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Development of Finite Element Models for 3-D Forming Processes of Paper and PaperboardLinvill, Eric January 2015 (has links)
Paper materials have a long history of use in packaging products, although traditional paper-based packaging is limited in its shape and design. In order to enable more advanced paper-based packaging, various 3-D forming processes for paper materials have been studied. Since 3-D forming processes typically include the application of moisture and/or temperature, the effects of moisture and temperature on the mechanical response of paper have also been investigated. In Paper A, an experimental study of the combined effects of moisture and temperature on the uniaxial mechanical properties of paper was conducted. These experiments provided new insights into how moisture and temperature affect both the elastic and plastic properties of paper materials. These experiments also provided the framework from which the effects of moisture and temperature were modelled in Paper C. In Paper B, an explicit finite element model of the paperboard deep-drawing process was developed. An orthotropic material model with in-plane quadrant hardening was developed and verified for paper. The simulation results matched the trends from experimental deep-drawing up to when micro-scale wrinkling occured. Since most experimental failures occur prior to wrinkling, this model provided quantitative understanding of failure in the paperboard deep-drawing process. In Paper C, an explicit finite element model of paper hydroforming, utilizing the same material model for paper materials as in Paper B, was developed and verified. The simulation results matched well with experimental results, and a parametric study with the finite element model produced quantitative understanding of the hydroforming process for paper materials. Additionally, drying was identified as an important phenomenon for determining the extent of formability of paper materials. / Papper har länge använts som förpackningsmaterial men traditionella pappers- och kartongförpackningar är begränsade i form och design. Olika 3-D formnings processor har studerats för att möjliggöra mer avancerade pappersbaserade förpackningar. Effekterna av fukt och temperatur på pappers mekaniska egenskaper har också undersökts eftersom fukt och temperatur har stor betydelse för slutresultatet i 3-D formningsprocesser. I Artikel A har den kombinerade effekten av fukt och temperatur på de uniaxiella mekaniska egenskaperna av papper undersökts experimentellt. Dessa experiment visar hur fukt och temperatur påverkar både elastiska och plastiska egenskaper hos papper samt ligger till grund för modelleringen av inverkan av fukt och temperatur i Artikel C. I Artikel B har en explicit finita element modell för djupdragning av kartong utvecklas. En ortotropisk materialmodell baserad på en rektangulär flytyta har utvecklats och verifierats för kartong. Simuleringen följde trenderna i experimenten fram till den punkt där mikroskopiska rynkor bildas. Resultaten från analyserna med modellen ger kvantitativ förståelse för materialbrott i djupdragningsprocessen eftersom de flesta experimentella materialbrott inträffar innan mikroskopiska rynkor bildas. I Artikel C har ett explicit finita element modell av hydroformning av papper baserad på materialmodellen från Paper B utvecklats och verifierats mot experimentell hydroformning av papper. En parameterstudie med finitaelement-modellen producerade kvantitativ förståelse för hydroformningsprocessen för papper. Dessutom identifieras torkning som ett viktigt fenomen för att fastställa graden av formbarheten för pappersmaterial. / <p>QC 20150907</p>
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The Influence of pH, Temperature and Number of Wash Steps on the Washing Efficiency of CTMP PulpMonlars, André January 2021 (has links)
In this report, the washing efficiency of chemi-thermomechanical pulp (CTMP) from Norway spruce (Picea abies) was investigated when adjusting the temperature and pH during washing as well as implementing different number of wash steps. Concurrent effects of having a high pH and temperature were also examined. CTMP pulp has many uses, one of which is for the manufacturing of packaging board. Lately, this end product has seen a precipitous increase due to the increasing demand of an environmentally friendly alternative within the food packaging sector. A notorious problem associated with all mechanical pulps is how extractives are to a large extent still present after the pulping process, especially unsaturated lipids which are subject to oxidation. This results in the formation of odorous aldehydes that can be easily transferred into the food product, thus contaminating it by altering the perception of taste and odor. This is a frequent problem faced by the status quo liquid board industry. Washing is thus employed late downstream to lower the final wood resin content. Here, available literature has been collated for some basic introductory subjects such as softwood anatomy, wood resin and structures. All of this is described with a focus on softwood, leading up to a thorough breakdown of P. abies. Mechanical pulping and relevant deresination methods for CTMP production are also described, including washing. The objective of this thesis is to evaluate the trends of the final resin concentration as the chosen parameters are altered during washing. The pulp was provided by Rottneros Mill and their industrial process was simulated by using a Büchner funnel for washing. A Soxhlet extractor was used for determining the final extractive contents. It was found that the implementation of additional wash steps reduced the final resin content (1–4 wash steps). The same was found with increasing temperature (60, 70, 80 and 90 °C). The implementation of a fourth wash step seemed to be more efficient at higher temperatures. No conclusions could be drawn from altering the pH due to scattered data points with high uncertainties (pH 7, 8 and 9). The results are limited in terms of significance and are also subject to bias. / I denna rapport undersöktes tvätteffektiviteten av kemitermomekanisk massa (CTMP, chemi-thermomechanical pulp) tillverkad från gran (Picea abies) och hur den påverkas vid justeringar av temperatur, pH och antal tvättsteg. Ytterligare undersöktes förekomsten av eventuella samverkande effekter vid högre temperatur och pH. CTMP-massa har många användningsområden, däribland vid produktion av vätskekartong. På sistone har efterfrågan av vätskekartong ökat markant som ett svar på en allt större strävan efter ett mer miljövänligt alternativ inom matförpackningssektorn. Ett välkänt problem associerat med mekanisk massatillverkning är den stora mängden exktraktivämnen som kvarhålls i den färdiga massan. En viss del av dessa extraktivämnen utgörs av fleromättade fetter vilket är benägna att genomgå oxidation. Detta leder i sin tur till bildandet av flyktiga aldehyder som kan föras vidare till matprodukten och ge dem förändrad smak och lukt; ett problem som dagens vätskekartongproducenter står inför. Tillgänglig litteratur har sammanställts, där en inledande teoridel beskriver koncept såsom anatomi, strukturer och extraktivämnen hos barrved. Teoridelen övergår därefter till att ge en mer detaljerad beskrivning av P. abies och dess extraktivinnehåll. Ytterligare beskrivs mekanisk massatillverkning över lag och metoder för att eliminera extraktivämnen under produktionen av CTMP-massa (inklusive tvättning). Syftet med detta examensarbete är att utvärdera de trender i den slutliga extraktivhalten då de valda parametrarna justeras under tvättning. Massan tillhandahölls av Rottneros Bruk och deras tvättningsprocess simulerades med hjälp av en Büchner-tratt. En Soxhlet-extraktor användes för att utvärdera den slutliga extraktivhalten. Det visade sig att vid varje insättning av ett ytterligare tvättsteg (1–4 tvättsteg) gav en lägre extraktivhalt hos CTMP-massan. Desamma gällde vid ökande temperatur (60, 70, 80 and 90 °C). Implementering av ett fjärde tvättsteg tycks vara mer effektivt vid högre temperaturer. Det kunde dock inte dras några slutsatser huruvida pH påverkade tvättningen då dessa mätvärden fick stor spridning med höga osäkerheter (pH 7, 8 och 9). Resultaten besitter begränsad signifikans och kan även ha blivit utsatta för bias.
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Wet Spinning of Cellulose-Lignin Precursor for Carbon Fibers : Effect of Coagulation Bath Composition & Spin FinishSundmark, Julia January 2023 (has links)
Carbon fibers (CF) are a material with a composition of over 90% carbon, which has high mechanical properties and low density. This unique combination of properties makes it requirable in applications such as vehicles, aerospace, wind power, and space industries. Commercially made CF are made using the fossil raw material polyacrylonitrile (PAN). In order to make a more sustainable precursor fiber (PF), this project has focused on other raw materials; cellulose and lignin. The PFs were produced with a cellulose and lignin mixture (70:30 wt%). In order to make a more green production of PF, cold alkali system was used as the solution in conjunction with wet spinning with an acid:salt coagulation bath. The acid:salt baths used was the P system with phosphoric acid and ammonium dihydrogen phosphate (ADHP), and the S system with sulphuric acid and sodium sulphate with varying concentrations of both acid and salt. The objectives for this thesis was to evaluate the effect of the acid:salt coagulation bath composition, as well as the spin finish. This was done using tensile tests where Young’s modulus, strain to failure, and tensile strength (TS) were determined. The spin finish was evaluated using thermogravimetric analysis (TGA). The results showed that the P system had a significantly higher Youngs modulus and tensile strength compared to the S system, whilst the S system had a higher strain to failure. For the different concentrations of the S system, the tensile tests showed no significant difference between the concentrations. The fibers contained more phosphorus when ADHP was added to the spin finish, making them more flame retardant.
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Effect of Refining on Softwood Pulp with Addition of Eucalyptus for Greaseproof Paper Production : Vacuum Dewatering in Laboratory Scale / Effekt av malning på barrvedsmassa med tillsats av eukalyptus för produktion av fettresistent papper : Vakuumavvattning i laboratorieskalaNordling, Anton January 2023 (has links)
We are provided countless products from the forest industry and has been through many years. Paper, paper board, packaging materials and furniture to mention a few. A special type of paper used in food packaging for example, is greaseproof paper. Many producers of greaseproof papers use the toxic and harmful group of chemicals called per- and polyfluorinated alkyl substances (PFAS) in coating since they possess grease resistance. Nordic Paper is a manufacturer of iamKraft® kraft paper and greaseproof paper with over a hundred years of experience without the use of PFAS. Without PFAS, they instead rely on excess refining to form a very dense paper. Nordic Paper has decided to introduce the addition of eucalyptus fibers to the softwood sulfate pulp to enhance the formation of the paper. This study aims to investigate the effects of ~20% addition of eucalyptus fibers to softwood sulfate pulp in regard to refiner energy expended, air permeance (as a measure of grease resistance) and formation. Laboratory work has been done on hand made sheets with a vacuum suction box in laboratory scale. Eight different pulps (four with addition of eucalyptus), provided from Nordic Paper Seffle AB, Säffle, with different refining degree was used in this study. The vacuum pressure used was 20 kPa through all tests, with dwell times 0, 1, 2.5, 5, 10, and 20 ms on sheets with a grammage of 50 g/m2. The study has shown that the pulp with ~20% addition of eucalyptus achieved 86°SR with only 82% expended energy relative to the softwood pulp, which had a refining degree of 87°SR. This small difference in refining degree led to a similar development in dewatering after 20 ms dwell time and 20 kPa, where the softwood pulp achieved a dryness of 9.2% and the pulp with addition of eucalyptus achieved 9.0% dryness. The formation of the softwood pulp was worse, which was the reason for the implementation of addition of eucalyptus. The air permeance on the other hand was not improved by the eucalyptus, but more data is needed to confirm since it is based on only one occasion. So, if the air permeance (grease resistance) allows, Nordic Paper Seffle AB may be able to save 20% in expended energy for refining of softwood sulfate pulp with addition of eucalyptus. / Vi tillhandahåller otaliga produkter från skogsindustrin och har gjort i många år. Papper, kartong, förpackningsmaterial och möbler för att nämna några. En speciell typ av papper som används i till exempel livsmedelsförpackningar är fettresistent papper. Många tillverkare av dessa papper använder den giftiga och skadliga gruppen av kemikalier som kallas per- och polyfluorerade alkylämnen (PFAS) i beläggning eftersom de har fettbeständiga egenskaper. Nordic Paper är en tillverkare av iamKraft® kraftpapper och ”greaseproofpapper” med över hundra års erfarenhet utan användning av PFAS. Utan PFAS förlitar de sig istället på extra malning av fibrer för att bilda ett mycket tätt papper. Nordic Paper har beslutat att införa tillsats av eukalyptusfibrer till sulfatmassa av barrved för att förbättra formationen på papperet. Denna studie syftar till att undersöka effekterna av ~20 % tillsats av eukalyptusfibrer till barrsvedssulfatmassan med avseende på förbrukad malningsenergi, luftpermeans (som ett mått på fettbeständighet) och formation. Laborationer har utförts på handgjorda ark med vakuumsuglåda i laboratorieskala. Åtta olika massor (fyra med tillsats av eukalyptus), tillhandahållna från Nordic Paper Seffle AB, Säffle, med olika malningsgrad användes i denna studie. Vakuumtrycket som användes var 20 kPa genom alla tester, med uppehållstider 0, 1, 2.5, 5, 10 och 20 ms på ark med en ytvikt på 50 g/m2. Studien har visat att massan med ~20% tillsats av eukalyptus uppnådde 86°SR med endast 82% förbrukad energi i förhållande till sulfatmassan, som hade en malningsgrad på 87°SR. Denna lilla skillnad i malningsgrad ledde till en liknande utveckling i avvattning efter 20 ms uppehållstid och 20 kPa, där sulfatmassan uppnådde en torrhalt på 9.2% och massan med tillsats av eukalyptus uppnådde 9.0% torrhalt. Formationen på sulfatmassan var sämre, vilket var anledningen till genomförandet av tillsats av eukalyptus. Luftpermeansen å andra sidan förbättrades inte av eukalyptusen, men mer data behövs för att bekräfta detta eftersom den enbart är baserad på ett enda tillfälle. Så om luftpermeansen (fettbeständigheten) tillåter kan Nordic Paper Seffle AB spara 20% i förbrukad energi för malning av barrvedssulfatmassa med tillsats av eukalyptus.
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Hantera slöseri i omrullningsprocesser : En fallstudie på ett pappersföretagEdvardsson, Linnea, Spåls, Klara January 2023 (has links)
Följande studie syftar till att kartlägga planeringsprocessen och identifiera brister med den, samt ge förbättringsåtgärder för omrullningen på ett fallföretag. Genom utvecklingen av en generell konceptuell modell för att förbättra planeringsprocesser av omrullning. Under alla år har efterbehandlingsprocessen varit nedprioriterad på fallföretaget, och därmed också planeringsprocessen av den. Vid produktion av papper sker, som i många industrier, ett oväntat utfall av produkter som fått defekter under tillverkningen. Produkterna som har defekter kan oftast räddas och säljas genom att efterbehandlas, och en av dessa efterbehandlingar kallas omrullning. Att undersöka och förstå processer inom företag är avgörande för att göra förbättringar. Studien presenterar förbättringsförslag som baserats på de brister som identifierades med planeringsprocessen. Förslagen innefattar bland annat att skapa ett effektivare IT-system, etablera tydliga kommunikationsvägar och öka engagemanget från ledningen. Dessa insatser kan öka effektiviteten, minska slöseri och bättre tillgodose kundernas behov, vilket ökar konkurrenskraften och lönsamheten inom pappersindustrin. Företaget kan implementera detta förbättringsarbete genom att tillsammans analysera och bryta ner målbilden till mindre små mål som går att uppnå på kort sikt. Baserat på insamlade data presenterar studien en konceptuell modell för att analysera och förbättra planeringsprocessen för omrullning. Förslag på vidare studier har getts, där det kan undersökas samma process på flera företag för att se om samma problematik finns där. Det är också vidare forskning att på fler företag använda den framtagna modellen för att analysera och förbättra planeringsprocesser för efterbehandling för att öka generaliserbarheten. / The following study aims to map the planning process and identify deficiencies within it, as well as provide improvement measures for the rewinding process in a case company. By developing a general conceptual model to enhance rerolling planning processes. Over the years, post-processing operations have been overseen, including the planning process associated with them. In paper production, like in many industries, defective products are generated during manufacturing. These defective products can often be salvaged and sold through post-processing, with one such process being rewinding. Examining and understanding processes within companies is crucial for making improvements. This study aims to map the planning process of rewinding and develop a conceptual model to enhance post-processing planning. The study presents improvement suggestions based on the deficiencies identified in the planning process. The suggestions include creating a more efficient IT system, establishing clear communication channels, and increasing management involvement. These efforts can enhance efficiency, reduce waste, better meet customer needs, thereby increasing competitiveness and profitability within the paper industry. The company can implement these improvement efforts by collectively analyzing and breaking down the target vision into smaller short-term goals that can be achieved. Based on the collected data, the study presents a conceptual model for analyzing and improving the rerolling planning process. Suggestions for further studies have been provided, where the same process can be examined in multiple companies to determine if similar issues exist. Additionally, further research can be conducted in more companies using the developed model to analyze and improve post-processing planning processes, aiming to increase generalizability.
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Prediction of Plastic Fragments in Recycled Paper Using Near-Infrared SpectroscopyAlieva, Fidan January 2023 (has links)
Sustainability has gained a lot of attention in the field of research. Researchers and consumers both prioritize sustainability and environmental issues over previously dominant materials, such as plastic. Packaging and disposable items that used to be made of plastic have largely been replaced with paper. Unfortunately, paper does not perform as well as plastic regarding barrier properties against grease, oxygen, or water vapor. Barrier properties are an important factor when choosing packaging material for food, among other things, as they help maintain the shelf life of the product. In order to improve the properties of the paper packaging and expand its use, the paper is coated with a polymer. However, the polymer contributes to challenges in the recycling of the products as some of the polymer attaches to the fibers, causing difficulties in the separation of each material. Small fragments of plastic may end up in the material streams and the recycled pulp due to the existing challenges in completely removing plastic from cellulosic substrates during recycling. This thesis analyzes the possibilities of identifying and classifying plastic fragments of polyethylene (PE) and polyvinyl alcohol (PVOH) in recycled paper sheets using near-infrared spectroscopy together with multivariate data analysis. The purpose of the work is to develop models that can identify possible residues that may appear in recycled products from various industries. Paper sheets of two different grammages and six different compositions of recycled fiber and virgin fiber were created and scanned by NIR, with and without plastic film under the sheets. The scans were used to develop classification models to identify and categorize scans not included in the calibration data set. The performance of the models was tested by applying them to images of sheets of paper with plastic fragments of different sizes and different type underneath. The results indicated potential in the method. The prediction of the paper sheets with a lower grammage was mostly correct, whereas the classification of polyethylene showed the best performance. There was some noise in the prediction of the plastic fragments, regardless of the grammage of the paper. The noise may be due to a wide variation in the calibration data set since it consisted of paper sheets of six different compositions. A large part of the noise was incorrectly classified as polyvinyl alcohol, which can be due to differences in the manufacturing process of the plastic films. The conclusion of the thesis is that it is feasible to identify and categorize plastic fragments of polyethylene and polyvinyl alcohol in recycled paper sheets with a certain margin of error. It can be stated that the method shows promise, but further research and development in the field is required to build models that can be applied to a wider range of samples.
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Topographical micro-changes in corrugated board production : effects on flexographic post-print qualityRehberger, Marcus January 2007 (has links)
The appearance and design of a package are key properties to attract and to focus the attention of a customer. Print quality contributes to a great degree to achieve these requirements. Most critical perceived in terms of quality are print defects like mottling, gloss and stripiness, which all appear in the printing of corrugated board. Stripiness is especially critical because it is a defect directly caused by the corrugated board construction. A further cause can be generated by the production process of corrugated board. Pre-studies by Odeberg Glasenapp (2004) revealed a difference in surface micro-roughness between the regions on the peak line of the liner and the regions in the valley between two peaks of the corrugation. This knowledge was the basis for the work described in this thesis. In a first stage, laboratory trials were conducted with sets of coated and uncoated samples of various grammages. The trial was set-up in order to simulate the conditions in the corrugator as closely as possible. In the evaluations, it was found out that the settings were too high. For that reason, the coated samples were influenced to a too high degree and needed to be excluded from further evaluations. With the uncoated samples, on the other hand, a change in micro surface roughness was detectable. The roughness is decreased on the peaks and the gloss appearance was the conclusion. The analysis of the printed samples focused on shifts in colour and print density. It is unclear if both are affected only surface roughness changes and/or by the typical corrugated board effect of washboarding. A full-scale test was performed in order to confirm the results of the laboratory test. A test series was chosen with coated and uncoated outer liners. Contrary to the lab-test results, the uncoated grades showed no surface roughness changes. Instead, the coated samples were affected to a great extent. The changes in surface roughness and gloss appearance were similar to the lab-test. This confirms that the lab-test samples were exposed to heat, pressure and shear to a too high degree. The print analysis of the full-scale test did not agree with the laboratory test. Gloss lines were visually detectable, but they were difficult to measure. A reason could be that the ink is capable on forming an ink film layer on top of the surface of the paper. This would cover the micro roughness of the matt parts thereby creating an almost homogeneous glossy appearance. / QC 20101116
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Resin Profile in a Bleached Kraft Pulp ProcessBerglund, Jennie January 2012 (has links)
The aim with this project was to investigate how the amount and composition of resins varied during the process producing bleached birch pulp at the mill SCA Packaging Munksund. A literature study about how the resin removal can be improved has also been included. Problems with resins in the process are common at pulp and paper mills, especially when birch is used as a raw material. The resin can cause deposits on the equipment leading to process stops, but also lowered mechanical properties and spots on the paper products. The addition of tall oil to the digester is one way of improving the removal of resins, seasoning of wood, and a good debarking are other ones. Also the different washing and bleaching steps can affect the amount of resin remaining in the pulp. In this study pulp samples from eight different positions in the process were analyzed. To extract the samples a Soxtec device was used. Results showed that the most effective resin removal happened during the washing in their first washing step after the digester, a DD-washer. Here 77 % of the resin was removed, of totally 88 % during the whole process. Another step which was effective was the final washing step, the PO-press. About 36 % of the remaining resins in the pulp which entered the PO-press were washed out here. The extracts were analyzed with GC-FID and GC-MS to identify and quantify the substances, and determine how the composition varied over the manufacturing process. Twelve different compounds were identified, and the birch bark resin, betulinol, turned out to be the hardest component to remove. Over all, the sterols and triterpenols were hard to deresinate, while the removal of resin acids, fatty acids, and fatty alcohols was more effective. The PO-reactors showed a positive effect on the fragmentation of components consisting of long carbon chains and double bonds, like squalene and betulaprenols. / Målet med projektet var att utreda hur mängden och sammansättningen av hartser varierade i den blekta björkmassan under tillverkningsprocessen på pappersbruket SCA Packaging Munksund. Att göra en litteraturstudie för att ta reda på vilka metoder som kan användas för att förbättra avhartsningen var en annan del av målet. Att pappers- och massatillverkare har problem med hartser är vanligt, speciellt när björkved används som råmaterial. Hartserna kan orsaka beläggningar på utrustningen som i sin tur kan leda till processtop, men även prickar och försämrade mekaniska egenskaper hos pappersprodukten. Att tillsätta tallolja till kokaren är en vanlig metod som används för att förbättra hartsreningen, att lagra träet innan koket, och lägga fokus på att förbättra barkningen är andra metoder. Även de olika blek- och tvättstegen som används under tillverkningen av massan kan påverka hartshalten. I denna studie analyserades massaprover från åtta olika positioner i processen. En Soxtec-utrustning användes för att extrahera massaproverna. Resultatet visade att den mest effektiva avhartsningen sker under tvätten i det första tvättsteget efter kokaren, DD-filtret. Här tvättades 77 % av hartserna ut, och totalt minskade mängden hartser med 88 % under hela processen. PO-pressen var ett annat tvättsteg som var effektivt ur avhartsningssynpunkt. Här togs 36 % av den kvarvarande mängden hartser bort från massan. Extrakten som erhållits från extraktionen analyserades vidare med GC-MS och GC-FID. Dessa metoder användes för att identifiera och kvantifiera extraktivämnena, och bestämma hur sammansättningen varierade under tillverkningsprocessen. Tolv olika ämnen identifierades och den substans som visade sig vara svårast att tvätta bort var björkbark hartset, betulinol. Stort sett så var steroler och triterpenoler svårast att bli av med, medans avhartsingen av hartssyror, fettsyror och fettalkoholer var mer effektiv. Det visade sig även att PO-reaktorerna hade en sönderdelande effekt på substanser såsom squalen och betulaprenoler, dessa består av långa kolkedjor med många dubbelbindningar mellan kolatomerna.
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Fractionation of textile fibres from denim jeans / Mekanisk fraktionering av textilfibrer från denim jeansChroona, Gustaf January 2016 (has links)
The structure and composition of denim jeans is complex. In addition to cotton, which is the dominating type of textile fibre, there may be up to about 20 % synthetic fibres. The synthetic fibres are found in the sewing thread and in the elastic yarns that are used to make stretch denim jeans. In total it was found that up to six different types of textile fibres may be present in the material. To be able to recycle cotton in jeans by producing regenerated cellulose fibres a very high purity with respect to cotton is required. The purpose with this project was to investigate the possibility to fractionate the textile material found in denim jeans to obtain a pure cotton fraction that can be used in the viscose process to produce regenerated cellulose fibres, which then can be used to manufacture new clothes. In this project traditional wet mechanical separation equipment found in the pulp and paper industry, in the form of a laboratory screen (used as a model for a pressure screen) and hydrocyclone, was used to fractionate the textile material from cut and shredded denim jeans. The degree of separation of synthetic fibres from cotton fibres was quantitatively evaluated by measuring the glucose content after acid hydrolysis. The results from the experimental work showed that there were runnability problems both regarding disintegration and fractionation. Regarding the fractionation, plugging was found to be a problem and no significant separation of synthetic fibres from cotton fibres was obtained with the conditions of the experiment. / Strukturen och sammansättningen i denimjeans är komplex. Utöver bomull, vilken är den dominerande typen av textilfiber, kan de innehålla upp till 20 % syntetiska fibrer i tyget. De syntetiska fibrerna finns i sytråden och i elastiska garner som används för att tillverka stretchdenimjeans. Den här studien visade att upp till sex olika typer av textilfibrer kan förekomma i materialet. För att kunna återvinna bomull i denimjeans genom att producera regenererade cellulosafibrer krävs en mycket hög renhet med avseende på bomull. Syftet med projektet var att undersöka möjligheten att fraktionera textilmaterialet i denimjeans för att erhålla en ren bomullsfraktion som kan användas i viskosprocessen för att tillverka regenererade textilfibrer, vilka sedan kan användas för att tillverka nya kläder. I projektet användes, inom massa och pappersindustrin traditionell våtmekanisk separationsutrustning i form av en laboratoriesil (här använd som en modell av en trycksil) och en hydrocyklon, för att fraktionera textilmaterialet från klippta och sönderslitna denimjeans. Separationsgraden av syntetiska fibrer från bomullsfibrer bestämdes kvantitativt genom att mäta glukoshalten efter sur hydrolys. Resultatet från det experimentella arbetet visade att det finns körbarhetsproblem både gällande uppslagning och fraktionering. För fraktioneringen visade sig pluggning vara ett problem och ingen signifikant separation av syntetiska fibrer från bomullsfibrer erhölls med förhållandena i experimentet.
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Initial evaluation of briquetting possibilities of CaO-containing paper production waste : For use in metallurgical processesXia, Wei January 2018 (has links)
Paper and pulp industry and steel industry are two major industries in Sweden, both of which are facing big challenges to treat their waste products properly. In this thesis work, initial evaluation of mechanical properties of briquettes made of waste products was performed. Three different CaO-containing waste products (Mesa, Kalk, Fly Ash) from Stora Enso and SCA were pressed with one kind of binding material (AOD slag) from Outokumpu. Drop tests were carried out to test the impact strength of the lab-made briquettes. Three different parameters were investigated of their influence on the impact strength of the briquettes: 1) Composition of briquettes 2) Heat treatment procedure 3) Exposure time to open air. A total of 97 briquettes were pressed. Drop test results show that for different material based briquettes, heat-treatment and exposure to open air had different influence on the final impact strength. In order to get best impact strength, MB briquettes (90% Mesa +10% AOD slag) heat treated at 850℃, KB briquettes (90% Kalk +10% AOD slag) heat treated at 850℃ and FC briquettes (80% Fly Ash + 20% AOD slag) exposed to open air for 20 days are recommended. Melting experiment was carried out to investigate the sulphur removal ability of the briquettes in metallurgical processes. Thermodynamic calculation of sulphide capacity was done. / Pappers-, massa och stålindustrin är två stora industrier i Sverige, vilka båda står inför stora utmaningar för att hantera sina avfallsprodukter på rätt sätt. I denna avhandling utfördes en första utvärdering av mekaniska egenskaper hos briketter av avfallsprodukter. Tre olika CaO- innehållande avfallsprodukter (Mesa, Kalk, Fly Ash) från Stora Enso och SCA pressades med ett bindande material (AOD slagg) från Outokumpu. Dropptest utfördes för att testa slaghållfastheten hos de laboratoriegjorda briketterna. Tre olika parametrar undersöktes av deras påverkan på briketternas slaghållfasthet: 1) Brikets sammansättning 2) Värmebehandlingsförfarande 3) Exponeringstid för friluft. Totalt 97 briketter pressades. Dropptestresultat visar att för olika materialbaserade briketter hade värmebehandling och exponering för utomhusluft ett annat inflytande på den slutliga slagstyrkan. För att få bästa slaghållfasthet, värmebehandlades MB-briketter (90% Mesa + 10% AOD-slagg) värmebehandlad vid 850 ° C, KB-briketter (90% Kalk + 10% AOD-slagg) vid 850 ° C och FC-briketter (80% Fly Ask + 20% AOD slagg) utsatt för öppen luft i 20 dagar rekommenderas. Smältningsexperiment utfördes för att undersöka svavelfjernningsförmågan hos briketterna imetallurgiska processer. Termodynamisk beräkning av sulfidkapacitet gjordes.
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