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Investigation of the effect of tool geometry on the machining processDeng, Baoqin January 2019 (has links)
Cutting tool geometries play important roles in tool performance, such as tool life, surface
integrity, and cutting force. The most common commercial tools edge geometries are honed,
chamfered and hone-chamfered. This study investigates new ways to develop tool geometry.
An uncoated carbide tool is used in the orthogonal cutting of AISI 4140. By observing the tool
geometry changes in the machining process with white light interferometry, a new tool wear
geometry model has been proposed. A non-destructive tool wear measurement is discussed
as well. In addition, this study presents the machining result comparison between the new
and conventional geometries as well as the failure analysis from both experimental and FEA
perspectives. / Thesis / Master of Applied Science (MASc)
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Developing a Test Method to Evaluate the Blackout Effect of Uncoated Curtains at Varying AnglesMuminovic, Sara, Lindén, Christina January 2023 (has links)
This study aimed to explore the integration of varying angles in small-scale measurements and assess the light transmission performance of uncoated curtains. A total of four curtains were evaluated: blackout curtain samples 1 and 2 had a weft satin structure, while daytime curtain samples 3 and 4 consisted of a twill structure. The primary challenge was the inadequacy of a standardized test method for measuring the blackout effect, which led to inefficiencies and resource consumption for Company X. To address this, the study emphasized the need to investigate and establish a reliable and efficient evaluation method for uncoated curtains. By developing a standardized test method, it is possible to reduce waste material, labor costs, and resource consumption, enabling companies to operate more efficiently, sustainably, and responsibly. In the pursuit of understanding the blackout effect and evaluating the structural parameters of uncoated curtains, this study explored various test methods and parameters. More specifically, parameters such as air permeability, porosity, and thickness together with microscopic evaluation, were investigated to shed light on their influence on light transmission. The voids in the fabric were found to be a significant factor, along with porosity and air permeability, which demonstrated a correlation with lower values for the blackout curtains. The construction of the test method in a small-scale required a controlled space in the form of a lightbox. Light proofing of the box was required and successfully achieved in Prototype 1 using plywood, sealing strips, and fixtures, resulting in a lower lux value compared with the previous internal method. Objective measurements using the Konica CL-500A lux meter provided a repeatable and reliable test method with a lower tolerance value of 0,05 lx. The developed test method, theoretical Prototype 2, incorporates different sun angles by adjusting the curtain’s position, in the angles of 0°, 15°, 30°, 45° and 60°, and the rotation of the sample within 0° to 360° in intervals of 45°. The important parameters of weft density and the subsequent increase in weight were key factors in the results of light transmission, air permeability, and porosity. Furthermore, properties of the uncoated curtains such of continuous filaments and darker color showed a higher blackout effect. After the identification of complications with the lamp used in the measurement, there has been a focus on discussing the significance of a light diffuser. Additionally, alternative approaches to measure light transmission have been presented, such as digital image analysis and air permeability.
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Tactile Perception - Role of Physical PropertiesSkedung, Lisa January 2010 (has links)
<p>The aim of this thesis is to interconnect human tactile perception with various physical properties of materials. Tactile perception necessitates contact and relative motion between the skin and the surfaces of interest. This implies that properties such as friction and surface roughness ought to be important physical properties for tactile sensing. In this work, a method to measure friction between human fingers and surfaces is presented. This method is believed to best represent friction in tactile perception.</p><p>This study is focused on the tactile perception of printing papers. However, the methodology of finger friction measurements, as well as the methodology to link physical properties with human perception data, can be applied to almost whichever material or surfaces.</p><p> </p><p>This thesis is based on three articles.</p><p> </p><p>In Article I, one participant performed finger friction measurements, using a piezoelectric force sensor, on 21 printing papers of different paper grades and grammage (weight of the papers). Friction coefficients were calculated as the ratio of the frictional force and the normal force, shown to have a linear relationship. The values were recorded while stroking the index finger over the surface. The results show that measurements with the device can be used to discriminate a set of similar surfaces in terms of finger friction. When comparing the friction coefficients, the papers group according to paper surface treatment and an emerging trend is that the rougher (uncoated) papers have a lower friction coefficient than the smoother (coated) papers. In the latter case, this is interpreted in terms of a larger contact between the finger and paper surface.</p><p> </p><p>In addition, a decrease in friction coefficient is noted for all papers on repeated stroking, where the coated papers display a larger decrease. XPS (X-ray Photoelectron Spectroscopy) reveals that skin lipids are transferred from the finger to the paper surface, acting as a lubricant and hence decrease friction. Nevertheless, there is evidence that mechanical changes of the surface cannot be completely ruled out.</p><p> </p><p>The reproducibility of the finger friction measurements is elaborated in Article II, by using many participants on a selection of eight printing papers out of the 21. The trends in friction are the same; once again, the coated papers display the highest friction. There are notably large variations in the exact value of the friction coefficient, which are tentatively attributed to different skin hydration and stroking modes.</p><p> </p><p>These same participants also took part in a tactile study of perceived paper coarseness (“strävhet” in Swedish). The results reveal that the participants can distinguish a set of printing papers in terms of perceived coarseness. Not unexpectedly, surface roughness appears to be an important property related to perceived coarseness, where group data display that perceived coarseness increases with increasing surface roughness. Interestingly, friction also appears to be a discriminatory property for some subjects. A few participants showed opposite trends, which is evidence for that what is considered coarse is subjective and that different participants “weigh” the importance of the properties differently. This is a good example of a challenge when measuring one-dimensional perceptions in psychophysics.</p><p> </p><p>In Article III, a multidimensional approach was used to explore the tactile perception of printing papers. To do this, the participants scaled similarity among all possible pairs of the papers, and this similarity data are best presented by a three-dimensional space solution. This means that there are three underlying dimensions or properties that the participants use to discriminate the surface feel. Also, there is a distinct perceptual difference between the rougher (uncoated) and smoother (coated) papers. The surface roughness appears to be the dominant physical property when discriminating between a real rough paper and a smooth paper, whereas friction, thermal conductivity and grammage are more important when discriminating among the smooth coated papers.</p>
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Felkällor och systematiska avvikelser i kvalitetsuppföljningen av tidnings- och journalpapper / Sources of error and systematic deviation in following up of quality in news- and journal paperBergendahl, Rikard January 2008 (has links)
<p>I papperstillverkning ställs det krav inte bara på kvalité och kvantitet utan också att stickprov från produktion utförs och tas hand om på ett korrekt sätt. Från det att ett stickprov tas ut och undersöks på brukets laboratorium kan en del källor till förändringar på provresultatet uppstå. Sådana förändringar kan uppstå för det första vid hanteringen av stickprov från pappersmaskin och provens transportering till laboratoriet och för det andra vid laboratoriets hantering och uppföljning av kvalitén. En annan faktor som kan påverka stickproven är klimatet. Årstiderna vår och höst är de tider som proverna kan påverkas mest. Prover undersöks med jämna mellanrum från färdigt papper och används till kalibrering av on-line mätning på pappersmaskin. Vissa av provresultaten skickas direkt till kunden i form av ett analyscertifikat.</p><p>I detta examensarbete var syftet att analysera vissa felkällor i provhanteringen och vad klimatet hade för påverkan på provresultatet. Det undersöktes hur varierande klimatförhållanden på pappersmaskin kunde påverka provresultaten för prov som undersöktes direkt på laboratoriet. Resultat från de proven har sen jämförts med prov som konditionerades en tid på laboratoriet i ett fast klimat (23°C, 50 % RH). Prov konditionerades både efter att provet tagits ut direkt och efter att provet hade legat uppe i maskinhallen under en längre tid. I arbetet ingick det att årstider skulle simuleras och det utfördes på Stora Enso Research Center i Falun i ett speciellt klimatrum. Klimaten som papper undersöktes i då var extremt torrt och extremt fuktigt och dessa resultat jämfördes med resultat från normalt provtagningsklimat.</p><p>Papperskvalitéerna som undersöktes var 45 g/m2 standard tidningspapper från PM 11 och 52 g/m2 SC-papper (obestruket journalpapper) från Kvarnsvedens nya maskin PM 12. Det som undersöktes var de kritiska parametrarna där det föreligger risk för att papper måste kasseras. De kritiska egenskaperna som har kassaktionsgräns är ytvikt, ljushet, nyans och i även vissa fall ytråhet och rivstyrka.</p><p>Resultaten visade att vid extrema klimatförhållanden från undersökningen på Stora Enso Research Center hade många prover påverkats till den grad att de hade lett till kassaktion. För SC-papper var ytråheten den egenskap som var mest kritisk vid extremt torrt klimat och vid fuktigt klimat var ytvikt den mest känsliga egenskapen. För standard tidningspapper var ytvikt och rivstyrka de egenskaper som påverkades mest av extremt klimat och pappret hade fått kasseras vid både extremt torrt och fuktigt klimat.</p><p>Vid undersökningen på Kvarnsveden visade resultaten att fukthalten i pappret påverkades mer än vad papprets övriga egenskaper gjorde. Förändringarna i papprets övriga egenskaper var endast marginella och höll sig inom respektive gränsvärde för kassaktion. Nyans och de andra optiska egenskaperna hade marginella förändringar för både varierande och extrema klimatförhållanden och förändringarna kan i de flesta fall anses försumbara för produktionen.</p><p>I de fall där det råder extrema klimatförhållanden som det kan göra vid vissa årstider är det mycket viktigt att operatörens hantering av stickprov sker på ett korrekt sätt. Då gäller det att stickproverna skickas ner till laboratoriet så snabbt som möjligt där påverkan är mindre än vad den kan vara inne i maskinhallen.</p> / <p>In paper production demands are set not only on quality and quantity, but it is also required that samples from the production are taken out and handled in a correct way. From the moment when a sample is taken out and up to the point when it is examined in the laboratory of the mill, a number of factors may affect the sample and thus the test result. Such changes can arise from the handling of samples from the paper machine and the transport of the samples to the laboratory and also from the handling of the samples in the laboratory. Another factor that can influence the samples is the climate and the seasons spring and autumn is the times when the samples are influenced most. Samples are examined with even intervals from finished papers and is used for calibration of on-line measurement on the paper machine and some of the sample results are sent directly to the costumer in the form of an analysis certificate.</p><p>The purpose of this project was to analyze certain error sources in the sample handling and the impact of the climate on the sample result. It was examined how varying climates on the paper machine could influence the sample results for samples that were examined directly and compared with samples that were conditioned for one hour on the laboratory in a permanent climate (23°C, 50% RH). Samples that were conditioned were either taken directly to the lab or left by the paper machine for an extended period of time. In the work, it was included that seasons would be simulated and it was carried out on Stora Enso Research centre in Falun in a climate room. The climates that papers were examined in then were extreme dry and extreme damp and these results were compared with results from normal climate for testing paper.</p><p>The paper qualities that were examined where 45 g/m2 standard newspaper from papermachine 11 and 52 g/m2 SC-paper (uncoated journal papers) from the new papermachine 12 in Kvarnsveden. What were examined were the critical parameters were it exists risk to rejection of papers. The critical properties that have a limit when the papers are rejected are grammage, ISO-brightness and nuance and in certain cases also roughness and tear strength.</p><p>The results showed that at extreme climate relations from the studies on Stora Enso Research centre samples had been influenced to that degree that many of the samples had to be rejected. For SC-paper roughness was the property that was most critical at extremely dry climate and at damp climate the grammage was the most sensitive property. Standard newspaper was very sensitive at both extremely damp and dry climates for grammage and tearing strength.</p><p>The study on Kvarnsveden showed that the moisture content in the paper was influenced more than the other properties but its changes were only marginal and within the respective limit for rejection. Nuance and the other optic properties had only marginal changes for both varying and extreme climates and the changes can in most cases be considered negligible for the production.</p><p>In those cases when there are extreme climates, like during certain seasons, it is very important that the operator handles the samples correctly. Then, it is important that the samples are sent down to the laboratory as fast as possible where the impact is smaller than if the samples stay in the machine room.</p>
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Felkällor och systematiska avvikelser i kvalitetsuppföljningen av tidnings- och journalpapper / Sources of error and systematic deviation in following up of quality in news- and journal paperBergendahl, Rikard January 2008 (has links)
I papperstillverkning ställs det krav inte bara på kvalité och kvantitet utan också att stickprov från produktion utförs och tas hand om på ett korrekt sätt. Från det att ett stickprov tas ut och undersöks på brukets laboratorium kan en del källor till förändringar på provresultatet uppstå. Sådana förändringar kan uppstå för det första vid hanteringen av stickprov från pappersmaskin och provens transportering till laboratoriet och för det andra vid laboratoriets hantering och uppföljning av kvalitén. En annan faktor som kan påverka stickproven är klimatet. Årstiderna vår och höst är de tider som proverna kan påverkas mest. Prover undersöks med jämna mellanrum från färdigt papper och används till kalibrering av on-line mätning på pappersmaskin. Vissa av provresultaten skickas direkt till kunden i form av ett analyscertifikat. I detta examensarbete var syftet att analysera vissa felkällor i provhanteringen och vad klimatet hade för påverkan på provresultatet. Det undersöktes hur varierande klimatförhållanden på pappersmaskin kunde påverka provresultaten för prov som undersöktes direkt på laboratoriet. Resultat från de proven har sen jämförts med prov som konditionerades en tid på laboratoriet i ett fast klimat (23°C, 50 % RH). Prov konditionerades både efter att provet tagits ut direkt och efter att provet hade legat uppe i maskinhallen under en längre tid. I arbetet ingick det att årstider skulle simuleras och det utfördes på Stora Enso Research Center i Falun i ett speciellt klimatrum. Klimaten som papper undersöktes i då var extremt torrt och extremt fuktigt och dessa resultat jämfördes med resultat från normalt provtagningsklimat. Papperskvalitéerna som undersöktes var 45 g/m2 standard tidningspapper från PM 11 och 52 g/m2 SC-papper (obestruket journalpapper) från Kvarnsvedens nya maskin PM 12. Det som undersöktes var de kritiska parametrarna där det föreligger risk för att papper måste kasseras. De kritiska egenskaperna som har kassaktionsgräns är ytvikt, ljushet, nyans och i även vissa fall ytråhet och rivstyrka. Resultaten visade att vid extrema klimatförhållanden från undersökningen på Stora Enso Research Center hade många prover påverkats till den grad att de hade lett till kassaktion. För SC-papper var ytråheten den egenskap som var mest kritisk vid extremt torrt klimat och vid fuktigt klimat var ytvikt den mest känsliga egenskapen. För standard tidningspapper var ytvikt och rivstyrka de egenskaper som påverkades mest av extremt klimat och pappret hade fått kasseras vid både extremt torrt och fuktigt klimat. Vid undersökningen på Kvarnsveden visade resultaten att fukthalten i pappret påverkades mer än vad papprets övriga egenskaper gjorde. Förändringarna i papprets övriga egenskaper var endast marginella och höll sig inom respektive gränsvärde för kassaktion. Nyans och de andra optiska egenskaperna hade marginella förändringar för både varierande och extrema klimatförhållanden och förändringarna kan i de flesta fall anses försumbara för produktionen. I de fall där det råder extrema klimatförhållanden som det kan göra vid vissa årstider är det mycket viktigt att operatörens hantering av stickprov sker på ett korrekt sätt. Då gäller det att stickproverna skickas ner till laboratoriet så snabbt som möjligt där påverkan är mindre än vad den kan vara inne i maskinhallen. / In paper production demands are set not only on quality and quantity, but it is also required that samples from the production are taken out and handled in a correct way. From the moment when a sample is taken out and up to the point when it is examined in the laboratory of the mill, a number of factors may affect the sample and thus the test result. Such changes can arise from the handling of samples from the paper machine and the transport of the samples to the laboratory and also from the handling of the samples in the laboratory. Another factor that can influence the samples is the climate and the seasons spring and autumn is the times when the samples are influenced most. Samples are examined with even intervals from finished papers and is used for calibration of on-line measurement on the paper machine and some of the sample results are sent directly to the costumer in the form of an analysis certificate. The purpose of this project was to analyze certain error sources in the sample handling and the impact of the climate on the sample result. It was examined how varying climates on the paper machine could influence the sample results for samples that were examined directly and compared with samples that were conditioned for one hour on the laboratory in a permanent climate (23°C, 50% RH). Samples that were conditioned were either taken directly to the lab or left by the paper machine for an extended period of time. In the work, it was included that seasons would be simulated and it was carried out on Stora Enso Research centre in Falun in a climate room. The climates that papers were examined in then were extreme dry and extreme damp and these results were compared with results from normal climate for testing paper. The paper qualities that were examined where 45 g/m2 standard newspaper from papermachine 11 and 52 g/m2 SC-paper (uncoated journal papers) from the new papermachine 12 in Kvarnsveden. What were examined were the critical parameters were it exists risk to rejection of papers. The critical properties that have a limit when the papers are rejected are grammage, ISO-brightness and nuance and in certain cases also roughness and tear strength. The results showed that at extreme climate relations from the studies on Stora Enso Research centre samples had been influenced to that degree that many of the samples had to be rejected. For SC-paper roughness was the property that was most critical at extremely dry climate and at damp climate the grammage was the most sensitive property. Standard newspaper was very sensitive at both extremely damp and dry climates for grammage and tearing strength. The study on Kvarnsveden showed that the moisture content in the paper was influenced more than the other properties but its changes were only marginal and within the respective limit for rejection. Nuance and the other optic properties had only marginal changes for both varying and extreme climates and the changes can in most cases be considered negligible for the production. In those cases when there are extreme climates, like during certain seasons, it is very important that the operator handles the samples correctly. Then, it is important that the samples are sent down to the laboratory as fast as possible where the impact is smaller than if the samples stay in the machine room.
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Tactile Perception - Role of Physical PropertiesSkedung, Lisa January 2010 (has links)
The aim of this thesis is to interconnect human tactile perception with various physical properties of materials. Tactile perception necessitates contact and relative motion between the skin and the surfaces of interest. This implies that properties such as friction and surface roughness ought to be important physical properties for tactile sensing. In this work, a method to measure friction between human fingers and surfaces is presented. This method is believed to best represent friction in tactile perception. This study is focused on the tactile perception of printing papers. However, the methodology of finger friction measurements, as well as the methodology to link physical properties with human perception data, can be applied to almost whichever material or surfaces. This thesis is based on three articles. In Article I, one participant performed finger friction measurements, using a piezoelectric force sensor, on 21 printing papers of different paper grades and grammage (weight of the papers). Friction coefficients were calculated as the ratio of the frictional force and the normal force, shown to have a linear relationship. The values were recorded while stroking the index finger over the surface. The results show that measurements with the device can be used to discriminate a set of similar surfaces in terms of finger friction. When comparing the friction coefficients, the papers group according to paper surface treatment and an emerging trend is that the rougher (uncoated) papers have a lower friction coefficient than the smoother (coated) papers. In the latter case, this is interpreted in terms of a larger contact between the finger and paper surface. In addition, a decrease in friction coefficient is noted for all papers on repeated stroking, where the coated papers display a larger decrease. XPS (X-ray Photoelectron Spectroscopy) reveals that skin lipids are transferred from the finger to the paper surface, acting as a lubricant and hence decrease friction. Nevertheless, there is evidence that mechanical changes of the surface cannot be completely ruled out. The reproducibility of the finger friction measurements is elaborated in Article II, by using many participants on a selection of eight printing papers out of the 21. The trends in friction are the same; once again, the coated papers display the highest friction. There are notably large variations in the exact value of the friction coefficient, which are tentatively attributed to different skin hydration and stroking modes. These same participants also took part in a tactile study of perceived paper coarseness (“strävhet” in Swedish). The results reveal that the participants can distinguish a set of printing papers in terms of perceived coarseness. Not unexpectedly, surface roughness appears to be an important property related to perceived coarseness, where group data display that perceived coarseness increases with increasing surface roughness. Interestingly, friction also appears to be a discriminatory property for some subjects. A few participants showed opposite trends, which is evidence for that what is considered coarse is subjective and that different participants “weigh” the importance of the properties differently. This is a good example of a challenge when measuring one-dimensional perceptions in psychophysics. In Article III, a multidimensional approach was used to explore the tactile perception of printing papers. To do this, the participants scaled similarity among all possible pairs of the papers, and this similarity data are best presented by a three-dimensional space solution. This means that there are three underlying dimensions or properties that the participants use to discriminate the surface feel. Also, there is a distinct perceptual difference between the rougher (uncoated) and smoother (coated) papers. The surface roughness appears to be the dominant physical property when discriminating between a real rough paper and a smooth paper, whereas friction, thermal conductivity and grammage are more important when discriminating among the smooth coated papers.
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