Colin Marsh, of Resolute DTG, advises on the key differences between DTG print heads and which type will best suit your needs
At the heart of every DTG printer is its print heads. These play a massive part in the time it takes a printer to produce a shirt and the number of T-shirts it can print in an hour. However, with many different types of print head available, it can be a minefield knowing what to look for when researching your next printer purchase. Here, I’ll look at the differences between piezo print heads, why some cost more than others, and compare industrial-type single heads with print heads that have multiple (four or more) channels combined into a single housing.
Let’s look at two particular piezo heads and what makes them so different…
The Epson DX5
One of the most commonly used print heads in the entry-level DTG market is the Epson DX5. This is a piezo print head and there are a few variations but, on the whole, its physical properties remain the same across the range. This print head has eight channels combined in a single housing, which makes it more economical to manufacture. A lower manufacturing cost makes for a more affordable printer, which could be attractive for new entrants to the market, those with limited budgets or those with only low production volumes. On the flipside, this configuration will restrict the use of your printer if just one of those channels becomes damaged or stops printing.
The print head chamber has one entry point for the ink with the exit point being through the nozzles. Throughput is achieved by vacuum from the capping station, or when the print head is actually jetting ink under a print command. A single-entry point restricts the circulation of white ink through the print head, and this can leave the ink chamber vulnerable if regular cleaning cycles are not performed. The damper above the print head, a simple filter with pressure-release valve to stop the print head from flooding, can also collect pigment from the white ink and, over time, this can choke the filter.
The white particles in DTG ink are titanium dioxide, which is much heavier than the modified water solution used to carry it through the head and on to the garment. When the pigment splits out due to lack of regular use, the head chamber or damper can starve the piezo mechanism, causing it to clog. However, with regular maintenance, this shouldn’t happen and the print head will continue to perform for quite some time before wearing out, rather than clogging.
The Epson DX5 has eight channels in a single housing: with regular maintenance it will perform well
The single-head Ricoh Gen 4 has twin-entry points, which help eliminate pigment settling in the chamber
The Ricoh Gen 4
The Ricoh Gen 4 print head is made from stainless steel and has two channels per head. As an industrial print head, it has two entry points into the head. This allows ink to be circulated through the print head, eliminating pigment settling in the chamber. It also reduces the number of cleaning cycles required, therefore reducing wasted ink during maintenance. Any print head’s ability to jet ink quickly and accurately will depend on the materials used to manufacture it, the quality of its build and also on the drop size. The Ricoh Gen 4 has a larger drop size which, when utilised, offers very fast printing – printers like the Ricoh Ri 6000 that are fitted with these heads generally print much faster than those fitted with the Epson DX5. The Ricoh Gen 4 can also jet ink with a much higher viscosity (density), so a thinner layer is required, resulting in a softer hand once the print is cured. Higher viscosity inks also allow for better durability in the wash. The flipside is that this print head costs more than the DX5: as you will require multiple print heads, this will increase the build cost of the printer.
Speed versus cost
The results of a side-by-side speed test at Resolute DTG’s technical department were an eye opener. We used an R-Jet 5 fitted with a DX5 print head, which produced between six and 10 dark shirts an hour. The cost of this printer new was £9,950. When printing the same artwork at the same size, the Ricoh Ri 6000 achieved 30 dark shirts an hour. The cost of this printer new is £23,950. So the Ri 6000 costs just under two and half times as much as the R-Jet 5 when purchased new and is capable of producing three times as many shirts in a given time. These numbers are summarised in the Production Figures & ROI table, (below), which are based on a profit margin of £5 per printed shirt. As the table shows, the difference in the return on investment period (ROI) between the two printers is less than 10 days when they are working at full capacity. Bear in mind, however, that the earning potential of the Ricoh Gen 4 machines is greater once the ROI has been achieved.
How, then, does this information affect your decision over which new printer (and print heads) to purchase? In short, your investment should match your production requirements. My advice would be: don’t spend more than you need to, and match the printer’s throughput to your production volumes. For example, if you’re only ever likely to be printing 25 shirts per day then the ROI on the DX5 print head printer would be nearer to 80 days whereas on the Gen 4 print head printer it would be nearer to 192 days. But choose wisely: you can’t make a printer run any faster than it is designed to operate. If your budget can stretch to it, and you anticipate that your future production volumes will warrant it, consider a printer with industrial heads – it is likely to require less maintenance, and will give both ink savings and higher profit potential over the long term.