Thermos flask with a long time, the bottle will give birth to a layer of scale and difficult to remove. If we go down point in dilute hydrochloric acid thermos bottle, tightly capped bottle, gently shake a few, and then stand for 30 minutes, rinse with water several times, and scale can be removed.
Also desirable to some tea, put in thermos bottles, and then poured into the boiling water, cover the cork, over 15 to 20 minutes after drinking one can of tea. The bottle of scale in the effect of theophylline, it will fall off down the sink bottom. With bubble several times, would be better. Can also be poured into a concentration of 1% of about 500 grams of baking soda water, soda or water heating into the bottle, shake gently rinse, scale can be removed.
The two egg shells can also crumble a little, put into the bottle, and then into Bangang cold water, plug the cork and hold down with your index finger, thumb and other fingers holding the bottle neck in one hand push up bottom, vertical and horizontal rotary shaking. About 20 minutes, remove the cork, pour the shell, rinse rinsed twice just fine.