled. Air is extracted from this gap during production to create a vacuum. There is also a layer of copper between the stainless steel walls.
How does this help to keep my drinks hot or chilled?
Physically, heat can escape (or enter) your bottle in three ways: Conduction, convection and radiation.
Conduction and convection are minimized by the vacuum between the double wall. The additional copper layer reduces heat radiation.
The drinks inside the bottle therefore remain cold for up to 24 hours or hot for up to 12 hours.
How does it work in detail?
Every aspect of keepDGREE technology is designed to minimize one possible path of heat transfer out of and into the bottle:
Conduction: this is the process by which heat is transferred through direct material contact. In a double-walled bottle, this path is minimized by the vacuum between the two stainless steel walls. Since a vacuum contains no matter, there are no particles that could transfer heat by conduction. This keeps the heat inside and prevents heat from penetrating from the outside.
Convection: Convection occurs when heat is transferred through a liquid or gaseous medium (such as air or water). The movement of this medium transports heat from one place to another. In the closed, double-walled bottles, convection cannot take place within the vacuum, as there is no medium in which heat could spread through movement. The outside air has no access to the inside of the bottle, which prevents convection losses.
Radiation: Radiant heat transfer takes place via electromagnetic waves and does not require a medium. All bodies emit radiation, especially at higher temperatures. The additional copper layer in the bottle construction reflects the infrared radiation, which carries the heat, back into the inside of the bottle instead of letting it escape through the outer wall. This significantly reduces heat loss through radiation.