Inkjet printing has long been available to manufacturers who need to mark their products with traceability information. Industry standard large character printers and continuous inkjet offer a dot-matrix print effect, suitable for batch and date codes and basic product information. Now the next generation of high-resolution printers allow the addition of fine detailed information such as machine-readable codes and logos, as marking systems specialist, T-Mark, explains.
The latest innovation in inkjet printing has opened up new opportunities, particularly on surfaces that are notoriously difficult to print, such as polyethylene (PE) pipes.
T-Mark offers printers with integrated UV curing modules. By plasma treating the surface to be printed and UV curing the ink, the latest printing systems can produce a mark that is scratch resistant and solvent resistant.
Doncaster-based egeplast UK approached T-Mark, looking to improve the quality of its printing on the wastewater and drinking water PE pipes it manufactures. It had been using a continuous inkjet (CIJ) printer to print information on the PE pipes, but the manufacturer wanted to improve the quality of the mark and include its company logo. In addition, the print needed to be solvent – specifically petrol–resistant.
T-Mark used 32mm piezo printheads from its supplier, Yeacode, to solve the problem. Using UV-curing white ink onto a plasma-treated pipe, egeplast was able to achieve all its objectives and print its logo and product specification information on both sides of its PE pipes.
In the egeplast installation, the printer and UV curing module are mounted 1mm away from the curved surface of the pipe, producing a sharp print in white against the dark surface of the pipe. Non-contact marking is an essential feature of the system due to the risk of any pressure on the pipe leading to squashing and ‘ovality’.
This technology is also being used by a new customer that specialises in subsea engineering to mark its ocean floor cables at 1m intervals with product information and a logo.
The customer had been using a combination of laser marking and CIJ printing in an attempt to make a permanent, clear mark on the product.
However, the CIJ dot matrix effect print quality was not as sharp as was desired and the print was rubbed off during the haul-off part of the production process, leaving a mark that was blurred and illegible.
T-Mark constructed a frame that incorporates a UV plasma treatment module, a Yeacode piezo inkjet printer, and a UV curing LED so that the customer can print and cure a clearly legible mark that won’t rub off with the application of either solvent or pressure.
UV curing inks are also available for T-Mark’s thermal inkjet (TIJ) printers, which have the advantage of being low cost and requiring zero maintenance. The easy-to-use cartridge system means that any problems with print quality or requirement to change ink colour can be easily addressed by simply swapping out the ink cartridge. The printhead is incorporated in the cartridge, so there is no need to flush through a cleaner if wishing to change from printing in black, say, to white.
While shown to its best advantage printing onto plastic surfaces, UV-cured inks are also suitable for timber applications, producing a mark that is darker than standard, which does not fade when exposed to sunlight.
Industrial printing has come a long way since the first CIJ printers were introduced. The new technologies produce a higher resolution mark allowing for greater variety of printed content, including machine-readable codes. And being able to UV cure the latest generation of ink types onto a plasma treated surface means that manufacturers are able to apply a mark that, once printed, is there for good.
