Tubing/pipes are produced by means of the so-called extrusion technique. This involves pressing a warm liquid material through a template giving it its form when it comes out of the machine. These products are manufactured from non-porous material that should be coded with solvent-based or UV curable ink. Despite their dense surfaces, they can be coded effectively because the ink is dried by the flash of a UV light, or because the solvent evaporates from it, leaving the dye behind adhering to the surface.
Tubing is mostly coded by Hi-Res Inkjet in combination with solvent based ink. For this, the inkjet is placed right behind the extrusion machine. As the formed tube comes out of the machine it is transported along the print head and coded. Because the tubes are still warm after extrusion, the solvent evaporates immediately and the ink adheres quite quickly. An encoder can then be used if the extrusion speeds vary. With this the printer will adjust the print speed to the production speed automatically.