1. Simple identification method for vacuum heat preservation performance: pour boiling water into the heat preservation cup and screw the bottle stopper or cup cap clockwise for 2-3 minutes, then touch the outer surface of the cup body with your hand.
2. Identification method of sealing performance: after the cup is filled with water, screw the bottle stopper and cup cap clockwise, and place the cup flat on the table, without water leakage; The cup cover and cup mouth shall be rotated flexibly without clearance.
3. Identification method of plastic accessories: The new food grade plastics are characterized by small odor, bright surface, no burr, long service life and no aging. Common plastics or recycled plastics are characterized by strong smell, dark color, many burrs, and easy aging and fracture of plastics.