In industrial inkjet printing, there are two basic kinds of printheads: Continuous Inkjet (CIJ) heads and Drop-on-Demand (DOD) heads. At Engineered Printing Solutions, we specialize in DOD industrial inkjet printing machines. What is the difference between the two technologies, and what are the advantages and disadvantages of each? This post will explore these questions. But first, a quick explanation of the two differing technologies.
As the name implies, CIJ printheads dispense a continuous stream of ink. The ink that is not needed for the print job is collected and recirculated back to the reservoir. With drop-on-demand inkjet printing, the printhead dispenses ink only when needed. Drop-on-demand technology, when combined with variable drop sizes, permits greyscale printing, creating both photorealistic gradients and also vivid blacks, even on porous surfaces such as corrugated cardboard.
Continuous inkjet printing is an older technology. The advantages that it provides include high drop velocity, permitting longer throw distances and faster throughput rates. Additionally, since the nozzle is in continuous use, clogging is not usually a problem. Drawbacks to CIJ printing include a high degree of wasted ink due to recirculation, and also the need for solvent-based inks in CIJ printheads.
Drop-on-demand inkjet printing, on the other hand, uses only enough ink to create the image, and DOD printheads can create gradients and greyscale effects at effective resolutions of 1200 dpi and higher. With the use of fast-curing UV-LED based inks, DOD inkjet printers can match the throughput rates of CIJ systems at a fraction of the unit cost. All of our singlepass inkjet printers use drop-on-demand printheads, as do our flatbed industrial inkjet printers. DOD technology is sought after by the Ad Specialty sector because it is what enables the vivid designs that promotional product printing demands.
Want to learn more about Drop-on-Demand industrial inkjet printing technology? Drop us a line!
written by Debbie Thorp, Business Development Director – Global Inkjet Systems Ltd. for Screen Print Magazine
The digital revolution has its sights on a new challenge, and decorating three-dimensional objects offers no shortage of puzzles or possibilities.
Product decoration using inkjet technology isn’t new – systems have in fact been on the market for many years. But recent developments have made decorating three-dimensional objects (not to be confused with 3D inkjet or additive manufacturing) one of the most talked-about segments in the industry.
Sales of small-format flatbed printers designed for decorating promotional items are increasing; more vendors are entering the market and the systems feature new capabilities. Also, we’ve seen significant developments in the mid- to high-end range of production printers. Systems that were demonstrated at tradeshows a few years ago are now proving themselves in real production environments.
Personalization and engagement are buzzwords that have been permeating marketing campaigns and social media in recent years with companies vying for “likes” on Facebook and developing ever more innovative ways of enticing us to buy their products. Numerous fast-moving consumer goods companies are now using digital printing technologies to add value to their brands and increase the “user experience.” What arguably started with Coca Cola’s “Share a Coke” campaign has exploded into personalized Nutella jars, Heinz soups, My Heineken bottles, and even customized dog food with Purina’s Just Right range – and there are many, many more examples.
The benefits and drivers for using digital printing technologies are well-known, including cost-effective short runs; just-in-time production; design freedom; no screens, clichés, pads, or time-consuming setup costs; and variable-data capability offering the potential for every product to be different. Then there are the particular advantages that inkjet technology brings as a noncontact technology that can print onto different product shapes – not only flat objects, but also tubes, conical shapes, and even tubs. Inkjet can also print onto structured surfaces, creating unusual visual and haptic effects, enabling decoration in areas not possible with labels. In short, inkjet can potentially operate in the same space as screen, dry offset, and pad printing – and yet offer the additional high-value benefits of a digital print technology.
Printing onto spheres, cylinders, and uneven surfaces is a challenge inkjet developers have happily embraced, offering direct print alternatives in applications where pad printing or labels would have been used in the past. Courtesy of Roland DGA.
view the rest of the article here – http://ow.ly/h0ok30dA5kF
Companies speak of guiding principles, vision statements and of strategic objectives. Companies proudly track significant achievements on timelines as a memorial to their evolution. I think it is important to have this perspective as Carl Sagan once said “You have to know the past to understand the present.”
Since our founding in 1985 we have important events we keep track of, most are facility expansion benchmarks required to keep pace with a continuous increase in projects moving through our shop floor. One of those transformative projects found its way back to the floor recently.
For some it seemed a bit out of place. Older technology, tattered graphics, comments like “it just looks used”. For others it marked an important point in our trajectory as an organization, a turning point that has led us down a pretty incredible path. It was here on our floor again because the client wanted to update it with the latest technology installed on the new printer recently put into production.
This was the first industrial inkjet printer we designed and built in 2009 to bring the customer into the digital manufacturing revolution. This engineered solution was built to solve two important problems, first to cut labor cost and secondly to cut product loss….Could we design a first of its kind machine, completely unique in their industry in a way that made financial sense?
This new digital machine had to replace six separate rotary table pad printing cells that required nine full time operators running in three shifts a day, seven days a week. There was a perceived need to eliminate inefficiency of changing out inks and clichés after each 144 print count, every day. Production had flat-lined and the product margins were being squeezed by an increase in overtime pay. The project proved difficult but those challenges the team encountered changed our company and the functional teams approach and ultimately our companies’ philosophy. Our (long term) partner broke through their comfort zone and took a risk on an unproven design.
After successful factory acceptance testing the machine was put into production on the facility floor. As the initial weeks went by there was a enthusiasm from the shift staff about the level of production they were achieving. Each day they noticed output improvements and were eventually able to eliminate the weekend shifts. Worker morale improved because the difficult change-out process had been eliminated. The machine software was integrated seamlessly into the internal SAP system helping streamline the ordering process.
A year later a second printer was installed at another site. Finally a third system was ordered in 2014. Each machine took advantage of design improvement and new technologies. LED cure inks became available, resulting in a reduction of energy consumption while eliminating the need for elaborate cooling systems. There was a new smaller more efficient flow through ink management system with better control of ink viscosity
The original printer will be productive on a manufacturing floor again soon.
The machine is not viewed as an eyesore now. It is viewed as a part of the proud legacy that shaped the direction of our company well into the future. The original project ushered in a new direction for EPS. This project was the catalyst behind the words ‘engineered’ and ‘solutions’ in our company name.
A vision is not where you are now. A vision is where you want to be in the future. Our partner for this project had a vision and was willing to take a risk that led to completely project cost recovery in three months by reducing the number of operators, overtime and nearly all product waste.
In this edition of EPS Weekly, I caught up with Dan Leiter, sales engineer here at Engineered Printing Solutions. Dan has been in the printing industry for 25 years, with the last 10 years of it providing industrial printing solutions to clients via both pad printing and inkjet technology. We had an interesting conversation that touched upon a number of things related to the dynamics of the customer relationship. This ranged from the inception of the EPS/Client relationship to ongoing support and maintenance of a solution that has already been designed and delivered.
What do you think is the most critical consideration when beginning to work with a client toward the custom design of an industrial printing machine, be it a pad or inkjet printing solution?
“The qualification process of defining the customer’s needs and delivering a solution or product that meets those needs is by far the most critical part of the process. It can be a difficult job, because a lot of our larger customers often have the involvement of numerous people from various departments such as engineering, operations, and marketing. The project might start out with a very simple process for a company, but as more players get involved, more requirements get brought in to the mix that have to be met.
As a result, we have worked hard over the years to establish and confirm expectations as early in the project as possible. We have achieved this through extensive specifying of needs with our customers to minimize unnecessary research and development costs, as well as keep projects on schedule.”
Do you feel that taking this ‘deeper dive’ with specifying needs early on with the customer has been successful in defining what the customer is truly looking for and needs?
“Yes. It has allowed us to define things, so that invariably when a customer approaches us later in the process regarding a specific functionality (or feature) that was requested, we can in turn reassure them that they will be getting exactly what was detailed in the design documentation.
On the other hand, if the customer is requesting additional features and/or functionalities after an entire process and procedure has been documented, that’s something different. Yes, we are always going to go above and beyond to make our customers extremely satisfied with the end product. However, add-ons and change requests in the middle of a machines design inevitably result in more project hours and thus additional costs.
The pre-build specification process places a milestone in the path, which protects both the customer and EPS by minimizing the probability of unforeseen costs and completion delays. So ultimately, it’s about getting as granular as possible when establishing expectations, and keeping everybody on task.”
As a sales engineer, what are some of the things that you find most gratifying (as well as challenging) when you’re working toward a custom, industrial printing solution for a customer?
“I’ve been in the graphic arts industry my entire adult life. We all claim to have ‘ink in our veins’. As a result, I have a natural inclination toward the entire printing process, including direct-to-shape, which I’ve been doing here at EPS over the last 10 years.
What makes it challenging is that we often have to reinvent the wheel to meet our customer’s specific needs. Every job can be an entirely different product – every job can comes with an entirely different set of requirements. You have to ‘define’ all of these requirements and then develop a solution that is going to ‘address’ all of them…each and every time.
I would say what makes it gratifying is taking a complex set of requirements (that are unique in nature) and exceeding the customer’s expectations in the end. A lot of what we do here is about helping our customers bring an innovation and/or invention to life. We are playing an active part in making entrepreneurial visions a reality. This is why we refer to our customers as partners. It’s a reference that is used all too often, but is completely fitting in our business.”
Tell me more about the customization side in all of this. What do you mean when you say “every job is different”? Can you give some examples?
“There is almost always a difference and/or variation when it comes to the automation that we customize for a client. This ranges from the type, size and shape of the product that they’re looking to decorate on, to the way in which they are looking to decorate on it. Product examples as simple as a tape measure, a glass bottle, a flashcard (to name a few), still have specific print areas that the customer wants to decorate. This in and of itself creates the need for a custom fixture, and that makes it unique to that particular customer. Even with similar shaped products, it’s different from customer to customer. Customers manufacturing the same type of product can have different processes in which our equipment needs to fit.
They’re all trying to create new processes to improve their quality and efficiencies. It’s exciting, but at the same time challenging. That being said, we love being part of it!”
Can you think of a specific industrial printing solution (pad or inkjet) that stands out as far as size and scope?
“A project that comes to mind is a printing services company that was looking for a digital inkjet machine that would exclusively work on their direct mail campaign. The machine needed to offer heavy personalization, short run capability and high throughput. In addition, the client wanted a solution that would print onto a pen 180 degrees (around the circumference of the pen barrel), in two different colors, and onto a dozen different pen styles.
These requirements required a digital inkjet printer that was highly customized from both an automation and software standpoint. When you’re working with a number of variables that require specific robotic features and heavy software programming, you’re now looking at a fairly complex and sophisticated machine. You are also looking at a significant investment.
In the end our mechanical and software engineers worked together to deliver a heavily customized XD-70 Industrial Inkjet Printer. (Click link for more information on standard configuration). The machine met all the demands that the client requested and we’ve been providing ongoing training and field support since it was deployed to their manufacturing environment last year.”
What do you think the future landscape of industrial printing looks like, and do you see it changing how you work with your customers?
“In terms of the direction that the industry is going, digital is clearly driving the bus now. Digital is still in its relative infancy as far as a decorating technology. Where digital needs to go to achieve broad market acceptance primarily involves pretreatment and ink adhesion.
Getting the ink to stick to the product and meet customer durability standards is paramount. Most of our customers are not printing on ‘throwaway’ items and have stringent requirements when it comes to this. The image needs to be able to maintain its quality while being exposed to various degrees of wear and tear, cleaning and expected life of the product.
It is my belief that new methods of pretreatment will be entering the market and gaining acceptance. Currently we use various methods; a chemical wipe, a flame, corona, and plasma treatments. Although they all have their strengths, ink adhesion with glass, metal and ceramics come with challenges. It is the new pretreatments that are expected to largely address these challenges, allowing greater ink adhesion and durability.
As far as how we are going to be working with our customers towards solutions, it will still be a lot of customization based on customer needs, and probably more. This is because customers (particularly large ones) will be looking for an all in one machine specific to their product line. A company that wants to print on 18 different products (all of various shapes, sizes and substrate types), and wants a single machine to accomplish is what you’re looking at here. That’s where we come in, because that’s what we do at EPS. That’s what we’ve already been doing for quite some time.”
For more information about Engineered Printing Solutions custom solutions, such as standard pad printers, industrial inkjet, consumables and auxiliary equipment, visit www.epsvt.com, email email@example.com or call 1-800-272-7764.
EPS Weekly is a new resource that we’re starting here at Engineered Printing Solutions. Its purpose is multifold, as it is intended to inform, educate and provide an inside look at the many factors that go into industrial printer manufacturing. We’ll start by describing the initial steps in designing a custom industrial inkjet printer for product-marking and decorating.
This week, I had the opportunity to sit down with Kevin Metcalfe, Applications Engineer in our single pass digital inkjet division. Kevin’s role is a critical one, as it primarily involves determining the process in which EPS can satisfy customer requirements when designing a machine specific to their industrial printing need(s). This involves working with all aspects of product decoration from adhesion testing, print quality, throughput requirements and any other specifications that the customer may have. A large part of Metcalfe’s expertise lies in performing extensive feasibility studies to troubleshoot potential issues related to direct-to-shape printing, such as scratch resistance, color gamut, substrate composition and contour, pretreatment methods and testing, testing and more testing.
How it Starts
The process typically begins with a set of predefined requirements from the customer. Samples are sent to the EPS facility to be sample printed, delivered back to the customer for review, and the journey toward a custom solution begins! It is during this process that a lot of discovery takes place and the relationship between EPS and the client becomes more of a partnership as new ideas are exchanged, possibilities discussed and limits pushed.
Meeting our customer’s adhesion requirements is paramount, and various methods are implemented during testing to determine what will produce the best results. Corona treatment, atmospheric plasma, flame and primer are all examples of pretreatment methods utilized in acquiring necessary adhesion to specific substrates.
Meeting adhesion requirements ranges in difficulty, depending on the substrate and the complexity of the desired result. For example, while polystyrene is a simple substrate to achieve adhesion with using UV inks with no pretreatment, other substrates such as polypropylene or high-density polyethylene are more difficult and require more process development. This is what makes Metcalfe’s position a very important one.
Cost and Compromise
Sometimes the ability to produce a difficult solution for the customer comes down to capital expenditure and/or compromise with respect to what their expectations were at the beginning of the project. While some are willing to invest in additional research & development to achieve their goals, sometimes the answer requires changing how the substrate is manufactured.
“It is a series of stages that is prudent to follow. If you haven’t dotted your I’s and crossed your T’s with regard to the process (the right ink, the right pretreatment, the necessary cure and adhesion), you can find yourself in a position where you have built a machine that does not yet meet customer requirements, so we must be thorough in our feasibility studies well in advance of building a machine.”
The Speed of Inkjet
The industrial inkjet printers built at EPS range from basic, single head monochromatic machines to complex staggered head array solutions capable of printing multiple colors, primers and clear coats.
“One of the great advantages of single pass inkjet is incredible throughput. The faster that you can run the parts beneath the print heads in a single pass formation the faster they come out the other end, while still meeting whatever other requirements that the customer may have” says Metcalfe.
EPS’s single pass applications are UV curable, meaning that the inks are cured using targeted wavelength ultraviolet radiation.
When is Inkjet the Answer?
There are many reasons to embrace digital technology for decoration over analog solutions. The desire for short runs, better print quality, just-in-time manufacturing, and quick job changeovers are just a few of the reasons to switch to digital.
The question of when to switch to digital comes down to the customer’s requirements, and whether or not these can be met via inkjet technology. The industry is still scratching the surface with regard to its capabilities. One of the more interesting aspects of Kevin’s position is overcoming a decorating challenge where there was initial uncertainty as to its feasibility.
“The challenge is both interesting and intriguing, because you’re pushing at the edge of an envelope here and the technology is constantly changing. Despite what others may say, there are always opportunities to do something more.”
What Makes EPS Different?
A history of being willing to custom design and build a machine to meet a customer’s needs clearly sets EPS apart from other companies. Our foundation is rooted in the analog process of product decoration, and this experience informs our design choices when building a digital solution.
“At the end of the process, once all the hurdles have been cleared, every customer we partner with receives an engineered printing solution that has been purpose-built to suit their specific manufacturing and decoration needs. Once installed in their facility it is extremely rewarding to watch their decorated product racing off the end of the conveyor.”
For more information about Engineered Printing Solutions custom solutions, such as standard pad printers, industrial inkjet, consumables and auxiliary equipment, visit www.epsvt.com, email firstname.lastname@example.org or call 1-800-272-7764.
When it comes to UV inkjet printing, reflective, transparent or glossy substrates do not always ‘play nice’. These substrates can be anything from glass and crystal to simply any type of shiny media that causes UV light to bounce back into the print heads. The problem with UV light reflecting back into the print head is that it results in curing the inks within the nozzles and on the nozzle plate itself. This can cause serious (and costly) damage to the print head and therefore shorten the life of the head unnecessarily.
The following are some tips on how to prevent UV curing from damaging print heads:
- Eliminate the use of refractive materials when manufacturing fixtures or printer jigs. When designing a fixture, be sure it is a dark matte finish material, and covers any negative space between parts to block UV light from bouncing back to the print heads.
- Consider the angle and intensity of the UV lamps. You should always use the lowest amount of UV possible to gain full cure for your application. If your machine was not supplied with UV light shims, contact the technical service department to inquire about this feature.
- Always print onto substrates that are ‘flat’ or parallel to the head array, and be sure the platen gap is no larger than 1.5mm. If you happen to be printing on a mirrored substrate that is flexible, be sure to attach it to a flat material first.
- Be proactive and check the health of your nozzles frequently. Perform an auto cleaning every other platen and to ensure that all nozzles are working, run nozzle checks every hour of production. If you notice that ink is curing either in the nozzles or on the face plate, flush the affected head with maintenance fluid.
- Always perform ink nozzle checks at the end of a shift. If any nozzles are missing, clean your print heads before powering down the printer.
Prematurely damaged print heads (due to UV light refraction and reflection) are expensive and unnecessary. Follow the tips above to avoid this issue and ensure proper care and functionality of your inkjet printer.
That’s the million dollar question! (Don’t worry. It won’t cost that much.) We’ve already outlined how you might benefit from the addition of an inkjet printer, and how to justify the cost of another piece of equipment, in a previous post. Now you have to match your workload and job requirements to the right machine configuration.
What’s the best inkjet machine solution?
That depends. Here are a few criteria used to get that answer:
Image quality – higher resolution means higher priced heads (or more passes).
- Throughput – there are “multi-pass” versus “single-pass” options (more on that later).
- Part size – limitations on height / width = machine size.
- Image size = part size = machine size.
- Substrate used – Regardless of the print technology, some substrates (PP & PE come to mind) still require pre-treatment for best image adhesion.
- Number of colors required – dark substrates will need White base-coat layer, plus CMYK
What’s the best inkjet technology for me?
Do you need high volume / throughput with minimal part handling? Consider an automated conveyor, single-pass inkjet printer. You’ll typically get:
- Up to 14″ per second of print speed
- A print width that will be a minimum of 2.75″ and can be wider on a custom configuration.
- Print resolutions up to 720 dpi in a single pass.
This is a great configuration for in-line applications, especially when pre-treatment is required. In many applications, you might require tooling of some sort to make sure parts are spaced and aligned consistently. Some units will incorporate a series of sensors to detect the part, and software that tells the heads when the part is in position for printing. We’ll help you with those.
Do you need higher resolution (up to 1200 dpi) but less speed? Perhaps a flatbed printer is your best option. These units offer:
- An advantage for smaller / identical parts that can be placed in machined trays or nests.
- A vacuum platen so you can print flat “stock.”
- A series of print heads (arrays) on a rack that moves across the bed, printing and curing as it goes, giving you the capability of printing in a single direction, or printing in both directions, depending on your needs. It’s not as fast, but print resolution may be a higher priority.
With either of the above technologies, you will have the capability of adjusting print speeds, ink density / droplet size, head heights, and color hues. Speaking of colors, if you are printing process color on a dark substrate, you will need to print a white base layer first, but both technologies can accommodate that. In addition, it’s possible to print a clear-coat to protect the image or provide a more glossy appearance, but you’ll probably have to sacrifice one of the white arrays.
Do you only print in one color? Obviously, it’s possible to print monochrome or spot colors with inkjet, but keep in mind that it’s not practical to change or flush colors in the same array. With most high end industrial inkjets, ink is fed from bulk tanks, not cartridges (helps to keep the consumable costs down).
Therefore, if you are thinking of printing with one color only, monochrome machines are available, but you need to be very sure that you will only require that one color. Custom machines have been built with white and black arrays, so the customer can print either (and even mix both to get a gray hue).
Does your customer ask to make changes on press or repeat exact specs? Inkjet will usually provide the capability to manipulate the images at the machine, with the assistance of on-board graphic art software such as Adobe Illustrator or CorelDRAW. Some machines are capable of storing jobs (or job “queues”) so operators can simply select from a drop-down box. Custom machines are network-capable, so jobs can be entered remotely, and many in-line / automated units can be accessed remotely for both job entry and diagnostic capabilities.
Now you know a lot more about industrial inkjet printers than the average pad printer. Don’t forget: at EPSVT we build your industrial inkjet printer the same way we build your pad printer — from the ground up to your specifications. That makes it clean, efficient and engineered for accuracy and cost effectiveness.
Call our toll-free number 800-272-7764 or go on-line at Ink Adhesion Part 3: Ink Mixing, Contamination, Blooming and Mold Release Agents and click on Live Chat. We’ll start you down a two-lane inkjet/pad printer highway to greater success.
The XD070 Industrial Inkjet Printer “image direct” from computer to print. The perfect solution for short or long runs with quick changeovers and variable data. This printer is ideal for multicolor printing on flat and semi-flat surfaces on a variety of substrates and can be customized to meet your printing needs.
Now, let’s talk fixtures and print job setup! With 3-dimensional parts, proper presentation of the product to the print head is critical. The closer and more level the part can be presented relative to the face-plate, the better the quality of the print will be. Calipers and a level are tools which can make this process more simple, but the ability to actually advance the product into the machine to more precisely gauge your proximity is optimal. By employing the “Setup a Job Print Position (by Test)” standard software utility on the XD070, the Operator is able to advance the fixtured product into the printer to visually set the print head-to-product offset (print height), as well as the cross track (left to right) offset. This capability provides for faster initial job setup and decreased printer crashes saving both time and frustration for the Operator.