Manufacturing technology of thermos bottle

The core component of thermos bottle is bottle liner. There are four steps to make bottle liner: ① preparation of bottle blank. Glass for thermos bottles belongs to commonly used soda-lime silicate glass. Take the homogeneous high-temperature molten glass without impurities, and blow it into an inner glass bottle blank and an outer glass bottle blank with a wall thickness of 1 ~ 2mm in a metal mold (see glass manufacturing). ② Bile-making blank. The inner bottle is placed in the outer bottle, the bottle mouth is sealed into a whole, and the bottom of the outer bottle is provided with a silver-plated suction duct. This glass structure is called bottle blank. There are three main methods to make glass bottle liner: bottom-pulling sealing method, shoulder-shrinking sealing method and waist-joining sealing method. Bottom-pulling sealing method is to cut the inner bottle blank and the outer bottle blank to cut the bottom. The inner bottle is inserted from the bottom of the outer bottle, fixed with asbestos plug, then the bottom of the outer bottle is rounded and closed, connected with a small tail pipe, and the two bottle mouths are fused and sealed. Shoulder sealing method is to cut the inner bottle blank and the outer bottle blank. The inner bottle is inserted from the upper end of the outer bottle and fixed with asbestos plug insert. The outer bottle shrinks the shoulder of the harvesting bottle, the two bottle mouths are fused and sealed, and then the small tail pipe is connected. The waist sealing method is to cut the inner bottle blank, the outer bottle blank and the waist into two sections, put the inner bottle into the outer bottle, weld the waist again and connect the small tail pipe. ③ Silver plating. A certain amount of silver ammonia complex solution and aldehyde solution as reducing agent were poured into the interlayer of the bottle liner through a small tail pipe for silver mirror reaction, and silver ions were reduced and deposited on the glass surface to form a thin mirror silver film. ④ vacuumizing. Connect the tail pipe of silver-plated double-layer bottle blank with vacuum system and heat it to 300 ~ 400℃ to promote the release of various adsorbed gases and residual moisture from glass. At the same time, when the vacuum degree of the interlayer space of the bottle liner reaches 10-3 ~ 10-4 mmhg, the tail pipe is sealed with a vacuum pump.