2024 Program
Join us in Switzerland for two full days of technical talks, multiple opportunities to network and meet with exhibitors, including a tour and demonstration session at iPrint and and optional 1-day Advanced Inkjet Printing Workshop.
To accommodate travel, the conference starts the afternoon on the first day and finishes early afternoon on the last day. Optional auxiliary events fill out the remaining 1.5 days. Program details will be posted as they are confirmed.
AT-A-GLANCE
29 January
13:00 - 17:30 Technical program, Exhibitor profiles, Exhibits, Networking time
30 January
9:00 - 18:00 Technical program, Exhibitor profiles, Poster Session, Exhibits, Breaks, Group Lunch
18:00 - 22:30 Conference Dinner
31 January
9:00 - 12:30 Technical program, Exhibitor profiles, Exhibits, Breaks, Group Lunch
14:00 - 17:30 Exhibitor Equipment Demonstrations: Conference exhibitors provide live demonstrations of and answer questions about their equipment. Takes place at iPrint facilities and may or may not be combined with the iPrint Tour.
14:00 - 15:00 Optional iPrint Tour: Upon signature of an NDA, participants may visit the iPrint laboratories to discover the world of cutting-edge inkjet research.
1 February
8:30 - 17:30 Optional 1-day Advanced Inkjet Printing Workshop (additional fee required)
Preliminary Program
Monday, 29 January
Droplet generation and visualization
13:00 - 15:00
Welcome
Yoshinori Domae, iPrint (Switzerland)
13:10
Keynote A Helicopter View of Ink Jet Printing, Stephen Temple, Cambridge University (UK) [view abstract and bio]
Abstract coming.
Stephen Temple is a Fellow Commoner of Clare Hall College, Cambridge University, and a retired inventor. His work covers various topics: mentoring for the Impulse Program at the Maxwell Centre, Cambridge; helping new entrepreneurs; restoring an ancient windmill; and carrying out wind analysis in the context of planning applications that affect windmills.
14:00
The Power of Waveforms and How to Find the Perfect One, Raphael Wenger, Droptimize Sarl (Switzerland)
[view abstract]
Achieving an optimal print quality in inkjet application relies on the precise definition of waveform parameters. This process, however, remains a challenging scientific endeavor characterized by its complexity and a lack of well-defined methodologies.
In this presentation, we will dive into the science behind optimizing waveforms. One major challenge lies in balancing factors like drop volume, speed, and stability to achieve the desired print quality. We'll explore the latest developments, such a machine learning and iterative solvers. These algorithms rely on big data to analyze vast datasets of printing outcomes, helping to refine waveform settings for improved quality. Such innovations may revolutionize this field, making high-quality, precise prints more accessible across various applications, from graphics to functional electronics.
14:20
Femtolitre Drop Generation in Industrial Inkjet Printheads, Fernando Rodriguez Llorente, iPrint Institute (Switzerland)
[view abstract]
In this paper we report what we believe is the first-time observation of femtolitre drop generation from a nozzle in an industrial inject printhead. While femtolitre drops have been observed and reported, it has been mostly in the context of jet ligament thinning and subsequent breakdown into drops by Rayleigh-Plateau instability. This communication will show jetting of femtolitre size drops directly from the ink meniscus formed on the nozzle exit of two different industrial printheads. The printheads are from different manufacturers, with different microchannel and piezoelectric structures, and the two inks used are very similar, one of them having one extra polymer component used to increase the ink viscosity. The jetting events happen at random times, from immediately after the ligament detachment from the nozzle up to several hundreds of microseconds later. While the physical mechanism underlying this jetting phenomena is not understood, we will analyse our results and compare with existing theories small drop formation, to try to build an understanding of how this jetting process works.
14:40
Novel Jetting Status Inspection Method for Acquiring the Spatial and Temporal Information of Ink-jetted Droplets, Dong-Youn Shin, Pukyong National University (South Korea)
[view abstract]
Inkjet printing has been widely used in conventional graphic arts, publishing, textile industries, and more. It has also been adopted in the production lines of TFT LCD TVs for forming a PI layer and depositing liquid crystal, and OLED/QD-OLED TVs for forming a thin film encapsulation layer and colorant subpixels. However, the jetting precision and reliability required for the color pixelation of QD-OLED TVs are far higher than those for conventional applications. Although all nozzles of inkjet printheads need to be inspected before printing, the existing jetting status inspection methods are incapable of inspecting tens of thousands of nozzles within a minute. Furthermore, they hardly provide historical data of nozzles whether they worked well during the inspection period. In this presentation, a novel jetting status inspection method is introduced that provides spatial and temporal information on the jetting status during the inspection period.
15:00
Exhibitor Presentations I
15:20 - 15:50
Exhibits and Coffee
Inkjet-based processes in new application domains
15:50 - 17:30
15:50
Biotech and Printing Technology for Next Generation Computer Storage, Tomaž Karčnik, Marko Matijević, and Rok Luzar, BioSistemika d.o.o. (Slovenia)
[view abstract]
DNA holds exceptional promises as a medium for storing digital data due to its exceptional data density, data longevity, and maintenance-free storage. The key requirement of the "write-to-DNA" process is manipulating a massive number (millions per second) of minuscule droplets (pL) whose composition is determined on demand. The droplets consist of a mix of chemical reagents, selected from a larger set, depending on the data to be recorded. Water-based inks, pure demineralized water, and various oils are used for DNA synthesis, cleaning, and evaporation prevention respectively. The potential of Drop-on-Demand (DoD) printing technology for such an application is obvious, as it addresses several key challenges.
We developed an experimental DoD based Liquid Handling Machine (LHM), used to synthesize digital data-carrying DNA strands. The output from LHM passes through sensitive chemical post-processing before proceeding to storage. The development challenges included ink development, maintaining cleanliness, establishing cleaning procedures, novel print head control, reliable mixing of many reagents, and preventing evaporation. Some of these challenges and approaches will be presented in detail.
We successfully recorded limited amounts of digital data on DNA strands using LHM. The challenges of advancing the LHM technology to the next level will be discussed at the end.
16:10
Inkjet Platform for Additive Manufacturing Processes in Electronics Production, Jochen Seeser and David Hahn, Notion Systems GmbH (Germany)
[view abstract]
The presentation aims at providing an overview of the potential as well as limitations of additive technologies for the manufacturing of electronic devices. Inkjet printing of solder mask for PCB production will serve as a blueprint of an additive process that has been adopted successfully in mass production. Already saving the adopters energy and waste. At the same time, the 3D nature of inkjet printing has the potential to replace or simplify other electronic components.
The presentation will also give an insight in the vision of the EU funded TINKER project. It’s goal is to provide a new cost- and resource efficient pathway for RADAR and LIDAR sensor package fabrication with high throughput, improved automation, improved accuracy and reliability to the European automotive and microelectronic industry via additive manufacturing.
Within the TINKER project, an advanced inkjet platform was developed which also includes components for IR-ink drying, UV curing and laser sintering. In the presentation it will demonstrated how fully digital inkjet printing expands the capabilities of conventional manufacturing processes with a maskless, multi material and high precision process.
16:30
Indirect Part Printing by using Inkjet, in the New Innovative MoldJet Process, Robert Teuber, Chóngliàng Zhòng, and Thomas Weißgärber, Fraunhofer Institut für Fertigungstechnik und Angewandte Materialforschung Dresden (Germany)
[view abstract]
This study describes the use of inkjet technology in sinter-based additive manufacturing. In the context of additive manufacturing, inkjet printing is mostly used for the direct printing of components in the plastic, ceramic or metal sector. In the so-called MoldJet process, a new approach is being pursued. In this additive manufacturing process inkjet is used to print a paraffin-based ink layer by layer. This ink layer forms the negative of the later components. The resulting cavities are afterwards filled with a metal or ceramic paste of the later components. The indirect printing of the parts enabling a printing process with virtually no design restrictions, from filigree, porous structures to large-volume components. Not only the large design variety but also the high productivity result in the key for series production with the MoldJet process. This study will describe the implementation and the currently prevailing process limitations.
16:50
Printing of Use-cases by Direct-to-shape Inkjet Printing with Industrial Robot, Philip Kessler, Johannes Renner, Benoît Sahli, Vincent Schneuwly, Vincent Nidegger, and Gilbert Gugler, iPrint Institute, HEIA-FR, HES-SO University of Applied Sciences and Arts Western Switzerland; Florian Fässler, Polytype AG; and Danijel Tipura, MABI Robotic AG (Switzerland)
[view abstract]
iPrint worked with IXLA, a company specialized in laser personalization of security documents, to develop a UV inkjet printing system for their security document printers.
For this purpose, an ink screening was first carried out to find suitable inks that met the requirements of the specifications. Then, in a close collaboration, the inkjet printing system was developed and integrated into a prototyping platform. This prototyping platform was then used to optimize and define the entire inkjet process. The waveform was optimized to print high-resolution images, as well as the UV curing parameters. Extensive testing and analyses were performed to understand and optimize the adhesion and abrasion behavior of the ink on the substrate. This information was used to develop an initial prototype laser and inkjet platform. This platform will be introduced to the market in November.
In the foreseeable future, the interaction between laser and UV inkjet printing will be investigated with goal to develop potential new, innovative security features. Long-term tests with the prototype and field experience with the first commercial systems will help to further improve the system and increase its reliability and longevity. Other features such as printing varnish or security ink shall be added to the system over time.
17:10
Exhibitor Presentations II
17:30
day ends
Tuesday, 30 January
Novel printing technologies
09:00 - 10:55
9:05
Keynote Rheology and High Viscous Fluid, TBA, TriJet [view abstract and bio]
Abstract and biography coming.
9:55
Introduction of "GELART JET" Technology: Expanding Graphic Painting based on Valvejet Technology, Ryo Idehara, Ricoh Digital Painting Company Ltd. (Japan)
[view abstract]
Our "GELART JET" technology is built upon the foundation of "Valve Jet" technology and has evolved in a unique way. From now on we aim to achieve even greater growth and provide value by integrating with the Ricoh Group's inkjet technology. This time, we will introduce an example of a system configured by combining multiple types of GELART JET heads and special ink. We hope this presentation will serve as a valuable resource to enable all of you to connect the potential of our innovative "JELART JET" technology for your own applications.
10:15
Transforming Industrial Manufacturing: Harnessing the Potential of Ultra High Viscosity Jetting for Functional Printing, Ramon Borrell, Quantica (Germany)
[view abstract]
The potential for transforming industrial manufacturing lies in the utilization of jetting ultra high viscosity fluid, merging the scalability, flexibility, and digital printing capabilities of inkjet technology with the superior properties of functional materials. This talk explores the growing array of functional materials compatible with ultra-high viscosity jetting, shedding light on their characterization and the measurement of their electrical, mechanical, and other functional attributes. This expanding palette of options holds great promise for the advancement of Additive Manufacturing processes. In parallel, researchers are making significant strides in expanding the scope of jettable materials through Quantica's Novojet inkjet technology. This advancement not only empowers material manufacturers to create superior materials but also equips development engineers with effective tools for functional printing.
10:35
A New Printhead Generation that Breaks Technical Barriers of Inkjet Technology in Terms of Resolution and Ink Viscosity, Patrick Galliker, Scrona AG (Switzerland)
[view abstract]
Electrohydrodynamic (EHD) Printing has long been known as a potentially superior printing technology compared to conventional inkjet. Back in the 80’s, EHD was explored for graphical applications by major players but has long since been abandoned. Beginning of the century, new activities have emerged mainly in relation to emerging industrial applications like printed electronics. The problems that keep the technology from becoming industrially relevant remain the same though. EHD printheads are not manufacturable with large nozzle counts, mainly because of cross-talk issues, unbearably high driving voltages as well as general long-term stability challenges.
At Scrona, first MEMS-based EHD printheads have been created that eliminate all these problems at once. Scrona’s new EHD printheads contain nozzles at a density that can be more than five times higher than that of modern piezo-driven inkjet heads and they can be individually operated with less than 100V which makes them compatible with massively scaled driving electronics. Specialized nozzle architectures not only keep liquid in place, but also strongly reduce clogging issues by a highly efficient recirculation flow.
10:55 - 11:25
Exhbits and Coffee
Novel micro-manufacturing technologies
11:25 - 12:45
11:25
The Possibilities for Printhead Manufacturers of Next Generation Electroforming, Dave Dekker, Veco Precision (the Netherlands)
[view abstract]
Electroformed nozzle plates have long been a common sight within inkjet printheads. Veco Precision has over 40 years’ experience in this field and now introduces new possibilities using advanced lithography electroforming.
Veco is a world-leading manufacturer of micro- precision parts. It serves the world’s most innovative, hi-tech companies from industries that demand high quality and precision.
To meet customers’ specifications and demands, Veco has developed high standards of performance in Electroforming. This technology allows a powerful combination of precision and economical production; for high volumes and prototypes, standard and custom-made products.
Veco combines the well-known bell mouth shaped electroformed nozzles with conical nozzles and functional integration through multi-layer setups. This enables channel integration and glue-less adhesion of components.
The continuous advancement of lithographic possibilities have allowed Veco to make the next step in electroforming nozzle plates, combining the robustness and reliability of metal nozzle plates with sub-micron accuracy, low nozzle-to-nozzle pitch and minimal spread in first-to-last nozzle pitch not previously seen in this technology.
Get an insight in Veco’s toolbox for customizing the nozzle cross section, nozzle plate thickness, pitch, integrated channels and metal coatings to product specific requirements.
11:45
Innovative Fabrication of Glass Nozzle Heads, Ink Manifolds, and Nozzle Guards for Advanced Inkjet Printheads using LIDE Technology, Rafael Santos, Norbert Ambrosius, Aaron Vogt, and Roman Ostholt, LPKF Laser & Electronics SE (Germany)
[view abstract]
Inkjet printheads play a pivotal role in modern printing technology, demanding high precision and durability. This paper presents a groundbreaking approach to fabricating essential components of inkjet printheads by using glass as the core material, namely nozzle heads, ink manifolds, and nozzle guards. With Laser Induced Deep Etching (LIDE) technology, we achieve excellent outcomes in terms of positional and dimensional accuracy, surface quality, and functionality due to the design freedom LIDE provides.
Glass has unique properties and LIDE allows leveraging them to create high-precision glass nozzle plates with a wide range of nozzle dimensions, pitch and arrangements, in different cross-section geometries such as straight through-holes, tapered, V-shaped, and funnel-shaped. The resulting glass components exhibit exceptional chemical resistance, thermal stability, abrasion resistance, high rigidity providing mechanical stability, while also exhibiting very high transparency which could be of high interest when using UV-curable inks, for example. We demonstrate the versatility of LIDE by fabricating surface structures and through-glass structures in the same substrate and process step, allowing the fabrication of ink manifolds with complete design freedom. Our technology doesn’t generate any defects and maintains all the material characteristics of glass, particularly mechanical ones, which is of particular importance for glass-based nozzle guards.
12:05
Ultrafast, 3D Laser Micro-manufacturing of Novel Glass-based Microfluidics, Davide Farina and Alexander Steimle, FEMTOprint SA (Switzerland)
[view abstract]
The present work aims to introduce the novel FEMTOPRINT® microfabrication technology, based on ultrafast laser and chemical wet etching processing, to create three-dimensional, high-precision patterns into transparent, glass materials for a wide range of applications and microdevices. Thanks to the ability to generate 3D geometries with micrometric precision, to treat surfaces to achieve optical transparency on virtually any surface topography, and to laser weld hermetically microdevices without the need of glue or adhesive, new horizons for integrated microfluidics are yet to be explored.
More specifically in the inkjet industry, novel micronozzle arrays with a high degree of shape freedom and features dimensional repeatability over centimeter long substrates, within an exceptionally stable material as it is glass, can be now conceived at an industrial scale. Beyond that, the technology enables the integration of certain functional coatings to modify surface properties or the application of 3D electrodes, contributing to a new microfabrication approach suitable for a wide spectrum of microfluidic devices.
12:25
Exhibitor Presentations III
Latest news about inkjet printheads
14:00 - 15:20
14:00
A Numerical Analysis of Piezoelectric Inkjet, San Kim, Dong Kee Sohn, and Han Seo Ko, Sungkyunkwan University (South Korea)
[view abstract]
The jetting behavior and pressure inside the piezoelectric inkjet head was investigated using numerical methods. A computational fluid dynamics model was developed for a cylindrical inkjet head, facilitating the calculation of multiphase flow and acoustic pressure wave propagation. This developed model reliably simulated jetting and meniscus behaviors. In addition, a lumped element method model was constructed to quickly predict the internal pressure and flow rate. Both numerical models demonstrated good agreement in their pressure calculation. The developed numerical models can provide practical information that is challenging to obtain experimentally and can be employed to optimize the operating conditions, such as the waveform shape.
14:20
Epson’s MEMS Technology: PrecisionCore—Development Strategy and Future Plan, Eiju Hirai, Seiko Epson Corporation (Japan)
14:40
Xaar’s Ultra High Viscosity Technology: Redefining the Boundaries of Inkjet Printing, Renzo Trip, Xaar plc (Sweden)
[view abstract]
Traditionally, inkjet has been limited by its ability to print fluids of viscosities between 10 to 25cP, however, Xaar’s Ultra High Viscosity Technology has redefined this. Fluids of up to 100cP at jetting temperature (approximately 1000cP at room temperature) can now be used, revolutionising the opportunities for inkjet. In this presentation we will: 1) demonstrate the high viscosity capability of Xaar printheads, 2) explain how it is done, and 3) discuss what benefits high viscosity brings to various inkjet markets. What does high viscosity mean for ink formulators, integrators, and end-users? Water-based inks will have a central role, as a higher viscosity can help to overcome challenges, such as high opacity whites and drying energy requirements.
15:00
Development of Effective Driving Methods for Inkjet Drop-on-demand Jetting of High Viscosity Liquids, Takayuki Shimizu and Masakazu Hirata, SII Printek Inc., and Masanori Tamura, SEIKO FUTURE CREATION INC. (Japan)
Poster Session and Coffee
15:20 - 16:40
Fully Integrated Airflow Visualization System for Improved Inkjet Printing, Johannes Renner, Yoshinori Domae, Jonas Maturo, Vincent Schneuwly, Benoît Sahli, and Gioele Balestra, iPrint HEIA-FR HES-SO (Switzerland)
[view abstract]
Several new inkjet printing applications require high throw distances or high printing speeds. In such configurations, complex airflows occur in the gap between the printhead and the substrate, potentially jeopardizing the print quality by deviating the ink droplets. To better understand the airflow effects on the droplet’s trajectories, a novel inkjet printing platform has been developed. The latter allows the full control of the different parameters, from the laser sheet intensity to the axis motion, to the fog generation, to the print head driving waveform. The system has been fully automatized and allow for large parametric study to be performed, key for unstable flows requiring for statistics.
Inertial Microfluidic based Particle Sorting Device, Thibault Maillard and Gioele Balestra, iPrint HEIA-FR HES-SO (Switzerland)
[view abstract]
More and more functional inks are developed to enlarge the applications of inkjet printing. Yet, the stability of the inks is often challenging. For example, particles might agglomerate and clog the printhead, eventually compromising the whole printing process. Having a reliable filtering system is therefore key for complex inks. Here, we present a novel passive filtering system based on the inertial microfluidic concept that can potentially be used to filter inkjet inks in a continuous manner. The system has been first optimized thank to numerical simulations and then characterized experimentally.
New Designs and Manufacturing Possibilities for Inkjet Print Head Nozzle Plates, Gioele Balestra, Jonas Maturo, Jérémy Vuilleumier, Johannes Renner, and Yoshinori Domae, iPrint HEIA-FR HES-SO (Switzerland)
[view abstract]
The design of today’s inkjet printheads is often limited by the micromanufacturing methods used. Furthermore, today’s inkjet technology suffers from several limitations in term of ink viscosity, particle size and jetting distance. Yet, new micromanufacturing technologies have been recently developed. In this work, we explore the potential of using femtosecond laser glass micromanufacturing to fabricate inkjet printheads parts. The performance of such modified printheads is compared to their commercial counterparts.
Smart Materials by Inkjet, Muriel Mauron1, Lucie Castens Vitanov1, César Michaud1, Raphaël Wenger1, Derek Kiebala2, Gilbert Gugler1, Stephen Schrett2; 1iPrint Institute, HEIA-FR, University of Applied Sciences and Arts Western Switzerland and 2Adolphe Markle Institute, University of Fribourg (Switzerland)
[view abstract]
Through the vehicle of inks with different softness grades which are doped with mechanochromic additive, we have developed a multi-material inkjet platform, which allows to create gradient materials with new performance. The additive has helped to characterize this new kind of materials on one hand and on the other hand it’s the start of creating new smart materials with gradient properties by inkjet. The first drop casting tests of these two inks has proven the mechanochromism by the measurement of the ratio between the intensity of the monomer and the excimer under UV light. The intensity in the mixing zone was measured at different strain. Finally, it was proven that the hardness in the mixing zone could be defined.
Combining Laser Engraving and UV-Inkjet Printing for Personalization of Security Documents, Philip Kessler, iPrint Institute, HEIA-FR, HES-SO University of Applied Sciences and Arts Western Switzerland (Switzerland) and Mauro Costantini, IXLA s.r.l. (Italy)
[view abstract]
iPrint worked with IXLA, a company specialized in laser personalization of security documents, to develop a UV inkjet printing system for their security document printers.
For this purpose, an ink screening was first carried out to find suitable inks that met the requirements of the specifications. Then, in a close collaboration, the inkjet printing system was developed and integrated into a prototyping platform. This prototyping platform was then used to optimize and define the entire inkjet process. The waveform was optimized to print high-resolution images, as well as the UV curing parameters. Extensive testing and analyses were performed to understand and optimize the adhesion and abrasion behavior of the ink on the substrate. This information was used to develop an initial prototype laser and inkjet platform. This platform will be introduced to the market in November.
In the foreseeable future, the interaction between laser and UV inkjet printing will be investigated with goal to develop potential new, innovative security features. Long-term tests with the prototype and field experience with the first commercial systems will help to further improve the system and increase its reliability and longevity. Other features such as printing varnish or security ink shall be added to the system over time.
Drop Watcher for Automated Waveform Development and Inkjet Analysis, Johannes Renner, School of Engineering and Architecture Fribourg (Switzerland)
[view abstract]
The development of performant piezo DoD (Drop on Demand) waveforms with commercial state of the art drop watching systems often requires an extensive amount of work for a skilled operator. With current commercial solutions, successful optimization of printing performance heavily depends on the skills of the operator who is also required to ensure correct correlation between drops and adjust ROI parameters.
Due to our nature as engineers, at iPrint we strongly dislike reoccurring manual labor work, that could potentially be automated, so we took the effort to develop a device that can do (most of) the job for us. A number of key features, such as dual camera imaging for reliable automatic drop correlation, waveform amplitude & drop speed regulation, a freely user programmable waveform designer and many standard analyses, were developed to realize a system that allows for user independent inkjet analysis and optimization.
Multi-nozzle Inkjet 3D Printing with CNC Motion, Johannes Renner, School of Engineering and Architecture Fribourg (Switzerland)
[view abstract]
3D printing with current multi-nozzle drop on demand print heads is lacking in terms of surface quality (without post treatment) or printing of overhanging structures without support material in contrast to single nozzle inkjet 3D printing (where the part perimeters are printed with a CNC motion), which in turn is lacking in terms of volume throughput (and therefore only used for the fabrication of small parts) as everything has to be printed with one nozzle.
In order to print with enhanced surface quality and overhanging structures - free of support material – as well as reasonable productivity for the production of larger 3D parts, a printing process for industrial multi nozzle printheads with CNC printing motion was developed. First 3D parts printed with paraffin wax were produced and characterized to estimate the potential of this process.
Lateral InkJet Printhead for Narrow Gaps, Marco Hölzle and Urs Lippuner, Eastern Switzerland University of Applied Sciences (Switzerland)
[view abstract]
A new concept in inkjet technology exploits the intrinsically low design height of MEMS components. Since the nozzle is not attached at the front but laterally, drops can also be deposited in narrow gaps.
Inkjet and drop-on-demand immediately recall inkjet nozzle heads, pipetting and aliquoting systems, or 3D printing. These are systems in which the aim is to position the independently controllable and fillable nozzles as closely as possible. That is why these systems are designed as printheads. This means that they are not primarily limited in the upward direction.
However, there is a category of applications for such inkjet and drop-on-demand systems where a drop needs to be deposited at a specific point in a particularly narrow gap. In this situation, it is thus impossible, for purely geometrical reasons, to inject an inkjet (or droplet), however straight, from the side of the gap to the position.
For such applications, a concept was designed and realized at OST at the Institute for Microtechnology and Photonics and tested in an industrial environment at Leister Technologies AG.
Piezo self-sensing: unlock new opportunities
16:40 - 18:10
16:40
Focal Talk Why Inkjet Printing Systems Need Closed-Loop Control, Yoshinori Domae, iPrint HEIA-FR HES-SO (Switzerland)
[view abstract]
17:10
Recent Progress in Inkjet Monitoring based on Piezo Self-sensing, Kye-Si Kwon, Jeong Yeop Jo, and Sang Hyeon Park, Soonchunhyang University (South Korea)
[view abstract]
Inkjet technology is widely employed in manufacturing processes due to its high throughput, utilizing multiple nozzles for simultaneous inkjetting. However, not all nozzles remain in optimal condition, and the presence of misfiring nozzles necessitates their exclusion from the printing process. Additionally, the state of some nozzles may undergo changes even during printing, making real-time monitoring of nozzle status a crucial concern in inkjet-based manufacturing.
In this presentation, we delve into recent advancements in real-time inkjet monitoring methods utilizing piezo self-sensing signals. The utilization of piezo self-sensing eliminates the need for external sensors or cameras in the monitoring process. Our discussion encompasses the circuitry, data acquisition system, and software involved in the monitoring process. We also explore the feasibility of extending this method to encompass multiple heads. To enhance monitoring algorithms and validate the proposed approach, we present an analysis of long-term jet behavior. By examining scatter plots derived from over 140,000 jetting instances, we investigate the influence of various parameters on the monitoring reliability.
Furthermore, we explore the integration of machine learning techniques to enhance classification accuracy. The results indicate successful classification of jet failures based on symptoms such as low jetting speed, mis-directionality, wetting, and ink supply issues. Presently, we are developing a monitoring module capable of simultaneous monitoring of up to 64 heads. Importantly, parallel processing allows for efficient monitoring without significant increases in monitoring time.
In conclusion, this presentation not only underscores the present achievements but also outlines future prospects of the monitoring system. The adoption of piezo self-sensing signals offers promising avenues for real-time monitoring, addressing nozzle issues promptly and contributing to the enhancement of inkjet-based manufacturing processes.
17:30
In-process Ink Rheology Monitoring for Inkjet Printing using Piezo Self-sensing, Sebastian Filliger and Luca Brügger, iPrint (Switzerland)
[view abstract]
Inkjet technology is gaining popularity in digital production due to its high productivity rates and compatibility with various fluids and substrates. The core of the inkjet system is the printhead, a sophisticated device depositing ink accurately and on demand through thousands of independent nozzles. This complexity presents challenges when it comes to maintenance and stable operation. Therefore, maintaining precise control over all process parameters is essential to ensure consistent quality and optimal performance.
Ink rheology is a very important parameter to control. Changes in rheology caused by solvent evaporation, ink aging, sedimentation or simply a slightly different formulation of the manufacturer can lead to major quality flaws in the printing process.
There exist multiple commercial solutions for rheology measurements. However, such measurement devices can only measure viscosities at frequencies of up to 10-20 kHz and the measurement takes place outside of the printing process.
iPrint developed a measurement system which can monitor the rheology in the process at internal resonance frequencies of 100-200kHz with an accuracy of 1 mPa*s using only the printhead as the measurement device together with a printing electronics which has piezo self-sensing capabilities. This system is an upgrade to a previously developed and industry tested nozzle status monitoring system that uses the inverse piezo electric effect to map printhead internal acoustics for nozzle failure detection.
17:50
Piezoelectric-based Monitoring of Pressure Variations in Inkjet Printheads, Loïc Bullot and Carlos Chabert Ull, iPrint (Switzerland)
[view abstract]
The popularity of inkjet technology is growing in the industry due to the many benefits it brings. However, the complexity of the process and hardware required to deliver a drop on demand accurately and at high speed poses a reliability challenge. With many complex parameters in the ink and printhead affecting drop quality, maintaining a stable environment is key.
There has been growing interest in sensing technologies that use the piezoelectric actuator in the nozzle to measure the acoustic response of the nozzle chamber. Several papers have been published on the use of piezo sensing to detect nozzle status.
The aim of this presentation is to show an innovative way of measuring the ink pressure in the nozzle chamber using piezoelectric sensing. The measurement is performed using custom hardware to measure the acoustic response in the piezo after actuation. The variations in response frequency can then be correlated with the variations in pressure.
This method makes it possible to measure pressure variations along the print head. It also allows the fluidic resistance of the head to be determined by applying a constant flow of ink and comparing the pressure between the first and last nozzles of the printhead.
18:30 - 20:30
Transportation to/from and Conference Dinner
Wednesday, 31 January
Key technologies of inks: formulation, supply, and drying
09:00 - 10:25
9:00
Customized Design of Dispersing Agents and their Application: Improving Inkjet Ink Reliability and Performance, Nils De Vos, ChemStream bv (Belgium)
[view abstract]
Developing (inkjet) inks from scratch is often not an easy feat. Most of the time, there are several (quite strict) limitations and/or requirements in place for the inks, which can only be attained by using a specific ink composition. Over the years, ChemStream has been developing and improving in-house methods for designing and formulating (inkjet) inks and their components such as dispersing agents, binders, etc. One important example of such methods is the use and combination of Hansen Solubility Parameters and Design of Experiments. Using this know-how, ChemStream’s aim is to incorporate sustainable and circular solutions into water-based as well as UV-curable and solvent inkjet inks, through the design and synthesis of new polymeric dispersing agents. These dispersing agents allow for an improvement in dispersion/ink sustainability as well as an increase in flexibility for ink formulation through a more targeted approach to the molecular design and composition of these polymers. In this lecture, we will shed some light on the development and implication of this methodology, how it benefits ink quality and performance, and what ChemStream can offer you in the development of (inkjet) inks and encapsulators.
9:20
Printing Semiconductors Pixel by Pixel, Franziska Krieg, Avantama AG (Switzerland)
[view abstract]
In the last years the Perovskite nanocrystals (PNC) have gathered enormous attention from worldwide scientific community, due to their outstanding optical properties. High photoluminescence quantum yields in combination with narrow emission widths and high absorption coefficients are unbeatable by any quantum dot technologies.
Avantama AG pioneered work on commercialization of PNCs into the display industry. This presentation will show advantages as well as challenges of using PNCs in broad variety of display technologies ranging from LCD, OLED to micro-LED with a focus on their device inclusion using additive printing technologies.
9:40
Liquid Diaphragm Pumps for Controlling Static and Dynamic Meniscus Pressure in Printheads, Raphael Frey and Manuel Roos, KNF Flodos AG (Switzerland)
10:00
Drying as a Digital Process, Gunther Ackermann, Lambda Technology GmbH (Germany), and Christian Gächter, Lambda Technology GmbH (Austria)
[view abstract]
Drying inks is a complex process where you need to be able to set parameters in a stable and controlled way. By setting and controlling radiation intensity, wavelength, time, internal and external air flow, managing drying air temperature and volumes, removing excess radiation and finally recovering and reusing energy we can create a more cost-efficient, resource and energy saving and less polluting drying process.
10:20 - 10:55
Coffee and Exhibits
When ink drops meet substrates
10:55 - 12:45
10:55
Keynote Inkjet dot spreading and liquid penetration: Modeling and analysis from solid- and liquid surface energies, Ulrich Hirn, Graz University of Technology (Austria) [view abstract and bio]
Abstract and biography coming.
11:45
Decoration of Plastic Pieces Directly from the Molding Tool Straight into the Printing Process, Klaus Ammann, Mankiewicz Gebr. & Co. (Germany)
[view abstract]
The problem: for inline production, where cycle times have a significant influence on the profitability of the investment, attempts are often made to print components coming directly from the molding tool. In this case, the components still have high temperatures and are not yet completely cured. The surface properties are therefore: warm and not yet fully cooled. Printing on this surface is a great challenge for digital printing! Whether there are solutions or not will be described in this presentation based on a developed system for a project.
12:05
Decreasing Observation Error for Rub Resistance of Printouts Located on Previously Bent Substrates: Development of Device and Method, Frédéric Mondiot, Claudiu Neagu, and Serge Marchioni, Markem-Imaje, Dover Europe Sàrl; and Philip Kessler and Benoît Sahli, iPrint Institute, HEIA-FR, HES-SO University of Applied Sciences and Arts Western Switzerland; and Jan Huber and Gabrielle Thurnherr, iSIS Institute, HEIA-FR, HES-SO University of Applied Sciences and Arts Western Switzerland (Switzerland)
[view abstract]
Rub resistance is a parameter of major importance when describing the quality of inkjet printouts used in marking and coding onto bent substrates. It becomes even more challenging to evaluate when the substrate has been bent prior to testing, like in the case of electrical cables, wires, optical fibers.
Methods widely used in the industry to evaluate rub resistance under such circumstances rely on bending the substrate supposedly around the finger and rubbing it with the thumb. Resistance of the printout to rubbing is then assessed visually. Intrinsically, this approach to evaluate rub resistance comes with a high degree of variability.
The high variability of this method calls for a more structured and systematic approach to evaluating the rub resistance in this setting. The solution is an operator-independent, automated method.
The aim of this communication is to present a solution embodied by a prototype machine specifically designed and built for this purpose and a testing method associated with it.
In particular, all the parameters of interest, i.e. the bending speed, angle and radius, and the rubbing speed, frequency and applied force, can be adjusted over a range representative of the real industrial constraints. The processing of the data allows a precise quantification of the rub resistance of the ink printed on previously bent substrates.
12:25
Product Quality Evaluation for Textile Digital Prints, Shasha Yang and Yi Ding, Donghua University (China)
[view abstract]
Digital textile printing, as a new printing technology, has many advantages such as high printing precision, environmentally friendly processes, rich colors, and flexible responses. It has attracted increasing attention from more and more people, and the importance of a reasonable quality assessment method for digital textile printing is becoming increasingly prominent. This project, based on the digital printing process, summarizes the factors that affect the quality of digital textile printing in the pre-treatment, inkjet printing, steaming and baking, washing, and post-finishing processes. It covers both visual quality and intrinsic quality and provides an overview of the methods for evaluating the quality of digital textile printing. Furthermore, it proposes elements and testing methods for evaluating the quality of digital textile printing products, creating a model for assessing the quality of digital textile printing products. The research findings can serve as a reference for manufacturers of digital textile printing products.
Conference ends / Lunch
12:45 - 14:30
iPrint presentation & visit
14:30 - 15:30
Exhibitor demonstrations
14:30 - 17:30
Thursday, 1 February
Advanced Inkjet Workshop
8:30 - 17:30
Separate registration required