How to choose a thermos cup

How to choose a thermos cup
Thermal insulation performance identification method
Pour boiling water into a thermos, cap the bottle tightly and let it sit for a few minutes. Then touch the body of the cup with your hand. If there is obvious warming, especially if the bottom of the cup heats up, it indicates that the cup has lost its vacuum degree and the insulation performance is not good. If the cup is always cool, it indicates that the insulation effect of the cup is good.
Sealing performance identification method
This method is relatively simple, and most people should be familiar with it. That is to fill the cup with water, then invert it, or shake it vigorously to verify whether its sealing performance is good.
Choose cups based on appearance
A good insulated cup can be felt from packaging to appearance, and the quality of the inner and outer surfaces of the cup can be observed. Generally, the inner and outer surfaces of a good insulated cup are relatively smooth, without scratches or bumps, and the cup mouth is smooth without burrs or welds.
Plastic parts identification method
No matter what material of insulation is used, plastic accessories are generally included. Whether the accessories used are healthy and environmentally friendly is a crucial thing, which can be distinguished by smell. If the insulation cup is made of food grade plastic, its odor will be small, the surface will be bright, without burrs, and it will have a long service life and is not easy to age; If it's ordinary plastic, then the overall quality of this insulated cup won't be much better.