Method for printing on an object in an inkjet printing process
A method for printing on an object, for instance on an object made of a foamed material, includes applying ink to a surface of the object in accordance with digital image information in an inkjet printing process and irradiating the ink by electromagnetic radiation, preferably containing an IR proportion, to cure or dry the ink. The ink is directly heated by the irradiation and the material of the surface is indirectly heated by the irradiation by thermal conduction from the ink, causing the material in a region to experience a volume change. In this way, it is possible to simultaneously print on the material and to provide the material with a relief structure/to digitally emboss it.
1. A method for printing on an object, the method comprising the following steps:
providing an object having surface formed of a material;
applying ink to the surface of the object in accordance with digital image information in an inkjet printing process;
directly heating the ink by irradiating the ink using electromagnetic radiation to cure or dry the ink; and
indirectly heating the material of the surface in a region underneath the ink using the radiation by thermal conduction from the ink, causing the material in the region to experience a volume change.
2. The method according to claim 1 , which further comprises:
reducing a volume in the region, causing the ink to sink in, or
increasing the volume in the region, causing the ink to be raised.
3. The method according to claim 1 , wherein the electromagnetic radiation includes ultraviolet radiation curing the ink by cross-linking.
4. The method according to claim 1 , wherein the electromagnetic radiation includes infrared radiation.
5. The method according to claim 1 , wherein the electromagnetic radiation includes infrared radiation drying the ink by dehumidification.
6. The method according to claim 1 , wherein the material does not absorb the electromagnetic radiation.
7. The method according to claim 1 , which further comprises melting the material in the region.
8. The method according to claim 1 , wherein the material is a foamed material.
9. The method according to claim 8 , wherein the material in the region loses its foamed condition.
10. The method according to claim 1 , wherein the material is a foamed rigid expanded polystyrene.
11. The method according to claim 10 , wherein the material in the region loses its foamed condition.
12. The method according to claim 1 , which further comprises:
carrying out the step of applying ink to the surface of the object by using an inkjet print head;
carrying out the step of irradiating the ink by using an emitter; and
moving the object and the inkjet print head as well as the object and the emitter relative to one another by using a single-axle or multi-axle robot.