1 Insulation performance identification.
This is the main technical indicator of the thermal insulation flask. After filling with boiling water, tighten the bottle stopper or cup cover clockwise. After 2 to 3 minutes, touch the outer surface and lower part of the cup body with your hands. If the body and the upper part of the flask are obviously warm, it means that the inner pot has lost the vacuum degree and cannot achieve a good heat preservation effect.
2 To identify the sealing performance. Fill a glass of water and invert it for four or five minutes, screw the lid tightly, put the bottle flat on the table, or shake it a few times, if there is no leakage, it means the sealing performance is good
3 See if the lid and the mouth of the flask are screwed together flexibly and if there is a gap. The environmental protection of the three accessories is also a matter of concern. It can be identified by smell. If the flask 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 odor, dark color, many burrs, and the plastic is easy to age and break.