Printability Analysis of Compostable Films by Flexographic Water Based Ink

2020 ◽  
Vol 843 ◽  
pp. 26-32
Author(s):  
Aran Hansuebsai ◽  
Samatcha Nawakitwong

This research analyzed the printability of compostable films commercialized in the Thai market such as PLA/PBAT and PBAT/starch; and to comply with EN 13432 standard by using flexographic water based ink. A narrow web flexographic printing press was set up and opperated. Print quality parameters such as optical density, tone reproduction, print contrast and print uniformity were investigated. Results showed that these compostable films were hydrophobic in nature, in combination with fracture and voids of substrates’ surface. Even the substrates could be printed relatively well but showed poor ink adhesion. Surface treatment, therefore, was necessary, but having limitation. Anilox line screen 700 lpi and printing speed at 30 m/min were preferable to achieve the optimum tone reproduction and print contrast. This was based on the image resolution of 133 lpi and corona dosage at 500 watt-min/m2. Images of printed samples from SEM and SPM indicated that the fracture surface and void of films could lead to decrease their printability. It was found that starch blend gave better results as being a filler of the surface roughness of the substrate..

2010 ◽  
Vol 174 ◽  
pp. 381-384 ◽  
Author(s):  
Chun Jiang Jia ◽  
Guang Xue Chen ◽  
Xiao Zhou Li

At present, we are taking more and more attention on environment protecting, food and medicine safety, and more researching and applying on green printing and packaging technique has been done abroad. Around these, water-based ink has been accepted by the market step by step, but the printing press on this area still with some problems: Lower drying efficiency and lower printing speed. To solve these problems, we analysis the hot-air drying process based on model Logarithmic. We suppose the experiment environment as follow: the temperature is 50°C, the hot air speed is 6m/s, meanwhile we suppose the experiment keep to second Fick-law: The liquid equally distributing around the solid at the beginning; during the drying process, the diffusing modulus keep steady; the resistance of external diathermanous medium is ignored and keep linear diffuse. Under this experimental condition, we record the data about the volume of liquid in the solid during the process, and then analyze the data by the software SPSS, we evaluate the model by the square of relating parameters, and then revise the model so that it can keep the same with the drying process. The model can forecast the drying rate of the water-based ink. This model can supply basal dada for the designing work of water-based ink; at the same time, it has actively influence on speedup the printing press.


TAPPI Journal ◽  
2016 ◽  
Vol 15 (4) ◽  
pp. 253-262 ◽  
Author(s):  
ERIK BOHLIN ◽  
CAISA JOHANNSON ◽  
MAGNUS LESTELIUS

The effect of coating structure variations on flexographic print quality was studied using pilot-coated paperboard samples with different latex content and latex particle sizes. Two latexes, with particle sizes of 120 nm and 160 nm, were added at either 12 parts per hundred (pph) or 18 pph to the coating formulation. The samples were printed with full tone areas at print forces of 25 N and 50 N in a laboratory flexographic printing press using a waterbased ink. A high ratio of uncovered areas (UCAs) could be detected for the samples that contained 18 pph latex printed at a print force of 25 N. UCAs decreased with increased print force and with decreased amounts of latex in the coating formulation. The fraction of latex covered area on the coating surface was estimated to be 0.35–0.40 for the 12 pph, and 0.70–0.75 for the 18 pph samples. The ink penetration depth into the coating layer could be linked to the fraction of latex-free areas on the coating surface. Optical cross section microscopy indicated that a higher printing force did not increase the depth of penetrated ink to any greater extent. Higher printing force did increase contact between plate and substrate, leading to an improved distribution of the ink. This, in turn, increased print density and decreased UCAs. On closer inspection, the UCAs could be categorized as being induced by steep topographic changes. When appearing at other locations, they were more likely to be caused by poor wetting of the surface. To understand the wetting behavior of the coating surface, observed contact angles were compared with calculated contact angles on surfaces of mixed composition.


TAPPI Journal ◽  
2010 ◽  
Vol 9 (10) ◽  
pp. 7-15
Author(s):  
HANNA KOIVULA ◽  
DOUGLAS BOUSFIELD ◽  
MARTTI TOIVAKKA

In the offset printing process, ink film splitting has an important impact on formation of ink filaments. The filament size and its distribution influence the leveling of ink and hence affect ink setting and the print quality. However, ink filaments are difficult to image due to their short lifetime and fine length scale. Due to this difficulty, limited work has been reported on the parameters that influence filament size and methods to characterize it. We imaged ink filament remains and quantified some of their characteristics by changing printing speed, ink amount, and fountain solution type. Printed samples were prepared using a laboratory printability tester with varying ink levels and operating settings. Rhodamine B dye was incorporated into fountain solutions to aid in the detection of the filaments. The prints were then imaged with a confocal laser scanning microscope (CLSM) and images were further analyzed for their surface topography. Modeling of the pressure pulses in the printing nip was included to better understand the mechanism of filament formation and the origin of filament length scale. Printing speed and ink amount changed the size distribution of the observed filament remains. There was no significant difference between fountain solutions with or without isopropyl alcohol on the observed patterns of the filament remains.


Author(s):  
Shao-Hsien Chen ◽  
Chih-Hung Hsu

AbstractThe nickel alloy has good mechanical strength and corrosion resistance at high temperature; it is extensively used in aerospace and biomedical and energy industries, as well as alloy designs of different chemical compositions to achieve different mechanical properties. However, for high mechanical strength, low thermal conductivity, and surface hardening property, the nickel alloy has worse cutting tool life and machining efficiency than general materials. Therefore, how to select the optimum machining parameters will influence the workpiece quality, cost, and machining time. This research will be using a new experimental design methodology to the cutting parameter planning for nickel-based alloy cutting test, and used the uniform design methodology to cutting test to reduce the number of experiments. Three independent variable parameters are set up, including cutting speed, feed rate, and cutting depth, and four dependent variable parameters are set up, including cutting tool wear, surface roughness, machining time, and cutting force. A nickel alloy turning parameter model is built by using regression analysis to further predict the I/O relationship among various combinations of variables. The errors between actual values and prediction values are validated. When the cutting tool wear (VB) is 2.72~6.18%, the surface roughness (Ra) is 4.10~7.72%, the machining time (T) is 3.75~8.82%, and the cutting force (N) is 1.54~7.42%; the errors of various dependent variables are approximately less than 10%, so a high precision estimation model is obtained through a few experiments of uniform design method.


2018 ◽  
Vol 2 (4) ◽  
pp. 80 ◽  
Author(s):  
Mir Molaie ◽  
Ali Zahedi ◽  
Javad Akbari

Currently, because of stricter environmental standards and highly competitive markets, machining operations, as the main part of the manufacturing cycle, need to be rigorously optimized. In order to simultaneously maximize the production quality and minimize the environmental issues related to the grinding process, this research study evaluates the performance of minimum quantity lubrication (MQL) grinding using water-based nanofluids in the presence of horizontal ultrasonic vibrations (UV). In spite of the positive impacts of MQL using nanofluids and UV which are extensively reported in the literature, there is only a handful of studies on concurrent utilization of these two techniques. To this end, for this paper, five kinds of water-based nanofluids including multiwall carbon nanotube (MWCNT), graphite, Al2O3, graphene oxide (GO) nanoparticles, and hybrid Al2O3/graphite were employed as MQL coolants, and the workpiece was oscillated along the feed direction with 21.9 kHz frequency and 10 µm amplitude. Machining forces, specific energy, and surface quality were measured for determining the process efficiency. As specified by experimental results, the variation in the material removal nature made by ultrasonic vibrations resulted in a drastic reduction of the grinding normal force and surface roughness. In addition, the type of nanoparticles dispersed in water had a strong effect on the grinding tangential force. Hybrid Al2O3/graphite nanofluid through two different kinds of lubrication mechanisms—third body and slider layers—generated better lubrication than the other coolants, thereby having the lowest grinding forces and specific energy (40.13 J/mm3). It was also found that chemically exfoliating the graphene layers via oxidation and then purification prior to dispersion in water promoted their effectiveness. In conclusion, UV assisted MQL grinding increases operation efficiency by facilitating the material removal and reducing the use of coolants, frictional losses, and energy consumption in the grinding zone. Improvements up to 52%, 47%, and 61%, respectively, can be achieved in grinding normal force, specific energy, and surface roughness compared with conventional dry grinding.


2013 ◽  
pp. 67-69
Author(s):  
Mariann Móré ◽  
Zita Burján ◽  
Zoltán Győri ◽  
Péter Sipos

The yield and quality of wheat are mainly determined by the plant production system, thus we studied the effect of mineral fertilization. The field trials were set up in 1983 at the Látókép Research Institute of the University of Debrecen. We examined effect of different Nfertilizer doses (60 kg ha-1 N/P/K, 120 kg ha-1 N/P/K) on Lupus, Mv Toldi and GK Csillag's protein properties in 2012. During the tests, three quality parameters were determined: wet gluten content (%), wet gluten spread (mm/h) and gluten index (%). In the experiment the effect of different doses of N-fertilizers significantly influenced by the wet gluten content and gluten index of Lupus.


KREATOR ◽  
2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Soebardianto . ◽  
Septia Ardiani ◽  
Romi Setiawan

The quality control activities, in particular the measurement of density values, are part of the quality control parameters carried out by each company. Companies sometimes forget about the quality parameters of the name, even though the quality can give the printed products a good guarantee in the eyes of consumers. To achieve the quality level, of course, the business does not stand idle, there are several things that need to be done or provided by the business to support the quality, namely man (human), machine (machine), material (material), and method (method). In the development of technology in an increasingly advanced digital world, companies want to continue to compete with a digital world by making inroads, this of course gives the products produced by the company a good or a good level of quality. In this discussion, there is an identification of problematic aspects arising from the deviation of density values as well as ways to obtain standard density values and factors that affect the quality of prints on book cover prints using a Heidelberg machine.Keywords—Quality Control, Density, Standart, Product, Deviation


Lubricants ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 96
Author(s):  
Hui Wu ◽  
Hamidreza Kamali ◽  
Mingshuai Huo ◽  
Fei Lin ◽  
Shuiquan Huang ◽  
...  

Eco-friendly and low-cost water-based nanolubricants containing rutile TiO2 nanoparticles (NPs) were developed for accelerating their applications in industrial-scale hot steel rolling. The lubrication performance of developed nanolubricants was evaluated in a 2-high Hille 100 experimental rolling mill at a rolling temperature of 850 °C in comparison to that of pure water. The results indicate that the use of nanolubricant enables one to decrease the rolling force, reduce the surface roughness and the oxide scale thickness, and enhance the surface hardness. In particular, the nanolubricant consisting of 4 wt % TiO2, 10 wt % glycerol, 0.2 wt % sodium dodecyl benzene sulfonate (SDBS) and 1 wt % Snailcool exhibits the best lubrication performance by lowering the rolling force, surface roughness and oxide scale thickness by up to 8.1%, 53.7% and 50%, respectively. The surface hardness is increased by 4.4%. The corresponding lubrication mechanisms are attributed to its superior wettability and thermal conductivity associated with the synergistic effect of rolling, mending and laminae forming that are contributed by TiO2 NPs.


Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 405 ◽  
Author(s):  
Haibo Xie ◽  
Ken-ichi Manabe ◽  
Zhengyi Jiang

A comprehensive research on the flat rolling deformation characterization of microwire has been conducted systematically through finite element simulation and testified by the results from the experimental analysis. The obtained results are compared in terms of lateral spread, geometrical characteristic, contact area width and surface roughness considering the effects of pass reduction and initial wire diameter. The size effect has been identified and surface layer modeling has been set up based on surface grain share and grain size distribution. The numerical method combined with varied flow stress has been verified by experimental value with a maximum difference of 3.7% for the 1.5 mm wire. With the increase of the height reduction, the curvature radius is decreased while the lateral spread and contact area width are increased. Surface roughness evolution in the range of 0.52–0.85 µm for the rolled wire has also been investigated.


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