Why can the straw suck drinks?
The earth is surrounded by a thick layer of air, called the atmosphere. Where there is air, there is atmospheric pressure. Put the straw into the cup. There is air inside and outside of the straw, and both are subject to the same pressure of the atmosphere. As soon as we sucked the straw, the air in the straw was sucked away, and the pressure on the water surface in the straw was lower than the pressure outside the straw. In this way, atmospheric pressure will press the beverage into the straw, causing the water level in the straw to rise, and the beverage will enter the mouth.
How to choose a safe straw?
first is “look”. It is necessary to check whether the outer packaging of the straw is equipped with QS (Quality and Safety Mark); whether the straw is colored or not, if there is a color, the safety of the straw will be reduced. The darker color should be paid special attention; whether there are black spots in the straw. Or broken bubbles, because these are the characteristics of substandard products.
Secondly, “smell”. Smell for any pungent odor before the straw is in contact with the drink. If there is any odor, it must be the problem straw.
The third is “Pinch”. If the straw is flattened by pinching it, it means that the straw is made of thinner material and the quality is poor, and it will be easily flattened during use.
Knowing these answers, I want to remind the children to use straws as little as possible. The milk and cola we usually drink can be drunk in a cup without the need to use a straw. Even if you need to use a straw, you should choose a transparent straw as much as possible, and don’t use it to drink hot things, and don’t let the straw stay in the drink for too long.