Ricoh introduces TH5241 printhead
Earlier this summer Ricoh announced a new printhead, the TH5241, which is the first Ricoh head to use a MEMs thin film piezo actuator and has been designed specifically for industrial applications.
However, the history behind this printhead is almost as interesting as the head itself. Back in 2016 Ricoh announced that it would develop an inkjet printhead for industrial applications using its thin film piezo actuator. This was to use a new type of actuator produced by Ricoh’s Sol-Gel process for producing solid material from the solution of raw materials. But Ricoh itself did not actually introduce a thin film printhead at that time.
Instead, Ricoh announced a strategic collaboration with Xaar in 2016, which led to the Xaar 1201 GS2p5 being shown at Drupa 2016. This head was based on a design from Ricoh with the thin film actuator itself coming from Rohm Semiconductor, based near Kyoto.
Xaar gave up on its plans to sell thin film printheads and has since returned to its roots in bulk piezo printheads – which I’ll deal with in a separate story. That has left Ricoh free to take back its original design for this printhead and to offer its own version, which is the genesis behind the new TH5241 printhead. John Mills, CEO of Xaar says that the Ricoh TH5241 is essentially the old Xaar 1201 head but adds: “Collectively we understood where the limitations of the 1201 were and I think that the new product from Ricoh fixes some of the challenges with the 1201.”
Consequently, Ricoh’s TH5241 can be seen as a direct replacement for the 1201, which Xaar no longer sells. Mills explains: “The customers we sold the 1201 to, we encouraged them to re-engage with Ricoh because we didn’t want to let those customers find themselves without somebody who could support them so it was a very well managed transition where we handed back customers who were using the 1201 to Ricoh so there was continuity of supply there as much as possible. And our relationship with Ricoh remains very good.”
Graham Kennedy, head of commercial inkjet business at Ricoh Europe, says that Ricoh has been working on thin film for a number of years, noting: “We certainly see thin film as a technology that’s going to help transition multiple industrial markets from analogue to digital inkjet over a period of time.”
He continues: “The TH5241 is targeted at a lower end scanning application, primarily sign graphics or textile areas. The advantage is that it’s a compact head. It delivers high resolution and high productivity at an affordable price in a single package.”
He says that it has some advantages over Ricoh’s existing GH2220 head: “The GH2220 is a silicon head but it’s a two colour 300 dpi head, so each colour at 150 dpi, whereas the TH52411 has four ink channels, each of which can be 300 dpi so you have twice the number of ink channels and twice the resolution but also you have twice the pumping power as well because you can drive it at a higher frequency.”
The TH5241 is a compact head that measures just 52.7mm wide, 45.4mm deep and 55.4mm high and delivers a print width of 27.1mm. It features four rows of nozzles, with 320 nozzles per row, making a total of 1,280 nozzles. Each row can act as a separate channel so that one head can jet up to four colours. Each row delivers 300npi so that two rows can be paired to produce 600dpi, or all four rows combined for 1200 dpi.
It operates at 40ºC, with the temperature controlled via an integrated thermistor. It’s compatible with UV, solvent, and aqueous inks and takes fluids up to 7mPa•s in viscosity. There’s no recirculation on this head as it is aimed at low end scanning applications such as sign graphics, textiles and labels as well as industrial and direct to shape printing.
Kennedy adds: “We have a thin film program that might address industrial single pass markets in the future and different features and specifications will be under consideration for those. But for this TH5241, the market it’s aimed at we don’t see the necessity for recirculation or temperature control.”
The TH5241 has a choice of jetting frequency, including 40kHz, which can produce two grey levels – 0 and 3pl – or 24kHz for four levels, including 6 and 12pl. The different drop sizes are created through changes in the waveform. Kennedy says: “You could drop the same native drop and merge it in flight to get different grey levels but we have the ability to merge different drop sizes so there are two different drop sizes that can merge to create the larger drop. You could merge lots of drops at the same 3pl size if you had the waveform to control it but I don’t know many applications where you would need more than four grey levels.”
Kennedy says: “We have a completely open wave form. We can train customers to do that or can do it for them, the choice is really up to them. Some customers want to do this themselves and have the capability, others need a little bit of hand holding. We like to welcome people to our lab at Telford, UK to help them do that but more recently we are having to do that training virtually. It’s an open platform, with an open design, there are no secrets.”
He adds: “We work with GIS and Meteor and have other partners in Asia. Some customers want to develop their own drive electronics and we provide them with all the electrical interface detail and support.
These printheads are available now, and have already been used in at least one printer, the Apache TH6090 Geni. You can find further details on the TH5241 from ricoh.com.