This is the main technical indicator of the insulation cup. After filling with boiling water, tighten the stopper or lid clockwise. After 2~3 minutes, touch the outer surface and lower part of the cup body. If you find the cup. There is obvious warmth in the body and the cup, which indicates that the liner has lost the vacuum and can not achieve good insulation effect.
Recipe 2 to identify the sealing performance filled with a cup of water inverted for four or five minutes, screw the lid tightly, put the cup flat on the table, or force it a few times, if there is no leakage, it means good sealing performance; See if the screwing of the lid and the cup is flexible and there is a gap.
The environmental protection of plastic accessories is also a problem worthy of attention. It can be identified by smell. If the cup is made of food grade plastic, the smell is small, the surface is bright, no burr, long service life and not easy to age. Ordinary plastics or recycled plastics have large odor, dark color, many burrs, and easy aging of plastics.