UV direct printing

from Wikipedia, the free encyclopedia
UV direct printing on metal

The UV direct printing is a printing method that the large format printing ( large format printing is to you, LFP).

UV printing is a type of digital printing in which the image is transferred directly from the computer to the printing machine. The ink lies on the respective surface and does not harden immediately until it is exposed to ultraviolet light. The result is a color film on the printed material. The UV-reactive ink used for this purpose does not contain any solvents and is therefore kind to the environment.

The main difference to conventional inkjet printing (water-based or solvent-based) is that the ink does not completely penetrate the material, but lies on the material to be printed. This makes it possible to print on almost all materials.

UV direct printing on glass

functionality

The ink does not dry in the ambient air - as on a sheet of paper, for example - but is hardened with ultraviolet light immediately after being applied to the surface of the printing material (substrate). The dried ink has a slightly satined appearance that comes very close to printed high-quality paper. This results in a disadvantage in durability under sunlight or adverse weather conditions. On the one hand, the UV curing increases the strength of the print and, on the other hand, there is a slight protection against yellowing.

Advantages and disadvantages of direct printing

advantages

  • low costs (by printing directly on the material, no further processing such as lamination is necessary)
  • high numbers of items possible due to short production time (see first point)
  • high flexibility of the printing materials
  • Printing on structured materials (e.g. checker plate) possible
  • very high maximum print height (approx. 10 cm)
  • Printing color white as masking / background or spot color

disadvantage

  • no protection against mechanical stress as with laminated materials
  • mostly limited plate size (common UV direct printers usually only have a maximum print size of 3.20 m × 2.05 m)
  • Without lamination or painting, no change in the surface appearance is possible.

durability

The durability of UV direct printing according to today's standard is given as two to three years outdoors. Red tones in particular can fade before this period in strong sunlight. An essential component of these shelf life information is, however, the choice of material. Depending on the weather and climatic influences, the print may peel off after this time because the ink is on the material.

Common printing materials

  • PVC rigid foam panels (e.g. Kömacel) and PVC free foam panels (e.g. Forex)
  • Aluminum composite panels (e.g. Dibond)
  • Twin-wall sheets, especially for short-term use such as B. Suitable for elections
  • PETG (similar to polycarbonate)
  • Wood
  • metal
  • cardboard
  • Acrylic / Plexiglas / mirror / glass (adhesion must be guaranteed by an adhesive primer or special inks. The primer does not completely rule out streaking)

Due to the roll option of some direct printers, it is also possible to print classic roll materials such as paper or tarpaulin with a direct printer. Especially in the area of ​​short-term trade fair use, this production method can also be used with classic presentation media such as folding walls. The advantage here is that the ink is completely dry before further processing. This saves time in processing.

Manufacturer of direct printing machines

In the meantime, UV direct printers are offered by almost all known printer manufacturers. The main differences between the machines of the major manufacturers are the achievable print resolution, the white print / lacquer option, the roll option and the maximum print size. In 2010, the print quality of the major manufacturers rose to almost the same level. It can be foreseen that the next step will be the achievable square meter output with constant print quality. This has almost doubled in the last two years since 2008.

Another special feature are the different safety precautions on the printer. B. Prevent bruising and prevent the operator from being directly exposed to UV light from the lamps. Uncured inks that are released into the environment as aerosols also harbor considerable dangers. Extensive protection against “ink misting” (ink mist) is essential.

Print quality

The initial print quality of UV direct printing was far inferior to that of conventional solvent printing on vinyl film (e.g. for advertising signs). In 2006 this was a maximum of 300 dpi. In 2008 the maximum achievable print resolution increased to 1,440 dpi. This means that high-quality photo prints such. B. on acrylic glass or aluminum composite materials possible. The print quality is now hardly inferior to conventional printing and is often used for decoration products precisely because of the satin surface of the print.

See also

Individual evidence

  1. ↑ What is UV printing? Retrieved February 20, 2020 .
  2. ↑ UV direct printing. Retrieved November 15, 2017 .