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Today, economic consumption of biodegradable polymers is significant in many applications. Thermoplastic starch (TPS) and polylactic acid (PLA) are two bio-based and biodegradable polymers that are increasingly being used to replace the petrochemical-based polymers. Adding TPS into a PLA matrix can also decrease material cost and increase its biodegradation rate. This work tested the printability of TPS/PLA films. For this purpose, TPS was first prepared by the addition of sorbitol and glycerol as softeners using an internal mixer at 140°C. Then, it was added to the PLA in internal mixer at 180°C. To analyse the data, design of the experiment was done according to Box–Behnken design (BBD) method for three variables in three levels by using Design-Expert software, which led to the preparation of 15 samples. Individual and interactive effects of wt% of PLA in TPS/PLA mixture, the wt% of starch in TPS, and the ratio of sorbitol to glycerol on the tensile properties, thermal properties and printing properties (optical density) were investigated. Solvent-based flexographic ink was applied to test printability of the films. It has been found that the PLA can be successfully printed with flexographic solvent inks to achieve a quality comparable to that of common packaging films. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether PolyJet technology, which uses rubber-like materials for printing and is known for its high resolution and performance, could be suitable for producing flexographic printing plates. In our research, we designed test plates that were printed using PolyJet technology with TangoBlackPlus FLX9870-DM resin. These 3D-printed plates were evaluated for their resistance to various flexographic inks and solvents, and their contact angles were measured. Subsequently, the prints were made on a Flexiproof device using water-based ink with both the test plates and traditional photopolymer plates across six different substrates. The print quality was assessed using densitometry and spectrophotometry. Our findings indicate that the 3D-printed plates are suitable for printing solid areas and lines with water-based inks. However, the print quality of the 3D-printed plates is slightly lower than that of the photopolymer plates, with the optical density values for the high-quality prints on coated papers being approximately 10% lower. Additionally, the plates printed with TangoBlack Plus resin appear to be suitable for UV inks due to their high resistance, but they are not resistant to the solvents used in solvent-based inks. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether PolyJet technology, which uses rubber-like materials for printing and is known for its high resolution and performance, could be suitable for producing flexographic printing plates. In our research, we designed test plates that were printed using PolyJet technology with TangoBlackPlus FLX9870-DM resin. These 3D-printed plates were evaluated for their resistance to various flexographic inks and solvents, and their contact angles were measured. Subsequently, the prints were made on a Flexiproof device using water-based ink with both the test plates and traditional photopolymer plates across six different substrates. The print quality was assessed using densitometry and spectrophotometry. Our findings indicate that the 3D-printed plates are suitable for printing solid areas and lines with water-based inks. However, the print quality of the 3D-printed plates is slightly lower than that of the photopolymer plates, with the optical density values for the high-quality prints on coated papers being approximately 10% lower. Additionally, the plates printed with TangoBlack Plus resin appear to be suitable for UV inks due to their high resistance, but they are not resistant to the solvents used in solvent-based inks.

Solution processing of metal halide perovskites offers the potential for efficient, high‐speed roll‐based manufacturing of emerging optoelectronic devices such as lightweight photovoltaics and light emitting diodes at lower cost than achievable with incumbent technologies (e.g., Silicon). However, current perovskite fabrication methods are limited in their speed, uniformity, and patterning resolution, relying on subtractive postdeposition scribing for integration of modules and device arrays. Here, a method for flexographic printing of MA0.6FA0.4PbI3 at 60 m min−1, the fastest reported perovskite absorber deposition and the first report of inline drying integrated with roll‐based printing, is presented. This process delivers high‐resolution patterning (< 3 µm line edge roughness) and precise thickness control through rheological design of precursor inks, allowing scalably printed 50 µm features over large areas (140 cm2), while obviating damaging scribing steps. 2D scanning photoluminescence (PL) is applied to resolve correlations between ink leveling dynamics and optoelectronic quality. Integrating these highly uniform printed perovskite absorbers into n‐i‐p planar perovskite solar cells, photovoltaic conversion efficiency up to 20.4% (0.134 cm2), the highest performance yet reported for any roll‐printed perovskite cells is achieved. This study, thus, establishes flexography as a scalable approach to deposit precisely‐patterned high‐quality perovskites extensible to applications in emitter and detector arrays. [ABSTRACT FROM AUTHOR]

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ZD-tester is a measurement technique for rapid compression in Z-direction. The strain rate of compression of this device is far beyond the ordinary mechanical testing methods applied in papermaking industries. Thus, it provides insights to the material responses which are relevant to industrial applications, e. g. calendaring, printing, etc where the strain rate ranges from hundreds to thousands per second. A physics model that describes the dynamic process of the probe has been developed, where a linear Maxwell model is used to account for the viscoelasticity of paperboard. The simulation has successfully reproduced both the general features and quantitative details of the experiment. The model reveals that the ratio of the elastic modulus to the viscosity modulus of the material governs the amplitude attenuation while the angular frequency of the striking-rebounding cycle depends mainly on the elastic modulus. The dropping height determines the initial striking velocity but has no direct impact on either attenuation or angular frequency. The model and simulation provided interpretations of both experimental observations and dynamic behaviours of the material. With help of simulation, the impacts of the individual parameters, e. g. the Young's modulus, E, the viscosity modulus, η, and the drop height, H, were also explored. [ABSTRACT FROM AUTHOR]

Electrode architectures significantly influence the electrochemical performance, flexibility, and applications of lithium‐ion batteries (LiBs). However, the conventional bar coating for fabricating electrodes limits the addition of customized architecture or patterns. In this study, as a novel approach, patterns are integrated into electrodes through large‐scale roll‐to‐roll (R2R) flexographic printing. Additionally, flexible, recyclable, and biodegradable paper are innovatively used as a printing substrate during printing LiBs manufacturing, which exhibited superior printability. Moreover, the paper is modified with a thin‐layer Al2O3 to function as the separator in the printed LiB. The Al2O3‐coated paper enables an admirable wettability for printing, excellent mechanical properties for high‐speed R2R manufacturing, and outstanding thermal stability for the safe and stable operation of LiBs. The assembled paper cells exhibit nearly 100% discharge capacity retention after 1000 cycles at 3 C and outstanding rate performance. This work inspires future large‐scale microbatteries manufacturing integrated with high‐resolution architecture designs. [ABSTRACT FROM AUTHOR]

Melanins (from the Greek μέλας, mélas, black) are bio-pigments ubiquitous in flora and fauna. Eumelanin is an insoluble brown-black type of melanin, found in vertebrates and invertebrates alike, among which Sepia (cuttlefish) is noteworthy. Sepia melanin is a type of bio-sourced eumelanin that can readily be extracted from the ink sac of cuttlefish. Eumelanin features broadband optical absorption, metal-binding affinity and antioxidative and radical-scavenging properties. It is a prototype of benign material for sustainable organic electronics technologies. Here, we report on an electronic conductivity as high as 10-3 S cm-1 in flexographically printed Sepia melanin films; such values for the conductivity are typical for well-established high-performance organic electronic polymers but quite uncommon for bio-sourced organic materials. Our studies show the potential of bio-sourced materials for emerging electronic technologies with low human- and eco-toxicity. [ABSTRACT FROM AUTHOR]

Perovskite solar cells have potential to deliver terawatt‐scale power via low‐cost manufacturing. However, scaling is limited by slow, high‐temperature annealing of the inorganic transport layers and the lack of reliable, large‐area methods for depositing thin (<30 nm) charge transport layers (CTLs). We present a method for scaling ultrathin NiOx hole transport layers (HTLs) by pairing high‐speed (60 m min−1) flexographic printing with rapidly annealed sol–gel inks to achieve the fastest reported process for fabrication of inorganic CTLs for perovskites. By engineering precursor rheology for rapid film‐leveling, NiOx HTLs were printed with high uniformity and ultralow pinhole densities resulting in photovoltaic performance exceeding that of spin‐coated devices. Integrating these printed transport layers in planar inverted PSCs allows rapid fabrication of high‐efficiency (PCE > 15%) CsxFA1−xPbI solar cells with improved short circuit currents (Jsc) of 22.4 mA cm−2. Rapid annealing of the HTL accelerates total processing time by 60X, while maintaining the required balance of optoelectronic properties and the chemical composition for effective hole collection. These results build an improved understanding of ultrathin NiOx and reveal opportunities to enhance device performance via scalable manufacturing of inorganic CTLs. [ABSTRACT FROM AUTHOR]

Flexographic printing is promising for large‐area electronics due to high print‐speed and roll‐to‐roll capability. There have been recent attempts in using graphene as an active pigment in inks, most notably for slower techniques such as inkjet and screen printing. However, formulation of graphene‐enhanced inks for high‐speed printing and its effect on key metrics have never been investigated. Herein, graphene nanoplatelets (GPs) are incorporated to a conductive flexographic ink without compromising the rheological properties. An industrial scale at 100 m min−1 is printed on paper and polyethylene terephthalate (PET) substrates using a commercial flexographic press, and statistical performance variations are investigated across entire print runs. It is shown that GP‐incorporation improves sheet‐resistance (Rs) and uniformity, with up to 54% improvement in average Rs and 45% improvement in the standard‐deviation on PET. The adhesion on both the substrates improves with GP‐incorporation, as verified by tape/crosshatch tests. The durability of GP‐enhanced samples is probed with a 1000 cyclic bend‐test, with 0.31% average variation in resistance in the flat state on PET between the first and last 100 bends, exhibiting a robust print. The statistically scalable results show that GP‐incorporation offers a cost‐performance advantage for flexographic printing of large‐area conductive patterns without modifications to traditional high‐speed graphics printing presses. [ABSTRACT FROM AUTHOR]

Flexographic technology usage is increasing in recent years. Predicted growth in the technology usage intensifies the demand for improved quality. It is expected that flexographic printing will achieve greater results than ever before. Since this technique is used in the printing of shrink sleeve packaging, it is imperative to meet the technical and economic requirements of the shrink sleeve product. This is primarily to ensure gliding of the white printing material. The amount of white should be as small as possible, making the sliding of the material optimal and the quality of the print better. Therefore, the quality of the printing was measured by changing the conditions of slippage and white color. This research has established a correlation between the thickness of the white layer and the reduction of print quality over thin lines.

Printed graphene electrodes have been demonstrated as a versatile platform for electrochemical sensing, with numerous examples of rapid sensor prototyping using laboratory-scale printing techniques such as inkjet and aerosol jet printing. To leverage these materials in a scalable production framework, higher-throughput printing methods are required with complementary advances in ink formulation. Flexography printing couples the attractive benefits of liquid-phase graphene printing with large-scale manufacturing. Here, we investigate graphene flexography for the fabrication of electrodes by analyzing the impacts of ink and process parameters on print quality and electrical properties. Characterization of the printed patterns reveals anisotropic structure due to striations along the print direction, which is related to viscous fingering of the ink. However, high-resolution imaging reveals a dense graphene network even in regions of sparse coverage, contributing to robust electrical properties even for the thinnest films (< 100 nm). Moreover, the mechanical and environmental sensitivity of the printed electrodes is characterized, with particular focus on atmospheric response and thermal hysteresis. Overall, this work reveals the conditions under which graphene inks can be employed for high-speed flexographic printing, which will facilitate the development of graphene-based sensors and related devices. [ABSTRACT FROM AUTHOR]

The paper presents considerations on quality assurance for products such as preformed boxes, made out of thin cardboard, created through flexographic printing. The elements specific to the technological process are analysed, followed by the setting of the levels of product conceptualisation after the analysis of its functions and the defining characteristics of its optimal quality. In addition, the paper covers some of the procedures which are specific to the quality assurance of the flexographic printing procedures which were implemented in the typography where the case study for certifying the process in compliance with SR EN ISO 9001:2015 was carried out.

Shrink label today is one of the leading innovative solutions in the field of packaging labeling. Heat-shrinkable film has mechanical strength, elasticity and moisture-proof properties, easily changes linear dimensions under the influence of temperature, which allows it to take the form of packaged products, prevents unauthorized opening and forgery, and attracts buyers through original design solutions. The technology of heat-shrinkable labelling of products is used in the pharmaceutical, cosmetology, food, dairy, confectionery industries. To preserve the product’s proper appearance until the end of its service life, as well as to be able to decorate it printing on the shrink label is performed on its inner side. Gravure and flexographic printing technologies are mainly used to apply images to shrink labels. The specifics of the technological process of manufacturing a shrink label determines the use of materials with different physical properties: transparency, gloss, thickness, strength, coefficients of friction and tensile, temperature, percentage and time of shrinkage, which significantly affects its final cost. The most widely used are PET and PVC films. PVC film is deformed at lower temperatures and is more resistant to the external environment, while the use of PET films allows to achieve better thermal shrinkage and, accordingly, to ensure higher print quality. When applying the information to the heat-shrinkable film, it can be used water-based inks, but then there is a possibility of blurring of the image when passing the package through the steam furnace. As an alternative to printing on such films, UV fixing inks are used, which allows to apply multi-color complex images on any type of material, but this method is quite expensive due to the high cost of inks and printing equipment. Therefore, it is important to conduct system-technical, economic analysis and determine the most cost-effective and efficient technology for the production of shrink labels.

Resistive random-access memory is a candidate for next-generation non-volatile memory architectures. In this study, we use flexographic roll-to-roll printing technology for deposition of the resistive layer, a printing method that allows fast and cost-effective fabrication to create non-volatile resistive memory devices. Metal-free organic polymers blends composed of poly(methyl methacrylate) (PMMA) and a surplus of poly(vinyl alcohol) (PVA) serve as the active layer. Microscopic studies of the roll-to-roll printed layers show circular domains of PMMA embedded in PVA. The influence of the PMMA content in the polymer blend is investigated with respect to the performance and reliability of the resistive memory cells. Electrical characterization reveals a retention time of at least eleven days, a Roff/Ron ratio of approx. two orders and write/erase voltages of + 1/−2 V. [ABSTRACT FROM AUTHOR]

PLA films, as non-absorbent materials, require modification of the surface before the printing process in order to improve the wettability of the substrate and to obtain proper ink adhesion to the substrate. In this paper, the surfaces of two kinds of PLA films were modified using plasma activation with parameters enabling high surface free energy (SFE) values, and then the films were printed on using different kinds of flexographic inks. Two gases, oxygen and argon, were used for activation, as these make it possible to obtain good hydrophilicity and high SFE values while having different effects on the roughness, or the degree of surface etching. Plasma-activated films were subsequently subjected to the measurements of: contact angle with water, diiodomethane and three printing inks, roughness, weight change, strength properties, color and gloss change, and SFE was determined. Unmodified and activated films were flexographically printed in laboratory conditions and then the quality of obtained prints was analyzed. The results showed a strong effect of activation with both oxygen and argon plasma on the SFE value of the films and the contact angles of water and inks, with the gas used for plasma activation and the type of film significantly influencing the thickness of the fused ink layer and the resultant color. Moreover, plasma activation had a especially favorable and significant effect on the quality of prints made with water-based inks, while it had little effect when printing with solvent-based inks. [ABSTRACT FROM AUTHOR]

Flexographic technology usage is increasing in recent years. Predicted growth in the technology usage intensifies the demand for improved quality. It is expected that flexographic printing will achieve greater results than ever before. Since this technique is used in the printing of shrink sleeve packaging, it is imperative to meet the technical and economic requirements of the shrink sleeve product. This is primarily to ensure gliding of the white printing material. The amount of white should be as small as possible, making the sliding of the material optimal and the quality of the print better. Therefore, the quality of the printing was measured by changing the conditions of slippage and white color. This research has established a correlation between the thickness of the white layer and the reduction of print quality over thin lines. [ABSTRACT FROM AUTHOR]

Even though textile labels are not often the subject of research, their quality must not be neglected. Printed typographic elements (i.e. letters and texts) must be visible regardless of textile ribbons and typeface or type size to be printed. Thus, the aim of the research was to qualitatively and quantitatively analyze and evaluate the text printed with flexography in two different typefaces (Helvetica and Verdana) in three different type sizes (4, 6 and 8 point) on five textile ribbons made of polyester and polyester/cotton mixture in two different weaves (plain and satin). The results of our research showed that the quality of printed letters is influenced by the properties of textile ribbons as well as by the chosen typographic features. When textile ribbons were composed of polyester filaments, the quality of prints was better than in the case of the mixed composition with cotton fibers. The coating and previously dyed textile ribbons had a positive influence on the quality of printed letters. The typeface Verdana gave more distinct and contrasted printed letters than Helvetica. The quality of printed letters (measured by the cover factor) decreased with the reduced type size; letters (and text) in a smaller type size (4 point) were hence, depending on the properties of textile ribbons, less visible. [ABSTRACT FROM AUTHOR]

Flexographic printing has received tremendous attention in the printing field due to the advantages of short preparation processes and high printing efficiency. Its printing quality heavily depends on the preparation of the printing plate. However, plate clarity and plate softness are contradictory. This paper reports the development of a clear and soft self-plasticizing modified polyvinyl alcohol (m-PVA) coating that can be UV-cured at room temperature. Glycidyl methacrylate (GMA) was used to prepare unsaturated m-PVA (m-PVA-GMA) in an aqueous system. Meanwhile, the effects of acidic and alkaline environments on the grafted products have been further investigated, suggesting that they differ from those obtained via the dimethyl sulfoxide system. The structural comparison has demonstrated that the reactivity of GMA and m-PVA is higher in alkaline aqueous than in acidic conditions. When the unsaturation degree increases, the crystallization of PVA chain segments will be effectively destroyed. The photographic film, which can be directly photo-crosslinked, was prepared by m-PVA-GMA and washed away the uncrosslinked portion with water. The glass transition temperature (31.4 °C) of the photographic m-PVA-GMA film prepared under alkaline conditions is close to room temperature, and the crosslink density is as high as 3.01 × 103 mol m−3. More importantly, the elongation at break after water washing and the elastic recovery are 110.8 ± 5.3 % and 99 %, respectively. In addition, irradiating selected areas and then removing the non-irradiated portions with water could produce patterns. The m-PVA-GMA film prepared under alkaline conditions has outstanding development accuracy, much higher than the commercially available product nyloprint®. This direct UV-curable film with water-soluble and water-developable properties enables it to be a promising candidate in the fine flexographic printing industry, such as photoresists, electronic devices, and sensors. • Glycidyl methacrylate was grafted onto self-plasticized polyvinyl alcohol molecular chain. • After washing, the elastic recovery rate of the photosensitive film can be up to 99 %. • The modified UV curing film has clearer images than the commercial product. [ABSTRACT FROM AUTHOR]

Transistors are one of the major components of everyday consumer electronics. With the huge demand for low‐cost and flexible consumer electronics, modern industrially‐compatible transistor‐fabrication techniques such as roll‐to‐roll printing techniques must be given due consideration with a view to replacing conventional complex lithography techniques which make use of toxic chemicals. Such traditional methods are not only time‐consuming but also pose a threat to human health. This review article is concerned with offering insights into the deployment of flexographic printing which has been widely used for food packaging and newspaper production, as a cost‐effective technique for the production of transistors. More specifically, it discusses in detail both advantages of the printing technique and its contributions to fabrication of different vital transistor components such as gate, source, drain, semiconductor, and dielectric layers. It also attends to prepatterning of surfaces for the formation of transistor electrodes using the printing technique. Finally, it addresses the challenges associated with implementing such a technique in industry. [ABSTRACT FROM AUTHOR]

Flexographic printing is the most usable technology in the packaging industry. But the lack of proper adhesion of water-based ink on cardboard coated with polyethylene is one of the most important problems. Silane adhesion promoters are considered among the best compounds used as the crosslinking and waterproofing agents in coating and ink industries. In this study, N-(2-Aminoethyl) (3-aminopropyl) methyldimethoxysilane and 2-(3, 4-Epoxycyclohexyl) ethyltriethoxysilane were used to improve the adhesion of water-based ink on paper boarded-coated with polyethylene. Results showed that highest amount of adhesion were achieved by adding 5% of N-(2-Aminoethyl) (3-aminopropyl) methyldimethoxysilane to ink. Adding silane compounds to ink formulation increased the contact angle of the ink film on the surface of cardboard coated with polyethylene which means that inks containing silane compounds act more successful in the formation of hydrophobic surface. It is worth noting that surface tension was decreased by addition of silane components to the formulation of the ink.

Advances in printed electronics are predicated on the integration of sophisticated printing technologies with functional materials. Although scalable manufacturing methods, such as letterpress and flexographic printing, have significant history in graphic arts printing, functional applications require sophisticated control and understanding of nanoscale transfer of fluid inks. Herein, a versatile platform is introduced to study and engineer printing forms, exploiting a microscale additive manufacturing process to design micro‐architected materials with controllable porosity and deformation. Building on this technology, controlled ink transfer for submicron functional films is demonstrated. The design freedom and high‐resolution 3D control afforded by this method provide a rich framework for studying mechanics of fluid transfer for advanced manufacturing processes. [ABSTRACT FROM AUTHOR]

An efficient and low-cost approach to manufacture Opto-Mechatronic Interconnect Devices will be obligatory to handle the strongly increasing amount of data. The presented approach is based on a flexographic printing process. To adjust the transferred material the printing form is functionalized by means of laser-induced structures using an ultrashort-pulsed laser. The long-term goal is to adjust the printing result through microstructures in the printing form in order to create spatially resolved material transfer. In this work, first the ablation parameters are investigated at different repetition rates using a femtosecond laser. Further, a line structure is inserted in the material transferring areas of the printing form, which is consequently widened. Its influence on the printing result is presented. [ABSTRACT FROM AUTHOR]

Lately, printed oxide electronics have advanced in the performance and low‐temperature solution processability that are required for the dawn of low‐cost flexible applications. However, some of the remaining limitations need to be surpassed without compromising the device electronic performance and operational stability. The printing of a highly stable ultra‐thin high‐κ aluminum‐oxide dielectric with a high‐throughput (50 m min−1) flexographic printing is accomplished while simultaneously demonstrating low‐temperature processing (≤200 °C). Thermal annealing is combined with low‐wavelength far‐ultraviolet exposure and the electrical, chemical, and morphological properties of the printed dielectric films are studied. The high‐κ dielectric exhibits a very low leakage‐current density (10−10 A cm−2) at 1 MV cm−1, a breakdown field higher than 1.75 MV cm−1, and a dielectric constant of 8.2 (at 1 Hz frequency). Printed indium oxide transistors are fabricated using the optimized dielectric and they achieve a mobility up to 2.83 ± 0.59 cm2 V−1 s−1, a subthreshold slope <80 mV dec−1, and a current ON/OFF ratio >106. The flexible devices reveal enhanced operational stability with a negligible shift in the electrical parameters after ageing, bias, and bending stresses. The present work lifts printed oxide thin film transistors a step closer to the flexible applications of future electronics. [ABSTRACT FROM AUTHOR]

The structural vibration of the center impression cylinder in the flexographic printing machine will bring about production quality problems such as printing ghosts. To this problem, it become an important method to analysis the dynamic characteristics of the center impression cylinder. In this paper, a three-dimensional structural model of the central impression cylinder is established, and builds the dynamic model in finite element software. The vibration modes of the central impression cylinder were studied in the simple-supported system at both ends of the static impression cylinder. In view of the real existence of the rotating dynamic load, the evolution law of the natural frequency and mode shape of the cylinder with the rotating dynamic load is discussed. It is found that as the rotation speed increases, the natural frequency undergoes two steps, and the natural frequency after each step will keep continuity with the high first-order natural frequency, and the modal shape is the same as the high-order original mode. Then, the mode shape is continuously changed, not have a step. [ABSTRACT FROM AUTHOR]

PLA films, as non-absorbent materials, require modification of the surface before the printing process in order to improve the wettability of the substrate and to obtain proper ink adhesion to the substrate. In this paper, the surfaces of two kinds of PLA films were modified using plasma activation with parameters enabling high surface free energy (SFE) values, and then the films were printed on using different kinds of flexographic inks. Two gases, oxygen and argon, were used for activation, as these make it possible to obtain good hydrophilicity and high SFE values while having different effects on the roughness, or the degree of surface etching. Plasma-activated films were subsequently subjected to the measurements of: contact angle with water, diiodomethane and three printing inks, roughness, weight change, strength properties, color and gloss change, and SFE was determined. Unmodified and activated films were flexographically printed in laboratory conditions and then the quality of obtained prints was analyzed. The results showed a strong effect of activation with both oxygen and argon plasma on the SFE value of the films and the contact angles of water and inks, with the gas used for plasma activation and the type of film significantly influencing the thickness of the fused ink layer and the resultant color. Moreover, plasma activation had a especially favorable and significant effect on the quality of prints made with water-based inks, while it had little effect when printing with solvent-based inks.

Training printing workers in the use of flexography requires extensive time, as they are expected to gain knowledge on-site, through hands-on practice, resulting in high costs for the employer. This paper addresses the issue by providing practical information up front. Applying this information correctly during the printing process leads to a quality product. The study was created to analyse the following aspects: problems in printing - nonconformities and defects; quality of the print - seen as a habit of working neatly and correctly; quality when working with die cuts; quality in the prepress process.

Since the invention of movable type in ancient times, relief printing, often called flexographic printing, has been performed to mass-produce artifacts ranging from decorative graphics to printed media. Polyvinyl alcohol (PVA) substrates are soluble in water with low toxicity but have the disadvantages of poor elasticity and brittleness. Thus, this study aims to improve the resilience of water-developable photopolymer resin plates by modifying PVA with allyl polyoxyethylene ether (APEG) in solution polymerization. In order to better control polymerization, the reactivity ratios of both were investigated (r VAC = 0.32 and r APEG = 0.12). Impressively, the lowest glass transition temperature (T g) of the modified PVA (m -PVA) can reach −49.98 °C, which is significantly lower than that of PVA0599 (degree of polymerization = 500, degree of hydrolysis = 99 mol%) (T g = 52.02 °C). Moreover, this resultant m -PVA exhibits superior elongation at break (443.23 ± 37.65 %) than PVA0599 (9.98 ± 3.95 %). It is found that photopolymer plates of m -PVA have maintained a 98 % elasticity recovery rate even after water washing. Due to the better elasticity of m -PVA, the clarity of the photopolymer plate is higher than that of traditional PVA. This water-soluble self-plasticized m -PVA is expected to be applied to the fine flexographic printing industry, such as electronic devices, components, and sensors. • Allyl polyoxyethylene ether was copolymerized into polyvinyl alcohol molecular chain. • After modification, the elastic recovery rate of the UV cured coating was improved. • The modified UV curing film has clearer images. [ABSTRACT FROM AUTHOR]

The printability tester is defined as a device for uniformly applying a reproducible amount of ink to a substrate under specified conditions using a motorized control of the ink transfer process specific function. This repeatable print operation characteristic may also facilitate the correlation of the actual printing condition set by the primary process parameters specified by printing process, substrate, ink, screening, printing order, etc. By extending the usage and functionality of the printability tester, printers have the possibility to use laboratory test prints as means of process control and correction at a fraction of cost and time.

The article presents a preliminary study of the correlation between films properties and flexographic print quality defined as the optical density of full tone. It is also an attempt to answer the question whether traditional plastic films can be replaced by biodegradable and compostable films as printing substrates and as materials for packaging. Four kinds of films were used in the experiments – two plastic films (PP and PET) and two biodegradable films (PLA and cellulose). The permeability to water vapour and oxygen, as well as the tensile strength and elongation at break of the material were investigated for all samples. The measurements of the contact angle with water, diiodomethane and printing ink were also conducted for these films, and their surface free energy was determined. All samples were printed on laboratory equipment by a flexographic technique using water-based inks and the optical density of copies was measured. It has been found that the print quality was determined by the type of film used. Furthermore, the correlation between optical density and wettability defined as the contact angle between film and water or printing ink turned out to be significant. Other important parameter is surface free energy, albeit to a little lesser extent. The barrier and mechanical properties of the material have an even weaker impact on optical density. In addition, it is possible to choose the biodegradable film with properties corresponding to conventional, commonly used films which enable high quality prints.

Model elastic inks were formulated, rheologically characterised in shear and extension, and printed via flexography to assess the impact of ink elasticity on print uniformity. Flexography is a roll-to-roll printing process with great potential in the mass production of printed electronics for which understanding layer uniformity and the influence of rheology is of critical importance. A new set of flexo-printable Boger fluids was formulated by blending polyvinyl alcohol and high molecular weight polyacrylamide to provide inks of varying elasticity. During print trials, the phenomenon of viscous fingering was observed in all prints, with those of the Newtonian ink exhibiting a continuous striping in the printing direction. Increasing elasticity significantly influenced this continuity, disrupting it and leading to a quantifiable decrease in the overall relative size of the printed finger features. As such, ink elasticity was seen to have a profound effect on flexographic printing uniformity, showing the rheological tuning of inks may be a route to obtaining specific printed features. [ABSTRACT FROM AUTHOR]

Considering the increasing amount of data for communication and infotainment applications, fabrication of optical networks and bus systems is a challenging task for production engineering. A two-step manufacturing process for polymer optical waveguides is presented. By improving the highly efficient flexographic printing technology by laser functionalization of the printing tool in combination with a subsequent spray application, high-quality waveguides are accomplished. By adjusting the resulting surface energy of the foil substrate in the first fabrication process, the spray application achieved high-aspect ratio waveguides with a low attenuation of 0.2dB/cm at 850 nm. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to determine the methodology for assessing key factors that affect the quality and efficiency of a flexographic printing process. The subject of theoretical considerations is quality evaluation and basic information about efficiency method evaluation, like OEE, SMED and other. The article also presents an evaluation survey of the quality level of printing requirements for customers, conducted by the author. The presented results reveal that those methods are suitable as advanced tools for measuring the quality and efficiency level of manufactured products and the production processes, which also improve customer satisfaction. [ABSTRACT FROM AUTHOR]