Method 1: "Brush" cleaning method
Clean carefully with a brush, and any gaps can be cleaned. A simple sponge cup brush can rotate 360 degrees to clean the inside of the thermos cup, and the brush handle is particularly long, so the bottom of the thermos cup can be easily cleaned.
This is the most direct cleaning method, but what if there is no long-handled brush?
Method 2: eggshell cleaning method
Pour 1/5 water into the cup, then break the egg shell into small pieces, put it into a thermos cup, tighten the lid of the cup and shake it vigorously. After three or five minutes, pour out the egg shell and water inside, and the scale in the cup will be removed together. This method can be used for any deep cup.
The reason why egg shell can clean scale is because the main component of egg shell is calcium carbonate, which is slightly soluble in water and makes water alkaline. Scale belongs to salt, slightly soluble in water, slightly acidic, and acid-base neutralization reaction will occur between them, so egg shell can remove the scale in the cup, which is the chemical action of egg shell.
The physical function of eggshell can also clean the scale in the thermos cup. The tips of eggshell fragments have many edges and corners, which will cause friction when you keep shaking, and can also clean the scale on the inner wall of the thermos cup well.
Method 3: Rice cleaning method
Pour 1/5 rice into a cup, then add a little more water than rice, cover it and shake it for ten minutes.
This rice cleaning method mainly uses the grindability of rice. In the process of constantly shaking the cup, the rice plays the role of rubbing the cup wall. It's as simple as washing the cups.