thermos stainless coffee thermos bottles /glass refills/ vacuum flask /water bottle /teapot 1000ml

• High material: stainless steel  body, plastic stopper, glass refills
• Capacity:1.0L
• Keep beverage hot for 24 hour
• Customized logo are welcome
• Handle can be made on it
• Inner packing:1pc/the color box with pp bag
• Outer packing:12pcs/ctn
• After 24 hours heat preservation in accordance with international standards
• Keep beverage hot or cold for 24 hour

What is a vacuum flask glass refill&thermos flask

The vacuum flask consists of two flasks, placed one within the other and joined at the neck. The gap between the two flasks is partially evacuated of air, creating a near-vacuum which prevents heat transfer by conduction or convection. Heat transfer by thermal radiation may be minimized by silvering flask surfaces facing the gap but can become problematic if the flask's contents or surroundings are very hot; hence vacuum flasks usually hold contents below the boiling point of water. Most heat transfer occurs through the neck and opening of the flask, where there is no vacuum. Vacuum flasks are usually made of metal, borosilicate glass, foam or plastic and have their opening stoppered with cork or polyethylene plastic. Vacuum flasks are often used as insulated shipping containers.

How to test insulation quality of the vacuum flask?

• Check the inside (that is, the suction mouth) is intact, if there is a break between layers is damaged inside the vacuum, lost heat preservation ability.

• Look inside presence of blowout trace.

• See if bottle is round. If you don't round bottle, bottle stopper can't seal, will reduce the heat preservation ability.

•Fill it with boiling water and cap it.

•Measure its temperature with a thermometer every hour or two and see what the temperature graph looks like