PURPOSE: To seal simply and reliably a plastic vessel, by a method wherein a mouth part of the vessel made of thermoplastic is pressed into a recessed part of a mold heated at the plasticizing temperature or higher while plasticizing the same and sealed.
CONSTITUTION: A cylindrical plastic vessel 1 is inserted into a recessed part 2a of a mold 2 through one end mouth part 1a side. Then the mold 2 is heated by putting on a heating furnace 3 and at a point of time when a temperature of the mold 2 becomes higher than the plasticizing temperature of plastic forming the vessel 1, a mouth part 1a of the vessel 1 is pressed into the recessed part 2a. Consequently, the mouth part 1a of the vessel 1 is deformed after a form of the bottom of the recessed part 2a, the fringe of the mouth part 1a is fused to each other and sealed. In this instance, a thickness of a sealed part 11 of the vessel 1 can be controlled arbitrarily, by controlling a heating temperature of the mold 2 and a pressing-in temperature of the mouth part 1a. Then after rapid cooling and taking-out of the heating furnace 3, the vessel 1 is taken out of the mold 2 and the plastic vessel 1 where the mouth part 1a is sealed is obtained.
YOSHIHARA MINORU
KIYOKAWA SUSUMU
SAKAGUCHI SHIYOUKICHI
MISATO KK