1 preform preparation. The glass material used for the thermos is a commonly used soda lime silicate glass. A high-temperature glass liquid with uniform impurities and no impurities is sprayed into a glass inner preform and an outer preform (see glass manufacturing) having a wall thickness of 1 to 2 mm in a metal mold. 2 bile. The inner bottle is placed in the outer bottle, and the bottle mouth is integrally sealed, and a silver plated and evacuated pipe is arranged at the bottom of the outer bottle. The glass structure is called a bottle blank. There are three types of glass bottle blanks: the bottom sealing method, the shoulder sealing method and the waist sealing method. The bottom sealing method is to cut the inner preform and cut the bottom of the outer preform. The inner bottle is inserted from the bottom end of the outer bottle and fixed with an asbestos plug, and then the bottom of the outer bottle is closed and closed, and the small tail pipe is connected. The mouth of the bottle is sealed. The shoulder sealing method is to cut the inner preform and cut the outer preform. The inner bottle is inserted from the upper end of the outer bottle and fixed with an asbestos plug. The outer bottle is reduced in diameter to form the bottle shoulder and the two bottles are sealed, and the small tail catheter is connected. . The waist joint sealing method is to cut the inner preform, cut the outer preform and cut the waist into two sections, put the inner bottle into the outer bottle, re-melt the waist, and connect the small tail catheter.
3 silver plated. A certain amount of silver ammonia complex solution and an aldehyde solution as a reducing agent are poured into the bottle liner through a small tail pipe, and a silver mirror reaction is performed, and silver ions are reduced and deposited on the surface of the glass to form a thin layer of mirror silver film. 4 vacuum. The tail pipe of the silver-plated double-layer bottle blank is connected to a vacuum system and heated to 300-400 ° C to promote the release of various gases and residual moisture adsorbed by the glass. At the same time, the vacuum pump is used for pumping, and the tail pipe is melted when the vacuum of the bottle liner space reaches 10-3~10-4 mmHg.