In winter, a thermos can play a big role in every age. When you walk into a shopping mall or supermarket, you’ll find plenty of thermos cups on the shelves with different price tags. In general, the more expensive thermos has better quality. When purchasing a thermos cup, there are some tips that a salesman will not take the initiative to tell you.

#1. Check if the insulation performance of the thermos flask is good

When buying a thermos cup, undoubtedly the most important thing is to check the insulation performance. In general, the sealing of the cup has a great impact on the thermal insulation. If the seal is not good, the cup will not keep warm and air will leak. Obviously this makes it less safe for people to use thermos.

It’s very simple to see how well a cup is sealed. We fill the cup with water and tighten the lid. Then turn the cup upside down and it always leaks, which proves that the seal is not so good.

Although the sealing has an effect on the thermal insulation, it does not mean that the cup can be completely sealed, insulation is particularly good. To check the warm keeping performance, fill the glass with water and place it upside down on the table. After about three or four minutes, touch the cup and check if you can clearly feel that the cup is hot. If so, then it means that the cup is not holding heat very well.

#2. Check the material of the thermos flask

The material of the thermos is very important. Because we’re going to fill it with very hot water. In high temperature, the material of poor thermos cup can release harmful substances to the human body. In general, the material and other information will be clearly marked on the cup box, which can be used as a basis for us to judge the material of the thermos cup. Most thermos cups are made of stainless steel. So, we have to check if food grade stainless steel such as SUS304 or SUS316 is applied. This can be easily recognized by the logo on the thermos.

#3. Check the mancraft of the thermos flask

High quality thermos flask does not only preserve hot drinks well, but also do not leak, and the production process is very sophisticated. This can be checked by a hand touch. A good thermos flask will have a smooth rim and body, no burrs and no odors.