| 51. |
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| 52. |
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| 53. |
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| 54. |
- Lestelius, Magnus, et al.
(författare)
-
Order/disorder gradients of n-alkanethiols on gold
- 1999
-
Ingår i: Colloids and Surfaces B. - : Elsevier. - 0927-7765 .- 1873-4367. ; 15:1, s. 57-70
-
Tidskriftsartikel (refereegranskat)abstract
- This paper explores the interfacial properties of one-dimensional molecular gradients of alkanethiols (HS-(CH2)(n)- X) on gold. The kinetics and thermodynamics of monolayer formation are important issues for these types of mixed molecular assemblies. The influence of chain length difference on the contact angles with hexadecane (HD), theta(a) and theta(r), and the hysteresis, has been studied by employing alkanethiols HS-(CH2)(n)-CH3, with n = 9, 11, 13, 15 and 17, in the preparation of the self-assembled monolayers (SAM) gradients. The contact angles with hexadecane, at the very extreme ends of the gradients, show characteristic values of a highly ordered CH3-like assembly: theta(a) = 45-50 degrees. In the middle of the gradients theta(a) drops noticeably and exhibits values representative for CH2-like polymethylenes, theta(a) = 20-30 degrees, indicating a substantial disordering of the protruding chains of the longer component in the gradient assembly. As expected, the exposure of CH2-groups to the probing liquid increases with increasing differential chain length of the two n-alkanethiol used, in this case eight methylene units. However, the contact angles always display a non-zero value which means that even at a chain length difference of eight methylene units there is a substantial exposure of methyl (CH3) groups to the probing liquid. With infrared reflection-absorption spectroscopy (IRAS) we have monitored the structural behavior of the polymethylene chains along the gradient. We find complementary evidence for disordered chains in the gradient region, and the IRAS results correlate well with the contact angle measurements. (C) 1999 Elsevier Science B.V. All rights reserved.
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| 55. |
- Lestelius, Magnus, 1968-, et al.
(författare)
-
Oxygen permeabilityand economic-environmental impact studies of some polyvinyl alcohol dispersionbarrier coatings for packaging applications
- 2017
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Purposes of employing barrier coatings in packaging, and in particular food packaging, can be to increase the shelf life, preserve colour, odour, and taste, and to protect from a harmful environment in general. Barrier coatings can thus help to reduce food waste along the value chain until end use. Including both materials choice for packaging and the possible fates of the used package, even further steps to provide greater knowledge for decisions on choices of packaging solutions. To that end, we have conducted several experimental and transport modeling studies on oxygen barrier coatings performance. The coating system of choice has been dispersion coatings of poly vinyl alcohol (PVOH), with additions of kaolin. Physical and chemical features of the coatings were characterized to obtain information on polymer crystallinity, free volume and filler orientation as these characteristics are influential to the oxygen mass transport performance. In turn, the oxygen mass transport was also measured, both in steady state and dynamically. In so doing, we obtained information useful for developing a general model to describe the oxygen permeability taking into account the physical and chemical features, described above, of the coating layer. Attempts on describing the interdependence and impact, for instance between crystalline and amorphous polymer regions and moisture, was added to the model. The model showed agreement to experimental data for PVOH-kaolin coating in this particular case. However, the basic permeability model has been applied to many different polymers.To further explore the potential of these types of coating, which are technically possible to produce in paperboard production, an economic-environmental impact comparison to other existing material solutions was made. Four barrier material alternatives – starch, polyethylene, ethyl vinyl alcohol (chosen as an alternative for PVOH, where data was difficult to obtain) and kaolin, and latex and kaolin, were analyzed with respect to cost and global warming potential. Weighting and comparing cost to environmental aspect, weighting factors based on interviews with experts in the packaging value chain, starch emerges as the most sustainable alternative. However, previous coating and mass transport studies also shows how these renewable materials require some further technical development to be competitive.The mass transport model can serve as a tool for customizing barrier coatings and to predict the barrier performance, as permeability is obtained and thus shelf-life estimation is possible. The overall concept, the combination of assessment of structural performance and the environmental studies, can be employed to find sustainable food packaging solutions.
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| 56. |
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| 57. |
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| 58. |
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| 59. |
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| 60. |
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| 61. |
- Lidbrand, Isabell, et al.
(författare)
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Paper Bags vis-à-vis LDPE Bags : Gleanings from Peer-reviewed E-LCA Publications [Torby papierowe a torby foliowe LDPE: wnioski z recenzowanych publikacjina temat oceny cyklu życia (E-LCA)]
- 2023
-
Ingår i: Studia Ecologiae et Bioethicae. - Poland : Scientific Publishing House of the Cardinal Stefan Wyszynski University. - 1733-1218 .- 2719-826X. ; 21:4, s. 63-76
-
Tidskriftsartikel (refereegranskat)abstract
- Fossil-plastics or paper? Or for that matter, bio-plastics and paper? This is a wellentrenched question in academic research, industrial, social and policy-making circles. Asenvironmental life-cycle analyses (or more appropriately, sustainability analyses) show timeand again, no single product or process or mode of operation is a ‘total villain’. There are goodsand bads, and at times, more of the one than the other. This paper, which is based on a coursereport written by the first author at Karlstad University (Sweden), restricts itself to a review ofpublications which have opted to compare paper bags with low density polyethylene (LDPE)plastic bags, on the basis of their environmental impacts. Environmental impact categoriesinclude the global warming potential, energy demand, fossil fuel depletion, water usage,acidification, eutrophication, and a range of toxicities – human, terrestrial, freshwater-aquaticand marine-aquatic. The articles were obtained through Google Scholar, read and reviewed toglean the results presented therein. The ‘What’, ‘How’ and ‘Where’, so to say were studiedcarefully to understand the reasons behind any differences or similarities detected. On the basisof this focused review, even though no new knowledge is being added, the common belief thatthe paper bag is environmentally superior to the LDPE alternative is further consolidated.However, if one focuses on water usage and would assign a high weightage to thatenvironmental impact, LDPE perhaps may score a few ‘brownie points’ over paper. One mustalso not forget that plastics (LDPE in this instance) can be recycled without significantdeterioration in its functional properties. In a circular economy (the bioeconomy part of whichgradually will expand over time), while introducing more and more bio-based products into thetechnosphere by way of trans-materialization is recommended, plastics will still continue toexist – albeit in much smaller amounts – and it would be perfectly fine if the degree of recyclingis augmented significantly. Speaking of a holistic sustainability analysis, the socio-economicaspects of a choice between LDPE and paper bags must also be factored in, and studied. Muchdesired change happens when the top-down meets the bottom-up somewhere midway.
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| 62. |
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| 63. |
- Lundberg, Anna, 1977-
(författare)
-
Ink-paper interactions and effect on print quality in inkjet printing
- 2011
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis concerns paper and ink interactions related to inkjet printing. Themain purpose of this work was to gain a deeper understanding in whichparameters control the flow of ink into papers and how the ink interacts with thepaper surface. The overall objective was to find key parameters to optimize theprint quality in inkjet printing. Characterization of paper-surfaces in terms of porosity, surface roughness andsurface energy was made. Objective and subjective measurements were used forprint quality evaluation. Light microscopy imaging and SEM was used to see howink interacts with the paper surface in a printed image. A high speed camera wasused to study the absorption of picolitre sized inkjet droplets into fine papers.An initial study on the effect of paper properties on print quality was made.Result indicated that there were small differences in print quality for pilot paperswith different composition (in a specific parameter window) and the commercialpaper COLORLOK® reproduced a noticeable high colour gamut compared to theother samples.Research was made to see how surface fixation can affect the print quality forprintouts made with pigmented ink. Surface fixation promotes retention of thepigmented colorant in the outermost surface layer of the paper and has beendenoted “colorant fixation” in this thesis.It was shown that applying colorant fixation onto a paper surface beforeprinting can increase the detail reproduction in a printed image. Differentconcentrations of calcium chloride were applied onto the paper surface on fullscaleproduced non-commercial papers. Test printing was made with a SoHo(Small office/Home office) printer using pigmented ink and results showed thatusing calcium chloride as surface treatment can lead to aggregation of pigments atthe surface resulting in a higher detail reproduction.Fast absorption of the carrier liquid into the paper and fast fixation ofcolourants on the surface is important in inkjet printing to avoid colour to colourbleeding. These demands will be more pronounced when the printing speedincreases. It is important to understand which parameters affect the absorption process tobe able to control the mechanisms and to optimize the print quality.A study of absorption of picolitre size inkjet droplets into fine paper was madein this work. Theoretical equations describing fluid absorption into capillaries weretested and compared with experimental results. The result showed that the timedependence in the Lucas-Washburn (L-W) equation fits fairly well to data whereasthe L-W equation overestimates the penetration depth.The results are directly applicable to paper and printing industry and can beused as a base for future studies of absorption of picolitre sized droplets intoporous materials and for studies of aggregation of colloidal particles on surfaces.
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| 64. |
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| 65. |
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| 66. |
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| 67. |
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| 68. |
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| 69. |
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| 70. |
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| 71. |
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| 72. |
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| 73. |
- Montibon, Elson, et al.
(författare)
-
Electroconductive paper - a study of polymer deposition and conductivity influenced by sheet forming and fibre beating
- 2010
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 25:4, s. 473-480
-
Tidskriftsartikel (refereegranskat)abstract
- A conducting polymer modified paper was produced by depositing poly(3,4-ethylenedioxy thiophene)/poly(4-styrene sulfonate) (PEDOT:PSS) and N-methylpyrrolidone blend onto dynamically-formed and handsheet-formed paper substrates. The effect of fibre beating on the conducting polymer deposition and the bulk conductivity of the coated papers was investigated. A bulk electrical conductivity of the order 10(-1) S/cm was, established for unbeaten samples coated with PEDOT:PSS dispersion. It was observed that the bulk conductivity of the coated papers depended on the quantity of PEDOT:PSS deposited; although at a lower polymer application, degree of fibre beating was of higher consequence. This was due to the increased surface contact of the highly refined and well-packed fibres which decreased the distance between PEDOT molecules. To understand the nature of the conductance, the location of the conducting polymer within the paper substrate was investigated by mercury porosimetry, nitrogen adsorption analysis and scanning electron microscopy. Results showed a preferential deposition of PEDOT:PSS at fibre crossings as a remnant of the wetting front. In addition, traces of PEDOT:PSS could be seen throughout the fibre network. Still, the detailed conductance process remains unknown as the presence and contribution of ions to conductance cannot be excluded. The influence of the deposited polymer on the physical behaviour of the substrate was examined by tensile index data and contact angle measurement. No detrimental effect of the water from the PEDOT:PSS solution was observed.
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| 74. |
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| 75. |
- Montibon, Elson, 1979-
(författare)
-
Modification of Paper into Conductive Substrate for Electronic Functions : Deposition, Characterization and Demonstration
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis investigates the modification of paper into an ion- and electron-conductive material, and as a renewable material for electronic device. The study stretches from investigating the interaction between the cellulosic materials and the conducting polymer to demonstrating the performance of the conductive paper by printing the electronic structure on the surface of the conductive paper. Conducting materials such as conducting polymer, ionic liquids, and multi-wall carbon nanotubes were deposited into the fiber networks.In order to investigate the interaction between the conducting polymer and cellulosic material, the adsorption of the conducting polymer poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonate) (PEDOT:PSS) onto microcrystalline cellulose (MCC) was performed. Electroconductive papers were produced via dip coating and rod coating, and characterized. The Scanning Electron Microscopy (SEM) / Energy Dispersive Spectroscopy (EDS) images showed that the conducting polymer was deposited in the fiber and in fiber-fiber contact areas. The X-ray Photoelectron Spectroscopy (XPS) analysis of dip-coated paper samples showed PEDOT enrichment on the surface. The effects of fiber beating and paper formation, addition of organic solvents and pigments (TiO2, MWCNT), and calendering were investigated. Ionic paper was produced by depositing an ionic liquid into the commercial base paper. The dependence to temperature and relative humidity of the ionic conductivity was also investigated. In order to reduce the roughness and improve its printability, the ionic paper was surface-sized using different coating rods. The bulk resistance increased with increasing surface sizing. The electrochemical performance of the ionic paper was confirmed by printing PEDOT:PSS on the surface. There was change in color of the polymer when a voltage was applied. It was demonstrated that the ionic paper is a good ionic conductor that can be used as component for a more compact electronic device construction.Conductive paper has a great potential to be a flexible substrate on which an electronic structure can be constructed. The conduction process in the modified paper is due to the density of charge carriers (ions and electrons), and their short range mobility in the material. The charge carrying is believed to be heterogeneous, involving many charged species as the paper material is chemically heterogeneous.
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| 76. |
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| 77. |
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| 78. |
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| 79. |
- Montibon, Elson, 1979-
(författare)
-
Preparation of Electroconductive Paper by Deposition of Conducting Polymer
- 2009
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis describes an investigation into the interaction between the conducting polymer and cellulosic materials, and the preparation of electroconductive paper. The adsorption behavior of the conducting polymer onto cellulosic materials was characterized. Poly(3,4-ethylenedioxythiophene) doped with poly(4-styrene sulfonate) (PEDOT:PSS) was used as conducting polymer because of its attractive properties in terms of conductivity, water solubility, and environmental stability. The model substrate used for adsorption was microcrystalline cellulose (MCC). Various pH levels and salt concentrations were explored to completely understand the adsorption behavior of PEDOT:PSS. The variation in surface charge characteristics when the pH and salt concentration were changed was monitored by polyelectrolyte titration and zeta potential measurement. The adsorption isotherm showed a broad molecular distribution of the conducting polymer and considerable interaction between the polymer and MCC. As the pH of the solution was increased, the adsorbed amount decreased. With varying salt concentrations, the adsorption passed through a maximum. The extent of deposition of PEDOT:PSS on the surface of cellulosic fibers was investigated using X-ray Photoelectron Spectroscopy (XPS) with a commercial base paper as substrate. XPS analysis of dip-coated paper samples showed PEDOT enrichment on the surface. The degree of washing the dip-coated paper with acidic water did not significantly affect the PEDOT enrichment on the surface. A base paper was coated with PEDOT:PSS blends to produce electroconductive papers. The bulk conductivities (σdc) of the coated papers were measured using a four-probe technique and impedance spectroscopy. One-side and two-side coating gave comparable conductivity levels. Various organic solvents added to the PEDOT:PSS dispersion at different concentrations showed various effects on the bulk conductivity of the coated paper. Blends containing sorbitol and isopropanol did not enhance the bulk conductivity of the coated paper, and at high concentrations these organic solvents lowered the conductivity. Paper samples coated with a PEDOT:PSS blend containing N-methylpyrrolidinone (NMP) and dimethyl sulfoxide (DMSO) exhibited a higher conductivity than when coated with pure PEDOT:PSS, due to conformational changes and their plasticizing effect. The effect of calendering was investigated and only the sample subjected to 174 kN/m line load after coating showed significant conductivity enhancement. The addition of TiO2 pigment lowered the bulk conductivity of the paper. Contact angle measurements were made to monitor the effect of coating the paper with PEDOT:PSS blends on the hydrophilicity of the paper samples. The amount of PEDOT:PSS deposited in the fiber network was determined using total sulfur analysis. Thus, this study makes use of conventional paper surface treatment as method for achieving bulk conductivity of paper in the semi-conductor range without significantly decreasing the paper strength.
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| 80. |
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| 81. |
- Nyflött, Åsa, 1986-, et al.
(författare)
-
Influence of kaolin addition on the dynamics of oxygen mass transport in polyvinyl alcohol dispersion coatings
- 2015
-
Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 30:3, s. 385-392
-
Tidskriftsartikel (refereegranskat)abstract
- The permeability of dispersion barriers produced from polyvinyl alcohol (PVOH) and kaolin clay blends coated onto polymeric supports has been studied by employing two different measurement methods: the oxygen transmission rate (OTR) and the ambient oxygen ingress rate (AOIR). Coatings with different thicknesses and kaolin contents were studied. Structural information of the dispersion-barrier coatings was obtained by Fourier transform infrared spectroscopy (FTIR) spectroscopy and scanning electron microscopy (SEM). These results showed that the kaolin content influences both the orientation of the kaolin and the degree of crystallinity of the PVOH coating. Increased kaolin content increased the alignment of the kaolin platelets to the basal plane of the coating. Higher kaolin content was accompanied by higher degree of crystallinity of the PVOH. The barrier thickness proved to be less important in the early stages of the mass transport process, whereas it had a significant influence on the steady-state permeability. The results from this study demonstrate the need for better understanding of how permeability is influenced by (chemical and physical) structure.
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| 82. |
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| 83. |
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| 84. |
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| 85. |
- Nyflött, Åsa, 1986-
(författare)
-
Structural Studies and Modelling of Oxygen Transport in Barrier Materials for Food Packaging
- 2014
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The requirements of food packages are to ensure food safety and quality, to minimize spoilage, and to provide an easy way to store and handle food. To meet these demands for fibre-based food packages, barrier coatings are generally used to regulate the amount of gases entering a package, as some gases are detrimental to food quality. Oxygen, for example, initiates lipid oxidation in fatty foods. Bakery products may also be sensitive to oxygen.This thesis focused on mass transport of oxygen in order to gain deeper knowledge in the performance of barrier coatings and to develop means to optimize the performance of barrier coatings. This experimental study along with computer modelling characterized the structure of barrier materials with respect to the mass transport process.This project was performed as part of the multidisciplinary industrial graduate school VIPP (www.kau.se/en/vipp) - Values Created in Fibre Based Processes and Products – at Karlstad University, with the financial support from the Knowledge Foundation, Sweden, and Stora Enso.
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| 86. |
- Nyflött, Åsa, 1986-
(författare)
-
Structure-Performance Relations of Oxygen Barriers for Food Packaging
- 2017
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Food packaging should ensure the safety and quality of food, minimize spoilage and provide an easy way of storing and handling it. Barrier coatings are generally used to meet the demands placed on fibre-based food packages, as these have the ability to regulate the amount of gases that can enter them. Some gases are detrimental to food quality: oxygen, for example, initiates lipid oxidation in fatty foods. Using both experimental data and computer modelling, this thesis explains some aspects of how the structure of barrier coatings influences the mass transport of oxygen with the aim of obtaining essential knowledge that can be used to optimize the performance of barriers.Barrier coatings are produced from polyvinyl alcohol and kaolin blends that are coated onto a polymeric support. The chemical and physical structures of these barriers were characterized according to their influence on permeability in various climates. At a low concentration of kaolin, the crystallinity of polyvinyl alcohol decreased; in the thinner films, the kaolin particles were orientated in the basal plane of the barrier coating. The experimental results indicated a complex interplay between the polymer and the filler with respect to permeability.A computer model for permeability incorporating theories for the filled polymeric layer to include the polymer crystallinity, addition of filler, filler aspect ratio and surrounding moisture was developed. The model shows that mass transport was affected by the aspect ratio of the clay in combination with the clay concentration, as well as the polymer crystallinity. The combined model agreed with the experiments, showing that it is possible to combine different theories into one model that can be used to predict the mass transport.Four barrier coatings: polyethylene, ethylene vinyl alcohol + kaolin, latex + kaolin and starch were evaluated using the parameters of greenhouse gas emissions and product costs. After the production of the barrier material, the coating process and the end-of-life handling scenarios were analysed, it emerged that starch had the lowest environmental impact and latex + kaolin had the highest.
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| 87. |
- Nyflött, Åsa, 1986-, et al.
(författare)
-
The influence of clay orientation and crystallinity on oxygen permeation in dispersion barrier coatings
- 2016
-
Ingår i: Applied Clay Science. - : Elsevier BV. - 0169-1317 .- 1872-9053. ; 126, s. 17-24
-
Tidskriftsartikel (refereegranskat)abstract
- In this study oxygen permeability in dispersion barriers produced from poly(vinyl alcohol) (PVOH) and kaolin clay blends coated onto polymeric supports was investigated. To determine the oxygen permeability, two measurement methods were used: the oxygen transmission rate (OTR) and the ambient oxygen ingress rate (AOIR). It was found that with increasing kaolin content the oxygen permeability increased, up to about 5 wt% kaolin, whereafter the oxygen permeability decreased, as was expected. The increased (> 5%) kaolin loading lowered the diffusion because of an increased tortuosity. Structural information about the dispersion-barrier coatings, such as kaolin orientation and polymer crystallinity, was obtained from Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Kaolin orientation was influenced by the drying temperature, the thickness of the samples, and the kaolin concentration. The polymer crystallinity increased in thicker samples. The drying temperature did not show any clear effect on the crystallinity of thin samples, while for the thicker barriers, combined with a kaolin concentration lower than 20 wt%, a higher crystallinity was achieved at lower drying temperatures. This study demonstrates the strong influence of chemical and physical structures on the permeability of the investigated coatings.
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| 88. |
- Nyflött, Åsa, 1986-, et al.
(författare)
-
The influence of moisture content on the polymer structure of polyvinyl alcohol in dispersion barrier coatings and its effect on the mass transport of oxygen
- 2017
-
Ingår i: JCT Research. - : Springer. - 1547-0091 .- 2168-8028. ; , s. 1345-1355
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a study of the effect of moisture on the gas permeability of polyvinyl alcohol (PVOH) and PVOH–kaolin dispersion barrier coatings. The oxygen permeability was measured at different humidity levels, and the material properties were characterized under the same conditions: polymer crystallinity, kaolin concentration, and kaolin orientation were all evaluated. The experimental results revealed that the water plasticizes the PVOH material of the coatings, and the presence of kaolin filler is unable to affect such behavior significantly. The PVOH crystallinity was affected drastically by the humidity, as water melts polymer crystallites, which is a reversible process under removal of water. The permeability data were analyzed using a thermodynamicbased model able to account for the water effect on both the solubility of the gas and the diffusivity coefficients in the polymer and composite. The results showed good agreement between the model’s predictions and the experimental data in terms of the overall permeability of the material.
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| 89. |
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| 90. |
- Olsson, Robert, et al.
(författare)
-
Effects on ink setting in flexographic printing : coating polarity and dot gain
- 2006
-
Ingår i: Nordic Pulp & Paper Research Journal. - Sundsval : Mittuniversitetet. - 0283-2631 .- 2000-0669. ; 21:5, s. 569-574
-
Tidskriftsartikel (refereegranskat)abstract
- Research has been carried out to study the factors that affect ink setting, with particular focus on the effects of coating polarity and the printing pressure in flexographic printing. Different coating layers were prepared on non-porous polyester films. The coating colours were based on calcium carbonates of different particle sizes, lattices of different polarities and a carboxymethyl cellulose (CMC) thickener. Two latex films were prepared to characterise the surface tension properties through contact angle measurements, which were repeated several times for each latex film and testing fluid. The coating layers were printed in a laboratory printing press under different printing pressures using a water-based flexographic ink. Results showed different print densities for a given amount of ink transferred on the different substrates, with the latex character rather than the pore size of the substrates affecting the print density. Compared with the less polar substrate, the more polar substrate resulted in a higher print density. A non-linear relationship between physical dot enlargement and printing pressure was visualised, resulting from increasing printing form deformation. A mathematical model for printing plate deformation has been proposed that takes into account elastic deformations. It was found that the diameter of the printed halftone dot was larger in the print direction than in the cross print direction. (7 fig, 6 tab, 17 ref)
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| 91. |
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| 92. |
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| 93. |
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| 94. |
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| 95. |
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| 96. |
- Olsson, Robert, 1977-
(författare)
-
Some aspects on flexographic ink-paper and paperboard coating interaction
- 2007
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Flexographic printing is a process that employs a flexible printing form and low viscous ink, often water-based. The flexible printing form is favourable for printing on rough surfaces, but the high surface tension of the ink may cause printability problems.This work has focused on the interaction between paper/paperboard coating and water-based flexographic ink, aimed at increasing the knowledge about the printing process in form of physical/chemical parameters that are important for ink setting. The effects of printing conditions on print quality, such as printing pressure and temperature, have also been in focus.The work has shown that fluids of different polarities, i.e. different dipole moments, behave differently when being absorbed by a coating layer. Due to their chemical compatibility to the coating layer, fluids with large dipole moment fill the pore matrix of the coating to a lesser extent but penetrate further into the coating than fluids with small dipole moments. On the other hand, polarity of the coating layer also affects the print. When printing on coatings with different polarities, higher print densities was obtained on the more polar substrates. As a tentative explanation, it is proposed that the ink builds different layer structures during drying depending on the coating polarity.Print gloss is related to the ink setting which, in turn, is affected by the solvent retaining capacity of the ink. Large water holding capacity allows the ink components to smoothen out before the structure is set, resulting in a higher print gloss. The rheology of inks is affected by temperature; at a higher temperature the viscosity is reduced. The reduction in ink viscosity at higher temperature has been shown to affect the print quality, e.g., print density and dot gain. It is suggested that a thicker layer is immobilised during impression due to the lower viscosity and that it is an explanation of the higher print density at a higher printing temperature.The influence of impression pressure on dot gain has been experimentally evaluated and mathematically modelled with good agreement. The dot gain is shown to respond non-linearly to the applied printing pressure.Studies based on pilot coated and printed paperboards is also reported, and it is shown that the print quality, e.g. print density, print gloss and dot gain, is largely dependent on the type of ink chosen and on the coating characteristics. Higher clay content in the coating resulted in increased dot gain and a decreased mottling.
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| 97. |
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| 98. |
- Otterbring, Tobias, 1985-, et al.
(författare)
-
Let there be light! : An initial exploratory study of whether lightning influences consumer evaluations of packaged food products.
- 2014
-
Ingår i: Journal of sensory studies. - : Wiley. - 0887-8250 .- 1745-459X. ; 29:4, s. 294-300
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates how lighting influences consumer evaluations of packaged food products. Fifty-eight participants evaluated two identical packaged meals (alternated between subjects) in a laboratory setting. The products were stored in a freezer with cold light (blue light-emitting diode [LED]) on one side and warm light (yellow LED) on the other side. A three-way mixed multivariate analysis of variance (MANOVA) revealed that, independent of package color and gender, food products were evaluated more negatively in the cold light than in the warm light in terms of quality, attractiveness and inferred taste. Therefore, lighting may influence consumers' overall evaluations of packaged meals. This finding also highlights the managerial problem whereby the lighting standards that exist at print agencies in order to eliminate ambiguities when making decisions about package design are rare for in-store lighting. Consequently, products that look attractive at the print agency may look unappealing in a store. The results are discussed in terms of processing fluency and cross-modal correspondences.
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| 99. |
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| 100. |
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