Little research has been done to determine the stress states developed in an industrial sawblade for various operating conditions. The stresses are developed from the forces generated during the cutting of materials, and also from the vibration of the sawblade. The difficulty of analyzing these stresses and vibrations results from the sawblade's high speed of rotation, which make it difficult to instrument the sawblade for analysis. Stress and vibration can ruin the sawblade from loss of material properties due to heat build-up and fatigue failure. The sawblade industry raised natural frequencies away from the operating frequencies to overcome the vibrations. To raise the natural frequencies of the sawblades away from the operating frequencies, residual stresses have been intentionally induced in the sawbody. The residual stresses come from plastically deforming the sawbody with one or more concentric rings. Experts who determine the location, depth, and number of residual stress rings are called "saw doctor". This thesis quantifies the residual stresses induced by saw doctors. Developing and evaluating finite element models of an industrial sawblade while undergoing the effects from rotating and cutting are also included in the thesis. In addition, the effects on the sawblades performance due to various numbers and lengths of expansion slots and sawblade tensioning are explored. Models of the sawblade are plastically deformed leaving residual stresses which are analyzed to determine the natural frequencies of the sawblade. The thesis quantifies the above mechanisms for a sawblade under the loads developed from rotation and a load case representing the cutting process. The work developed in this thesis is a first step toward characterizing the effects of specific mechanisms which can be used to design better, longer lasting sawblades. / Master of Science

Visando determinar os valores ótimos para o processo de serramento de anéis bobinados de filme metalizado ultrafino de alumínio com dielétrico de poliéster a partir das condições atuais do processo de fabricação de capacitores pela empresa Epcos do Brasil, realizou-se a avaliação de diferentes tipos de serras circulares variando-se a velocidade de rotação (n) e o tempo de corte (tc). Desenvolvido projeto de experimento desses três fatores a fim de obter o resultado das interações entre eles quanto à resistência de isolamento (Riso) das peças cortadas. A serra de 160 dentes de metal-duro com revestimento de filme de carbono tipo diamante (DLC) apresentou os melhores resultados quanto à “Riso” acima de 0,378 G e quanto ao número de peças com valor abaixo deste. Constatou-se que “n” não influencia significativamente para a distribuição de “Riso”; porém, gera menos peças abaixo do especificado. Já “tc” não influencia significativamente o processo. Quanto ao tipo de dente, o perfil reto obteve melhor resultado para lâminas de serra com 80 dentes e perfil curvo para lâminas com 160 dentes. Já a espessura da lâmina não influenciou de forma expressiva o processo. A lâmina de aço-rápido apresentou adesão de alumínio na lateral do corpo da serra e, consequentemente, adesão de material na superfície de corte. As lâminas de metal-duro sem revestimento apresentaram falhas no filme metalizado por causa do atrito gerado entre a superfície de corte e a lateral da lâmina; esse inconveniente é eliminado quando ela é revestida com filme DLC apresentando melhorias quanto à “Riso” das peças para “n” menores. Também houve adesão de alumínio na parte inferior do dente devido a uma delaminação da camada de filme DLC. / In order to determine the optimal values for the sawing process of wound rings of metalized ultra-thin film with dielectric of polyester from current conditions of capacitor manufacturing process by Epcos company in Brazil, it was performed the evaluation of different types of circular saws varying the rotational speed (n) and the cutting time (tc). Developed experiment design methodology for these three factors in order to get the result of the interactions between them regarding to the insulation resistance (Riso) of cut parts. Through the analysis of the main effects, the cemented carbide saw with 160 teeth and diamond-like carbon (DLC) film coating showed the best results in terms of "Riso" above 0,378 G and regarding to the number of parts with value below the specified. It was found that "n" does not influence significantly the distribution of "Riso"; however, generates fewer parts below the specified. Now "tc" does not significantly influence the process. Regarding the tooth type, straight profile obtained better results for saw blades with 80 teeth and curved profile for blades with 160 teeth. However the thickness of the blade did not influence significantly the process. The high speed steel blade presented adhesion of aluminum on the side of the saw body and, consequently, adhesion of material on the cutting surface. The cemented carbide blades uncoated presented failures on metalized film because of the friction generated between the cutting surface and the side of the blade; this drawback is eliminated when it is coated with DLC film presenting improvements to the parts "Riso" for lower "n". There was also aluminum adhesion on the bottom of the tooth due to a delamination of the DLC film layer.

Visando determinar os valores ótimos para o processo de serramento de anéis bobinados de filme metalizado ultrafino de alumínio com dielétrico de poliéster a partir das condições atuais do processo de fabricação de capacitores pela empresa Epcos do Brasil, realizou-se a avaliação de diferentes tipos de serras circulares variando-se a velocidade de rotação (n) e o tempo de corte (tc). Desenvolvido projeto de experimento desses três fatores a fim de obter o resultado das interações entre eles quanto à resistência de isolamento (Riso) das peças cortadas. A serra de 160 dentes de metal-duro com revestimento de filme de carbono tipo diamante (DLC) apresentou os melhores resultados quanto à “Riso” acima de 0,378 G e quanto ao número de peças com valor abaixo deste. Constatou-se que “n” não influencia significativamente para a distribuição de “Riso”; porém, gera menos peças abaixo do especificado. Já “tc” não influencia significativamente o processo. Quanto ao tipo de dente, o perfil reto obteve melhor resultado para lâminas de serra com 80 dentes e perfil curvo para lâminas com 160 dentes. Já a espessura da lâmina não influenciou de forma expressiva o processo. A lâmina de aço-rápido apresentou adesão de alumínio na lateral do corpo da serra e, consequentemente, adesão de material na superfície de corte. As lâminas de metal-duro sem revestimento apresentaram falhas no filme metalizado por causa do atrito gerado entre a superfície de corte e a lateral da lâmina; esse inconveniente é eliminado quando ela é revestida com filme DLC apresentando melhorias quanto à “Riso” das peças para “n” menores. Também houve adesão de alumínio na parte inferior do dente devido a uma delaminação da camada de filme DLC. / In order to determine the optimal values for the sawing process of wound rings of metalized ultra-thin film with dielectric of polyester from current conditions of capacitor manufacturing process by Epcos company in Brazil, it was performed the evaluation of different types of circular saws varying the rotational speed (n) and the cutting time (tc). Developed experiment design methodology for these three factors in order to get the result of the interactions between them regarding to the insulation resistance (Riso) of cut parts. Through the analysis of the main effects, the cemented carbide saw with 160 teeth and diamond-like carbon (DLC) film coating showed the best results in terms of "Riso" above 0,378 G and regarding to the number of parts with value below the specified. It was found that "n" does not influence significantly the distribution of "Riso"; however, generates fewer parts below the specified. Now "tc" does not significantly influence the process. Regarding the tooth type, straight profile obtained better results for saw blades with 80 teeth and curved profile for blades with 160 teeth. However the thickness of the blade did not influence significantly the process. The high speed steel blade presented adhesion of aluminum on the side of the saw body and, consequently, adhesion of material on the cutting surface. The cemented carbide blades uncoated presented failures on metalized film because of the friction generated between the cutting surface and the side of the blade; this drawback is eliminated when it is coated with DLC film presenting improvements to the parts "Riso" for lower "n". There was also aluminum adhesion on the bottom of the tooth due to a delamination of the DLC film layer.

Visando determinar os valores ótimos para o processo de serramento de anéis bobinados de filme metalizado ultrafino de alumínio com dielétrico de poliéster a partir das condições atuais do processo de fabricação de capacitores pela empresa Epcos do Brasil, realizou-se a avaliação de diferentes tipos de serras circulares variando-se a velocidade de rotação (n) e o tempo de corte (tc). Desenvolvido projeto de experimento desses três fatores a fim de obter o resultado das interações entre eles quanto à resistência de isolamento (Riso) das peças cortadas. A serra de 160 dentes de metal-duro com revestimento de filme de carbono tipo diamante (DLC) apresentou os melhores resultados quanto à “Riso” acima de 0,378 G e quanto ao número de peças com valor abaixo deste. Constatou-se que “n” não influencia significativamente para a distribuição de “Riso”; porém, gera menos peças abaixo do especificado. Já “tc” não influencia significativamente o processo. Quanto ao tipo de dente, o perfil reto obteve melhor resultado para lâminas de serra com 80 dentes e perfil curvo para lâminas com 160 dentes. Já a espessura da lâmina não influenciou de forma expressiva o processo. A lâmina de aço-rápido apresentou adesão de alumínio na lateral do corpo da serra e, consequentemente, adesão de material na superfície de corte. As lâminas de metal-duro sem revestimento apresentaram falhas no filme metalizado por causa do atrito gerado entre a superfície de corte e a lateral da lâmina; esse inconveniente é eliminado quando ela é revestida com filme DLC apresentando melhorias quanto à “Riso” das peças para “n” menores. Também houve adesão de alumínio na parte inferior do dente devido a uma delaminação da camada de filme DLC. / In order to determine the optimal values for the sawing process of wound rings of metalized ultra-thin film with dielectric of polyester from current conditions of capacitor manufacturing process by Epcos company in Brazil, it was performed the evaluation of different types of circular saws varying the rotational speed (n) and the cutting time (tc). Developed experiment design methodology for these three factors in order to get the result of the interactions between them regarding to the insulation resistance (Riso) of cut parts. Through the analysis of the main effects, the cemented carbide saw with 160 teeth and diamond-like carbon (DLC) film coating showed the best results in terms of "Riso" above 0,378 G and regarding to the number of parts with value below the specified. It was found that "n" does not influence significantly the distribution of "Riso"; however, generates fewer parts below the specified. Now "tc" does not significantly influence the process. Regarding the tooth type, straight profile obtained better results for saw blades with 80 teeth and curved profile for blades with 160 teeth. However the thickness of the blade did not influence significantly the process. The high speed steel blade presented adhesion of aluminum on the side of the saw body and, consequently, adhesion of material on the cutting surface. The cemented carbide blades uncoated presented failures on metalized film because of the friction generated between the cutting surface and the side of the blade; this drawback is eliminated when it is coated with DLC film presenting improvements to the parts "Riso" for lower "n". There was also aluminum adhesion on the bottom of the tooth due to a delamination of the DLC film layer.

La société SIAT-BRAUN, premier de sciage résineux de France, présente une problématique industrielle liée à ses outils de coupe. Les scies débitant le bois doivent être les plus fines possibles afin de préserver la matière d'oeuvre, mais aussi très robustes pour supporter les conditions de coupe qui ne cessent de se durcir. La maîtrise de la matière première ainsi que des paramètres de réglage des machines sont des conditions sine-qua-none du bon travail des outils. Ainsi, nous arrivons à des situations limites où les règles actuelles ne répondent pas correctement aux exigences recherchées. Le mémoire comporte une étude technico-économique de la scierie et de son évolution, ainsi que du matériau bois employé. L'explication du fonctionnement de la ligne de sciage de l'entreprise, une des plus modernes, d'Europe, achève cette présentation.L'analyse des connaissances actuelles englobe les différents paramètres et calculs relatifs à l'usinage du bois, ainsi que les divers éléments composant une scie circulaire et ses géométries associées. Les interactions entre tous ces éléments sont aussi présentées. Le métier d'affûteur, personne en charge de la maintenance des outils et garante de leur bon fonctionnement, est présenté ainsi que des améliorations mises en place au niveau de la méthode ainsi que des machines de l'atelier.Pendant cette thèse, de nombreuses améliorations ont été réalisées sur les différents outils de coupe, afin de répondre aux exigences de la production en gardant une fiabilité la plus importante possible. La dernière partie proposera les améliorations restant à valider sur l'adéquation entre les matériaux et la géométrie angulaire des scies circulaires / SIAT-BRAUN is the largest industrial sawmill in France and faces typical industrial challenges with its sawing technologies.Wood saws must be as thin as possible, in order to maximize yield and save raw material and robust enough to endure tougher and tougher sawing conditions. Good raw material control and optimized machine parameterization are critical to ensure good results. The current theoretical background, does not always match these requirements and we are therefore always testing its limits.An economical and technical analysis of the sawmill and its evolution makes up the first part of this thesis. We will be detailing the key operations of one of the most modern sawmill in Europe.Current knowledge analysis must include the various parameters and calculations necessary to machine wood, as well as the different blade components and their geometric specifications. We will discuss the interactions between these elements. The job of the filer (the person in charge of tool maintenance) will also be discussed, as well as several improvements implemented in the workshop.Many improvements have been suggested and implemented while working on this thesis, in order to react to production needs while preserving reliability. In the last section of this thesis we will discuss several improvements that remain to be validated on how to best match appropriate cutting materials and blade geometry

This thesis describes a proposal for a rocker saw design. It addresses the general lack of current solutions, their description and it is drawing conclusions of these. The object of this thesis is to try to avoid potential problems which are being discussed in this thesis and therefore suggests solutions for enhancing the rocker saw, especially on the visual and ergonomic side.

The thesis deals with the optimization of project activities in the software EPLAN Electric P8. First part introduces electrotechnical software EPLAN, the basic functions, and explains the methodology of the work in the program environment. This is followed by an analysis of the state of the electrical documentation of the TAC 75 circular saw manufactured by Exactcut s. r. o., and the method of designing. The thesis is also focused on the individual problems that make barriers between the average and the high quality level of design and the ability to use the available features of the purchased software. Thereafter, individual optimization steps and partial methods of reaching aims are described. Part of the thesis is devoted to finding solutions for interconnection of two engineering branches, which are electric and fluid technologies and in the end are revealed expansion modules of software, which can be used to achieve a higher level of professional planning activity.

The concept duty of care is defined as heedful, careful guarding, supervision of a minor, and/or overseeing. An obligation rests on teachers to scrupulously see to the safety (and also the well-being) of all learners entrusted to them. Hence teachers are responsible for the physical safety of learners and for creating a safe haven for them. The Civil Technology workshop teacher has an increased caring duty towards his learners due to the potential life-threatening circumstances and conditions that can prevail in his workshop compared to, for instance, the ordinary classroom environment. Furthermore, a specific legal duty rests on a person when he is placed in control of dangerous objects or machinery, seeing that he has to see to it that he ensures the safety of others through positive action. Internationally, the circular saw is statistically speaking seen to be the most dangerous woodwork machine in the Civil Technology workshop. Circular saws are responsible for more accidents than any other machine, and the most claims for damages against teachers and school managements also arise from it. Due to the underlying dangers inherent to circular saws and the presence thereof in Civil Technology workshops, it increases the risks attached to the caring supervision duty of the Civil Technology teacher to a great extent. Civil Technology workshop teachers are therefore confronted by unique challenges in their workshops. Hence it is essential that they be equipped with sufficient knowledge pertaining to educational law so as to make head against these challenges. Civil Technology workshop teachers should therefore not only be aware of all common law principles, relevant legislation and case law as applicable to workshops, but also be able to apply it in practice in the workshop environment. This practical application furthermore requires workshop teachers to be knowledgeable to be able to maintain workshop machinery in a safe working condition through regular upkeep and maintenance. An empirical investigation (n=38) was launched, based on a questionnaire filled in by all Civil Technology teachers and their heads of department North West where Civil Technology is presented as a choice subject at high schools. The aim of the empirical investigation was to determine: * what the level of Civil Technology workshop teachers‘ expertise and knowledge is regarding legal key issues concerning their caring supervising duty, and * to what extent effective safety management of woodwork machinery in Civil Technology workshops is applied. The empirical investigation found, amongst others, that: * The respondents do not have sufficient knowledge of the principles pertaining to educational law to apply it in the Civil Technology workshops of the study population practically. * Civil Technology workshop teachers and heads of department should have a high degree of expertise with a view to execute their duty of care. Poor educational law training can possibly be proffered as reason why their level of expertise cannot be seen to be sufficient in a case where an increased level of duty of car is required in potentially dangerous workshops. Following on above-mentioned findings, specific recommendations were made to all role-players involved that are involved in learner safety in Civil Technology workshops. These recommendations may possibly contribute to increased and more effective caring supervision in promoting learner safety. / Thesis (MEd (Education Law))--North-West University, Potchefstroom Campus, 2012

The concept duty of care is defined as heedful, careful guarding, supervision of a minor, and/or overseeing. An obligation rests on teachers to scrupulously see to the safety (and also the well-being) of all learners entrusted to them. Hence teachers are responsible for the physical safety of learners and for creating a safe haven for them. The Civil Technology workshop teacher has an increased caring duty towards his learners due to the potential life-threatening circumstances and conditions that can prevail in his workshop compared to, for instance, the ordinary classroom environment. Furthermore, a specific legal duty rests on a person when he is placed in control of dangerous objects or machinery, seeing that he has to see to it that he ensures the safety of others through positive action. Internationally, the circular saw is statistically speaking seen to be the most dangerous woodwork machine in the Civil Technology workshop. Circular saws are responsible for more accidents than any other machine, and the most claims for damages against teachers and school managements also arise from it. Due to the underlying dangers inherent to circular saws and the presence thereof in Civil Technology workshops, it increases the risks attached to the caring supervision duty of the Civil Technology teacher to a great extent. Civil Technology workshop teachers are therefore confronted by unique challenges in their workshops. Hence it is essential that they be equipped with sufficient knowledge pertaining to educational law so as to make head against these challenges. Civil Technology workshop teachers should therefore not only be aware of all common law principles, relevant legislation and case law as applicable to workshops, but also be able to apply it in practice in the workshop environment. This practical application furthermore requires workshop teachers to be knowledgeable to be able to maintain workshop machinery in a safe working condition through regular upkeep and maintenance. An empirical investigation (n=38) was launched, based on a questionnaire filled in by all Civil Technology teachers and their heads of department North West where Civil Technology is presented as a choice subject at high schools. The aim of the empirical investigation was to determine: * what the level of Civil Technology workshop teachers‘ expertise and knowledge is regarding legal key issues concerning their caring supervising duty, and * to what extent effective safety management of woodwork machinery in Civil Technology workshops is applied. The empirical investigation found, amongst others, that: * The respondents do not have sufficient knowledge of the principles pertaining to educational law to apply it in the Civil Technology workshops of the study population practically. * Civil Technology workshop teachers and heads of department should have a high degree of expertise with a view to execute their duty of care. Poor educational law training can possibly be proffered as reason why their level of expertise cannot be seen to be sufficient in a case where an increased level of duty of car is required in potentially dangerous workshops. Following on above-mentioned findings, specific recommendations were made to all role-players involved that are involved in learner safety in Civil Technology workshops. These recommendations may possibly contribute to increased and more effective caring supervision in promoting learner safety. / Thesis (MEd (Education Law))--North-West University, Potchefstroom Campus, 2012