| 摘要 |
<p>PURPOSE:To improve the surface gloss and uniformity of a plastic vessel by selectively heating and treating an external surface in a short time between an extruder die and a blow molding die in a molten plastic parison, the external surface of which is composed of an olefin resin, and blow-molding the molten parison after heat treatment in the blow molding die. CONSTITUTION:A piping 8 is passed through a burner 7 and the mixed gas of fuel is supplied, the nozzle 10 of a flame 9 is formed to the inner circumferential surface of the burner 7 in the diametral inward direction, and a passing external surface heats the external surface of a molten plastic parison 6 consisting of an olefin resin in a short time. Consequently, the surface layer section of the parison 6 is brought to the state of excellent fluidity, and the irregularities of the surface of the parison are levelled sufficiently. The thermally treated parison 6 is held by a split mold 5, and a fluid is blown into the parison and the parison is blow-molded. The parison is easy to be elongated through flame treatment and fast stuck superiorly with the surface of the mold 5 at that time, thus acquiring a blow molded vessel having excellent surface gloss.</p> |
