Memjet has introduced its latest product line, DuraBolt, a new range of turnkey solutions for OEMs looking to build their own single pass inkjet printer. So far Memjet has announced two models: the four-colour DuraBolt 325C; and the wide web monochrome DuraBolt PrintBar.
Essentially, DuraBolt is a print engine in a box. Previously Memjet has offered various modules around each printhead design for OEMs to pick and choose what they wanted, but the DuraBolt has been conceived as the sum of its parts with everything needed to jet ink onto a substrate in one box, including servos to automatically position the printhead and an aerosol extraction unit order to take care of the ink mist as well as all the drive electronics. It also includes automated printhead maintenance and the DuraBolt casing opens up along its length to offer easy access to all of its internals for servicing.
Starting with the colour version, the DuraBolt 325C is a compact four-colour unit with a print width of 324mm or 12.77ins. It uses two printheads and sits between Memjet’s existing single colour DuraLink and four colour DuraFlex systems. The ‘ThunderBolt’ printheads have been adapted from the existing A3 DuraFlex design but combined with many of the components from its DuraLink systems to make for a more robust system than the typical DuraFlex engines. Whereas the DuraFlex heads run with four colours these heads have just two channels and use one complete strip of silicon for each colour. This has resulted in faster print speeds of up to 20 percent. The heads still have Memjet’s standard 1600 nozzles per inch density and produce binary 2.1 pl drop sizes.
This approach should also lead to better print quality by cutting down on the risk of banding artefacts occurring between the dies in the printhead. In this case, the two printheads are slightly offset so that the dies overlap, leading to greater uniformity, particularly in printing background solid areas.
It can produce 68 mpm or 225fpm in the best quality mode at 1600 x 1280 dpi but can reach 137mpm or 450 fpm at a lower resolution of 1600 x 640 dpi. It comes with a complete media profile library for these resolutions.
However, it’s hard to make a straight comparison between different technologies as Memjet tends to offer slightly different resolutions, and therefore different speeds, depending on the market that each head technology is targeted at. Memjet also appears to be open to tweaking the resolution for particular OEMs requirements though this does require making new media profiles.
As with all thermal printheads, these heads are consumable items. But Memjet has managed to double the ink life with each printhead able to jet up to 240 litres of ink and with four times nozzle redundancy for each colour.
Memjet does require its OEMs to use its own ink, which is hardly surprising since ink sales are a major revenue generator and the inks and heads are optimised to work together. The ink is the existing PZ Duraflex ink, which is an aqueous pigment-based ink that was first developed for use with the DuraFlex printheads. But DuraBolt is designed as a much faster print system, meaning that the ink will have to dry much faster.
Jason Thelander, Memjet’s CTO, told me: “Drying systems are very media dependant, we have several media types that we print as full speed on our press without the need for drying, but some media will need to be dried actively or speed reduced.”
It’s worth noting that Memjet also offers an Adphos dryer option. Interestingly, Thelander added that there is some flexibility in the choice of ink, suggesting that Memjet might be open to tweaking the ink formulation or using a different ink altogether if a customer wants to work with a particular substrate.
The DuraBolt unit comes with 10 litre ink tanks as standard though there is a bulk 55 litre option. The inks are aqueous pigmented inks that are said to be fully compliant with food safety certifications.
Dedicated front end
In the past, Memjet left its OEMs to sort out their own software, which in theory should have allowed each OEM to develop their own unique added value and to differentiate themselves from other Memjet OEMs. However, in practice, this simply slowed down the OEMs and Xitron took advantage of this by offering a version of its Navigator DFE specifically for driving Memjet-based printers. So for the DuraBolt engine, Memjet simply invited Xitron to develop a DFE that Memjet could offer exclusively to its OEMs. 
The result is a tight integration between the front end and the print engine with the Navigator software also controlling all of the press functionality from the dryers to the web tension. Most of the integration is handled through Modbus, which is a TCP/IP-based messaging structure for client-server communication between intelligent devices, and can be used to integrate different subsystems. It’s an extremely useful approach for anyone who wants to integrate a DuraBolt print engine to another device, such as a flexo press or converting line.
It includes a Human Machine Interface gives operators an intuitive and interactive dashboard as well as real-time status of consumable levels, press components, and environmental conditions.
Memjet also offers a remote monitoring system, Memjet Cloud, which allows its engineers to see if there are any errors in the system and to advise customers on how to deal with any problems. The DuraBolt engine includes a Raspberry Pi PC that can save the data and send it to Memjet cloud services.
The DuraBolt PrintBar
Memjet has also developed a monochrome option, the DuraBolt PrintBar, that’s been designed for wide web applications. This supports up to three of the DuraBolt modules with a choice of print widths of 324mm/12.75ins, 648mm/ 25.5ins and 990mm/ 39ins. It includes the stitching between them as well as automated head wiping, capping and print gap positioning, along with digital print-on-page positioning. Memjet quotes speeds of over 293mpm or 960fpm though this is a meaningless figure without knowing the resolution used.
So far Memjet has only described the PrintBar as a monochrome solution though there doesn’t seem to be any reason why it couldn’t also support the colour modules.
Memjet Direct
The DuraBolt engines also mark a new approach to the market, Memjet Direct, whereby printers and converters can buy the DuraBolt engines from Memjet to integrate into their existing systems without having to go through an OEM. In a way this makes sense since DuraBolt is a print engine in its own right and can be retrofitted to existing equipment without any further development needed. Of course, the DuraBolt modules will still have to be integrated into those existing systems, which is part of the Memjet Direct service though no doubt Memjet’s existing OEM customers and distributors will also offer an integration service.
Scott Desoto, Memjet’s Chief Revenue Officer, commented: “Printers can access the DuraBolt PrintBar direct from the technology provider. We know its capabilities and believe the best way to deliver it to the production printing industry is through direct engagement.”
In summary, the major advantage of the DuraBolt approach is that it allows OEMs to develop a single pass inkjet printer and bring it to market quickly. All the things that normally trip up a printer developer, such as optimising the ink, or the drying system, or the drive electronics or the DFE, have all been taken care of. Anything that helps manufacturers get to market faster will translate into lower development costs and improved market opportunity.
The disadvantage of course is that its going to be much harder for those OEMs to distinguish their products from other rivals that also used DuraBolt, but this may not matter if those OEMs are working with unique systems or applications.
It’s worth noting that Memjet has been actively promoting DuraBolt over the last six months or so to its existing customers. Thelander concludes: “We have already shipped engines to three customers with many more on order with new and existing customers. The applications vary, we have flexible packaging and commercial print applications underway.”
You can find further details from memjet.com.