Special sanding films (400 grit to 23 micron) and fine sandpapers (1200-1500 grit) can be used to surface increment cores containing narrow rings (e.g., >50 rings per cm) so that rings are clearly visible for microscopy and photography.

In this study, we developed and standardized a sanding method to evaluate the emission of airborne particles from products that contain carbon nanotubes (CNTs) under different conditions, including three types of sandpaper and three sanding disc speed. We also characterized the emission of the airborne particles from one neat epoxy test sample, four CNTs-incorporating test samples with different CNTs loading, and two commercial products. The total number concentration, respirable mass concentration, and particle size number/mass distribution of the emitted particles were calculated and compared, followed by an electron microscopy (EM) analysis. These data suggest that the sanding process can produce substantial quantities of airborne particles. Also, the emission of airborne particles was associated with different test conditions. EM analysis of the airborne particle samples showed embedded CNTs protruding from the outer surface, which was different from CNTs-incorporating bulk material. Our study suggests a potential generation of particles during the life cycle event of sanding. Further studies should be carried out to investigate the potential human health hazard in other life cycle events.

Made available in DSpace on 2014-06-11T19:32:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-06Bitstream added on 2014-06-13T19:26:23Z : No. of bitstreams: 1 tiburcio_ufo_dr_guara.pdf: 1741150 bytes, checksum: 8386659f2613e0cdff19e8b27ff268d8 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O processo de lixamento da madeira é uma prática comum para preparar sua superfície para o revestimento. A qualidade superficial da madeira é diretamente relacionada ao revestimento, aderência, custos de pós processamento e aparência estética do produto. Vários parâmetros influenciam no acabamento superficial da madeira como: espécie de madeira, processo de usinagem e granulometria da lixa. Nesta tese foram coletados dados de rugosidade superficial de amostras das espécies Eucalyptus grandis e Eucalyptus citriodora usinadas em torno tubular em três velocidades de avanço (10, 14 e 18m/min.) e lixadas em lixadeira de cinta vertical dupla por quatro jogos de lixas abrasivas de alumínio zirconado. Estes jogos foram compostos com lixas de granulometrias 80, 100 e 120 (80-100, 80-120, 100-120 e U80-120), sendo a primeira lixa para desbaste e a segunda para acabamento. Concluiu-se que para os três conjuntos de lixas novas empregadas, o conjunto de lixas de granulometrias 80 e 120, para desbaste e acabamento, respectivamente, foi aquele que apresentou o melhor desempenho quanto ao acabamento superficial para as duas espécies. O emprego de lixas usadas não demonstrou perda significativa de rendimento se comparadas às demais combinações de lixas novas. O conjunto de lixas 80-120 apresenta, numa razão proporcional, uma variação de 4% no valor de “Ra” para cada 4 m/min aumentado na velocidade de avanço do torneamento das amostras. Pode-se afirmar que, em condições ótimas de lixamento, em média, a cada 0,1mm/rot de aumento no avanço por dente no torneamento, tem-se o aumento de 1% em “Ra”. / The process of sanding the wood is a common practice to prepare the surface for coating. The surface quality of wood is directly related to the coating, adhesion, costs of post-processing and aesthetic appearance of the product. Several parameters influence the surface finish of the wood as wood species, machining process and particle size of sandpaper. In this thesis the analysis was based on data collected in surface roughness of samples of species Eucalyptus grandis and Eucalyptus citriodora machined in tubiform lathe three feed rate (10, 14 and 18m/min.) and sanded in double vertical belt sander by and four sets of abrasive zirconia aluminium. These sets were composed with grain sizes 80,100 and 120 mesh (80-100, 80-120, 100-120 e U80- 120), the first sandpaper for roughing and second for finishing. It was concluded that for the three new sets of sandpaper used, the combination of grit sizes of 80 and 120, for roughing and finishing, respectively, presented the best performance on the surface finishing for both species. The use of worn sandpaper showed no significant loss of income compared to the other combinations of new sandpaper. The set of sandpaper 80-120 provides, in proportion to a variation of 4% in the value of Ra for each 4 m/min increased the feed rate speed of the turning of the samples. Thus, can be conclude that, under optimal conditions of sanding, on average, every 0.1 mm/rev increased in feed per tooth, increases of 1% in Ra.

This work aims to explain what the production flow means, what methods are known for the analysis and to introduce us the company. It is also to introduce the process of painting and grinding within the company. Concept of the first part is the actual production flow and its division. The following chapters handle the methods of its analysis. The second part describes the company itself. It includes the introduction of the company, of the product and description of the painting process and grinding. In the last part of the work was made economic evaluation of these proposals.

No description available.

Este trabalho abrange o estudo do processo convencional de fabricação de moldes e matrizes, ou seja, passando por processos de fresamento, eletroerosão e lixamento. Estes três processos foram aplicados ao material AISI H13, usualmente empregado na fabricação de moldes e matrizes. Além disso, foram variadas condições de usinagem, como o uso de fluído de corte. No material, a integridade da superfície foi avaliada através: da rugosidade; da dureza; da existência de deformações plásticas, trincas, tensões residuais; entre outros. No processo de fresamento foram encontradas deformações plásticas que variam de 5 μm a 8 μm. Já para o processo de EDM, foi encontrada uma camada branca de aproximadamente 20 μm. Para o lixamento constataram-se marcas de riscos e micro-rupturas. O perfil de dureza encontrado para as condições empregadas mostram um valor médio menor próximo a borda do que para a base do material. Os resultados de ruído magnético de Barkhausen mostraram que os processos de usinagem empregados modificaram a estrutura da sub-superfície dos corpos-de-prova usinados, o que pode ser percebido também para os valores medidos de tensão residual pela técnica de difração de raio X. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-14T18:16:32Z No. of bitstreams: 1 Dissertacao Juliano M Oliveira.pdf: 16772078 bytes, checksum: 2563eb47fc3f04e372ff4f36edadc956 (MD5) / Made available in DSpace on 2014-05-14T18:16:32Z (GMT). No. of bitstreams: 1 Dissertacao Juliano M Oliveira.pdf: 16772078 bytes, checksum: 2563eb47fc3f04e372ff4f36edadc956 (MD5) / This work includes the conventional way of die and mold production. Process such as milling, EDM and sanding are discussed. These three processes of die and mold making were applied to the AISI H13 material, that is wide used by die and mold makers to produce the mold s parts. Besides that, some conditions were modified such as the cutting fluids applications. The surface integrity was observed in the machined material by the follow itens: the roughness, the hardness, the plastic deformations existence, chippings, residual tensile, among others features were observed. In the milling process the plastic deformations varied from 5 μm to 8 μm and a white layer with about 20 μm were found to the EDM process. In the sanding process were found risks mark s and micro-breaches. The average value measured for the hardness profile shows that in the boundary there is a low value than in the material base. The Barkhausen noise results show that the machining process employed had changed the sub-surface of the blank material. This changed can be seen analyzing the stress results measured by X ray diffraction.

Este trabalho abrange o estudo do processo convencional de fabricação de moldes e matrizes, ou seja, passando por processos de fresamento, eletroerosão e lixamento. Estes três processos foram aplicados ao material AISI H13, usualmente empregado na fabricação de moldes e matrizes. Além disso, foram variadas condições de usinagem, como o uso de fluído de corte. No material, a integridade da superfície foi avaliada através: da rugosidade; da dureza; da existência de deformações plásticas, trincas, tensões residuais; entre outros. No processo de fresamento foram encontradas deformações plásticas que variam de 5 μm a 8 μm. Já para o processo de EDM, foi encontrada uma camada branca de aproximadamente 20 μm. Para o lixamento constataram-se marcas de riscos e micro-rupturas. O perfil de dureza encontrado para as condições empregadas mostram um valor médio menor próximo a borda do que para a base do material. Os resultados de ruído magnético de Barkhausen mostraram que os processos de usinagem empregados modificaram a estrutura da sub-superfície dos corpos-de-prova usinados, o que pode ser percebido também para os valores medidos de tensão residual pela técnica de difração de raio X. / This work includes the conventional way of die and mold production. Process such as milling, EDM and sanding are discussed. These three processes of die and mold making were applied to the AISI H13 material, that is wide used by die and mold makers to produce the mold s parts. Besides that, some conditions were modified such as the cutting fluids applications. The surface integrity was observed in the machined material by the follow itens: the roughness, the hardness, the plastic deformations existence, chippings, residual tensile, among others features were observed. In the milling process the plastic deformations varied from 5 μm to 8 μm and a white layer with about 20 μm were found to the EDM process. In the sanding process were found risks mark s and micro-breaches. The average value measured for the hardness profile shows that in the boundary there is a low value than in the material base. The Barkhausen noise results show that the machining process employed had changed the sub-surface of the blank material. This changed can be seen analyzing the stress results measured by X ray diffraction.

Presented master’s thesis describes the design and the implementation of an experimental device used for the study of tribological aspects of wheel-rail contact. In this work, the reader will first learn the fundamentals such as adhesion, slip, traction curve, etc. Subsequently, the work is describing devices that are used for the study of wheel-rail contact around the world. This section is followed by the author proposed solution. The result is a twin disc device in the scale of 1:3. The device allows determining traction characteristics for different environmental conditions (presence of water, sand and oil in contact for different temperatures) and various operating parameters (contact pressure and speed). A part of this work are also the validation experiments and complete design documentation.

Presented master's thesis is focused on the experimental research of the sanding parameters in order to improve adhesion in the contact between wheel and rail. Sanding is the application of the sanding material directly in the wheel/rail contact. It is still common, most effective and traditional way how to deal with low adhesion problem, which is mainly caused by environmental contaminants. Research is important for the better understanding of the sanding process and also provides data, which are necessary for it's optimization and efficiency improvement. Newly developed twin-disc machine was used to carry out the presented experimental research. The influence of common contaminants on the adhesion is investigated, considering various operating parameters. Different amount of the applied sand is used to increase adhesion in the contaminated contact at various slip and rolling speed. Results show, that there is the amount of the sand, from which no significant adhesion increase occur. Obtained findings and the results presented in this thesis will be used to optimize sanding system, which will contribute to reduce cost associated with sanding and low adhesion.

No description available.