| 摘要 |
A method for controlling curl in laminating a protective film having a heat-softenable adhesive surface onto a relatively flexible substrate document, in which the adhesive surface of the film is heated, the film and the substrate are then passed between two pressure rolls, and the laminate thus formed is maintained in contact with the pressure roll that engages the substrate through an appreciable arcuate distance after the laminate clears the other pressure roll to control longitudinal curl. The pressure rolls engaging the substrate and the film may be of convex and concave configuration, respectively, to minimize transverse curl. Radiant heating is preferably employed, together with limited pigmentation in the adhesive portion of the film.
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