Vacuum flask manufacturing process
The core component of thermos bottle is bottle bladder. The production of bottle bile needs to go through the following four steps: 1. The glass used in the vacuum flask is made of sodium calcium silicate glass. Take even and impurity free high-temperature liquid glass and blow it into 1 ~ 2mm inner and outer glass bottles in the metal mold (see glass manufacturing). (2) billet. The inner bottle is placed in the outer bottle, the mouth of the bottle is sealed into a whole, and the outer bottom is provided with a catheter for silver-plating and air extraction operation. This glass structure is called the blank bottle. Making glass bottle billet basically has to pull bottom sealing method, shrink shoulder sealing method and waist to connect sealing method 3 kinds. The bottom sealing method is to cut the inner bottle blank and the outer bottle blank. The inner bottle is covered from the bottom of the outer bottle and fixed with asbestos insert. Then the outer bottle bottom is closed round, connected with small tail pipe, and the two bottle openings are sealed by melting. The shrink shoulder sealing method is to cut the inner bottle blank and the outer bottle blank. The inner bottle is covered from the upper end of the outer bottle and fixed with asbestos insert. The shrink diameter of the outer bottle is to cut the shoulder of the harvest bottle and melt and seal the two bottle openings. The waist sealing method is to cut the inner bottle preform and the outer bottle preform and cut the waist into two sections. The inner bottle is put into the outer bottle and the waist is re-fused and connected with the small tail tube. (3) silver plating. A certain amount of silver-ammonia complex solution and aldehydes as reducing agent were poured into the cylinder billet interlayer through a small tail tube for silver mirror reaction. The silver ions were reduced and deposited on the glass surface to form a thin mirror silver film. (4) vacuum. Connect the tail tube of the silver-plated double-layer bottle billet with the vacuum system and heat it to 300 ~ 400℃, which causes the glass to release all kinds of adsorbed gases and residual water. At the same time, the liner is sealed by melting when the vacuum degree of the cylinder interlayer reaches 10-3 ~ 10-4mmhg.