1.How does a thermos work
The secret of a thermos is that it cleverly “blocks” three ways of heat transfer.
Conduction: Heat is transferred from a high-temperature area to a low-temperature area through the object itself. The insulated cup adopts a double-layer stainless steel structure, and a vacuum is drawn between the two layers, effectively cutting off the path of heat conduction.
Convection: The transfer of heat through the motion of a fluid, such as air or water. The vacuum layer not only prevents conduction but also eliminates the possibility of convection, as there is no substance in the vacuum that can carry heat.
Radiation: Heat is directly emitted in the form of electromagnetic waves. High quality insulated cups are coated with copper or silver on the inner wall, which reflects heat radiation like a mirror and “bounces” the heat back into the cup.
2. How to choose a good thermos cup
(1) Look at the material
Food grade “304 stainless steel” is the basic requirement, while “316 medical grade stainless steel” is more corrosion-resistant and suitable for storing acidic beverages.
(2) Check the sealing performance
After filling with water, tighten the bottle cap and invert it for a few minutes to check for water leakage. Good sealing not only prevents water leakage, but also better maintains temperature.
(3) Vacuum technology
Vacuum technology determines the insulation performance. You can gently tap the cup body, and a truly vacuumed thermos will make a crisp and short sound.
3. Tips for using thermos cups
(1) It is recommended to clean with warm water and a small amount of neutral detergent for the first use, and do not use hard objects to scrub the inner container.
(2) Liquid acidic beverages (such as lemon juice), carbonated drinks, milk, etc. that are not suitable for storage are prone to spoilage or chemical reactions when stored in a thermos for a long time.
(3) Clean and maintain in a timely manner, especially after storing beverages such as coffee and tea that are prone to stains, to avoid residual odors.
