Effects of a stylus on the surface roughness determination in a contact method for paper and paperboard

2019 ◽  
Vol 34 (4) ◽  
pp. 442-452 ◽  
Author(s):  
Hyun Seok Jeong ◽  
Young Chan Ko ◽  
Hyoung-Jin Kim
Keyword(s):  
Surface Roughness ◽  
Surface Characterization ◽  
Paper Industry ◽  
Surface Friction ◽  
Thickness Measurement ◽  
Mean Deviation ◽  
Contact Method ◽  
Average Roughness ◽  
Practical Applications ◽  
Type Contact

Abstract Surface characterization is important and has many applications in the paper industry. It includes both surface roughness and surface friction. In determining the surface roughness of paper and paperboard, non-contact methods such as air-leak methods In characterizing the surface roughness of paper and paperboard, it has been a common practice that the average roughness with the coefficient of variation (COV) has been conventionally determined. This practice, however, this runs the risk of drawing wrong conclusions since two different surfaces having the same average roughness and COV can exhibit totally different properties. To avoid such mistake, a stylus-type contact method has been developed to determine surface roughness of paper and paperboard such as printing & writing (P&W), kraft and liners. In this method, surface roughness profile has been generated to determine its variability which has been defined as the mean deviation from the roughness average, referred to as MDRA. In determining the MDRA, it is noted that thickness measurement is not required. In this method, stylus shape and size, contact force of the stylus to the surface, scan speed and resolution have been identified as the key parameters of generating stable surface roughness profiles. It has been further identified that the optimal conditions on these parameters should depend on paper grade. It is suggested that a stylus-type contact method should be used to determine surface roughness of paper and paperboard to help determine their practical applications such as printing, coating and embossing.

Surface characterization of paper and paperboard using a stylus contact method

2020 ◽  
Vol 35 (1) ◽  
pp. 78-88
Author(s):  
Young Chan Ko ◽  
Lili Melani ◽  
Na Young Park ◽  
Hyoung Jin Kim
Keyword(s):  
Surface Roughness ◽  
Surface Characterization ◽  
Paper Industry ◽  
Surface Friction ◽  
Operating Conditions ◽  
Contact Method ◽  
Measuring Surface ◽  
Two Samples ◽  
Friction Measurements

AbstractSurface characterization is important and has many applications in the paper industry. Surface characterization requires both surface roughness and surface friction. The relationship between the two has not been fully established for paper and paperboard. It has been a common practice that only the average property and the standard deviation with the coefficient of variation (COV) are reported for surface roughness and friction measurements. This practice, however, provides few information on surface structure and can lead to wrong judgments because two samples having the same average and the COV can have different physical properties. To avoid such mistake, a new surface characterization method has been developed. To this end, surface roughness- and friction-profiles have been obtained using a latest version of Kawabata surface tester (Model: KES-SESRU, Kato Tech, Kyoto Japan). This new version uses the same stylus for both measuring surface roughness and friction under the same operating conditions. It was found that a correlation between the surface roughness and surface friction was very low. This indicates that they should be independent of each other. Therefore, both should be determined for surface characterization.

Surface characterization of paper products via a stylus-type contact method

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5667-5678
Author(s):  
Na Young Park ◽  
Young Chan Ko ◽  
Hyoung Jin Kim ◽  
Byoung Geun Moon
Keyword(s):  
Surface Roughness ◽  
Surface Characterization ◽  
Operating Conditions ◽  
Contact Method ◽  
Absolute Deviation ◽  
Acquisition Rate ◽  
Type Contact ◽  
Scan Speed ◽  
The Mean

Surface properties include both surface roughness and friction. With a stylus-type contact method, it is necessary to obtain either a surface roughness profile or a friction profile that is affected by stylus shape and size, its contact force on the sample, the scan speed, and the data acquisition rate. As a new surface parameter, the mean absolute deviation (MAD) from an average property has been introduced. It represents the deviation from either the roughness average (Ra) and the average coefficient of friction (COF), respectively. While Ra or average COF depends on the instrument and its operating conditions, the MAD should not depend on them because it represents the variations within the sample.

scholarly journals Characterization of surface roughness of new nanophotonic soft contact lenses using lacunarity and AFM method

2018 ◽  
Vol 72 (3) ◽  
pp. 157-166 ◽  
Author(s):  
Aleksandra Mitrovic ◽  
Bozica Bojovic ◽  
Dragomir Stamenkovic ◽  
Dejana Popovic
Keyword(s):  
Surface Roughness ◽  
Surface Characterization ◽  
Contact Lenses ◽  
Tear Film ◽  
Basic Material ◽  
Machining Processes ◽  
Soft Contact ◽  
Average Roughness ◽  
Soft Contact Lenses

The aim of this study was to develop new soft contact lens (SCL) materials which would, after recommended and existing machining processes, improve surface roughness. Nanomaterials (fullerene, fullerol and methformin hydroxylate fullerene) were incorporated into commercial material for SCL (SL38) based on PHEMA, which were derived by the technology in the production lab of the company Soleko (Milan, Italy). Nanophotonic SCLs (SL38-A, SL38-B, SL38-C, respectively) were produced in the company Optix (Belgrade, Serbia) from the obtained materials. For the surface characterization of SCLs, AFM analysis and lacunarity method were performed. The results showed that for the SL38-B average roughness value is lower than those of SL38-A and SL38. The topography parameters of SL38-C were between the parameters of SL38-A and SL38-B. Lacunarity analysis of AFM images confirmed that SCLs surface state should belong to either group of adequate (slanted p-diagram) or inadequate (contorted p-diagram) roughness concerning tear film stability. Nanophotonic SCL SL38-C exibits more acceptable performance considering SCL surface functional behavior as compared to other SCLs. The positive result of incorporating nanomaterials into basic material for SCL is better quality of the nanophotonic SCLs surfaces. On the bases of these experiments, the assumption that incorporation of fullerene derivate will not increase surface roughness parameters is confirmed.

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

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Javier Brugés Martelo ◽  
Mattias Andersson ◽  
Consolatina Liguori ◽  
Jan Lundgren
Keyword(s):  
Surface Roughness ◽  
Food Packaging ◽  
Surface Characterization ◽  
Paper Industry ◽  
Three Dimensional ◽  
Sem Images ◽  
Geometric Product ◽  
Measure Surface Roughness ◽  
Stereo Photogrammetry ◽  
Scanning Electron

Abstract 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.

scholarly journals Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1376
Author(s):  
Alex Quok An Teo ◽  
Lina Yan ◽  
Akshay Chaudhari ◽  
Gavin Kane O’Neill
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Surface Characterization ◽  
High Surface ◽  
Surface Characteristics ◽  
Post Processing ◽  
Stainless Steel 316L ◽  
Processing Methods ◽  
Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

The Surface-Roughness of Bearing-Surfaces and its Relation to Oil Film Thickness at Breakdown

1949 ◽  
Vol 161 (1) ◽  
pp. 73-79 ◽  
Author(s):  
A. Cameron
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Hydrodynamic Theory ◽  
Quantitative Relation ◽  
Metal Contact ◽  
Initial Contact ◽  
Frictional Drag ◽  
Average Roughness ◽  
Finished Steel ◽  
Oil Film

In this paper the relation of surface roughness of bearing surfaces to allowable film thickness is studied quantitatively with a simple Michell pad apparatus. The pads used were faced with white metal and ran against mild steel collars. The lubricants studied were water, soap solution, paraffin, and light oil. There was little difference in the frictional behaviour of any of the lubricants, except that the aqueous lubricants would not run with very finely finished steel surfaces. The onset of metal to metal contact was detected by an increase in the frictional drag, and also by the change in electrical conductivity between the pad and collar—an extremely sensitive method. The paper shows that there is, at any rate for this system, a quantitative relation between the total surface roughness of the rubbing surfaces and the calculated oil film thickness both at the initial metal to metal contact and seizure. Initial contact occurs when the outlet film thickness, calculated from normal hydrodynamic theory, falls to three times the maximum surface roughness and seizure occurs when it is double the average roughness.

Experimental Investigation on Surface Particle Interactions During Pool Boiling of Nanofluids

2011 ◽  
Author(s):  
Harish Ganapathy ◽  
V. Emlin ◽  
Anant Narendra Parikh ◽  
V. Sajith
Keyword(s):  
Surface Roughness ◽  
Interaction Parameter ◽  
Surface Characterization ◽  
Pool Boiling ◽  
Particle Interaction ◽  
Nucleate Boiling ◽  
Optical Measurements ◽  
Sorption Layer ◽  
Surface Particle ◽  
Enhanced Boiling

The pool boiling characteristics of nanofluids is affected by the interaction between the nanoparticles and the heater surface which forms a sorption layer and this layer increases the surface wettability and thereby enhances the CHF. While deteriorated nucleate boiling has been attributed to the decreased activation of cavities due to the increased wettability, it fails to explain the enhanced performance observed by several researchers, which can be explained only by an increase in surface roughness and hence a direct increase in the number of cavities, thereby compensating for the increase in wettability. Attempts to characterize the roughness of heater surfaces have been restricted to magnified visualizations and intrusive probing. No non-intrusive tests have been reported on flat heaters, which are ideal to conduct surface analyses. The present work is aimed at conducting a non-intrusive experimental study to analyse the surface roughness modification due to the sorption layer on flat plate heaters. Experiments have been carried out using electro-stabilized aluminium oxide water based nanofluids of different concentrations with heaters having varying values of surface roughness. The burn-out heat flux was measured and the effect of sedimentation time was studied. The surface-particle interaction parameter (Ra/dp) was varied to capture the phenomena of plugging as well as splitting of nucleation sites. An experiment having a high value of the interaction parameter shows enhanced boiling performance and that with a value close to 1 shows deteriorated performance. Further it was seen that this behaviour is dependent on the particle concentration. Detailed surface characterization has been done using an optical measurements setup and atomic force microscopy. Boiling on nano-coated heaters has been investigated and presented as an effective solution to counter the disadvantageous transient boiling behavior of nanofluids.

In Situ: A Novel Approach for the Production of Micro Holes

2010 ◽  
Vol 126-128 ◽  
pp. 885-890
Author(s):  
K.P. Somashekhar ◽  
N. Ramachandran ◽  
Jose Mathew
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Feed Rate ◽  
Machining Parameters ◽  
Average Roughness ◽  
Arithmetic Average ◽  
Quantitative Correlation ◽  
Good Surface ◽  
Novel Approach ◽  
Micro Holes

This work is on the preparation of microelectrodes for μ-EDM operation using μ-WEDG process. Electrodes of Ø500 μm are fabricated with various discharge energy machining conditions. Effects of gap voltage, capacitance & feed rate on the surface finish of the electrodes and overcut of the thus produced micro holes are investigated. The profile of microelectrodes is measured using surface roughness tester with 2μm stylus interfaced with SURFPAK software. The study demonstrated that for brass electrodes an arithmetic average roughness value as low as 1.7μm and an overcut of 3 µm could be achieved. The significant machining parameters are found using ANOVA. Surface of the produced microelectrodes are examined using Scanning Electron Microscope. μ-WEDG process parameters could be adjusted to achieve good surface integrity on microelectrodes. Experimental results showed that the surface roughness of microelectrodes depended primarily on feed rate of the electrode. The observations showed the clear and quantitative correlation existing between the micrometer level surface quality and process parameters. The resulting microelectrodes are found to be of exceptionally high quality and could be used for μ- EDM operation on different types of work materials.

scholarly journals Comparison of Polishing Methods Used in Extrinsic Discolouration of Primary Teeth in Terms of Surface Roughiness 

2021 ◽  
Author(s):  
Burcu Duman ◽  
Salih Doğan
Keyword(s):  
Surface Roughness ◽  
Primary Teeth ◽  
Plaque Formation ◽  
Tooth Surface ◽  
Primary Tooth ◽  
Average Roughness ◽  
Primary Molar ◽  
Biofilm Growth ◽  
Tooth Discoloration ◽  
Significant Difference

Abstract BackgroundSurface roughness is one of the main factors affecting bacterial adhesion, biofilm growth, plaque formation and coloration on the tooth surface. Improper polishing may increase roughness or not contribute to a reduction in roughness while removing biofilms on tooth surfaces. The aim of this study is to examine the effects of different polishing pastes applied to the enamel of primary teeth on the surface roughness through AFM, which enables a more detailed examination of the measurements, and to evaluate the roughness changes created by the paste on the surface. MethodsIn the present study, in order to compare polishing made using Septodent Détartrine, Kerr Cleanic, Shofu Mersaage Regular under the recommendations of the companies in addition to the application of pumice with a rubber brush, a total of 88 samples with 22 samples in each group were created using 88 primary molar teeth. Before and after polishing, roughness measurements and visualizations were performed with atomic force microscopy (AFM). After polishing, Ra (average roughness) values, which express the surface roughness of the re-scanned samples, were calculated so that the samples were the same as the first scanning. For statistical analysis, Shapiro-Wilk normality test and generalized linear models tests were applied and p <0.05 was considered as statistically significantResultsIn the groups; while there was no significant difference in terms of roughness values ​​(Ra) within the group (p> 0.05), a statistically significant reduction in roughness (Ra) was observed on the sample surfaces after polishing in all groups compared to the baseline (p <0.05). According to the data obtained; all polishing methods used in the treatment of primary tooth discoloration can reduce the plaque formation and thus the amount of recoloring by reducing the surface roughness at a similar level.ConclusionAccordingly, it has been observed that the current polishing pastes do not provide a significant advantage over the traditional polishing method (polishing brush with pumice) in terms of surface roughness in removing discoloration in primary teeth.

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