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Expancel mikrosfärernaspåverkan på bestrykningssmetoch bestruken kartong / The impact of Expancel microspheres on coating and coatedpaperboardChehade, Ahmad January 2022 (has links)
In Sweden, paperboard has been an essential product in the export market and is mainly used as packaging material. Packaging materials corresponded to 66% of all paper and board production in Sweden for the year 2020, which is an increase of 2,5% compared with the previous year [1]. The main function of the packaging is to protect the content inside from physical, chemical, and biological contamination [2]. Usually, paper boards are coated with pigment coatings to improve printing properties of the paperboard. Expancel microspheres are small plastic hollow spheres, which can improve the compressive properties of the paperboard. The purpose of this study is to investigate how Expancel microspheres affects the pigment coating, runnability and coated paper boards [30,31].Iggesund mill located in Iggesund manufacturer and coats high-quality paper boards. The coating formulas are based on existing recipes from the mill. The formulas where adjusted so that 12vol%,37vol% and 50 vol% of the pigments consisted of Expancel microspheres. Two different types of Expancel microspheres were used, one type of microspheres with a density of 80g/L and the other type had a density of 148g/L. To investigate how the microspheres affects the pigment coating the pH, dry content, ash content, viscosity, water retention and density were measured on the pigment coating. The paperboards were coated with pigment coating, containing different volume percentages of microspheres. The paperboard tests included gloss, surface roughness, grammage, thickness, compressibility contact angle and water adsorption.The mixture with 50 vol% of the pigments containing of microspheres with the density of 148g/L had a low pH value which can affect the results of the measurements as the pigment particles are not fully separated from each other. The low pH value resulted that the mixture had a high viscosity, which can create runnability problems. The increased number of microspheres resulted in decreasing solid content and density. The low solid content requires more energy for drying. The increasing amount of microspheres with a density of 80g/L showed an increasing viscosity with Hercules Hi-Shear. The high viscosity in Hercules Hi-Shear show that more force will be required to pump the coating mixture and that the flow in the pipes will be slower at higher viscosity.There is a difference between calculated thickness and the measured thickness of the coated paper boards. Calculated thickness where almost always less than the measured. The SEM(scanning electron microscope)-images showed that the microspheres affected the3thickness of the coated paper board. The size and shape of the particles affected the gloss. The higher content of carbonate 90(C90) resulted in higher gloss. The addition of microspheres lowered the gloss of the coated paperboards. Compressibility on the paperboard increased with the increasing addition level of microspheres. The SEM images showed that higher number of microspheres on the surface of the paperboard increased the compressibility of the surface. The contact angel measurement showed that the coating mixture containing of 50vol% with the density of 80g/L hade the highest contact angel. The Cobb60 method was used to examine the water adsorption the coated paper boards. The paper boards coated with mixtures containing the microspheres of density 80g/L had the lowest Cobb60-values.
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Det moderna handledsskyddet för snowboardåkare : en revidering av materialval, funktion och målgruppsanpassningHellström, Kasimir January 2010 (has links)
Projektet behandlar utvecklingen av ett handledsskydd anpassat för snowboardåkare. Den primäramålsättningen är att med hjälp av optimerad design för komfort och användarvänlighet kunnaerbjuda ett högkvalitativt och funktionellt skydd. Det senare uppnås med hjälp av material som medhänsyn till skadebilden hos utövarna här anses vara den bästa lösningen. Val av material gjordes efteren ingående litteraturstudie över handledsskyddets funktion och mekanismerna bakomhandledsskador. Studien, i kombination med en rad andra metoder för informationsinhämtning, lågäven till grund för designprocessen och den slutgiltiga produkten.Lösningar på befintliga problem hos existerande handledsskydd har applicerats på slutprodukten.Användarvänlighet och passform har tillgodosetts genom att frångå det traditionella systemet medkardborrelås, till produktanpassning av ett etablerat snörsystem. En ökad bekvämlighet tillgodosesgenom hela skyddets form, men även med utvalda material, då dessa tillåter luftgenomströmninggenom skyddet.Inom ramen för projektet besvaras också frågeställningar rörande varför så få utövare använderhandledsskydd, och vad som kan göras för att locka till användning. Handledsskydd är idagimpopulära hos utövarna, trots att frakturer på handled är den vanligaste skadan förknippad medsnowboard. Genom utveckling av bättre skydd kan skadestatistiken kraftigt förbättras. / The project aims to develop customized wrist guards for snowboarders. By using optimized design for comfort and ease of use, the primary aim is to offer the customer a functional and high-quality protection. This is achieved by using materials that, considering the injury status of the practitioners, herein are considered to best meet the demands of such a protection. The choice of materials was made after a comprehensive literature-based study on wrist guard function and mechanisms responsible for wrist injuries. This study, along with other collected data, has formed the basis for the design process and the final product. Solutions to current problems with existing wrist guards have been applied to the final product. Requirements on ease of use and accuracy of fit have been met by abandoning the traditional closure-system of Velcro, in favor for an established lacing system that has been adapted to the current product. The entire shape of the wrist guard, combined with the selected materials breathable qualities, offers the user an increased comfort. The complementary aim of the project is to understand why so few practitioners wear wrist guards, and bring forth solutions that attracts to the usage of such. Wrist guards are currently unpopular amongst snowboarders, despite wrist fracture being the most common injury associated with the sport. Through the development of better wrist guards the injury statistics can be greatly improved.
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Powder Rheology within AM production : Evaluating Compressibility, Permability, & Aeration for 316L Powders Within SLM Processes / Pulver Reologi Inom AM Production : Utvärdering av Kompressibilitet, Permeabilitet, och Luftning för 316L pulver inom SLM processerLeo, André January 2022 (has links)
Additive manufacturing with the use of metals have been a steadily increasing field, being able to create products with a higher degree of complexity than traditional processing techniques. SLM is a popular AM process that uses metal powder as feedstock, and one of the key components of this process is the powder rheology. In recent years the use of a powder rheometer has been shown to be a good way of evaluating powder rheology of metal powders used within AM processes, but there is a clear lack of standardised tests and methods. In this study the Compressibility, Permeability, and Aeration test for 316L powders used within SLM processes was evaluated with a FT4 powder rheometer. 15 powders that had undergone printing in SLM processes were studied. This showed that the compressibility test had the best results in differentiating the bad preforming powders, thereafter the Aeration test. The Permeability test wasn’t able to differentiate the bad preforming powders with the settings used. This study demonstrates that some tests with a powder rheometer can evaluate the powder performance in SLM processes, but further research to evaluate the tests and standardise the settings are needed for clearer test results. / Additiv tillverkning med metall är ett område som stadigt ökat i intresse, främst på grund av möjligheten att producera produkter med en mycket högre grad av komplexitet i jämförelse med traditionella processmetoder. SLM är en populär AM process som använder metallpulver som råmaterial, och en av huvudkomponenterna för processen är pulvrets reologi. Under senare år har användningen av en pulver-reometer visat sig ett bra sätt att utvärdera pulver-reologi för metallpulver som används inom AM, men det finns en klar avsaknad av standardiserade test och metoder. I denna studie utvärderas Kompressabilitet, Permeabilitet, och Aerabilitet testen för 316L pulver producerade för SLM processer med en FT4 pulver-reometer. 15 pulver som genomgått SLM printing studerades. Studien visar att kompressabilitets testets utfall bäst överensstämde med det som setts under SLM processen, och bäst urskilde pulvren som fungerat dåligt att printa med, därefter Aerations testet. Permeabilitets testet kunde inte urskilja de sämre pulvren med de inställningarna som användes. Studien demonstrerar att vissa test och index samlade med ett pulver reometer är mer tillförlitliga än andra när det gäller för att utvärdera pulvrets prestanda inom SLM processer, men vidare forskning och studier krävs för att utvärdera testen och standardisera inställningar baserat på pulvret som testas.
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