How Does a Thermos Work?

Heat is transferred by radiation, convection and conduction. The thermos has a vacuum insulator, silver plated flasks, a short bottleneck design structure that prevents and reduces the effect of heat transfer from the thermos.

The company, government and school and so on. All could contact Source EC to purchase customised thermos. Especially, when employees work in the office, using the thermos, looking at the company logo. This could strengthen their belonging to the company. Besides, it is also a good choice to send gifts to customers when the company has activity which could promote the company brand. Thermos is our daily necessity for drinking tea and restoring cold water in hot summer. 
How do the thermos work to maintain temperature? This article will introduce the principle of thermos to you.
 

The structure of the thermos

The stainless steel thermos has an inner wall, outer wall and stopper cap. There is vacuum insulation between the inner wall and outer wall. The inner wall is silver plated to maintain temperature.
 

The key to maintain heat

Heat is mainly transferred in three ways: by conduction, by convection, and by radiation.
 

Convection

Heat is transferred by convection in liquids and gases. So the gases between the inner wall and outer wall are vacuumed. The vacuum could stop the convection.

Production method

Bottle production

Vacuum pumping is one of the most important factors for the thermos insulation.
There are two vacuum pumping methods: tail vacuum and tailless vacuum.
Tail vacuum, also known as calandria vacuum, is a traditional vacuum method. It first vacuum the thermos, then seal the bottom of the thermos. Therefore, it leaves a suction tail at the bottom of the cup bladder. The suction tail is easily damaged by bumping because of carelessly falling, this could lead to the vacuum insulator leaking, which is bad for maintaining temperature competence.
The tailless vacuum, also known as no-tail vacuum, successfully overcame this drawback. It uses a special method to weld the tail to get rid of the sharp exhaust tail. 
The tailless vacuum is very advanced. The tailless vacuum removes the tail to make the thermos space more effective. If the thermos has the same appearance, tailless vacuumed one have bigger volume, less weight and better heat maintaining competence.
The advanced melt sealing technology seals the air hole tightly, which can avoid air leakage for a long time. Tailless vacuum thermos will have a long service life.
 

Cap production

The cap consists of rubber, plastic and silicone. The thermos inner space is surrounded by a vacuum insulator. The bottle rim is the only space to lose heat. The heat is easily lost in the bottleneck, so the bottleneck is designed as short as possible. For big volume thermos, the smaller the thermos rim is, the better it could maintain the heat.
 

Radiation

Heat transfer also could be transferred by radiation. The sun emits heat by radiation.The radiation is the heat flux by the form of electromagnetic waves. The heat flux happens when the thermos temperature and the circumstance temperature is different. 
 

Production method

The best method to stop heat radiation is using heat reflection. The thermos inner wall is silver plated to stop heat radiation. Because silver is one of the best materials to stop heat radiation. This could slow down the speed of losing heat.