High speed off-line embossing

System for seamlessly embossing micro- or nanostructures into at least one thermoformable layer of a sandwich structure, wherein

• the sandwich structure comprises a layer of carrier substrate and a cover made of the at least one thermoformable layer,
• whereby the micro- or nanostructures comprise at least embossing structures that are a combination of a plurality of structures, the combination comprising a first structure and a second structure, with respectively a first width and a second width in a scale of at least 5 to 1, or respectively a first height and a second height in the scale of at least 5 to 1,
• the system comprising
• a melting system configured for melting material of the at least one thermoformable layer to a viscous phase;
• an application system configured for applying the molten material of the at least one thermoformable layer onto the layer of carrier substrate to obtain the sandwich structure prior to embossing;
• the system further comprising
• a first thermal management system configured for maintaining the material of the at least one thermoformable layer in the viscous phase prior to embossing;
• a conveyer system configured for feeding the sandwich structure in a nip of a set of a first embossing roller and a second embossing roller configured to emboss the micro- or nanostructures into the at least one thermoformable layer, wherein
• the first embossing roller and embossing micro or nanostructures carried thereon are made from a single bulk material,
• the first embossing roller comprises the embossing micro- or nanostructures in form of at least a protrusion and/or at least a recess on its cylindrical surface,
• the second embossing roller has a smooth cylindrical surface, and
• the at least one thermoformable layer of material is oriented towards the first embossing roller and the layer of carrier substrate oriented towards the second embossing roller;
• and
• a second thermal management system configured for controlling a temperature of the sandwich structure at an output of the nip to a solidifying temperature of the at least one thermoformable layer.