Diss. (sammanfattning) Uppsala : Uppsala universitet, 2005. / Härtill 7 uppsatser.

Diss. (sammanfattning) Uppsala : Uppsala universitet, 2006. / Härtill 8 uppsatser.

<p>During this master thesis, wear and friction properties for the high-temperature alloy Kanthal APMT were studied. The results were also compared to 253MA. The initial tests showed, among other things, that the surface fineness of the muffle tubes matters in real applications like conveyor belts. A 253MA-sample wear-tested against a 253MA-tube showed lowest wear at 900°C while a pre-oxidized APMT-sample wear-tested against a APMT-tube had the lowest mean value of the friction force at 1100°C, compared to all other tests.</p>

During this master thesis, wear and friction properties for the high-temperature alloy Kanthal APMT were studied. The results were also compared to 253MA. The initial tests showed, among other things, that the surface fineness of the muffle tubes matters in real applications like conveyor belts. A 253MA-sample wear-tested against a 253MA-tube showed lowest wear at 900°C while a pre-oxidized APMT-sample wear-tested against a APMT-tube had the lowest mean value of the friction force at 1100°C, compared to all other tests.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 7 uppsatser.

Diss. Linköping : Univ., 2005.

Diss. (sammanfattning) Uppsala : universitet, 2006. / Härtill 6 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 6 uppsatser.

Med en värld som blir allt mer digitaliserad, där svenska skogsbruk har ett överflöd på pappersmassa. Samtidigt finns en marknad som efterfrågar textilier som ofta är negativa för både hälsa och ekosystem, finns ett behov av förändring. Ett sätt att möta problemet skulle vara att tillverka pappersgarn som skulle kunna stilla en viss efterfrågan på mer resurskrävande textila material och samtidigt hitta ett nytt an- vändningsområde för svensk pappersmassa. I detta arbete har en fördjupning gjorts i pappersgarn med ett mål att optimera det svenska pappersgarnets karaktär och göra det mer stickbart. Till en början i arbetet har fyra olika pappersgarn analyserats i FTIR spektrometer, för att undersöka om det existerar en skillnad i materialinehåll mellan dessa pappersgarner. Resultatet visade på att samtliga fyra garner var tillverkade av enbart cellulosa, men att det inte går att utesluta olika typer av cellulosablandningar. Efter analys fortsatte arbe- tet med två svenska pappersgarner med syfte att reducera friktionen mellan garn och nål. Dessa två garner impregnerades med kemikalierna fatty acid polyether glycols ester, mono-/dialkyphospate och dispersion wax i en Mathis foulard med trycket 3- respektive 5 bar. Där den andra impregneringen resulterade i fyra im- pregnerade pappersgarn. Efter impregnering och fixering räknades viktökningen i procent. Efter impregneringen analyserades pappersgarnernas ytstruktur i ett mikroskop. Det syntes tydligt att garnerna fått en förändrad yta efter impregnering, vilket på- verkade fortsatt analys. Efter analysen i mikroskopet utfördes friktionstest på pap- persgarnerna för att se om impregneringen förändrat friktionskoefficienten i gar- nerna. Ett specialutformat test utfördes där friktionskoefficienten räknades ut med hjälp av data som registrerades. Här visade resultaten på att det tunnare garnet med 3 bar hade den högsta friktionskoefficienten på ca 0,309 och lägst friktionskoeffi- cient hade 5 bar på ca 0,299. Dessa jämfördes mot tunt ej impregnerat garn med en friktionskoefficient på ca 0,300. Det tjockare garnet visade på ett slätare garn med växande friktionskoefficient. Det tjockare garnet som hade utsatts för 5 bar tryck visade på en yta där pappersgarnet hade börjat att lösa upp sig, vilket kunde vara förklaringen till den växande friktionskoefficienten. Vid analys av pappersgarnets stickbarhet i det sista momentet visade det sig att det tunnare garnet med 3 bar var svårstickat och bildade stickfel och hål i varan, detta misstänks bero på hårigheten och den kladdiga yta som lämnades efter impregneringen. Medan det tunnare garnet med 5 bar resulterade i en vara som var lättade att sticka utan stickfel med en mindre kladdig yta, som påvisar att den mekaniska bearbetningen som gav en lägre mängd impregnering resulterar i en sänkt friktionskoefficient. Det är viktigt att skogsbruk sker på ett hållbart sätt. Om det sker och en positiv utveckling görs för det svenska pappersgarnet, kan det så småningom nå en bredare marknad. / In a world that is becoming increasingly more digital we see patterns of the Swedish forestry having an overflow of pulp, and a market demanding textile that are negative for both our health and our ecosystem. There’s a clear need for change. One way to tackle this issue could potentially be to produce paper yarn that could act as a replacement rather than more resource-intensive textile materials and at the same time find a new area of use for Swedish pulp from the paper industry. In this project, a study has been made of paper yarn with the aim of optimizing the surface properties of Swedish paper yarn and by that increase the knittability of the yarn. At first four different paper yarns were analyzed in FTIR spectrometers, to investigate whether there where a difference in material content between the paper yarns. The results showed that all four paper yarns were made from only cellulose, and that it is not possible to identify different types of cellulose mixtures by the chosen method. After analysis, the project continued on with the Swedish paper yarns, one thinner and a thicker one. The aim was to reduce the friction between yarn and needle. The two paper yarns were impregnated with the chosen chemical’s fatty acid polyether glycols ester, mono-/dialkyphospate and dispersion wax in a Mathis foulard with a pressure of 3 or 5 bar each. Results from the second impregnation resulted in four different impregnated paper yarns. Further, the paper yarn surface and structure were analyzed under a microscope. Conclusions could be made that the paper yarns after impregnation showed a surface with a hairier appearance, which affected further analysis. A friction tests were performed on the paper yarns with the aim to see if the impregnation had changed the coefficient of friction. The test was performed in the tensile tests and the coefficient of friction was calculated using data recorded in the test. The results showed that the thinner yarn with 3 bar had a higher coefficient of friction with the value of 0,309 than compared with the 5 bar with 0,299. The thin yarn with 5 bar resulted in a slightly decreased coefficient in comparison with the un impregnated yarn with 0,300. The thicker yarn resulted in increasing the coefficient of friction, where the thicker yarn with 5 bar pressure showed a surface where the paper yarn had begun to dissolve, which could be the explanation for the growing coefficient of friction. When analyzing the knittability of the paper yarn, it turned out that the thinner yarn with 3 bar was difficult to knit, which resulted in defects in the product, this due to the hairiness and the sticky surface that was left after the impregnation. The thinner yarn with 5 bar resulted in a product that was easier to knit without defects, which shows that a lower impregnated yarn result in a lower friction coefficient. It’s important to maintain a sustainable forestry. If so and if further progress will success for the Swedish paper yarn, there are good hopes for a larger market.

Every year in the Nordic countries we are affected by winter road conditions. The roadsbecome unpredictable and many traffic accidents occur. This report aims to study thefriction on snow and ice and see how it is affected by different temperatures and surfaces.The friction will also be compared between tests made on outdoor tracks against tests onindoor tracks, and how the friction is affected after a studded tire passes and drives up thesurface. For this, several tests have been performed on Arctic Falls indoor and outdoortracks, where measurement data has been collected using two different ViaFriction carts.The data has then been analyzed in the program Matlab and compiled into several graphsand tables. The results show that there is a clear correlation between a varying temperature and howthe coefficient of friction is affected by it. Indoor tracks do not differ significantly fromoutdoor tracks, but more tests or time may be required to make a completely safeconclusion. Finally, one can clearly see a big difference in the friction/surface when astudded tire has passed, in some cases up to a halved coefficient of friction for the drivensurface.