Gloss Properties Research Articles

Specular gloss versus surface topography for oil‐filled nanoparticle coatings on paper

AbstractThe appearance or printing quality of paper surfaces is mostly characterized by their glossiness, measured with a glossmeter as specular reflectance. The gloss properties of a base paper substrate can be improved after application of a poly(styrene‐co‐maleimide) nanoparticle coating under pure conditions or in the presence of different vegetable oils. The specular gloss properties of 11 different nanoparticle paper coatings have been determined under 75° and 85° incident light angles, with good relation between values along parallel (machine) and perpendicular (transverse) direction. The gloss properties for the different coatings have been further related to the surface topography. Therefore, the statistical and spatial surface roughness parameters have been studied in detail at two length scales including non‐contact profilometry (1 × 1 mm2) and atomic force microscopy (2 × 2 μm2). Based on values of the Rayleigh parameter for non‐contact profilometry, the surfaces can be considered as optically rough. The gloss values cannot be directly related to statistical surface roughness parameters. Otherwise, an experimental power‐law model for gloss has been proposed as a function of (β/Sq) with correlation length β and root‐mean‐square roughness Sq. A best‐fit model illustrates that gloss properties of various nanoparticle paper coatings mainly relate to the spatial surface roughness parameters determined from non‐contact profilometry. © 2015 Wiley Periodicals, Inc. Col Res Appl, 41, 596–610, 2016

Research of Sericite in Mineral Technology

Based on the crystal structure research of sericite and muscovite in mineralogy, research of sericite was done by the analysis of XRD,IR ,SEM and microscope research in its color, chemical composition, gloss,and other properties. Applications were summarized in this paper and little difference was discussed between sericite and moscovite.

Effects of UV‐B irradiation on poly (vinyl alcohol) and Ixora siamensis anthocyanins‐coated glass

PurposeThe purpose of this paper is to evaluate the potential of natural colourants from fruits of Ixora siamensis for coating applications, to study its glossiness and effectiveness against UV‐B irradiation.Design/methodology/approachIn this study, natural colourants from the fruits of Ixora siamensis were extracted using trifluoroacetic acid‐methanol solution. Anthocyanins and organic acid variants were mixed together to form co‐pigments. Different concentrations of ferulic and gallic acid co‐pigments were added to a blended solution of poly (vinyl alcohol), PVA and anthocyanin (from Ixora siamensis) to form a coating system. The coatings were exposed to UV‐B irradiation at room temperature in air using a UV‐lamp which emitted radiation at 312 nm. The effects of UV‐B irradiation on the coating system were evaluated using glossiness test and UV‐visible spectroscopy.FindingsAnthocyanins are unstable and can quickly lose their colour. One of the methods of preserving the stability of these pigments is by co‐pigmentation. Co‐pigmentation of anthocyanin with organic acid variants resulted in an increase in both hyperchromic effects (ΔA) and bathochromic shifts (Δλ). In this study, ferulic acids yielded better results compared to gallic acids.Research limitations/implicationsSamples with co‐pigmentation give better result compared to the untreated samples. The addition of 0.5 and 1.0 per cent ferulic acid improves the gloss properties and resistivity of the samples towards the UV irradiation. Thus, in order to study the effectiveness of ferulic acid as additive and improving the properties of the samples, the percentage of ferulic acid added and exposure time could be increased.Practical implicationsThe method developed provided a simple and efficient solution for improving the UV resistance of anthocyanin blend with poly (vinyl alcohol), PVA UV absorber. Effect of ferulic acid as UV absorber, if added in more concentration, can be further studied for optimization.Social implicationsThe social implication is the use of local plant species as a low cost source of natural pigments in coating system.Originality/valueThe method for improving the resistance towards UV irradiation of anthocyanin blend with poly (vinyl alcohol), PVA was novel and could find numerous applications for natural product based on plant pigment.

Gloss perception in painterly and cartoon rendering

Depictions with traditional media such as painting and drawing represent scene content in a stylized manner. It is unclear, however, how well stylized images depict scene properties like shape, material, and lighting. In this article, we describe the first study of material perception in stylized images (specifically painting and cartoon) and use nonphotorealistic rendering algorithms to evaluate how such stylization alters the perception of gloss. Our study reveals a compression of the range of representable gloss in stylized images so that shiny materials appear more diffuse in painterly rendering, while diffuse materials appear shinier in cartoon images. From our measurements we estimate the function that maps realistic gloss parameters to their perception in a stylized rendering. This mapping allows users of NPR algorithms to predict the perception of gloss in their images. The inverse of this function exaggerates gloss properties to make the contrast between materials in a stylized image more faithful. We have conducted our experiment both in a lab and on a crowdsourcing Web site. While crowdsourcing allows us to quickly design our pilot study, a lab experiment provides more control on how subjects perform the task. We provide a detailed comparison of the results obtained with the two approaches and discuss their advantages and drawbacks for studies like ours.

Characterization of gloss properties of differently treated polymer coating surfaces by surface clarity measurement methodology

With one measurement configuration, existing gloss measurement methodologies are generally restricted to specific gloss levels. A newly developed image-analytical gloss parameter called "clarity" provides the possibility to describe the perceptual result of a broad range of different gloss levels with one setup. In order to analyze and finally monitor the perceived gloss of products, a fast and flexible method also for the automated inspection is highly demanded. The clarity parameter is very fast to calculate and therefore usable for fast in-line surface inspection. Coated metal specimens were deformed by varying degree and polished afterwards in order to study the clarity parameter regarding the quantification of varying surface gloss types and levels. In order to analyze the correlation with the human gloss perception a study was carried out in which experts were asked to assess gloss properties of a series of surface samples under standardized conditions. The study confirmed clarity to exhibit considerably better correlation to the human perception than alternative gloss parameters.

Preparation of hyperbranched polyester polyol-based urethane acrylates and applications on UV-curable wood coatings

In the present study, hyperbranched urethane acrylates (UA/HB-PEs) were synthesized by modifying the hydroxyl groups of hyperbranched polyester polyols (HB-PEs). The structure of oligomers were characterized by FTIR and 1H NMR spectroscopic techniques. Formulations containing UA/HB-PEs, reactive diluents, and photoinitiator were applied onto wood substrates and successfully polymerized under UV-irradiation. The coating performances and thermal properties of UV-cured films were evaluated. The studies on film characteristics reveal that the incorporation of UA/HB-PE afforded coatings with good adhesion and high gloss properties. It is observed that UV-cured coatings originated from [2,2-bis(4-β-hydroxyethoxy) phenyl propane] (HB-HEPA)- and [2,2-bis(4-β-hydroxyethoxy) phenyl 6F propane] (HB-HEPFA)-based oligomers possessed better surface and mechanical properties.

Evaluation of aesthetic durability of waterborne polyurethane coatings applied on wood for interior applications

Water-based coatings applied on wood are increasingly used for the respect of environmental legislation. The advantages of the reduced impact on the user and the environment are progressively associated to a high level of quality of coatings, comparable to solvent-based coatings. One of the requirements of coatings for furniture and interiors is the wide variety of aesthetic finishes and the ability to maintain a long-term appearance, colour and gloss stability in weathering and mechanical damage. In this work, the durability of waterborne polyurethane coatings with different aesthetic properties has been investigated. The samples were artificially weathered by ultraviolet radiation exposure. Colour and gloss measurements were carried out to evaluate aesthetic changes. Fourier Transform Infrared Spectroscopy was used to determine any chemical degradation of the polymer bonds. Taber test and falling abrasive test have been used to simulate the coating abrasion and erosion respectively. Gloss retention and weight loss were measured for the different coatings. Environmental scanning electron microscopy has been used to study the surface morphology after the damage. The obtained results highlighted the differences between transparent and pigmented coatings and the influence of initial surface roughness and gloss properties on coatings mar resistance.

Erratum to: On the reduction of gloss property of organic coated sheet metals after forming

Organic coated sheet metals (OCSM) are widely used in many industrial applications such as automobile or electrical appliances because of their corrosion resistance and satisfaction of ecological requirements. Nevertheless, original functions of the very thin coating layer in OCSM products may be altered after being formed which consequently leads to a reduction of the product’s quality. This paper deals with the reduction of gloss property of OCSM products. A forming limit diagram (FLD), a forming limit diagram of the coating layer (FLDC) of OCSM and a forming diagram for the prediction of gloss reduction are determined by using Nakajima tests. The Nakajima tests are performed with predefined strain states of the specimen. The experimental results show the dependency of the FLDC curve and the gloss reduction on both the equivalent strain and the strain ratio. Deep-drawing tests prove the applicability of the determined forming diagrams to predict coating fracture and gloss properties of OCSM after sheet metal forming and, thus, their potential as a tool for the process design for OCSM products.

Characteristics of Microwave-Esterified Cellulose Film from Corn Husk and Cotton: Effects of Degree of Substitution

The modified cellulose film was synthesized from corn husk and waste cotton fabrics in LiCl/DMAc solvent system by esterification reaction under microwave energy using lauroyl chloride and DMAP as an esterifying agent and a catalyst, respectively. By varying microwave power and reaction time used in the esterification reaction, modified cellulose powder with various degree of substitution (DS) was obtained. The structure of modified cellulose was proved by FT-IR and 1H-NMR analysis. The DS value of modified cellulose was measured by 1H-NMR. The modified cellulose films with different DS values were prepared by casting method. The influences of DS values on the properties of the prepared modified cellulose films were tested for their wettability, water absorption, gloss, and tensile properties. The results showed significant effect of the cellulose source and the DS values on the properties of modified cellulose film. The modified cellulose from corn husk resulted in the film with greater tensile strength and elongation at break than the film from waste cotton fabrics. The esteried-cellulose from both sources with high DS values yielded the film with higher tensile properties and lower water absorption.

Optical models of complex fenestration systems

The need for energy conservation in buildings has spurred innovations in window technologies. These products include windows combined with shading devices, and windows featuring complex glazing such as switchable glazing, diffuse glazing, translucent and transparent insulation, patterned or decorative glass, etc. Current fenestration simulation tools for energy performance product ratings do not cover complex fenestration products. This paper addresses the development of detailed calculation models to compute the optical characteristics of complex fenestration products made up of a mixture of clear and scattering glazing layers. The models take into account not only the optical properties of the individual glazing layers making up the window product, but also the haze and gloss properties of the glazing layers. Specific optical models are developed to compute the optics of a clear substrate with applied or laminated scattering film, and composite film made up of a number of homogeneous materials with known optical properties. A general optical model was also developed for screen-like glazing panes such as insect/shading screens, roller blinds, drapery sheets, honeycomb transparent insulation and fibreglass translucent glazing.

Digital Watermarking Using Clear Toner

It is often desirable to protect a document against unauthorized copying. This could be easily achieved by printing part of the image such that it can be readily observed by a human reader but not by a copier or scanner. An image can be printed using clear toner or ink so as to create a difference in reflected and diffused light that can be distinguished by a human reader who looks at the paper at an angle; however, this feature cannot be detected by copiers or scanners because they are restricted to reading at right angles to the page.In the printing industry, clear or white toners are often used to produce digital watermarks that cannot be copied or scanned but can be observed by a human reader. These methods need specifically matched paper and toners that have a considerable difference in gloss. It works with the combination of glossy toner on matte paper or matte toner on glossy paper. However, this approach does not work when glossy paper is used with a toner that provides images in the same gloss range. Such a combination is very common in the field of digital commercial printing.Several digital watermarking processes have been developed that embed a visually striking gloss image into one to four color images. In most cases, controlled angular dependence of image gloss is used to create visual differential gloss in the form of a digital watermark.Printing equipment with fifth imaging station allows for the production of digital watermarks with clear or low-pigmented toner. It provides a method to produce digital watermarks on paper without the limitations described above. This approach is not limited by the color or gloss properties of the toner, the substrate, and/or the selected fusing technology.This technology allows for the production of clear and visible watermarks using toners that produce an image of about the same gloss as the paper and image with the appropriate fusing technology.The additional clear toning station allows, as well, the addition of clear toner to areas of the digital watermarking process that alone cannot provide a sufficient digital watermarking effect in low-density and high-density areas.

Properties of paper coated with kaolin: The influence of the rheological modifier

The first part of this paper analyses the influence of the molecular weight and concentration of carboxymethyl cellulose (CMC) and of kaolin concentration on rheology of the coating colours and on paper properties coated with ultra lightweight coatings (ULWC). In the second part, relationships between the rheological characteristics of the coating colour formulations and coated paper surface quality was also studied.New indexes on paper roughness at micro-scale are presented (RZI and SRI). In general, they show good correlation with sheet gloss. A new gloss index (SGI) is presented, accounting for the contribution of gloss from machine direction (MD) and cross direction (CD). Porosimetry was used to access microstructural characteristics in order to correlate them with light scattering and gloss properties. The former property is closely related to Hg intrusion volume of the coated layer while gloss is related to surface porosity with pore diameters in the range of 7–15 μm as measured by Hg intrusion volume.

A Model for Surfactant Distribution in Latex Coatings

The presence of surfactants in dried latex films can adversely affect the adhesive, water-resistant, and gloss properties, so investigating the surfactant distribution in latex coatings is of prime industrial relevance. Here we present a model that predicts the distribution of surfactant in a latex coating during the solvent evaporation stage. The conservation equation for surfactant during solvent evaporation is solved in the limit of infinite particle Peclet numbers, a dimensionless quantity giving the measure of relative magnitudes of evaporative to diffusive fluxes. A parametric analysis using the model reveals that the surfactant adsorption isotherm is the determining physical parameter. The model always predicts surfactant excesses at the top surface and either excess or depletion at the bottom surface depending on the isotherm. Uniform distributions are predicted for low surfactant Peclet numbers. Attenuated total reflection Fourier transform infrared spectroscopic probes on film surfaces conform to the behavior predicted by the model.

Enhancement of Physical and Mechanical Properties of Hardboard Surface by Photo-curing with Epoxy Oligomer

Different polymeric formulations were developed with epoxy diacrylate (EA-1020) in combination with a trifunctional monomer trimethylol propane triacrylate (TMPTA) in the presence of a photoinitiator, Darocur 1173. Thin polymer films were prepared with these formulations under ultraviolet radiation and were characterized. Thin film produced by formulation containing oligomer 70% and TMPTA 28% yielded the highest film hardness whereas maximum gel content was observed from formulations containing 60% oligomer. Hardboard surface was treated with these formulated solutions and cured under UV radiation. Their physical and mechanical properties were studied. It was found that the formulation H4 containing 70% epoxy oligomer and 28% TMPTA exhibited comparatively better physical properties. The surface of the hardboard was pretreated by different percentages (3–10%) of ethanoic acid. The pretreated surface was again treated by the same polymeric formulations and cured by ultraviolet (UV) radiation. The pretreated surfaces were then featured with respect to the acid concentration. It was found that pretreatment enhanced pendulum hardness (PH), gloss, adhesion, and abrasion resistance properties of the surface coated by these formulating solutions.

Specular reflection, gloss, roughness and surface heterogeneity of biopolymer coatings

The gloss values of biopolymer coatings were predicted by the Fresnel model from solid film refractive index measurements. Measured gloss properties of transparent coatings fit the model better than did those of wax- or lipid-dispersion coatings. Lipid content and particle size of dispersion coatings had a large influence on coating gloss. The effect of surface roughness on gloss was small compared with that of surface heterogeneity. Whey protein isolate and shellac coatings had higher gloss than hydroxypropyl methylcellulose coatings. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2221–2229, 2001

Specular reflection, gloss, roughness and surface heterogeneity of biopolymer coatings

The gloss values of biopolymer coatings were predicted by the Fresnel model from solid film refractive index measurements. Measured gloss properties of transparent coatings fit the model better than did those of wax- or lipid-dispersion coatings. Lipid content and particle size of dispersion coatings had a large influence on coating gloss. The effect of surface roughness on gloss was small compared with that of surface heterogeneity. Whey protein isolate and shellac coatings had higher gloss than hydroxypropyl methylcellulose coatings. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2221–2229, 2001

Characterizing the gloss properties of hydrocolloid films

Hydrocolloid films were prepared by two methods, namely dehydration of thin layers of gels and of gum solutions. Gelatin gel films containing greater amounts of dry matter than all other prepared films provided by far the highest gloss values. Increase in gelatin concentration in the gels resulted in an increase in the mean gloss of the dry films in a linear fashion. Roughness measurements and scanning electron microscope (SEM) micrographs indicated that the gelatin films possessed very smooth surfaces. Similar to gelatin, increase in concentration of gellan resulted in an increase in gloss of resultant films. In direct contrast, mean gloss of both agar and agarose gel films decreased with increasing gel concentration. These trends may be due to the increase in roughness of films with increasing gel concentration, which in the case of agar was also noticeable in the SEM micrographs. Xanthan films provided the most glossy appearance of those prepared by drying of gum solutions, followed closely by alginate. Both exhibited the same trend of mean gloss increasing with gum concentration, similar to gelatin. In both instances, this behaviour could not be related to roughness, which also increased with gum concentration.

Gloss Properties and Surface Morphology Relationships of Fruits

ABSTRACTEggplants exhibited a higher average gloss reading (15.3 Gloss Units (GU)) than mature green tomatoes (12.0 GU) and apples (8.2 GU) using a flat surface glossmeter. The same trend was observed using a novel curved surface glossmeter. Scanning electron micrographs revealed that epicuticular wax covering eggplants had a smoother structure than that of tomatoes and apples, providing a more effective light scattering surface. Wax removal resulted in decreases in gloss, with average readings of 9.5, 7.4 and 6.3 GU for eggplants, tomatoes and apples, respectively. These results indicate the extent to which wax may influence shininess, although roughness measurements of flattened peel after wax removal suggest that surface topography also influences gloss.

Gloss of Fruits and Vegetables

A glossmeter, suitable for measuring the gloss on curved surfaces has been constructed. The gloss of ripe banana, green bell pepper, orange, tomato, eggplant and onion were checked with an incident laser light at 45° and 60°. Reflected light was collected by photosensors and the image was analysed using appropriate software. L, a, b, °Bx, pH and gloss of fruits and vegetables were checked once they reached the stage of ready to eat. Eggplant and green bell pepper presented the highest gloss properties under investigating conditions, while banana and unwaxed orange exhibited the lowest sheen. Results of our glossmeter were compared with a commercial glossmeter, designed to check gloss of flat surfaces. In such operations it was necessary to peel and flatten the skin. Gloss of the fruits and vegetables were ranked in a similar way by both apparatus. Linear correlation was found between results of gloss measured at 60° by both apparatuses. It must be emphasized that intact fruits cannot be checked by the commercial glossmeter because of their curved surfaces.

Genuine Vegetable Parchment Paper: Effects of Accelerated Aging on Some Physical and Chemical Properties

Characterization of paper provides information vital to the preventive care and conservation of vast collections of paper-based materials in museums, libraries, archives and research repositories. Tracing papers, a relatively cheap material used abundantly by folk artists and architects, pose particular problems because of reactivity and instability inherent in their compositions and structures. Previous research published in MRS investigated the aging properties and the impact of conservation treatment on natural, prepared, vellum, and imitation vegetable parchment tracing papers [1, 2]. An additional group, that of genuine vegetable parchment papers, needs particular evaluation with respect to other tracing papers, since they are made by controversial production methods which while considered to be economically advantageous, are environmentally questionable. This technical study characterized three types of genuine vegetable parchment papers, assessing their relative degree of deterioration after aging and their reactivity to solvents commonly used with tracing papers to remove mounts and repairs. The parchment papers were compared optically (fiber, surface, and cross-section morphology; colorimetric, opacity, and gloss properties), chemically (FT-IR, SEM/EDS, and pH), and mechanically (tensile measurements) to provide baseline information on aging properties important to preventive care storage, and relative reactivity important to conservation treatment protocols. The effects of solvents used for conservation treatments (deionized water, ethanol, acetone, toluene, and ammonium hydroxide) were evaluated by comparing relative degrees of reaction (absorption).