Simultaneous printing and thermo-forming of thermoplastic sheet - to minimise fabrication cycles and maintain print and form alignment

摘要

Sheet thermoplastic material such as PVC is printed while being thermoformed. Pref. the print is derived from flexible polyethylene film which is precoated with sublimal inks and then overlaid on the sheet to be thermoformed. opt. the film carries marks which can be detected photometrically to automatically locate the print pattern photometrically to the mould. The printed film may be pressed on to the surface of the plastic sheet by a mould tool which pref. is dressed with silicone oil to allow the printed film to stretch in response to local sheet deformation during the thermoforming.