| 摘要 |
1318739 Embossing RCA CORPORATION 22 Sept 1970 [29 Sept 1969] 45071/70 Heading B6J A method of replicating a holographic relief pattern having an average peak to valley depth of about 500 Angstrom units comprises embossing the pattern on to a flexible thermoplastics tape. The tape may be made of a plasticized, cast polyvinyl chloride-vinyl acetate copolymer or a vinyl coated "Mylar" base (Registered Trade Mark), and can be either transparent or opaque, for instance reflective. The tape 204 and a master tape 226 of plastics or metallic material, e.g. nickel, carrying the holographic relief pattern are passed through calender rollers 206, 208 having silicone rubber surfaces 222, 224, the master tape being heated via roller 208 to a temperature below the flow temperature of the thermoplastics tape, this tape being cooled by compressed air through orifices in a metal plate 230 before being peeled from the master. The thermoplastics tape may be heated up to 0�3 to 0�85 of its flow temperature and subsequently cooled to 25� C. to 50� C., the embossing pressure being between 10 and 200 p.s.i. |
