Laser Exposure of Dry Aqueous Ink for Continuous-Feed High-Speed Inkjet Printing

2015 ◽  
Vol 59 (2) ◽  
pp. 205011-205017 ◽  
Author(s):  
Akira Sakamoto ◽  
Manabu Numata ◽  
Yasuhiro Ogasawara ◽  
Mami Hatanaka ◽  
Yukari Motosugi ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
High Speed ◽  
Laser Exposure ◽  
Continuous Feed

scholarly journals Is ink heating a relevant concern in the High Speed Sintering process?

2021 ◽  
Author(s):  
Rhys J. Williams ◽  
Patrick J. Smith ◽  
Candice Majewski
Keyword(s):  
Cross Sections ◽  
Inkjet Printing ◽  
High Speed ◽  
Sintering Process ◽  
Significant Drop ◽  
Powder Bed ◽  
Consistent Manner ◽  
Fluid Properties ◽  
Different Temperatures ◽  
Accuracy And Repeatability

AbstractHigh Speed Sintering (HSS) is a novel polymer additive manufacturing process which utilises inkjet printing of an infrared-absorbing pigment onto a heated polymer powder bed to create 2D cross-sections which can be selectively sintered using an infrared lamp. Understanding and improving the accuracy and repeatability of part manufacture by HSS are important, ongoing areas of research. In particular, the role of the ink is poorly understood; the inks typically used in HSS have not been optimised for it, and it is unknown whether they perform in a consistent manner in the process. Notably, the ambient temperature inside a HSS machine increases as a side effect of the sintering process, and the unintentional heating to which the ink is exposed is expected to cause changes in its fluid properties. However, neither the extent of ink heating during the HSS process nor the subsequent changes in its fluid properties have ever been investigated. Such investigation is important, since significant changes in ink properties at different temperatures would be expected to lead to inconsistent printing and subsequently variations in part accuracy and even the degree of sintering during a single build. For the first time, we have quantified the ink temperature rise caused by unintentional, ambient heating during the HSS process, and subsequently measured several of the ink’s fluid properties across the ink temperature range which is expected to be encountered in normal machine operation (25 to 45 ∘C). We observed only small changes in the ink’s density and surface tension due to this heating, but a significant drop (36%) in its viscosity was seen. By inspection of the ink’s Z number throughout printing, it is concluded that these changes would not be expected to change the manner in which droplets are delivered to the powder bed surface. In contrast, the viscosity decrease during printing is such that it is expected that the printed droplet sizes do change in a single build, which may indeed be a cause for concern with regard to the accuracy and repeatability of the inkjet printing used in HSS, and subsequently to the properties of the polymer parts obtained from the process.

Time-dependent mechanical response of paper during web-fed high-speed inkjet printing

2019 ◽  
Vol 34 (1) ◽  
pp. 107-116
Author(s):  
Jussi Lahti ◽  
Jarmo Kouko ◽  
Ulrich Hirn
Keyword(s):  
Inkjet Printing ◽  
High Speed ◽  
Mechanical Response ◽  
Creep Compliance ◽  
Time Dependent ◽  
Print Quality ◽  
Wetting And Drying ◽  
Process Step ◽  
Tensile Tester ◽  
The Web

Abstract The influence of wetting and drying during high-speed inkjet (HSI) printing on the time-dependent mechanical behavior of commercial HSI papers was investigated using a custom-built C-Impact tensile tester. In HSI printing the water based ink solvent penetrates into the paper while the colorants adhere onto the surface. We found that water strongly affected paper stiffness and strength already 0.1 s after wetting. Creep compliance and paper strain at a typical HSI printing input tension of 180 N/m are varying strongly during the different process steps of HSI printing. In order to achieve a good color registration and print quality, we thus recommend that the web tension should be dynamically controlled in each process step to prevent straining after wetting or shrinkage during drying.

Polychromatic Coloring of Dental Zirconia by Inkjet Printing

2019 ◽  
Author(s):  
Christoph Rehekampff ◽  
Dominik Rumschöttel ◽  
Franz Irlinger ◽  
Tim C. Lueth
Keyword(s):  
Surface Tension ◽  
Pore Size ◽  
Inkjet Printing ◽  
High Speed ◽  
Three Dimensional ◽  
Droplet Impact ◽  
High Speed Camera ◽  
Color Transition ◽  
Color Scale

Abstract To enable the development of an automated coloring process, dental zirconia is examined in terms of porosity, pore size and shrinkage during sintering. The properties of commercially available metal ionic inks such as viscosity, density and surface tension are investigated. Droplet impact on the zirconia surface and the absorption into the pores is analyzed with a high speed camera. The color result after sintering is investigated and compared to tooth samples. A method is developed to achieve a realistic, smooth color transition on flat zirconia samples. This is achieved by mixing the single inks directly on the zirconia through sequential application. Consequently, the number of different inks required to reproduce the full dental color scale can be reduced. Additionally, three dimensional tooth replacements are colored with the developed method.

Studying Gas-Phase Flows in the Laser Exposure Zone during Selective Laser Melting

2020 ◽  
Vol 989 ◽  
pp. 806-810
Author(s):  
Pavel Anatolyevich Podrabinnik ◽  
C.E. Protasov ◽  
A.V. Gusarov
Keyword(s):  
Selective Laser Melting ◽  
High Speed ◽  
Ccd Camera ◽  
Opening Angle ◽  
Laser Exposure ◽  
Laser Melting ◽  
Schlieren Method ◽  
Outflow Velocity ◽  
All Optical ◽  
Powder Particles

The processes occurring during selective laser melting were studied with a high-speed CCD camera. In order to record all optical in-homogeneities, the camera was integrated into optical arrangement, that realized the Schlieren-method. Within the experiment three parameters were estimated, such as powder particles opening angle, their velocity and the outflow velocity of vapor-gas jet. The influence of laser setup parameters is given. It is shown that particle size and material composition, together with laser power, affect greatly on the opening angle and velocity of powder particles emission, respectively.

scholarly journals Effect of physical parameters and temperature on the piezo-electric jetting behaviour of UV-curable photochromic inks

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sina Seipel ◽  
Junchun Yu ◽  
Vincent A. Nierstrasz
Keyword(s):  
Inkjet Printing ◽  
High Speed ◽  
Theoretical Calculations ◽  
Uv Curing ◽  
Physical Parameters ◽  
Drop Formation ◽  
Visual Evaluation ◽  
Uv Curable ◽  
Functional Textiles ◽  
And Performance

Abstract Although resource-efficient processes like inkjet printing have a large potential to foster the development of smart and functional textiles, one bottleneck still is the development of functional inks. To make inkjet printing and UV curing given production techniques for smart and functional specialty products, e.g. photochromic textiles, deepened knowledge about the development, rheological behavior and jetting behavior of functional ink is needed. This paper focuses on the formulation and performance of UV-responsive and UV-curable inkjet inks, which are based on photochromic dyes and their application to produce UV-responsive textiles. Two commercial photochromic dyes—Reversacol Ruby Red (RR) and Sea Green (SG), which represent dyes of the naphthopyran and spirooxazine class, respectively, have been used to develop the inks. The photochromic inks are characterized according to their physical–chemical and rheological properties in respect to temperature. The influence of temperature on the drop formation of the inks in an industrial print head is analyzed using a high-speed camera, which reveals important information regarding challenges in ink jettability. It was found that the dye structure and type used in the ink can influence the jetting behavior of photochromic UV-curable ink. More pronounced temperature sensitivity of dyes can increase the temperature-related effects of drop formation as was observed for SG ink. The printability of the RR and SG inks is framed and underpinned by theoretical calculations of the Z number. Discrepancies are observed and discussed between existing theory of ink jettability and visual evaluation of the photochromic ink.

Synthesis and characterisation of dimeric triphenylmethane water-soluble dyes for high-speed inkjet printing

2021 ◽  
pp. 109737
Author(s):  
Seong Hyun Jang ◽  
Geonho Lee ◽  
Young Joon Han ◽  
Sang Yoon Lee ◽  
Hyun Kyu Lee ◽  
...  
Keyword(s):  
Inkjet Printing ◽  
High Speed ◽  
Water Soluble

Printed-Electronic PCB Circuit Inkjet Printing Control and Detection System

2012 ◽  
Vol 457-458 ◽  
pp. 1163-1168 ◽  
Author(s):  
Yong Hong Liao
Keyword(s):  
Circuit Design ◽  
Inkjet Printing ◽  
High Speed ◽  
Assembly Line ◽  
Electronic Circuit ◽  
Detection System ◽  
Software Systems ◽  
Electronic Technology ◽  
Line System ◽  
Electronic Circuit Design

Printed electronic technology is focus in industry as an efficient, low consumption, energy saving, environmentally friendly technology. Ink-jet printing technology is the core of fully printed electronic technology. This article design a Printed electronic Assembly line system consisted of Fixed inkjet array, which can Implement high-speed inkjet printing. It Adopt the print driver architecture In accordance with WDM models which cross kernel and user level. Embedded with electronic circuit design software systems, the electronic circuit design is directly printed to PCB. Interlaced Fixed Multi-inkjet Has parallel high-speed printing features, reduce assembly line machinery vibration, simplify electromechanical servo systems, improve the accuracy of printing. The Design Consist of sections of PCB Positioning, Image servo, Matching printing and Quality detection.

Analysis of time dependent thermal properties for high rates in selective laser sintering

2018 ◽  
Vol 24 (5) ◽  
pp. 894-900 ◽  
Author(s):  
Katrin Wudy ◽  
Maximilian Drexler ◽  
Lydia Lanzl ◽  
Dietmar Drummer
Keyword(s):  
Thermal History ◽  
Laser Power ◽  
High Speed ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Maximum Temperature ◽  
Laser Exposure ◽  
Heating Rates ◽  
Content Type ◽  
Impact Time

Purpose The thermal history during laser exposure determines part properties in selective laser sintering (SLS). The purpose of this study is to introduce a new measurement technique based on a CO2 laser unit combined with a high-speed DCS. A first comparison of the thermal history during laser exposure measured with Laser-high-speed-(HS)-differential scanning calorimetry-(DSC) and in SLS process is shown. Design/methodology/approach This Laser-HS-DSC allows an imitation of the SLS-process in a very small scale, as the sample is directly heated by a CO2 laser. For this study, the laser power and the impact time is varied for determining temperature and achieved heating rates. Consequently, the temperature levels measured by the Laser-HS-DSC are compared with measurements in SLS-process. Findings The influence of laser power and impact time on resulting maximum temperatures und heating rates during laser exposure are investigated. With increasing laser power and impact time the maximum temperature rises up to approximately 450°C without material degradation. The heating rate increases up to an impact time of 3 ms and stays almost equal for higher durations. Research limitations/implications The Laser-HS-DSC experiments are based on few particles limiting a complete comparison with SLS process. In SLS, one volume element is exposed several times. In this study the PA12 material was exposed only once. Originality/value For the first time, laser sintering experiments can be transferred to a laboratory scale to analyze the influence of laser exposure on resulting temperature field during laser exposure without superimposing effects.

Deflecting the Issue: The Origin of Nanoscale Material Build-up in Continuous Inkjet Printing

2020 ◽  
Vol 64 (5) ◽  
pp. 50403-1-50403-10
Author(s):  
Maria Cristina Rodriguez-Rivero ◽  
Julian M. Philpott ◽  
Alex B. Hann ◽  
Josephine L. Harries ◽  
Ronan Daly
Keyword(s):  
Electric Fields ◽  
Inkjet Printing ◽  
High Speed ◽  
Small Satellite ◽  
Visualization Technique ◽  
Nanoscale Material ◽  
Charged Droplets ◽  
Manual Intervention ◽  
Vital Component

Abstract Continuous inkjet printing relies on steering charged droplets accurately to the surface by using electric fields. A vital component is the set of deflecting electrodes within the printhead, which create these fields. Unwanted deposition of ink on the electrodes, known as build-up, is a concern for operators because this modifies the applied electric field, affects long-term reliability, and requires manual intervention. However, this has not been widely reported or explored. Here, the authors report a laser-based high-speed visualization technique to observe build-up and show that it stems from small satellite droplets that break off from the main printed drops. They characterize the material build-up and reveal its nanoscale particulate nature. Combining the tracking with characterization allows quantifying the charge-to-mass ratio of these droplets. This study provides a route to understanding the build-up phenomenon, and it will enable optimization of printing conditions and printing reliability.

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