| 摘要 |
PURPOSE:To allow the heat at a nozzle section to escape to the mold side so that a land section can be cooled quickly and the sprue section may solidify to its core thereby avoiding webbing and trailing by attaching a member of a material that is good in thermal conductivity to a pert of a nozzle tip where it will come in contact with a mold. CONSTITUTION:The tip of a nozzle 23 has a member 24 of a material good in thermal conductivity. Accordingly, after the completion of an injection step and when the nozzle 23 is separated from a mold 22, since the heat of the member 24 is transmitted to the mold 22 and the member 24 is cooled quickly, the resin of the land section 24a of the member solidifies quickly and cools to the core. Therefore, webbing would not occur. Further, the cutting of the sprue 21 is effected at the joint section A of the land section 28 at all times, and when the nozzle 23 is retracted, since the land section 24a of the member 24 is always vacant, hardly occurs. |
