Fire resistant sandwich board

A method of manufacturing a sandwich board comprising a core element having two opposite sides coated with a liner, said method comprising the steps of:

• providing a web of steel plate coated on one side with a layer of polyester with embedded polyamide spheres,
• providing a web of transfer material, which transfer material exhibits at least one face printed with indicia in a sublimable dye,
• bringing said webs together with said printed face in surface contact with a face of said steel plate web,
• running said contacting webs around part of the circumference of a heated roller while running a blanket around at least part of said roller in overlying relationship with said webs, said blanket being tensioned around said part of roller in order to substantially prevent any slippage between said webs,
• the extent of circumference covered by said webs, the speed of revolution of said roller, and the temperature of said roller being selected to allow a sublimation process to take place between said webs, which process yields a web of printed steel plate and a web of spent transfer material,
• separating said web of spent transfer material from said web of printed steel plate,
• air cooling said web of printed steel plate until the print has cured,
• bringing a web of polymer foil together with said web of printed steel plate in bonded contact whereby to provide a liner,
• winding said web of polymer foil together with said web of printed steel plate in bonded contact on a liner take-up roll, whereby to provide said coil,
• forming a web of liner by unwinding said coil,
• placing an adhesive material on said liner,
• cutting from said web of polymer foil together with said web of printed steel plate in bonded contact a pair of substantially identical sections,
• placing said sections in overlying sandwich arrangement and adhering said sections to said core element, and
• subjecting the sandwich to pressure and heat in order to cure the adhesive material to form the sandwich board.