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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Estudo da reciclagem mecânica de poli (cloreto de vinila) - PVC - proveniente deresíduos da construção civil /

Darbello, Sabrina Moretto. January 2008 (has links)
Orientador: Sandro Donnini Mancini / Banca: Maria Zanin / Banca: Steven Frederick Durrant / O Programa de Pós-Graduação em Ciência e Tecnologia de Materiais, PosMat, tem caráter institucional e integra as atividades de pesquisa em materiais de diversos campi da Unesp / Resumo: Em estudo realizado no Aterro Municipal de Inertes de Sorocaba determinou-se que a cidade envia ao aterro diariamente cerca de 500 toneladas de entulho, separando mensalmente 160 toneladas de recicláveis, sendo 1,4 toneladas resíduos de PVC rígido, principalmente tubos. Amostras desses tubos foram coletadas, moídas em duas granulometrias diferentes, lavadas, secas e caracterizados seus efluentes. Obteve-se 8,5% de teor de cinzas para os tubos moídos, o que serviu de base para a determinação da formulação do composto baseado em resina virgem: 84% de resina, 13,4% de Ca 'CO IND. 3', 1,9% de estabilizante e 0,7% de Ti 'O IND. 2'. Assim, três conjuntos de amostras (baseada em resina virgem e em resíduos de tubos moídos em duas granulometrias diferentes) foram submetidos a ensaios de tração, impacto, cor e de propriedades superficiais (resistividade, rugosidade, desgaste, dureza, XPS, infravermelho), sendo estes realizados antes e após tratamento a plasma com 'SF IND. 6' otimizado (80W,2 minutos e 100 mTorr), visando tornar e manter a amostra hidrofóbica. Os resultados de tração, impacto e dureza indicaram que a reciclagem não provocou alterações significativas. Já os resultados das propriedades superficiais apontam que os tratamentos realizados no material reciclado tendem a aproximar seus valores dos obtidos para o material virgem sem tratamento. Neste sentido, o material de granulometria grossa fornece resultados geralmente melhores. Isso indica que uma moagem menos demorada, além de gerar menos sólidos nos efluentes, origina um material menos susceptível a degradação durante o processamento. / Abstract: A study carried out at the Municipal Inert Landfill's Sorocaba, it was determined that the city sends to the landfill around 500 tons of rubble daily, separating 160 tons of recyclabe material monthly, of which 1.4 tons are rigid PVC residues, mainly in the form of tubes. Samples of these tubes were collected, ground in two different mesh sizes, washed, dried and its effluent characterized. The ground tubes contained 8.5% ash, which formed the basis to determine the formulation of the compound bases on virgin resin, 13.4% of Ca 'CO IND. 3', 1,9% of stabilizes and 0,7% de Ti 'O IND. 2'. So, three sets of samples (based on virgin resin and based on tubes ground in two different sizes) were submitted to tests of tensile, impact, color and tests of surface properties (resistivity, roughness, wear, hardness, XPS, infrared), the last ones being carried out before and after the 'SF IND. 6' plasma treatment optimized (80W,2 minutos e 100 mTorr) to make and maintain the sample hydrophobic. The results of tensile, impact and hardness tests indicated that recycling did not cause significant changes. The results of surface property measurements show that the surface treatments carried on in the recycled material draw their values towards those obtained for the virgin material without treatament. In this sense, the material originating from tubes ground to a coarse grain size generally offer better results. This indicates that a short grinding, produces less solid effluent washing and gives rise to material a less susceptible to degradation during the processing. / Mestre
2

Estudo da reciclagem mecânica de poli (cloreto de vinila) - PVC - proveniente deresíduos da construção civil

Darbello, Sabrina Moretto [UNESP] 16 December 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-16Bitstream added on 2014-06-13T18:55:41Z : No. of bitstreams: 1 darbello_sm_me_bauru.pdf: 1163846 bytes, checksum: 789eccc3f2835db4fdd954bf53c2a85e (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Em estudo realizado no Aterro Municipal de Inertes de Sorocaba determinou-se que a cidade envia ao aterro diariamente cerca de 500 toneladas de entulho, separando mensalmente 160 toneladas de recicláveis, sendo 1,4 toneladas resíduos de PVC rígido, principalmente tubos. Amostras desses tubos foram coletadas, moídas em duas granulometrias diferentes, lavadas, secas e caracterizados seus efluentes. Obteve-se 8,5% de teor de cinzas para os tubos moídos, o que serviu de base para a determinação da formulação do composto baseado em resina virgem: 84% de resina, 13,4% de Ca 'CO IND. 3', 1,9% de estabilizante e 0,7% de Ti 'O IND. 2'. Assim, três conjuntos de amostras (baseada em resina virgem e em resíduos de tubos moídos em duas granulometrias diferentes) foram submetidos a ensaios de tração, impacto, cor e de propriedades superficiais (resistividade, rugosidade, desgaste, dureza, XPS, infravermelho), sendo estes realizados antes e após tratamento a plasma com 'SF IND. 6' otimizado (80W,2 minutos e 100 mTorr), visando tornar e manter a amostra hidrofóbica. Os resultados de tração, impacto e dureza indicaram que a reciclagem não provocou alterações significativas. Já os resultados das propriedades superficiais apontam que os tratamentos realizados no material reciclado tendem a aproximar seus valores dos obtidos para o material virgem sem tratamento. Neste sentido, o material de granulometria grossa fornece resultados geralmente melhores. Isso indica que uma moagem menos demorada, além de gerar menos sólidos nos efluentes, origina um material menos susceptível a degradação durante o processamento. / A study carried out at the Municipal Inert Landfill's Sorocaba, it was determined that the city sends to the landfill around 500 tons of rubble daily, separating 160 tons of recyclabe material monthly, of which 1.4 tons are rigid PVC residues, mainly in the form of tubes. Samples of these tubes were collected, ground in two different mesh sizes, washed, dried and its effluent characterized. The ground tubes contained 8.5% ash, which formed the basis to determine the formulation of the compound bases on virgin resin, 13.4% of Ca 'CO IND. 3', 1,9% of stabilizes and 0,7% de Ti 'O IND. 2'. So, three sets of samples (based on virgin resin and based on tubes ground in two different sizes) were submitted to tests of tensile, impact, color and tests of surface properties (resistivity, roughness, wear, hardness, XPS, infrared), the last ones being carried out before and after the 'SF IND. 6' plasma treatment optimized (80W,2 minutos e 100 mTorr) to make and maintain the sample hydrophobic. The results of tensile, impact and hardness tests indicated that recycling did not cause significant changes. The results of surface property measurements show that the surface treatments carried on in the recycled material draw their values towards those obtained for the virgin material without treatament. In this sense, the material originating from tubes ground to a coarse grain size generally offer better results. This indicates that a short grinding, produces less solid effluent washing and gives rise to material a less susceptible to degradation during the processing.
3

Reprocessing and Characterisation of High Density Polyethylene Reinforced with Carbon Nanotubes / Mekanisk återvinning och karaktärisering av högdensitetspolyeten armerad med kolnanorör

Svensson, Sofie January 2017 (has links)
Nanokomposit innehållande högdensitetspolyeten och kolnanorör återvanns och analyseradesför att undersöka hur materialets egenskaper påverkas av återvinning. Kompositenproducerades med 3 viktprocent kolnanorör och återvanns tio gånger genom att extrudera ochmala ner materialet. Analyser gjordes efter varje cykel av extrudering. Dessutom utfördessimulerade tester med kontinuerlig extrudering i 20, 100 och 200 minuter motsvarande 10, 50och 100 cykler. Därav kunde nedbrytningen av kompositen efter längre tids bearbetninganalyseras. I projektet studerades ett referensmaterial bestående av den rena polymeren för attkunna jämföra resultat. Karaktärisering av materialen för att bestämma mekaniska egenskapergjordes med dragprovning, böjningstest och slagprovning. För att undersöka termiskaegenskaper användes Differential Scanning Calorimetry (DSC) och Gel PermeationChromatography (GPC) användes för att hitta molekylviktsändringar. Fourier TransformInfrared Spectroscopy (FTIR) utfördes för att identifiera materialet. Resultaten visade ingenstörre skillnad i egenskaper efter tio återvinningscykler, vilket indikerade att materialet harförmåga att behålla sina egenskaper vid återvinning. I de simulerade cyklerna minskade denoxidativa induktionstiden efter 50 och 100 cykler, vilket berodde på att antioxidanterkonsumerats under bearbetningen. Efter 50 simulerade cykler hade molekylvikten börjat sjunkaoch efter 100 cykler kunde en signifikant minskning obseveras, vilket tydde på attpolymerkedjorna förkortats under bearbetningen. För kompositen däremot var molekylviktenstabil, på grund av att kolnanorören skyddade polymeren vid nedbrytning. / Nanocomposite containing High Density Polyethylene (HDPE) and Carbon Nanotubes (CNTs)was reprocessed and characterised to investigate the effect on properties during recycling. Thecomposite was prepared with 3 wt-% CNTs and was recycled ten times by alternatereprocessing and grinding and thereafter the material was characterised. Furthermore, simulatedcycles with continuous processing at 20, 100 and 200 minutes were conducted, representing 10,50 and 100 cycles respectively, in order to investigate the degradation after longer time ofprocessing. In both trials, a reference material containing neat HDPE was studied. Thecharacterisation of the materials produced was conducted using tensile, flexural and charpyimpact testing for investigation of mechanical properties. Differential Scanning Calorimetry(DSC) was used for determining the thermal behaviour and Gel Permeation Chromatography(GPC) to find molecular weight changes. Fourier Transform Infrared Spectroscopy (FTIR) wasused for identification of the material. The results showed no major difference in propertiesafter ten recycling steps, which indicated that the material had the ability to retain its propertiesduring recycling. In the simulated cycles, the oxidative induction time was decreased after 50and 100 cycles, meaning that antioxidants had been consumed during processing. After 50cycles the molecular weight for the reference material was slightly decreased and after 100cycles significantly decreased, indicating chain scission of the polymer chains. For thecomposite the molecular weight was stable, due to that the carbon nanotubes protect thepolymer matrix during degradation.
4

OLD TO BECOME AS GOOD AS NEW : Pretreatment for gentle shredding

Namuga, Catherine January 2017 (has links)
In today’s World, sustainability is not just a buzz word but should be the new quality. In order to live in a pollution free environment, there is an urgent need to move towards a circular economy. The rapidly increasing demand of textiles results in high amount of textile waste leading to pollution. Textile to textile recycling is the most feasible solution to minimize textile waste while meeting the fashion demand. Mechanical recycling by shredding is one way of recycling textiles where, fabrics are broken down into their constituent fibres. The problem with this method is that, after shredding, there is huge reduction in fibre length due to the harsh process. This makes it difficult to use a high percentage of these reclaimed fibres in formation of new textile garments. The main focus of this thesis was to reduce the fibre length drop that occurs during shredding through lubricant pretreatment. It was anticipated that, inter-fibre friction would be the reason for the huge fibre length drop during shredding. Therefore, a method was developed to measure the inter-fibre friction of cotton and polyester staple fibres using a tensile tester. The effect of blending on inter-fibre friction was investigated. Different types of lubricants were used to alter the inter fibre friction. The lubricants were sprayed on the fibres and dried prior to carding. Two lubricants were chosen for pretreatment of fibres for yarn formation. The effect of the lubricant on the inter-fibre friction of carded fibre webs as well as yarn strength and spinnability were investigated. The results showed that, the method developed can be used to measure inter-fibre friction of staple fibres. It was also found that, inter-fibre friction in carded webs depends on the crimp and mechanical interlocking in the web. Inter-fibre friction in blended fibres depends on the percentage amount of each fibre in the blend. Addition of a small amount of lubricant significantly lowers the inter-fibre friction. The effect depends on the type of lubricant and type of fibre. Lubricant amount above 1.43% on weight of fibre lead to poor carding of fibres. Lubricant amounts between 0.29 % and 1% on weight of fibre lead to good carding of cotton and polyester fibres but the cotton fibre webs may not be spun. PEG4000 lubricant was found to significantly lower the inter-fibre friction compared to other lubricants. It was also found that, lubricants significantly affect the tensile strength of the yarn as well as their spinnability. Basing on the results, it was concluded that, lubricant pretreatment of fabrics prior to shredding will most likely provide a more gentle process. This was based on the fact that, the lubricants reduce the inter-fibre friction. This enables easier slippage of fibres within the yarns which facilitates easier deformation of the yarns during the shredding process. Thus reduce the fibre length drop. PEG 4000 is more likely to provide better results when used in amounts ranging from 0.1 to 0.71% on weight of fabric. Besides that, PEG is safe for the environment.
5

Torn to be worn? : Cotton fibre length of shredded post-consumer garments

Aronsson, Julia January 2017 (has links)
In 2015 the global fibre consumption was 96.7 million tonnes, which is an increase of 3.1% from the year before. Our high textile consumption has led to an increasing demand of raw materials and generation of textile waste. Only in Europe, a total amount of 4.3 million tonnes of apparel waste each year is sent to either incineration or landfills. Approximately 50% of the clothes we discard and donate are composed of cotton. In the future, the cotton production is predicted to stagnate since the world population is increasing and arable land to greater extent will be needed for food production. Thereby, it is important that we utilize the cotton waste generated. One of the most commonly used processes for recycling textile waste is the shredding process. In this method, textile waste is shredded back into their constituent fibres. The drawback with the shredding process is that the fibre length is reduced. The fibre length is an important property since it has a high influence on textile processing such as yarn production and final product quality. The aim of this thesis was to investigate how post-consumer cotton garments with different degree of wear affects the fibre length obtained in the shredding process. This was performed by analysing the input fibre length as well as the output fibre length. Additionally, several parameters were investigated: fabric construction and yarn structure. Degree of wear was categorized into two levels: low and high degree of wear. The fabric constructions used in this study were single-jersey and denim. The yarn structure were analysed in terms of yarn count, yarn twist and manufacturing process.  The result showed that the fibre length before shredding was statistically significant longer for the materials with low degree of wear compared to high degree of wear. After shredding, it was shown that the fibre length reduction was lower for the materials with high degree of wear. This indicates that longer fibres give higher fibre length reduction. In addition, it was found that finer yarn gives higher fibre length reduction. The result also showed that the yarn manufacturing process has a great influence on the ease of shredding and the fibre length obtained in the end.  Based on the result in this thesis it can be concluded that the shredding process needs to be improved in order to preserve the fibre length. The area of post-consumer textile waste is complex and the result showed that there is many underlying parameters that need to be taken into account to further develop the shredding process.
6

Propuesta de diseño estructural del pavimento rígido convencional y fibroreforzado de la Av. Sánchez Cerro en Piura usando la tecnología del reciclado mecánico / Structural design proposal for the conventional and fiber-reinforced rigid pavement of Sánchez Cerro avenue in Piura using mechanical recycling technology

Espinoza Gonzáles, Alvaro Javier, Vargas Guevara, Jessica Jeanette 31 August 2020 (has links)
Debido al incremento tránsito, el poco o nulo mantenimiento de la vía, la falta de drenaje pluvial y los estragos ocasionados por el fenómeno de “El Niño Costero”, la infraestructura vial de la Av. Sánchez Cerro se ha deteriorado a tal punto de presentar fallas estructurales y nulos niveles de serviciabilidad que no permiten un tránsito adecuado de los vehículos y peatones que circulan por la zona, afectando el confort del ciudadano y el paisajismo de la ciudad. Ante ello, y debido a que la zona es altamente comercial, con muchas interferencias producidas por los servicios públicos, las tendencias de sostenibilidad a nivel global y los niveles existentes en el proyecto, se ha realizado optado por realizar una propuesta de rehabilitación del pavimento mediante una base reciclada de asfalto con colocación de una losa de pavimento rígido que permita cumplir con los objetivos del proyecto. El objetivo principal del estudio es realizar el diseño del reciclado mecánico, también conocido como RAP, y el diseño de la losa de concreto del pavimento rígido mediante las metodologías AASHTO 1993, PCA 1984 y la “Yield Line Theory” (basada en Technical Report N° 34 del Eurocódigo) utilizada para el diseño de losas reforzadas con fibras que permita verificar las condiciones de diseño, brindando soluciones tradicionales y alternativas que permitan mantener los niveles de la vía. / Due to the increase in traffic, the lack of maintenance and drainage of the road and the damage caused by "El Niño Costero", the infrastructure of Sánchez Cerro avenue has deteriorated to the point of presenting structural failures and zero levels of serviceability that do not allow the transit of vehicles and pedestrians, affecting the comfort of the citizen and the landscape of the city. Given this, and because the area is highly commercial, with many interferences produced by public services, the global sustainability trends and existing levels in the project, it has been decided to carry out a proposal for the rehabilitation of the pavement through a recycled asphalt pavement (RAP) with the placement of a concrete slab that allows reach the objectives of the project. The main objective is to carry out the mechanical recycling design and the design of the rigid pavement concrete slab using the AASHTO 1993, PCA 1984 and “Yield Line Theory” methodologies (based on Technical Report No. 34 of the Eurocode) used for the design of slabs reinforced with fibers that allows to verify the design conditions, providing traditional and alternative solutions that allow maintaining the levels of the road. / Tesis
7

Impact of textile structure on mechanical recyclability

Bengtsson Creaser, Linnéa January 2023 (has links)
This thesis investigates the impact of yarn and fabric structure on the mechanical recyclability of textile structures. It focuses on variations in yarn twist and form (single or plied) as well as fabric type (woven or knitted) and their respective constructions. The study involved evaluating the mechanical recyclability of 21 cotton textile structures in different constructions, including woven and knitted fabrics, each made using one of the four yarns prepared for this study. The mechanical recyclability was evaluated based on the opening efficiency of the textile structures, together with the average mean fiber length and short fiber content post-tearing. According to the evaluation, a higher fraction of fibers sorted as open and longer fibers resulting from tearing indicated higher recyclability. Based on the evaluation, it was observed that the single yarns tended to be more favorable for mechanical recycling compared to plied yarns. In addition, the effect of the yarn plying twist was multifaceted, with lower yarn twists not necessarily benefiting recyclability. Testing was also conducted to characterize the yarn and fabric structures concerning properties such as count, strength, yarn twist, and thread density of the fabrics. It could be seen that it is of higher relevance to categories of fabric structures based on their density than their fabric type (weaved or knitted) in terms of recyclability. The denser fabric structures' recyclability was more dependent on their fabric construction, whereas, in less dense fabric structures, the yarn structure appeared to have a greater impact. Therefore, determining the interaction of the yarn and fabric structures is important to understand how variations in yarn and fabric structures impact the recyclability of textile structures.
8

Evaluation of the recyclabillity of a lignin-based biopolymer / Evaluación de la reciclabilidad de un biopolímero a base de lignina

Hacksell, Eric January 2021 (has links)
The use of plastic materials has changed the packaging industry, the construction industry, the automotive industry, and many others drastically. Plastics are also abundant in our everyday life. However, its downsides in the society are undeniable and are starting to get attention from law makers, the general public and industries alike. Because of their reliance on fossil feedstock and persistence in nature, efforts are being made to make plastics biobased as well as improving recycling of the material. However, the recycling process is complicated, unoptimized and also differs depending on the product and the country. The differences include the techniques and technology used for sorting, the plastics which are prioritized, and where they end up. This project investigated the recyclability of Renol®, a biopolymer based on lignin, a residual product from the forest industry. To do this, first it was established the most interesting viable thermoplastic resin for the Renol was PP. This was because one of the uses for Renol is in plastic packaging, where PP is one of the most recycled materials. Different compositions of the PP/Renol blend were then produced, containing 5, 10, 20, 30 and 50wt% Renol. Density testing and infrared spectroscopy were then used to determine the highest percentage by weight of Renol that could be included for the material to still be detected as PP in a plastics recycling station. For density, the highest concentration was determined to be 46wt% and 27wt%, for sorting methods using 1.00g/cm3 and 0.95g/cm3 as their thresholds, respectively. Using near-infrared technology and computer algorithms by TOMRA (the European company leading the industry in sorting materials), this value decreased to 20wt%. The quality of recycled polypropylene with Renol (Ren25 and Ren50) and without (rPP) was then measured using the tests stated in the RecyClass protocol for PP containers. It was found that both Ren25 and Ren50 had an elongation at break which was too low compared to rPP. There was a woody smell in the materials Ren25 and Ren50. This was reflected in the measurement for volatiles, where the materials were inserted into a 180°C oven and Ren50 lost the most mass out of the three materials. If the material were to be sent to an official recyclability test, it would most likely fail with the elongation at break, the smell and the volatile substances. In a packaging context it would most likely be sorted and recycled as colored PP at a maximum of 20wt% Renol and for other products with PP, most likely at a maximum of 46wt% Renol. / Användandet av plaster har drastiskt förändrat, bland många andra, förpacknings-, bygg- och bilindustrin. Plaster är också oerhört vanliga i vårt vardagliga liv. Dock är deras negativa egenskaper uppmärksammade av allmänheten, industrier samt lagstiftare. På grund av att traditionellt ha varit beroende av icke-förnybara fossila råmaterial samt dess långsamma nedbrytning i naturen studeras möjligheter till att producera biobaserade plaster samt att förbättra återvinningsprocessen för plaster. I praktiken är återvinningen dock komplex och skiljer sig från land till land och produkt till produkt. Teknologier som fungerar på en typ av plast och produkt fungerar inte nödvändigtvis på en annan. Detta projekt undersökte återvinningsgraden av Renol®, en biopolymer baserad på lignin, en restprodukt från skogsindustrin, och en syntetisk polymer. För detta syfte var det polypropen (PP) som valdes som blandpolymer, då PP är en av de mest återvunna polymererna samt att ett av användningsområden av Renol är förpackningar. Olika blandningar av Renol/PP blandningen producerades, med 5, 10, 20, 30 och 50 viktprocent (wt%) Renol vardera. Tester av de olika blandningars densitet samt analys med hjälp av infraröd spektroskopi användes sedan för att bestämma högsta procenthalten Renol materialet kan innehålla och fortfarande detekteras som PP i en återvinningsstation. Genom densitetsproven fastställdes maxkoncentrationen Renol till 46wt% och 27wt%, för sorteringsmetoder som använder 1.00g/cm3 respektive 0.95g/cm3 som tröskelvärden för PP. Genom infraröd teknologi och datoralgoritmer från TOMRA (europeiska ledare i materialsortering) blev maxvärdet fastställt till 20wt%.  Kvaliteten av återvunnen PP (rPP) jämfördes sedan med den av blandningar av rPP och Renol för att se hur deras egenskaper skiljer sig. Materialtester gjordes med hänvisning till de tester RecyClass-protokollet föreslog för PP-förpackningar. Många tester låg inom toleransen, dock var töjningen vid brott lägre hos Renolblandningen. Renol har också en speciell lukt som inte hittas hos ren rPP samt att den ger av mer volatila ämnen än rPP. Skulle materialet alltså skickas till ett officiellt återvinningstest hos RecyClass, skulle det troligen misslyckas på grund av en lägre töjning vid brott, dess lukt samt dess volatila substanser. Skulle materialet användas i en förpackning skulle den med stor sannolikhet sorteras som färgad PP vid en maxhalt av 20wt% Renol och för andra PP-produkter vid ett max av 46wt% Renol. / El uso de materiales plásticos ha cambiado drásticamente la industria de los envases, la de la construcción, la del automóvil y muchas otras. Los plásticos también abundan en nuestra vida cotidiana. Sin embargo, sus desventajas en la sociedad son innegables y están empezando a llamar la atención de los legisladores, el público en general y las industrias por igual. El proceso de reciclaje de plásticos no es sencillo, ya que requiere limpieza, clasificación y compradores dispuestos. También varía según el producto y el país. En este proyecto se investigó la reciclabilidad del Renol®, un biopolímero a base de lignina, un producto residual de la industria forestal. Para ello, primero se estableció que la resina termoplástica viable más interesante para el Renol era el polypropyleno (PP). Esto se debió a que uno de los usos del Renol es en los envases de plástico, donde el PP es uno de los materiales más reciclados. A continuación, se produjeron diferentes composiciones de la mezcla Renol/PP, que contenían 5, 10, 20, 30 y 50wt% de Renol. A continuación, se utilizaron las pruebas de densidad y la espectroscopia de infrarrojos para determinar el mayor porcentaje en peso de Renol que podía incluirse para que el material siguiera detectándose como PP en una estación de reciclaje de plásticos. En cuanto a la densidad, se determinó que la concentración más alta era del 46wt% y del 27wt%, para los métodos de clasificación que utilizan 1,00g/cm3 y 0,95g/cm3 como umbrales, respectivamente. Utilizando la tecnología de infrarrojo cercano y los algoritmos informáticos de TOMRA (la empresa europea líder en el sector de la clasificación de materiales), este valor se redujo al 20wt%. A continuación, se comparó la calidad del PP reciclado (rPP) con mezclas con rPP y Renol para comprobar que el Renol no empeora la calidad de material reciclado. Los ensayos se decidieron en base al protocol RecyClass para envases de PP. Varias propiedades estuvieron dentro de la tolerancia del protocolo, sin embargo el alargamiento de rotura fue menor en la mezcla Renol. El Renol también tenía un olor particular que no se encuentra en el rPP puro y al final libera más sustancias volátiles que el rPP. Por lo tanto, si el material se enviara a una prueba oficial de reciclaje en RecyClass, probablemente fallaría debido a una menor elongación a la rotura, su olor y sus sustancias volátiles. En caso de que el material se utilice en envases, lo más probable es que se clasifique como PP de color con un contenido máximo de 20wt% de Renol y para otros productos de PP con un máximo de 46wt% de Renol.
9

Från plagg till plagg / From Garment to Garment

Jemt Gardell, Emma, Racklin, Hannah January 2016 (has links)
De senaste decennierna har visat på en stor ökning av den textila konsumtionen som följd av efterfrågan, samtidigt som den textila återvinningen idag är nästintill obefintlig. Detta leder till att mycket av det textila materialet deponeras istället för att återvinnas, vilket innebär ett stort slöseri av redan befintlig råvara som skulle kunna användas till att skapa nytt textilt material. Genom att undersöka olika återvinningsmetoder och -processer skulle denna råvara kunna användas på nytt. Examensarbetet är en del av forskningsprojektet ”Från spill till guld” som leds av forskningsinstitutet Swerea IVF. Forskningsprojektets utgångspunkt är att minimera produktionsspill och att höja dess värde inom bland annat textilindustrin. Examensarbetet syftar till att undersöka termomekanisk återvinning av plagg gjorda av polyamid 6.6 (PA6.6) och elastan, smältspinna filament samt formspruta provstavar från denna nya polymerblandning utan att separera fibrerna. Andra syftet är att även hitta en lösning för produkterna som undersöks i detta examensarbete kan återvinnas i sin helhet, så att ingen demontering av produkterna ska behövas. Fyra olika plagg undersöktes i examensarbetet bestående av materialblandningen PA6.6 och elastan. Analyser av de fyra olika plaggen genomfördes för att fastställa materialen. Hela plagg tillverkade i de olika materialen klipptes eller maldes ned och smältes sedan om genom kompoundering, därefter tillverkades granulat. Materialen testades i spinnbarhet genom smältspinningsförsök, sedan smältspanns eller formsprutades materialen. Resultaten från smältspinningsförsöken analyserades i ljusmikroskop för att avgöra om elastanen är termoplastiskt eller inte då detta är en avgörande faktor vid smältspinning. Olika tester gjordes på materialen för att undersöka deras eventuella kemiska nedbrytning som resultat av kompoundering. Resultatet visade att smältspinning och formsprutning inte är möjligt från denna polymerblandning. Ett antagande kan göras att återvinningen inte fungerade på grund av PA6.6:s höga smälttemperatur, då elastanen antagligen bryts ned vid denna höga temperatur, vilket förstör materialet. Slutsatsen blir då att smältspinning och formsprutning inte är möjligt utifrån denna polymerblandning, men återvinning till plastdetaljer kan produceras vid kompounderingsstadiet och återanvändas i annan industri än textilindustrin. Potential finns för återvinning av plagg till plagg om ändringar görs under processens gång och om elastanen identifieras som termoplastisk eller inte. / The latest decades have shown a large increase in textile consumption as a result of demand, at the same time the textile recycling today is almost non-existent. This means that much of the textiles are used for landfill rather than being recycled, which generates a large waste of raw material that could be used to create new textiles. By exploring various recycling methods and processes this raw material could be used again. This thesis is part of a research project, “From Waste To Gold”, which is led by the research institute Swerea IVF. The research projects foundation is to minimize production waste and to increase its value in areas such as textile industries. This thesis’ foundation is to examine the mechanical recycling of garments made by polyamide 6.6 (PA6.6) and spandex, melt spin filaments and produce injection moulded samples from this new polymer blend, without separating the fibres. The other foundation is to find a solution for the products that are examined in this thesis so they could be recycled as a unit, no disassembly of the products would be necessary Four different garments was examined in this thesis, the materials were a combination of PA6.6 and spandex. Different analyses were made on the four different garments. Whole garments from the different materials were cut or milled and then re melted through compounding, after compounding granulates was made. The materials spin ability was tested through melt spinning trials, then the materials were either melt spun or injection moulded. The results from the spinning trials was analysed in a light microscope to examine if the spandex were thermoplastic or not, as this is a crucial factor when melt spinning. Various tests were conducted to analyse their chemical degradation after the compounding. The results from the melt spinning and injection moulding showed that it was not possible to recycle this polymer combination this way. An assumption can be made that the recycling methods did not work because of the high melt temperature of PA6.6, the spandex assumes to decompose at this high temperature and therefore destroys the material. The conclusion is that melt spinning and injection moulding is not possible to conduct with this polymer combination, but recycling to plastic details could be done at the compound stage and then be used in some other industry, not in the textile industry. There are potential for garment-to-garment recycling if changes are made during the recycling processes and if the spandex could be identified as a thermoplastic or a non-thermoplastic.
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Fabric conditioning for more gentle shredding : Pre-treatment for mechanical recycling of cotton and polyester

Sjöblom, Therése January 2018 (has links)
There is a growing need for fibres with increasing population. One way to solve this is to recycle the fibres from textile waste. In mechanical recycling by shredding the textiles are shredded back to fibrous form. The biggest problem with shredding is that it is a harsh process that reduces the fibre length and damages the fibre.   To make the shredding process more gentle and preserve more of the fibre length, pre-treatment that lowers the friction between the fibres have been investigated. Polyethene glycol 4000 (PEG 4000) is an environmentally friendly chemical that could be used to lower the friction of cotton and polyester, the two most used textile fibres. Another treatment evaluated is glycerol. The treatment should not affect further processing of the fibres. For evaluating the treatment, a test of the interfibre friction was performed on carded webs and fabrics that were untreated and treated. Prior to shredding four samples were made of fabrics of cotton, polyester and polycotton. From each fabric, one was left untreated, and one was treated with a low concentration of PEG 4000. The concentration of PEG 4000 was chosen from the test on fibres. Also from each fabric, two treatments that were not prepared by the author; one with a high concentration of PEG 4000 and the other with glycerol. All 12 samples were shredded back to fibres. The shredded material was analysed, and the fibre length was measured. The reclaimed fibres from the shredded material were also tried to be processed into yarns.   The main result was that it was possible to rotor spin yarn of 100% reclaimed fibres from cotton and polyester treated with PEG 4000, which means that the treatment did not interfere with the spinnability of the reclaimed fibres. Untreated cotton was also spinnable, but untreated polyester was not possible to card. The cotton and polyester treated with glycerol were possible to carded and made into a sliver but not spinnable. The reclaimed fibres from the polycotton fabric were not possible to card or process further. This result correlates with the analyses of the shredded material and the fibre length measurement. The best results were for polyester treated with 0.71 w% PEG 4000 that had 121% longer mean fibre length than untreated polyester. The best result for cotton was treated with 0.29 w% PEG 4000.

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