Print Process Identification for Forensic Document Examiners

The advent of current digital print technology has resulted in a drastic increase in the accessibility of counterfeiting currency and secure documents. In response, organizations such as the CIA, Secret Service and FBI must continually train and educate their employees and staff. To meet the increasing demands of these groups, the Rochester Institute of Technology has developed the Marking Engine Characterization (MEC) target to train and assist forensic document examiners in identifying print processes. The MEC target\u27s effectiveness in identifying print processes was tested by printing the target on a variety of marking engines and processes. These marking engines included: Heidelberg Speedmaster 74 - Offset Lithography Nexpress 2100 - Dry electro-photographic process Xerox DocuColor 6060 - Toner based electro-photographic process Indigo 3000 - Liquid ink electro-photographic process Fuji Pictroproof- Silver halide photographic process Iris Realist FX 5015 - Continuous inkjet process Epson 9600 - Piezo based inkjet process Kodak Approval NX - Thermal dye sublimation The substrate used during the study was limited to 100# Titan gloss to decrease variability, however, the Fuji Pictroproof, Epson 9600 and Iris Realist FX 5015 are not compatible with other brands of stock and used the following stocks: Fuji Pictroproof Matte Paper, Epson Premium Gloss Photo Paper and Iris Realist Inkjet Gloss Paper. SWOP specifications were used as benchmark settings for CMYK and the specific settings of each marking engines was documented using the Press Run Organizer. Thirtysix MEC targets were printed per marking engine and visually evaluated to ensure the marking engines were consistent. A group of samples were selected and evaluated by 13 observers who were participants in the Forensic Document Examiners Seminar held at RIT on November 18, 2005. The results of the observation group lead to several conclusions. Firstly, the MEC target is not effective in helping forensic document examiners identify print processes. Secondly, the attendees of the seminar did not have enough experience in digital processes to distinguish between them. Thirdly, the experience among the user group is varied. Fourthly, observers used many aspects of the target such as substrate and ink to determine the process. Finally, that there is no relationship between the observation group\u27s confidence level and a correct or incorrect answer

Recent Progress in the Development of INCITS W1.1, Appearance-Based Image Quality Standards for Printers

In September 2000, INCITS W1 (the U.S. representative of ISO/IEC JTC1/SC28, the standardization committee for office equipment) was chartered to develop an appearance-based image quality standard.(J),(2) The resulting W1.1 project is based on a proposal(4) that perceived image quality can be described by a small set of broad-based attributes. There are currently five ad hoc teams, each working towards the development of standards for evaluation of perceptual image quality of color printers for one or more of these image quality attributes. This paper summarizes the work in progress

3D printing of tablets using inkjet with UV photoinitiation

Additive manufacturing (AM) offers significant potential benefits in the field of drug delivery and pharmaceutical/medical device manufacture. Of AM processes, 3D inkjet printing enables precise deposition of a formulation, whilst offering the potential for significant scale up or scale out as a manufacturing platform. This work hypothesizes that suitable solvent based ink formulations can be developed that allow the production of solid dosage forms that meet the standards required for pharmaceutical tablets, whilst offering a platform for flexible and personalised manufacture. We demonstrate this using piezo-activated inkjetting to 3D print ropinirole hydrochloride. The tablets produced consist of a cross-linked poly(ethylene glycol diacrylate) (PEGDA) hydrogel matrix containing the drug, photoinitiated in a low oxygen environment using an aqueous solution of Irgacure 2959. At a Ropinirole HCl loading of 0.41 mg, drug release from the tablet is shown to be Fickian. Raman and IR spectroscopy indicate a high degree of cross-linking and formation of an amorphous solid dispersion. This is the first publication of a UV inkjet 3D printed tablet. Consequently, this work opens the possibility for the translation of scalable, high precision and bespoke ink-jet based additive manufacturing to the pharmaceutical sector

Fabrication of advanced ceramics and selective metallization of non-conductive substrates by inkjet printing

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 30/10/2002.Inkjet printing of ceramic components and gold conductive tracks was carried out in this study. A commercial inkjet printer, designed for printing one layer of 2D images on paper, was modified to give adequate resolution, to reverse the substrate for overprinting many layers and to accommodate the increase in thickness of 3D components during printing. Ceramic inks were prepared by wet ball milling and printed to form 3D structures. The powders used were alumina, zirconia, lead zirconate titanate (PZT) and barium titanate. The substrate used for printing the ceramic parts was an overhead transparency. Methods to stop or reduce ink flow were devised and used during printing of the ceramic parts. The alumina and zirconia powders were used for the fabrication of multi-layered laminates. The lead zirconate titanate was used to fabricate components with pillars, walls, vertical channels and x-y-z channel network. During printing of the x-y-z channel network, carbon was used as a support structure and then removed during firing. Barium titanate and carbon powders were used to form the first storey of a capacitor with a multi-storey car park structure. The printed parts were pyrolysed and fired in an oxidising environment and then characterised with scanning electron microscopy. The causes of micro structural defects found were discussed and prevention methods suggested. Organic gold powder was dissolved in methanol and then printed on three different substrates to form conductive gold tracks. The substrates used included alumina, glazed tile and microscope glass slides. The printed tracks were fired in air. The decomposition characteristics of the organic gold compound were studied with TGA and Differential Scanning Calorimetry (DSC). Scanning electron microscope was used to examine the fired gold film for defects and conductivity measurement of the tracks was carried out with a programmable multimeter

Polymer-Ceramic Composites for 3D Inkjet Printing

Als eine der wenigen additiven Fertigungsmethoden ermöglicht der 3D-Tintenstrahldruck die Multimaterialabscheidung. Es besteht jedoch ein Bedarf an Funktions- und Strukturmaterialien. Unter anderem werden thermisch leitfähige Polymer-Keramik-Komposite zur thermischen Regulierung benötigt. In dieser Arbeit wurden drei neue Arten von Al2O3-Partikel gefüllten Tinten hergestellt und untersucht. Allen voran sind es die thermisch leitfähigen, Partikel gefüllten Tinten, die anfänglich ohne, später aber mit volatilen Lösungsmitteln hergestellt wurden, um den Füllgrad zu steigern. Des Weiteren wurden Untersuchungen zu der Auswirkung von Nanopartikeln auf die Zähigkeit und Bruchdehnung von Kompositen angestellt, welche in lösungsmittelfreien UV härtbaren Tinten mündeten. Bei der Herstellung wurde die Keramik in einer Planetenkugelmühle homogenisiert und zerkleinert. Zeitgleich oder im Anschluss an die Mahlung wurden den Partikeln die Dispergatoren 3-(Trimethoxysilyl)propylmethacrylat oder 2-[2-(2-Methoxyethoxy)ethoxy]essig-säure hinzugegeben. Je nachdem, ob die Mahlung in einem volatilen Mahlmedium oder direkt schon in der organischen Matrix stattfand, wurden die Partikel im ersteren Fall getrocknet und im letzteren direkt für die Verwendung abgefüllt. Die getrockneten Partikel wurden im Anschluss in die organische Matrix eingearbeitet. Der Prozess wurde von Analysemessungen begleitet, welche zum einen das Pulver und zum anderen die fertige Komposit-Tinte charakterisierten. Die Charakterisierung der Tinten umfasste rheologische Messungen, Stabilitätsuntersuchungen und Tintenstrahl-Drucktests. Gedruckte Komposit-Prüfkörper wurden mechanisch und thermisch analysiert. Die Nanokomposit-Tinten zeigten keine nennenswerten Verbesserungen der mechanischen Eigenschaften bei den untersuchten Parametern. Die zweite lösungsmittelfreie Tinte führt zu einem Komposit mit einem Füllgrad von 30 Vol% und einer thermischen Leitfähigkeit von 0,6 W/(m·K). Die Untersuchung der lösungsmittel-haltigen Tinten ergab ein Material mit einem Füllgrad von 50 Vol% und einer thermischen Leitfähigkeit von 1 W/(m·K), ein bisher unerreichtes Ergebnis. Die mechanischen Eigenschaften zeigten einen E-Modul von 2,4 GPa, eine Zugfestigkeit von 40 MPa, eine Bruchdehnung von 1 % und eine Zähigkeit von 1,3 J/m³. Sowohl die lösungsmittelfreie als auch lösungsmittelhaltige Tinte wurden für die Herstellung von Komponenten zu Demonstrationszwecken verwendet

Gloss Dynamics of Inkjet Printers

Inkjet printing is a popular non-impact technology with widespread use in home and office applications. The basic principle involves propelling ink drops of different colors on a substrate. High quality images, near photographic quality, are now possible. The gloss of the printed substrate is an important quality attribute. Printed gloss depends on a number of characteristics of the media and the ink, but a good fundamental understanding is not available in the literature. The dependence of the gloss on the media and ink characteristics is reported in this work. The experimental results are compared with values predicted by a mathematical model. The dynamic post-printing gloss was studied with a specially constructed apparatus, which measured the laser reflectance of the printed surface within 40 ms after drop impact. Both pigmented and dye-based inks are used with rapidly absorbing porous media and swelling polymer-coated media. Various properties of the media such as surface roughness, ink absorption rates, pore size distribution, oil absorption capacity, wettability, and gloss were characterized along with ink properties like surface tension, viscosity, and filtercake resistance or the filtercake forming ability of the pigmented inks. The model and experimental results show that the gloss of dye-based inks on porous media depends on the media roughness. Gloss on swellable media depends on the roughness of the wet swollen polymer coating. The gloss of pigmented inks on porous media is determined by the ink pigment size and the dry media gloss. The gloss on swellable media is determined by ink pigment size and the wet roughness. The model predictions compare well to experiments for a wide range of parameters

A REVIEW ON THE PURSUIT OF AN OPTIMAL MICROWAVE ABSORBER

Mitigation of the electromagnetic radiations is essential for reliable communication of information. The challenges lie in achieving sufficiently good absorption over a broad range of frequencies. Considering the applications in airborne and handheld devices where light weight, thin, conformable and broadband absorbers are desired, numerous techniques and methods are applied to design broadband absorbers. In this review paper, a detailed analysis on electromagnetic absorbers including evolution, the materials used, and characteristics such as absorption efficiency over the years is presented. Progress on recent research on various polymer- based and metamaterial- based microwave shields are included along with their findings. Several prospects such as broadbanding, flexibility, multibanding are described here. Various material and structural composition offering good absorption performance in different frequency bands are also summarized whose the techniques can be used for suppressing electromagnetic interference and radar signature. The paper specifies the aspects one encounters while designing and realizing a perfect microwave absorber. Explored here are several works of distinguished authors  which are based on various techniques used to achieve good absorption performance with ease of mounting

Study on the variability of printed documents produced by laserjet Printers (hp laserjet p3005 printers)

This study looks at the variability of prints produced by LaserJet printers. Five HP LaserJet P3005 printers were used to print out a letter consisting of a mixed of letters and numbers at different fonts. Seven duplicates were printed from each printer and compared using a stereomicroscope. Printed samples were also obtained from two selected printers in time interval of a week over a period of about a month. Results based on microscopic examination by stereomicroscope on the printed documents from some printers of same brand and model had shown specific characterizations. Some specific individual patterns are shared by a subgroup of printers that used in our study. Though, it is difficult to link such printed material to an individual printer, this study helps to include or exclude the possible source of the printer from same brand and model. Microscopic examination on the printed documents printed over a period of four weeks revealed the drastic changes between first week and third or fourth week in terms of the thickness of the alphabets appears to be caused by insufficient toner. Hence, it enables to determine the order of printed materials in terms of the time interval of a few weeks. This study agrees with previous reported observation stating that individual characterization of the printed documents can be used to link a document to at least a group of possible printers

Gloss Development of Spray-coated Systems

A spray-coated system involves any substrate on which a liquid coating is applied in a drop-wise fashion. Inkjet printing is the controlled application of drops to print a surface and is the focus of this work. The gloss of the printed substrate is an important attribute of print quality. Print gloss depends on a number of factors, such as ink and media properties. Non-uniform gloss in different regions of a printed image can cause a decrease in quality of a printed sample. However, a good understanding of the gloss development of spray-coated systems is not available in the literature. Several combinations of inkjet inks and media were characterized in terms of physical properties. Both pigmented and dye-based inks were used with absorbing microporous coated media. These ink/media combinations were printed with an inkjet printer and the final gloss measured. A laser system was used to measure the gloss every millisecond right after printing, around 20 ms after drop impact. Some media were modified with chemicals or other treatments to modify physical and chemical properties. Fiber swelling in paper-based media was found to lower gloss in those media which contain fibers that can contact water. This reduction in gloss occurred one second after printing. Media with protected paper fibers do not exhibit this gloss reduction. Plastic-based media with porous coatings obtained the final gloss at 0.1 seconds. Inks can be destabilized by ions on the media surface that leads to low gloss. Some inks were not sensitive to ions on the media. Light color inks were found to have high gloss values at 50% fill compared to 100% fill while most other inks have the opposite behavior. This phenomenon is likely due to the secondary reflection at the ink/media interface; light is able to transmit through the ink layer and reflect at the media surface

3D printing of medicines: current challenges

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, 2021, Universidade de Lisboa, Faculdade de Farmácia.A impressão tridimensional tem vindo a ganhar relevância no desenvolvimento científico e, inevitavelmente, na área farmacêutica. Esta tecnologia permite o desenvolvimento de formulações individualizadas, ajustadas às necessidades do doente e, por isso, pode vir a tornar-se uma ajuda valiosa na área dos medicamentos órfãos. Para além disto, também permite o desenvolvimento de formas farmacêuticas com várias substâncias ativas e/ou diferentes perfis de libertação de fármaco, que poderá vir a permitir um aumento da adesão à terapêutica por parte dos doentes polimedicados. Apesar de atualmente já haver um fármaco impresso aprovado pela FDA desde 2015, o Spritam®, ainda há várias limitações associadas a esta tecnologia, nomeadamente a regulamentação, matérias-primas, controlo do processo e validação do mesmo, controlo de qualidade, estabilidade e a localização na cadeia de fabrico. Quanto à regulamentação, não havendo diretivas regulamentares específicas para esta tecnologia na área farmacêutica, acaba por se adaptar a regulamentação existente. A escolha das matérias-primas é limitada pela capacidade de impressão e a estabilidade físico-química, reduzindo a panóplia de materiais adequados para esta técnica. Para o controlo do processo seria benéfico adaptar um controlo em tempo real optando, preferencialmente, por métodos não destrutivos, pois não sendo esta tecnologia a ideal para produção em larga escala, a perda de qualquer unidade teria um peso negativo significativo no balanço geral do processo. A validação do processo deve ser elaborada de forma a garantir a qualidade, segurança e eficácia do medicamento. Para isso, é necessário validar não só o software, como todo o processo. No controlo de qualidade, mais uma vez, deve-se optar por métodos não destrutivos e selecionar, pelo menos, um para avaliar o sucesso da impressão, sendo que pode ser utilizada o Quality by Design como uma ferramenta para otimizar o processo. A estabilidade, tal como nos outros processos, também deve ser testada e a localização da impressão tridimensional no ciclo do medicamento é outra questão levantada, uma vez que tanto poderá ter um papel na farmácia hospitalar ou comunitária, como na indústria farmacêutica ou, já numa hipótese remota, na casa do doente.Three-dimensional printing is a technique that has been drawing attention recently in the scientific community and, inevitably, in the pharmaceutical field. As allows the development of personalized medicine, adapted to the patient’s needs, it can be a valuable tool for orphan drugs. On the other hand, it also allows the development of dosage forms with various active pharmaceutical ingredients and/or with different drug release profiles, which can improve patient compliance. Although there is a printed medicine approved by FDA since 2015, Spritam®, there are still a few limitations in this methodology, as regulation, raw materials, process controls and validation, quality control, stability, and even location. In terms of regulation, there are no specific regulatory guidelines regarding this technology in the pharmaceutical area, however, a 3D printed drug product should be produced following the existing guidelines that can be adapted. In terms of raw materials, the range available is limited by printability and physicochemical stability, reducing the suitable materials. For process control, it would be advantageous to adopt a real-time control and, favour non-destructive techniques, as the loss of any unit would harm the overall balance of the process. Process validation should be designed to ensure the quality, safety, and efficacy of the drug product. Taking this into account is necessary to validate the software to the process itself. In terms of quality control, should go for non-destructive methods, once again, and is going to be needed to assess the success of the print. Quality by design can be used as a tool to optimize the process. As in other methodologies, stability test must be conducted and the location of the three-dimensional impression on the drug cycle is another issue that arises, as it may play a role in the hospital or community pharmacies, as in the pharmaceutical industry or, in a more remote hypothesis, at the patient’s home