For several years now, LED and UV inkjet printing has become increasingly established in the international print market. In the early days, inkjet printing was unable to match the accuracy and quality of offset printing, but further developments in print heads and inks have resulted in major progress in recent years. Inkjet printing boasts a number of advantages compared to the more traditional printing techniques – especially for users of UV technology.
In the inkjet printing process, the ink reaches the substrate for printing without any kind of diversion. The split-second curing of the inks means that products can be processed immediately afterwards. Curing UV and LED systems deliver a high level of process reliability, and even small print runs can be produced economically.
Almost any substrate can be used for inkjet printing. As it is a non-contact printing technique, even 3D materials, complete with angles and curves, can be printed directly. Under certain circumstances, the substrate need to be pre-treated to prevent the ink “running” and to guarantee sufficient adhesion of solvent-free inks to the surface.
The first spheres of application for inkjet printing were coding and marking (e.g. printing best-before dates on food packaging) in continuous inkjet printing and using solvent-based inks. In the meantime, outstanding print results from improved inks and technology - including in the UV range - have now expanded the usage of LED and UV inkjet printing to a considerable extent.
No analog printing plate is required for inkjet printing, making it straightforward to print a variety of information on a substrate. This is particularly effective in operations in which parts need to be personalised or numbered consecutively. Inkjet is recommended for small print runs and/or content which changes at short intervals, e.g. for mailings, signage or in commercial printing and limited print runs. Examples here include posters, placards, banners and signs, maps, bar codes, numbering, best-before dates, direct mail and business documents.
With high-quality, non-contact printing on the most varied of substrates, completely new spheres of application will be opening up in industrial printing (direct printing on industrial products) in the future. Integration of print heads into the production line has made it possible to print the required content or graphics directly onto the end product inline, saving both time and resources.
However, industrial inkjet printing is not restricted solely to the graphic design of a product. Increasing improvements in head technology and precision machinery have now made it possible to print defined, extremely thin or delicate functional layers in the semiconductor industry. There is also a trend for 3D printers, which can inexpensively produce one-offs of any 3D shape using inkjet technology in production.
With regard to UV finishing, hybrid solutions comprising standard and LED UV technology are opening up new possibilities for special haptic effects on printed products. Optimum results are achieved by combining LED UV units for what is known as “pinning”, the pre-curing of inks during the printing process and a standard UV system for end-of-press drying. This opens up another niche for special print finishes. However, as the use of UV inks is neither economical nor indeed desired in many spheres (in corrugated cardboard printing or direct printing on cardboard, for example), a combination of water-based ink and warm air/infrared drying is used.
You are very welcome to contact us at any time with detailed questions about the applications!
Inkjet systems are now used for curing solvent-based inks across almost all materials and designs of press. The sphere of application ranges from large-format printing using mobile UV systems to industrial printing on wood/PVC at very large print widths to fast-running web-processing presses or label printers. The curing systems required for this consequently have to meet a number of different requirements, such as a compact, lightweight design, long service life and extreme output, for example.
The IST Metz group’s portfolio of UV systems (UV lamp and UV LED) is therefore the most comprehensive on the market for inkjet applications and can cover virtually every customer requirement. The modular design of the UV and LED systems means that it is perfectly straightforward to design customer-specific systems for curing industrial products.
As a result, UV LED pinning with final UV lamp curing or several powerful UV LED systems of different wavelengths can be fitted in combination, for example. Depending on requirements, there is the option of selecting between focussed and non-focussed UV LED systems or different reflector geometries for the UV lamp technology. It goes without saying that IST Metz also has the products and expertise for drying water-based inks - for example when printing directly on cardboard or corrugated cardboard.