Pen is the most common stationery. Pens with various functions and shapes accompany our study and work. I don't know if you have paid attention to it. But there is a small hole on the cap of a pen with a cap. What is the role of the small hole?
First, to save lives
Children who don't have certain judgment ability are easy to swallow the cap into their mouth by mistake when they study and draw, which causes the blockage of the trachea. Children like to crawl on the ground, and they like to put it into their mouth when they catch something, while pens are something that every family has. Sometimes the cap is swallowed by children, causing serious suffocation.
But after the small hole is added, even if the child swallows the pen cap, he can breathe through the small hole on the pen cap, so as to prolong the doctor's treatment time and save the child's life. According to statistics, this small change can save hundreds of children's lives in one year, which is a major and important invention.
There are also a few cases of adults biting pens. Because biting the pen can help people to relieve the tension to some extent, but sometimes too much concentration can also lead to swallowing the pen cover by mistake, resulting in the risk of suffocation.
Second, it is easy to pull out the pen
After a hole is opened, the air pressure inside and outside the pen cap can be kept the same. People can easily pull out the pen when using it, and it will not be difficult to pull out the pen due to the low air pressure inside the pen cap.
The national compulsory production standard for stationery and educational articles, pens with no air hole in the cap are all unqualified products, and are prohibited from circulation and sale in the market. According to the national standard, a continuous air passage of at least 6.8 mm2 must be set on the cap body, and the minimum ventilation capacity of the cap shall be 8 L / min under the maximum pressure difference of 1.33 kPa at room temperature.
So when choosing a pen, the first thing to look at is whether there is a life-saving vent on the pen cap. Only when there is a qualified product, can you buy it. Please leave a message to say whether all the pens you used have holes.