| 摘要 |
PURPOSE:To form easily a brittle part for insertion of a straw by irradiating a laser beam to the prescribed position of a vessel to burn said position down to a required depth. CONSTITUTION:A laser beam L radiated from a laser oscillator 15 is given a required pattern by a mask device 16, is then condensed by a condenser lens 17 and is irradiated to the required position, i.e., mark 11 of a container 1. Then the beam L burns the polyester film layer constituting the container 1 according to the prescribed pattern, thus forming a brittle part 8. the brittle part is thus easily and inexpensively formed simply by irradiating the laser beam to said position. |
