Navegando por Autor "Aurich, Jan C."

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Estimation of the minimum material removal thickness during the polishing process of ceramic tiles by laser triangulation
(Elsevier, 2018-04-01) Sousa, Fábio José Pinheiro; Soares Filho, José Elson; Aurich, Jan C.; Nascimento, Rubens Maribondo do; Paskocimas, Carlos Alberto
The possibility of controlling the thickness to be removed from each tile during the honing/polishing process of ceramic tiles would avoid unnecessary wear of the abrasive tools, directly minimizing energy and water consumptions. Such technology requires a conveyer belt capable of adjusting the height of the tile surface, together with a measuring system to estimate the most recommendable removal depth for each tile. While the former requirement is still not promptly available in the market, the on-line characterization of the geometrical characteristics of the tiles could be theoretically performed by many techniques. In this context, this study presents the 3D micro-inspection by laser triangulation as a promising technique to be employed at the production line prior to the honing process. To verify this hypothesis, six types of surfaces with different compositions were characterized in terms of 3D topography, waviness profiles, and surface roughness. The results indicate that the methodology adopted in this study is able to provide precise information regarding the minimum layer to be individually removed from the tile surfaces. In addition, it was also observed a relationship between the surface waviness and the tile composition. In contrast to the value of ca. 10% typically adopted in most ceramic industries, for the surfaces considered in this study, the minimum removal layers were found to be between 1.08% and 2.37% of the initial thickness
Experimental evaluation of on-line discrete tile rotations in the polishing process of ceramic tiles
(Elsevier, 2016-08) Sousa, Fábio José Pinheiro; Aurich, Jan C.; Nascimento, Rubens Maribondo do; Paskocimas, Carlos Alberto; Tartas, Danieli
This work evaluates a new kinematics for the industrial polishing process of porcelain stoneware tile. In addition to the typical motions available in industrial polishing trains, each ceramic tile undergoes a discrete rotation during the polishing process, so that more uniform gloss distributions can be obtained without radical changes in the industries facilities. The consequences of this alternative were quantitatively analyzed. A customized computer numeric control (CNC)-machine was used for obtaining the corresponding experimental results. A reasonable linear correlation between theoretical and experimental gains in uniformity was verified, making viable the use of computational simulations to assist the on-line decisions during the tile production
Micromachining of PMMA—manufacturing of burr-free structures with single-edge ultra-small micro end mills
(Springer, 2018-03-10) Sousa, Fábio José Pinheiro; Reichenbach, Ingo G.; Bohley, Martin; Aurich, Jan C.
Nowadays, the prototypes of microfluidic systems are generally produced via micromilling of thermoplastic polymethyl meth-acrylate (PMMA). The main limitations are the design of micro tools with diameters D ≤ 50 μm adapted for each application, and the understanding of the machining process itself. The objective of this research work is to contribute to mastering the process of PMMA micromilling with tool diameters D ≤ 50 μm on a 3-axes precision milling machine. For this purpose, the process design must include the complete process chain—from the CAD/CAM data up to the final structure geometry. The main requirements are the manufacture of microfluidic structures with Ra < 60 nm on the groove bottom and a top burr overhang h0 < 3 μm. Based on the experimental results, milling parameters were established and the influence of the tool geometry on the burr formation was determined. Finally, CAD/CAM machining strategies were recommended
Polishing performance of eco-friendly porcelain stoneware tiles reusing bricks and roof tiles wastes
(Elsevier, 2020-05-20) Paskocimas, Carlos Alberto; Soares Filho, José Elson; Aurich, Jan C.; Sousa, Fábio José Pinheiro; Nascimento, Rubens Maribondo do; Silva, A. H. A.
The industrial production of bricks and roof tiles plays a significant role in the economy of the state of Rio Grande do Norte, in northeastern Brazil. In the last years, production has grown exponentially, and so has the production of the waste from the breakage of those materials. Consequently, the concern has also arisen over the final disposal and reuse of this waste. Several studies reported the incorporation of this waste in the ceramic tiles matrix for porcelain stoneware tile, but only focused on the evaluation of basic technological properties. The present work investigates the influence of this waste over the gloss-gaining curve of the final products. The polishing behavior of three different eco-friendly compositions, with 5, 10 and 15% of waste from the breakage of bricks and roof tiles incorporated, was evaluated in comparison with standard composition, waste-free. For this purpose, porcelain stoneware tile samples were prepared and their corresponding microstructures were characterized. The industrial polishing condition was reproduced on a laboratory scale, keeping the same abrasive agent, SiC, in an automatic metallographic polishing machine. The roughness and gloss performances through the abrasive sequence adopted were investigated. Additionally, the texture of the surfaces was also evaluated. The results show a positive influence of the microstructure caused by the waste on the polishing performance, reaching a maximum of 72.7 gloss units for the composition with 15% of waste incorporated, representing an improvement of 13.7 gloss units comparing to the waste-free composition. Furthermore, the investigation indicates the feasibility and the promising potential of the polishing process of formulations containing this waste as an alternative raw material
Tool-life criteria and wear behavior of single-edge ultra-small micro end mills
(Elsevier, 2019-01) Sousa, Fábio José Pinheiro; Reichenbach, Ingo G.; Bohley, Martin; Aurich, Jan C.
Prototypes of microfluidic systems are often produced via micro milling, and the thermoplastic commonly used as substrate is polymethyl methacrylate (PMMA). A key challenge when manufacturing those systems is the confection of the micro tools, whose geometric design is limited by the current lack of knowledge about the process itself, especially for applications requiring micro tools with diameters D ≤ 50 μm. In terms of pro- ductivity, the tool-life capability is restrained by the machining conditions and the finish quality. Typical re- quirements for the manufacture of microfluidic structures with ultra-small micro mills are structures with Ra < 60 nm on the groove bottom and a top burr overhang h0 < 3 μm. This paper studies the tool-life cap- ability, including an analysis of the wear behavior of micro tools with diameters D ≤ 50 μm, providing the correlation between machining force signal, machining results (e.g. roughness or burr formation) as well as tool's characteristics before and after machining.

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Navegando por Autor "Aurich, Jan C."