There are many layers in the thermos cup, and its interlayer is generally vacuumed to prevent heat conduction! It is then plated with silver, which blocks heat radiation. Some cups have corks on top to prevent heat conduction.
Maintenance
Avoid collision and impact during use, so as not to damage the cup or plastic, resulting in thermal insulation failure or water leakage. When tightening the plug, the force should be appropriate, and do not rotate too hard to avoid failure of the screw. When you drink coffee, tea or beverages frequently, the color of the inner liner will be normal, which can be removed with toothpaste and toothbrush.
