What is the use of the silicone ring in the water cup?

We often find this phenomenon when using water bottles. Although the lid is tightened, there is still a small amount of water flowing out even when tilted. Therefore, you suspect that the lid was not properly closed the first time, and then you repeat the process twice, but the result is still the same. The direct cause of this problem is that the silicone ring inside the cup lid is damaged or misaligned.
So what is this rubber ring? Almost all cup lids have a silicone ring for the water cup. Don't underestimate this small rubber pad. Without it, you may have to drink mineral water when traveling. One of the main purposes of this silicone ring is to prevent leakage.

We can imagine that if we remove this rubber ring and screw on the cup lid, there will be a slight gap between the cup and the lid. Because both belong to hard glue, even with great force, it is impossible to tightly fit the cup and lid together. To solve this problem, a water cup silicone pad made of silicone material was chosen. Silicone is a non-toxic, environmentally friendly, high and low temperature resistant material, and when made into silicone rings, it has strong plasticity, so it can play a sealing role and prevent water from overflowing.
Generally speaking, the service life of this silicone ring is much longer than that of the cup. If you buy a stainless steel cup, it can accompany you for many years. But there is no absolute solution. Sometimes we accidentally expose the silicone ring to some greasy or acidic substances, which can cause significant damage to the silicone ring of the water cup. Because the silicone raw material used to make water cup silicone rings was not considered to come into contact with oil stains and acidic or alkaline liquids at the beginning of refining, some auxiliary materials were added less.

In this case, it is best not to use water bottles to hold liquids that can damage the silicone ring. And in daily use, attention should also be paid to cleanliness. What are the cleaning methods?
A common and simple way is to clean with toothpaste. Many silicone rings on water bottles can be removed. We can squeeze a little toothpaste on the ring, dip it in a little water, and then gently brush it with a small brush. Toothpaste has a good cleaning effect on tea stains. After brushing a few times, the rubber ring will show its original color.