| 摘要 |
PURPOSE:To prevent a card from curving or undulating, by covering the surface of a card base partly with a transparent plastic film piece, securing the piece, and sealing it by a high-frequency welder. CONSTITUTION:A transparent plastic film piece 5 suitable to be processed by a high-frequency welder is placed on a card base 11 so that the whole surface of an indication 2 and the periphery thereof may be covered. The film piece 5 has a thickness on the order of 50-100mum and possesses a plurality of notches 7 in the undersurface of its sealing section 6. They are placed on a platen 9 of a high-frequency welder so that the peripheral section of the film piece 5 may be sealed by a mold 10. When a switch is turned on, the mold 10 is lowered to press lightly the periphery of the film piece 5 covering the indication 2 and sealing is carried out for 2-3sec under a condition on the order of 40MHz.
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