Three-dimensional scanning electron microscopy used as a profilometer for the surface characterization of polyethylene-coated paperboard

In food packaging, low-density polyethylene (PE) coating is applied to paperboards to act as a functional barrier and to provide the smoothness required to enhance printability. These characteristics are related to the material’s surface roughness, the parameter monitored during the manufacturing process. Measurement of surface roughness using optical profilometry has gained importance in the paper industry. The optical instruments used to measure surface roughness are limited spatially by the relationship with the light wavelength at which they operate. A scanning electron microscope (SEM) is an alternative for overcoming the spatial resolution limitation, and the use of stereo-photogrammetry on SEM images can be seen as an alternative profilometry technique to measure surface roughness. In this investigation, the surface topography of industrially manufactured high-quality PE-coated paperboard was studied, comparing the SEM stereo-photogrammetry technique with a reference profilometry method, i. e., chromatic confocal microscopy (CCM). We found close agreement between the calculated surface roughness and the results of the techniques used and compared them according to the new ISO 25178 Geometric Product Specifications. We concluded that SEM stereo-photogrammetry provides comparable accurate alternative profilometry method for characterizing the surface roughness of PE-coated paperboard in the micrometer scale.

Effect of Fluoride Gels on the Surface Roughness of Different Composite Resins

Background: The pH of fluoride gels influences the roughness of composite resins, which affects their clinical durability. Objective: To evaluate the effect of fluoride gels (1.23% acidified phosphate fluoride and neutral fluoride) on the morphology of different composite resins after finishing and polishing. Methods: We prepared sixty specimens with a diameter of 5 mm and a height of 2 mm. The specimens were then divided into six groups (n = 10), according to the type of composite resin (Z250 micro-hybrid (Z), Filtek Z350 XT nanoparticles (XT), and Tetric N-Ceram nano-hybrid (TC)) and fluoride gel treatment (1.23% acidified phosphate (APF) or neutral fluoride (NF)) to measure surface roughness (Ra). The material was light-cured using an LED-curing unit (Elipar Freelight Deep Cure-3M/ESPE) for 20 s with a light intensity of 1.200 mW/cm2. Ra measurements were performed before and after treatment with different fluoride gels using a rugosimeter (Mitutoyo SJ210). After Ra, we selected two samples from each group for evaluation using scanning electron microscopy. Data were analyzed using the Shapiro-Wilk, ANOVA, and Tukey tests, with a significance of 5%. Results: The average Ra before and after NF did not differ statistically. The average Ra values of the groups treated with APF showed statistically significant differences. The photomicrographs of the groups treated with NF were similar to those of the groups without fluoride treatment. The APF-treated groups showed significant morphological changes. Conclusion: NF did not promote changes in the morphology of the evaluated composite resins, in contrast to APF, which caused significant changes.

Acoustic Roughness Measurement of Railhead Surface Using an Optimal Sensor Batch Algorithm

Contact and friction between wheel and rail during train operation is the main cause of the rolling noise for which railways are known. Therefore, it is necessary to accurately measure the surface roughness of wheels and rails to monitor railway noise and predict noise around tracks. Conventional systems developed to measure surface roughness have large deviations in measured values or low repeatability. The recently developed automatic mobile measurement platform known as Auto Rail Checker (ARCer) uses three displacement sensors to reduce measurement deviation and increase the accuracy of existing systems. This paper proposes enhancing the chord offset synchronization algorithm applied to the existing ARCer for high measurement precision with only two displacement sensors. As a result, when the two sensor-based measurement algorithm was applied, the spectrum level at λ = 0.314 m, the wavelength amplification associated with wheel diameter, was reduced to at least 6 dB in comparison with that of the three sensors based algorithm. We also verified the accuracy of the proposed batch algorithm through a field test on an operating rail track with a corrugated rail surface.

Surface Roughness of Nanohybrid Composites with Different Monomers after Finishing and Polishing with Different Polishing Systems

Background: The most frequently used monomer in commercial composite resins is bisphenol A glycidyl dimethacrylate. Bisphenol A glycidyl dimethacrylate free monomer and the long chain dimer acid based monomer were considered as an alternative method to improve mechanical and physical properties of composite resins. Objective: To study the surface roughness of different nanohybrid composites with different monomer compositions after finishing and polishing with different polishing systems. Materials and Methods: 72 composite disk specimens were prepared and divided into 3 groups (n=24) according to the resin composite that were used (harmonizekerr, venus diamondheraeuskulzer and n'duranceseptodont). Each group was subdivided into 4 subgroups (n=6) according to the polishing technique that was used (Jiffy natural universal wheelsultradent, sof-lex spiral wheels 3m espe, hilusterkerr or enhance system dentsply). Atomic force microscope was used to measure surface roughness. Results: There was statistical significant difference in surface roughness measuring among different n'durance, venus diamond and harmonize groups (Kruskal Wallis Test p<0.05). Post hock pairwise comparison revealed that venus diamond showed statistically significant higher surface roughness when compared with either n'durance and harmonize. Among the polishing systems, jiffy natural universal wheels produce the least surface roughness. Conclusion: Different monomer compositions may have direct effect on the final surface polish of the restorative materials. Clinical significance: The use of jiffy natural universal wheels may be found to result in the smoothest surface finish with the least clinical steps.

Towards the automated classification system of worn surfaces

Wear dictates the machine performance, its reliability, and ultimately its lifetime. It is therefore important to know what is the wear status of the machine. The assessment can be done visually which is costly and not always possible (e.g. engines). Therefore, the development of an automated analysis and classification system of worn surfaces is highly desirable. Before such system is developed, surface characterization and classification methods must be first developed and tested. In this paper, we show how the recently developed methods, i.e. directional blanket covering and directional blanket covering curvature, have been adapted to solve this problem. The methods, unlike current standards/methods, measure surface roughness and curvature complexities at individual scales and directions. The methods’ ability to differentiate between microscopy images of abrasive and adhesive wear surfaces was evaluated. Minute differences between the two wear modes were detected. This could be of importance in machine condition diagnostic since abrasive and adhesive wear account for most of the machine failures.

Analysis of chip geometry and surface roughness at low speed turning in various commercial steels

Rapid development of technology in manufacturing facilitates the industry to produce mass, high quality and affordable products. The challenge for small industries in manufacturing is to compete for product quality. Small manufacturing industries in controlling the quality of product deal with financial problems. Chip and surface roughness of low speed machining were tested to control the quality of material mechanical properties. The purpose of this study is to investigate the relation between chip characteristic and surface roughness with material hardness. This study used a conventional lathe with low rotation, cutting depth of 1 mm, dry turning process with variations of feed rate of 0.1 mm/rev, 0.2 mm/rev and 0.3 mm/rev, test material of AISI steel (1020, 1045, 1090, D2 and 4340) and tool material from carbides. Stereoscopic Optical Microscopy (SOM) was used to measure temporary shear angle while surface roughness tester was used to measure surface roughness. The results show that the shear angle of the chip and the surface roughness correlated with the hardness of the material.

Effect of Henna Addition on the Surface Roughness and Hardness of Polymethylmethacrylate Denture Base Material: An In-vitro Study

Statement of problem: Henna has been added to polymethylmethacrylate (PMMA) as a new type of antifungal agent; however, its effect on the latter&rsquo;s physical properties has not been investigated. Purpose: This study aimed to evaluate the effect of the addition of various henna concentrations on the surface roughness and hardness of PMMA denture base material. Materials and Methods: A total of 99 specimens of rectangular-shaped (10&times;20&times;3 mm3) acrylic specimens were prepared from heat-cured acrylic resin. Specimens were divided into one control group without the addition of henna and five test groups, which were prepared by adding Yamani henna powder to acrylic powder at concentrations of 1wt%, 2.5wt%, 5wt%, 7.5wt%, and 10wt%. The polymer was added to the monomer before being mixed, packed, and processed using the conventional water bath method. After processing, specimens were finished and polished, then kept in distilled water for 48+2 h. A profilometer and Vickers hardness tester were used to measure surface roughness and hardness respectively. Statistical data analysis was conducted via SPSS version 20.0 (IBM, USA). Results: The addition of henna at varying concentrations significantly increased surface roughness values (P &le; 0.01) while decreasing hardness (P &le; 0.0001). The most favorable addition value was 1% henna between all henna groups. Conclusion: The addition of henna to the acrylic resin may negatively affect the surface properties of PMMA acrylic denture base.

Electrical Characterization of Low-Profile Copper Foil for Reduced Surface Roughness Loss

Signal attenuation in transmission lines is a major issue for reliable transmission in high frequency range. Knowledge of the electrical parameters of printed circuit board (PCB), including dielectric constant and loss tangent, is critical. Moreover, surface roughness has a great effect on loss in high frequency. This paper demonstrates an effective simulation fitting method for electrical material characterization. Cavity resonator is chosen as the circuit for characterization. A methodology is presented to measure surface roughness from cross sections, and compared with values extracted from resonator measurements. Several materials and copper foils treatments, including low-profile, are analyzed in this paper.

Perbandingan Kekasaran Permukaan Resin Komposit Nanofiller pada Perendaman Saliva pH Asam

Nanofiller resin composite is a material used for dental restoration which will be in oral cavity so that interacted with the saliva. Saliva pH changes influenced by several factors, including bacteria in the oral cavity, enzymes, hormones and diet. Acid saliva can cause degradation in the composite, this degradation affects the surface roughness of resin composite. The purpose of this study is to compare surface roughness of nanofiller resins composite for 7 and 10 days of immersion in acid saliva.The samples used in this study were cylindrical mould dimension of diameter 5mm x 2mm, then polymerized with a visible light curing unit for 20s. Specimens immersed in acid artificial saliva (pH ± 4) for 7 and 10 days(4 specimens each group)and then stored in incubator at the temperature of 37ºC. The instrument used to measure surface roughness of resin composite was Surface Roughness Measuring Instrument (Surfcom 120A) that expressed in units of µm.Data were analyzedand the result obtainedwas p = 0.263 (p> 0.05), which mean there were no significant differences in the mean roughness of nanofillerresins compositesurface that were immersed in acidic pH for 7 and 10 days. The conclusion of this study was thatthe surface roughness of nanofiller resins composite immersed in acid saliva for 10 days is not rougher than which immersed for 7days.