| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce or eliminate the deformation at the time of marking with laser beam by using a jig to a part or the whole of moldings at the time of marking with the laser beam and holding to a prescribed shape. SOLUTION: A resin composition blending carbon black to polyacetal resin, is prepared and is injection-molded to obtain a thin sheet having 0.35 mm thickness and L1 width. The whole surface of the molded thin sheet 1 is interposed with transparent glass plates and fixed under flat surface state or made to under forming state by using the jig 2 so as to become -1 time, -3 times or -6 times size of corrected shape to execute the marking with the laser beam. In the marking condition, the condition, in which white color part of the marked part becomes the highest position, is selected and decided as a standard conditions. A focus beam diameter of the laser beam marker is made to 100 mm. After marking, this marked material is left to cool as it is for 10 min and thereafter, this material is released from the plates or the jig. At the time of using the jig 2, the distraction rate l1 /L1 % (wherein, L1 is the thin sheet length and l1 is the max. value of floating up in the case of being <=-6 times correcting magnification) is restrained to <=0.7%.</p> |
