| 摘要 |
PROBLEM TO BE SOLVED: To obtain varicolored moire patterns by combining former means by slightly shifting or inclining two kinds of same or slightly different embossed patterns to superposing them on a translucent plastic sheet or separately applying them to both surfaces thereof. SOLUTION: First embossing 2 is applied to the translucent plastic sheet extruded from a T-die 4 by a first embossing roll 5 and second embossing 3 is continuously superposed on the first embossing by a second embossing roll 6. In this case, since the plastic sheet to which first embossing is applied is slightly contracted in its width direction as a result of applying tension to the plastic sheet, the original embosses are crushed at parts where ridges and valleys collide with each other and parts where embosses become inconspicuous are generated at a constant cycle. Further, parts where embosses are crushed by the fluctuations of a tensile speed are changed to the left and right of the sheet and irregular moire patterns are developed. When first and second embossings are applied to both surfaces of the sheet, a moire phenomenon by light interference is produced. |
