| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection nozzle constituted so as to prevent a stringing phenomenon at the time of ejection of a molded product easy to occur in the molding of an optical element such as a lens or the like. SOLUTION: A small diameter short projection 11a is provided to the leading end of the injection nozzle 1 and a first small diameter orifice 13a is formed to the projection. Further, a second small diameter orifice 13b, which is smaller than a nozzle main body orifice 13 and has a diameter larger than that of the first small diameter orifice 13a, is formed corresponding to the transition part 11b between the projection and a nozzle main body part 11. When the small diameter short projection is cooled by a mold 2, the resin material 4 in the vicinity of the leading ends of the first and second small diameter orifices 13a and 13b is cooled to the temperature of the mold to be solidified and, since the solidified resin 5 is cut at the boundary of the first and second small diameter orifices at the time of ejection of the molded product, stringing is prevented certainly. COPYRIGHT: (C)2006,JPO&NCIPI
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