Gloss Measurements Research Articles

A comparative study of polishing systems on optical properties and surface roughness of additively manufactured and conventional resin based composites

This study aimed to compare polishing systems on color stability, surface roughness, and gloss of additively manufactured permanent and conventional resin composites. Totally 250 disc specimens (6 mm*2 mm) were prepared from resin-based materials [G-ænial Posterior (GP), Clearfil Majesty Esthetic (CME), SonicFill-2 (SF), Tescera (Tes), and Crowntec (CT)]. Following baseline color (ΔE00), gloss (GU), and surface roughness (Ra) measurements, the specimens were randomly divided into 5 groups (n = 10/group) according to polishing systems: Control (mylar strips); OneGloss; OneGloss + Platina Hi-Gloss; OptiDisc; and OptiDisc + Platina Hi-Gloss. Specimens were immersed in coffee for 144 h following polishing. ΔE00, GU, and Ra measurements were repeated. Atomic force microscopy images were taken in all groups. Spearman’s rho correlation coefficient, Robust ANOVA, and Bonferroni correction were used for statistical analysis. Significance level was taken as p < 0.050. Significant differences in ΔE00 values were found among resin-based materials, polishing systems, and their interactions (p < 0.001,p < 0.01, and p = 0.001). Regardless of polishing system, the lowest ΔE00 values were observed in CT, while lowest gloss (GU) values were found in Tes. The lowest surface roughness (Ra) values were detected at OptiDisc group (p < 0.001). A single type of polishing system may not be sufficient to achieve optimal results in resin-based materials.

The effects of microwave and microwave + infrared drying treatments of Pinus brutia and Picea orientalis on water absorption and physical properties

The goal of this study was to find a way to shorten wood drying time by using microwave and combined infrared + microwave drying methods and to analyze color and gloss changes. Wood samples prepared in three groups with dimensions of 20×20×30 mm were used in moisture tests and 75×5×150 mm were used in color change and gloss measurements, obtained from Red pine (Pinus brutia) and Eastern spruce (Picea orientalis) woods. The samples were oven dried, dried by microwave, or dried by infrared + microwave drying method. The wood samples all reached the target moisture. Their weight and volume were calculated in accordance with the principles of TS ISO 13061-1. Color change values were determined before and after drying with a portable color reader (Konica Minolta CR-10) device, and gloss measurements were taken with the Gardner brand gloss meter. By microwave drying for 15 min, 4% moisture content was reached in the wood samples, so both time and energy were saved. The moisture content values decreased compared to the whole drying methods. Most color change was observed in the drying methods using infrared for both red pine and eastern spruce.

From multilayer LDPE/EVOH flexible film scraps to new multilayer films

This study explores the mechanical and optical properties of multilayer films incorporating recycled materials, mimicking the structure of industrial films. Using a coextrusion blown film line with a three-layer ABC configuration extrusion head, films were produced using two different recycled multilayer films, from post-industrial scraps, in layers A and B and virgin low-density polyethylene (LDPE) in one of the external layers (C). These recycles result from multilayer films mainly constituted of LDPE; one has also linear-LDPE (LLDPE) Metallocene, and the other has Ethylene Vinyl Alcohol (EVOH). Both recycled materials enabled to maintain blown film extrusion process stability during film production. The multilayer films produced with the incorporation of recycles were characterized using scanning electron microscopy (SEM), haze and gloss measurements, and tensile tests. Films with Recycled EVOH presented haze values much higher than those obtained for the Recycled Metallocene. However, all films presented good mechanical properties when compared to single layer virgin LDPE film. Anisotropic behaviour was observed, emphasizing the directional dependence of mechanical properties. The findings provide insights into the behaviour of multilayer films with recycled content, offering valuable information for the development of sustainable packaging solutions.

Effect of Finishing Protocol on Obtaining and Maintaining Gloss in Four Nanohybrid Resin Composites.

Within the clinical objectives of performing direct restorations with resin composites is the achievement of an optimal surface in mechanical terms, while also resembling the natural optical characteristics of dental enamel. The aim of this study is to compare the gloss levels achieved in four nanohybrid resins using four different finishing/polishing (F/P) protocols and assess the retention of gloss after an aging process. Forty-eight A2-colored samples from four commercial brands (Filtek Z250 XT, Tetric N-Ceram, Zafira, and Spectra Smart) were prepared, with 12 specimens per resin. The samples were divided into four subgroups based on the F/P treatment: T1 (clinical polishing sequence with ShapeGuard system), T2 (metallographic polishing sequence), T3 (clinical polishing sequence with PermaSeal), and T4 (final polymerization through glycerin and clinical polishing sequence). Gloss measurements were taken before and after aging.ANOVA one-way was done. Before aging, Z250 showed the highest average gloss in T1 (77.2 gloss units - GU), while Zafira (43.8 GU), Tetric (39.5 GU), and Spectra (33.5 GU) had lower values. In T2, Zafira (92.7 GU) and Spectra (87.4 GU) had the highest average gloss, and Tetric (75.7 GU) and Z250 (78.3 GU) had the lowest. No significant differences were found in T3, and in T4, Z250 had the highest average gloss (78.9 GU), followed by Tetric (74.7 GU) and Zafira (52.5 GU), with Spectra having the lowest (42.7 GU). Control group gloss levels ranged from 61.8 to 71.8 GU and remained consistent after aging, except for Tetric in T1 (p=0.045). The impact of F/P strategies on gloss retention varies with the material, even within the same resin composite classification. The initial gloss level appears to be a more critical factor for long-term gloss retention than the specific F/P protocol used.

Biobased Self-Healing Thin Film Coatings Based on Poly (Itaconic Acid Esters).

Paper used for packaging applications is often coated with thin polymer coatings to improve the properties, like printability and barrier properties, respectively. Today, these coatings are still often based on petroleum-based polymers. In this study, the fabrication of biobased thin film coatings is described. Poly(itaconic acid ester)s, which are prepared by emulsion polymerization, are used as water-based coatings for paper. The thermal properties of the polymers are tuned by the side chain of the monomers (diethyl itaconate vs. dibutyl itaconate). Different formulations based on the polymer emulsion and additives, like rheology modifiers, are prepared and their film formation is studied. The usage of a rheology modifier results in excellent film formation. These polymer coatings feature an additional function - they are capable of self-healing. The healing ability is studied in scratch healing tests, in which almost complete recovery can be observed after healing at 100 °C. Moreover, the restoration of optical properties/aesthetics is studied. In gloss measurements before and after damage as well as after a healing time the complete recovery of the gloss can be observed. Furthermore, the barrier properties against fat are studied.

Acetyl zingerone methyl ether protects hair against oxidative damage incurred during and after treatment with permanent dyes and helps extend longevity of newly developed hair colour.

Use of permanent hair dyes causes unintended oxidative damage during the short time frame of the dyeing process that leads to perceivable changes in the feel, manageability and appearance of hair. Moreover, after hair has been dyed, regular exposure to the sun as a key environmental stressor continues to stimulate additional oxidative damage and to induce newly developed hair colours to fade prematurely or undergo changes in colour quality. To document the utility of acetyl zingerone methyl ether (MAZ) as a newly designed haircare ingredient to afford extra protection against oxidative damage and safeguard the integrity of hair colour. We demonstrate that MAZ is compatible chemically with the high alkaline conditions required for the colouring process and from theoretical calculations preferentially binds Fe and Cu ions relative to Ca or Zn ions. In model Fenton reactions MAZ effectively chelated active redox metals (Fe and Cu ions) in the presence of excess Ca+2 ions to inhibit the production of hydroxyl radicals, and in separate studies, MAZ neutralized singlet oxygen with greater efficiency than α-tocopherol by a factor of 2.5. When mixed into permanent dyes prior to hair tress application, MAZ significantly reduced combing forces, and SEM images led to substantial reductions in visual signs of surface damage. In a 28-day clinical study, relative to controls, mixing MAZ into hair dyes prior to application interfered neither with colour development nor with ability to cover grey hair and led to significant improvements in perceived attributes associated with hair's condition immediately following the dyeing process. Over a 28-day maintenance phase, especially between Day 14 and Day 28, continued use of shampoo and conditioner containing MAZ significantly preserved gloss measurements and hair colour in terms of longevity and colour quality as remaining desired and fresh compared to use of control shampoo and conditioner. This work establishes MAZ as a next-generation hair care ingredient for use in permanent dyes to attenuate oxidative damage and in shampoos and conditioners to promote longevity of hair colour and to maintain overall health and appearance of hair on a daily basis.

Effects of NIR-reflective pigments on waterborne polyurethane coatings and their thermal insulation performance

Waterborne coatings have garnered much attention and gradually occupied the coating market recently due to the significant advantages in volatile organic compound emissions compared with solvent-borne coatings. Waterborne polyurethane coatings are a majority portion of waterborne coatings. Unlike solvent-borne coatings, the film formation of waterborne coatings occurs in an inhomogeneous phase, which brings a challenge for pigmentation in waterborne coatings. However, the influence of pigment on film formation and the property of waterborne polyurethane coating remain unclear. In this study, the different contents of commercial black near-infrared (NIR) reflective pigments were incorporated into both commercial and synthetic waterborne polyurethane systems. The film formation process was monitored by multispeckle diffusing wave spectroscopy. The impact of the pigment content on dry films was assessed through scanning electron microscope, color and gloss measurements, dynamical thermal analyzer, and tensile testing. Furthermore, the thermal insulation performance of the waterborne polyurethane coatings was evaluated to study the function of the NIR reflective pigments. Our findings reveal that the addition of black NIR reflective pigments yields a multifaceted effect on film formation and coating morphology and improves thermal insulating property. Elevated pigment content correlated with increased crosslinking density, tensile stress, and Young's modulus.

Evaluation of Slurry-Eroded Rubber Surface Using Gloss Measurement

Slurry erosion testing is essential for evaluating the durability of materials under erosive conditions. This study examines the slurry erosion behaviours of chloroprene rubber (CR) under varying impact conditions to assess its durability. Traditional mass loss methods and qualitative techniques, including microscopy, SEM, and AFM, were employed to analyse eroded CR samples. Results indicate that cumulative material loss in CR increases linearly with sand impingement after approximately 60 kg of sand and correlates with an impact energy of about 30 kJ. The highest erosion rate was found at an impact angle of 15°. Erosion mechanisms vary with impact angle, affecting surface topography from cutting and ploughing at lower angles to deformation and crater formation at higher angles. Despite their efficacy, these methods are time-intensive and costly. This paper presents a novel approach utilising gloss measurement for continuous, non-destructive monitoring of eroded rubber surfaces. Gloss measurements are 24 times faster than traditional mass loss methods. Correlating gloss values with cumulative material loss, steady-state erosion, and impact energy offers significant time savings and an enhanced understanding of the erosion process. Experimental results demonstrate the effectiveness of gloss measurement as a reliable tool in slurry erosion testing of rubbers. The quantitative output from gloss measurements could support proactive maintenance strategies to extend service life and optimise operational efficiency in industrial applications, particularly in the mining industry.

Exploiting Turmeric’s Coloring Capability to Develop a Functional Pigment for Wood Paints: Sustainable Coloring Process of Polyamide 11 Powders and Their Strengthening Performance

Currently, the wood coatings industry is focusing on creating unique, vibrant finishes using new functional pigments. Simultaneously, there is a growing adoption of eco-friendly bio-based materials, reflecting trends in other sectors and supporting the circular economy. Thus, the aim of this study is to unveil a straightforward, cost-effective, and notably sustainable process for exploiting the coloring potential of turmeric powder and coloring polyamide 11-based fillers, employed as multifunctional pigments for wood coatings. Through the incorporation of this additive into a wood paint, the study demonstrates its dual effect of enhancing the aesthetics of the final composite layer while leveraging the beneficial protective properties inherent to polyamide 11. The impact of these additives on sample aesthetics is assessed through optical observations, as well as measurements of color, gloss, and surface roughness. The strengthening contribution of the functional pigment is evaluated using the Taber abrasion resistance test, static friction coefficient measurements, and Buchholz surface hardness test. Finally, the aesthetic consistency of the bio-based filler and the coloring efficiency of the sustainable process are tested by subjecting the samples to aggressive conditions, including the UV-B chamber exposure test, cold liquids resistance tests, and water uptake test. Ultimately, the study illustrates how this functional bio-based pigment not only provides sufficient protection but also meets current eco-requirements, thereby contributing to the sustainability of the wood coatings industry.

Effect of particle size distribution on the properties of celsian based glazes

AbstractThe microstructure and surface properties of ceramic glaze are influenced by chemical composition, particle size distribution, glaze application conditions, and firing parameters. This study specifically focused on the influence of glaze particle size distribution on the thermal behavior, microstructure, and surface appearance of barium frit based ceramic glaze in the floor tile firing process. The investigation involved examining the impact of four distinct particle size dimensions (d50: 5.7 μm, 6.8 μm, 7.5 μm, 10.9 μm) on the glaze properties by using hot stage microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), color and gloss measurements. The studies indicated that celsian is the dominant phase in the glaze structure. The sintering and softening temperatures of glazes decreased with the increase of milling time. A decrease in the particle size of the glaze slurry increased the whiteness index. As the average particle size (d50) of the glaze decreased, the number of crystals was also increased. The investigation results also suggested a relation between specular reflection and milling time. As the milling time extended, there was a corresponding increase in the magnitude of glossiness.

Enhancing wood coatings with red beetroot-derived pigments: Investigating synergy with UV absorber and composite filler for improved durability and aesthetics

The objective of this study is to assess the synergy among a specific bio-based pigment derived from red beetroot, a composite filler, and a UV absorber as additives for wood paints. The composite filler aims to enhance the mechanical properties of the coating, while the UV absorber is selected to improve the pigment's color stability under solar radiation. The impact of these additives on sample aesthetics is evaluated through color, gloss, and roughness measurements. Mechanical properties are analyzed using Buchholz surface hardness and Taber abrasion resistance tests. The protective role of the UV absorber is further examined through accelerated degradation tests in a UV-B chamber. To ensure that the additives do not compromise the coating's barrier properties, water uptake tests, resistance to liquids, and contact angle measurements are conducted. Overall, the study demonstrates how each additive serves a distinct purpose and their combined application offers benefits such as enhanced color retention and improved mechanical durability of the coating. It highlights the potential of using bio-based pigments to enhance color durability without sacrificing the protective performance of wood coatings.

Measuring gloss using spectral reflectance

Abstract Gloss is historically measured at three angles of incidence, 20°, 60°, and 85°, using a light source filtered to replicate Illuminant C and a colored glass filter designed to reproduce the CIE 1931 photopic luminous efficiency function. Herein an alternate method that relies on the spectral reflectance of a gloss standard and the sample, both measured with a new reference gonio-spectrometer and in accordance with the geometries specified in internationally recognized standards, is presented. The spectral reflectance measured with the aid of a spectrometer is converted to luminous flux which is then used to calculate gloss. This alternate method eliminates the errors associated with the source actual spectral power distribution vs. that of Illuminant C, and the actual spectral transmittance of the colored glass filter used vs. the spectral distribution of the photopic luminous efficiency function. Gloss measurement results for a synthetic quartz sample, Suprasil 311, are presented. The measured values averaged over three reflectance measurements are 71.3 ± 1.2 (k = 2), 82.2 ± 0.9 (k = 2), and 98.1 ± 3.0 (k = 2), and these agree exceptionally well with the theoretical values of 71.3, 82.1, and 98.1 Gloss Units at 20°, 60°, and 85°, respectively. Components of uncertainty are discussed. In addition, a gloss scale is proposed. The components of the scale have been selected from readily available optical glass types for ease of fabrication and relatively low cost. They span a range from 4.4 to almost 170 Gloss Units for light at 20° angle of incidence.

Gloss Analysis of Agglomerated Stones Subjected to Natural Cycling

Theoretical reference: Agglomerated stones are defined as composites formed by a mixture of resin, mineral aggregates and additives. Among the desired qualities of a stone is its gloss, which may change over time, exposure to the elements, use, among others. This problem can occur in both ornamental stones and agglomerated stones. Method/project/approach: 3 types of agglomerated stones measuring 7cm x 7cm were used to carry out the test. First, the samples were cleaned with running water without the use of cleaning products, and with the help of a soft bristle brush, then they were left to drain the excess water. After 10 minutes, they were placed in an oven at 75°C for 2 hours to dry. After drying, the first gloss measurement was carried out. After measuring the initial gloss, the samples were exposed in a natural environment exposed to the elements (wind, heat, sun and rain) for 285 days, and then the final gloss was measured. Results and conclusion: This work sought to compare the loss of gloss and chromatic observation in agglomerated stones subjected to natural cycling. The importance of the mineralogical composition of the samples can be seen, all of them have a percentage of quartz in their composition greater than 74%. The greatest loss of gloss, color change, occurs in the sample (A3). Research implications: Compare the loss of gloss between samples of three types of agglomerated stones and compare with the chromatic loss, evaluating these changes when the sample is subjected to weathering over time. Originality/value: perform gloss analysis on agglomerated stones, after natural cycling simulating weathering.

The Effect of Hot and Cold Check Tests on Surface Roughness and Glossiness in Varnished Wood Material

In this study, specimens from Scots pine (Pinus sylvestris L.), Anatolian chestnut (Castanea sativa Mill.) and Eastern beech (Fagus orientalis Lipsky) tree species, prepared according to ISO 3129, were conditioned according to TS ISO 13061-1. Cellulosic varnish, water-based varnish, and glass polish varnish were applied to their surfaces in accordance with ASTM-D 3023 principles. In the study, roughness (TS 2495 EN ISO 3274 and TS EN ISO 21920-3) and gloss (according to TS EN ISO 2813) values of the samples were calculated after hot and cold check test. Varnished test specimens prepared in 100 mm &amp;times; 100 mm &amp;times;10 mm dimensions were first kept in drying oven at (50&amp;plusmn;5) &amp;deg;C for 1 hour, then were kept in conditioning room for 1 hour, and then at (-20&amp;plusmn;2) &amp;deg;C for 1 hour, according to ASTM D1211-97. These processes were accepted as one cycle, and tests were continued until 15 cycles. Afterward, glossiness was measured as perpendicular and parallel to fibers at 60&amp;ordm; with a gloss measurement device, and surface roughness values of Ra and Rz were determined with a surface roughness measuring device. According to the results obtained, Scots pine (Pinus sylvestris L.), Eastern beech (Fagus Orientalis Lipsky), and Anatolian chestnut (Castanea sativa Mill.) varnish-coated wood material surfaces all showed a decrease in gloss values after hot-cold shock effect. While an increase occurred in Rz values of roughness for all wooden surfaces, Ra values roughness increased for Scots pine and chestnut and decreased for eastern beech. Gloss and roughness values of surface-treated wood materials against changing weather conditions can determine usefulness of the surface material used. The findings obtained in this study can be useful to manufacturers who use wooden products in the design of marine vehicles and those who export furniture to countries in different climatic conditions.

Specular gloss estimation by measuring the colorimetric data produced by a reflection measurement at 8° of incidence

This paper presents an experimental investigation into the estimation of specular gloss from the colorimetric data. The 28 samples were selected from the Natural Color System (NCS) gloss scale, which had different combinations of lightness and gloss levels. The samples’ spectral reflectance and colorimetric data Y and L* were measured by a d:8° geometry reflectance spectrophotometer in both SCE (Specular Component Excluded) and SCI (Specular Component Included) modes. Additionally, the specular gloss of the samples at three common angles 20◦, 60◦, and 85◦ was measured using a gloss meter. The correlation and relationship between DYSCI-SCE and DL*SCI-SCE and the specular gloss values measured for the samples at different angles were evaluated and analyzed with linear and second-polynomial regression functions. The results were validated with a different set of data acquired from 32 random solid-coated samples. The results showed the best fitting was achieved at 60◦ of gloss measurement with a second-polynomial function. As the specular gloss of DY decreased, like in a matt sample, the estimation error of specular gloss increased with a large error of over 10%.

Spatial variant gloss measurement of dielectric materials based on a polarized camera.

This study proposes an imaging method for gloss measurement solely by a single shot from a polarized camera. The system, comprising a polarized camera and well-diffused LED plate light, is inspired by the framework of ASTM D523, and it acquires images at 60° incident direction. The polarization characteristics of dielectric material samples were analyzed. A regression model was developed by using natural color system gloss scale and a commercial gloss meter. Subsequently, the gloss and spatial resolutions of this method were verified using various types of measurement samples. From experiments regarding different benchmarks, we concluded that the proposed method performs sufficiently for spatial variant gloss measurement.

Development of glossy and UV-resistant urushi coatings by thermal polymerization

The use and development of natural biomass-based plastics are attracting attention with the aim of limiting environmental pollution and conserving energy resources. Urushi, a natural curing resin traditionally used in numerous applications such as decorative arts, furniture, and tableware, has great potential as an environment-friendly alternative to petroleum-based plastics. In this study, we produced urushi coatings in a short time using a thermal polymerization method, which is more convenient than the conventional oxidative polymerization method. The thermal polymerization method requires less time and energy than conventional oxidative polymerization and hence is more environmentally friendly. The urushi coatings were exposed to UV-A irradiation for 0–30 days, and the effects of irradiation on the surface were evaluated using Fourier-transform infrared spectroscopy, water contact angle measurements, scanning electron microscopy, gloss measurements, and pencil hardness tests. As a result, we developed functional high-gloss urushi-coated films with excellent hardness using thermal polymerization; these films retain these properties even after prolonged UV-A irradiation.

Improving Surface Quality of Resin Impregnated Paper Used for Laminated Flooring Overlaid

This study aimed to improve the quality properties of impregnated papers used as a coating material in wood-based composites, especially for high-density fiberboard (HDF) floorings, using the Taguchi method and parameter design. Three factors were evaluated in determining the interactions as they are considered the most important in affecting the product quality characteristics such as particle size of Al2O3, surface modification agent and melamine raw material. Experiments were conducted in three replications using the L18 (21 &amp;times; 32) orthogonal array. Color and gloss measurements were evaluated together with the sensory analysis method, which takes into account the number of the spots in the sample as quality characteristics. The best values obtained as a result of statistical analysis were A2 for the melamine raw material, 30 to 60 &amp;mu;m for the particle size and N-methyl-3-(trimethoxysilyl) propylamine for the surface modifier agent. Whether the experimental factors have a meaningful effect on the quality characteristics was also tested separately by analysis of variance. Only 58 % of the effect of the evaluated factors on the outcome could be expressed with the linear model (R2adj = 0.5785).

Color and Gloss Measurements in Cultural Heritage Conservation Science: Recent Advances in France

Color and Gloss Measurements in Cultural Heritage Conservation Science: Recent Advances in France

Comparative study between natural and artificial weathering of acrylic‐coated steel, aluminum, and galvanized steel

AbstractSince testing organic coatings under natural conditions is a time‐consuming process, accelerated methods are needed to produce results in less time. A simulated environment cannot fully reproduce actual operating conditions, so it is important to investigate the correlation between accelerated and natural aging test results. In this article, the natural aging of painted steel, aluminum, and hot‐dip galvanized steel is studied for 1 year under continental climate conditions. The environmental parameters responsible for the change of the protective system in a continental urban environment were monitored: time of wetness, ultraviolet radiation, and temperature. The extent of deterioration is compared with similar samples weathered by accelerated testing using electrochemical impedance spectroscopy, differential scanning calorimetry, and gloss measurements. Neutral salt spray chamber, prohesion test, immersion in a quiescent salt solution, and ultraviolet B‐rays (UVB) exposure test are considered. The results of the accelerated cabinet tests are discussed, and the effect is evaluated for the various coated metals. This study highlights the major problems encountered in building a model to predict durability in such a critical area as the durability of organic coatings for metal structures.