1. Identification of the thermal insulation of the inner tank: This is the main technical indicator of the thermos cup. After filling with boiling water, tighten the cork or lid clockwise. After 2 to 3 minutes, touch the outer and lower parts of the cup with your hands. If the body and the upper part of the cup body have obvious warming phenomenon, it means that the inner liner has lost the vacuum degree and cannot achieve a good heat preservation effect.
2. Identify the sealing performance: fill a glass of water and invert it for four or five minutes, screw the lid tightly, put the cup flat on the table, or shake it a few times, if there is no leakage, it means the sealing performance is good; See if the lid and the mouth of the cup are screwed together flexibly and if there is a gap.
3. Identification of environmental protection of accessories: The environmental protection of plastic accessories is also a matter of concern. It can be identified by smell. If the cup is made of food-grade plastic, the smell is small, the surface is bright, there is no burr, and the service life is long and not easy to age. ; Ordinary plastic or recycled plastic has a strong smell, dark color, many burrs, and the plastic is easy to age and break.
