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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

Experimental Design for Ceramic Panel Production

Umirova, Arailym January 2021 (has links)
This thesis work is a continuation of a project aimed at the consolidation of insulation material (IM) to produce porous ceramics with sufficient porosity and compression strength for post-insulation of buildings. The porous structure and contact points are tailored to produce IM with ultra-low thermal conductivity.  One of the main goals is to introduce expandable microspheres, that are perfect lightweight fillers and blowing agents into production. They are relatively new materials in the market which are used to manufacture products with low weight and controlled foam structure. Therefore, it is of interest to be integrated into the construction field as a component for insulating materials.  The project is built on the advanced structuring of porous materials with tailored porosity to offer 5-10 times lower thermal conductivity value providing adequate insulation with an insulation cover of 2-10 mm in thickness. Enhancing the insulating capacity allows to limit the use of energy to improve energy efficiency. Thus, less energy is required to heat or cool the indoor climate. The success in achieving such thin effective IM will eliminate the need for any modification of existing window frames, electrical and heating installations. In the first stage, it is necessary to confirm the entire concept of creating a thermal IM with a controlled porous structure using various compositions of materials and an assessment of the structure, porosity, and functional properties. This project focuses on developing a composition of ceramic panels. The various components of the ceramic panels including the type of ceramic are adjusted and their effects on the composition are described. Pure alumina, activated alumina and silica have been investigated to find the optimized quality and price. In addition, various methods and conditions have been implemented for panel fabrication.  Prototypes of ceramic panels are prepared for demonstration, followed by upscaling at the facilities of industrial partners. The project has been performed in collaboration with companies i.e., Nouryon, HIPOR Materials AB, and LindePac AB as the industrial partner.
2

Cool Roof Coatings on Industrial Buildings : An Energy Study of Reflective Coatings

Sjödin, Isak January 2019 (has links)
To evaluate the effect of cool roof coatings containing Expancel® thermoplastic microspheres on industrial buildings, a warehouse was built-up in the computer simulation software IDA-ICE. The warehouse was modelled in line with ASHRAE 90.1. 2004 ”Energy Standard for Buildings Except Low-Rise Residential Buildings”. Four different cases were set up where the coating of the roof was the only variable. Two coatings containing Expancel® microspheres - one white and one red coating were compared to the same white coating without Expancel® microspheres and the ”base case” where there is no coating at all. The same circumstances were also implemented in a practical laboratory test using a model warehouse with a detachable roof. Four interchangeable roofs with different roof coatings constitute the various cases in the laboratory tests. A ”sun” consisting of statically mounted IR light bulbs were constructed, as well as a cooling system to measure the difference in cooling effect (maintaining a constant indoor temperature) between the different cases as a result of the change in insolation. The results of the computational simulations show that for a warehouse placed in Houston, Texas about 50 MWh in combined heating and cooling energy can be saved yearly between the best and the worst case, a reduction of 6.2%. Changing the geographic placement of the warehouse to Tepic, Mexico the corresponding savings were determined to 83 MWh or 13.5%. A way of determining the yearly savings in heating and cooling amount for the warehouse with a generic roof coating, only knowing the SRI value of the coating, was developed. It was determined that for every unit-increment of the SRI value the yearly savings for the warehouse placed in Houston, Texas were 718 kWh and 0.1%. The corresponding savings for the warehouse placed in Tepic, Mexico were determined to be 1252 kWh and 0.22%. The laboratory tests showed that the indoor temperature of the model warehouse decreased by close to 16°C between the best and the worst case.
3

Non-woven textilier från träfibrer genom papperstillverkningsmetoder / Investigation of making nonwoven textiles with wood fibres and papermaking technique

Lindberg, Elin January 2015 (has links)
Idag är den största delen av textilierna antingen olje-(60 %) eller bomullsbaserade (30 %). Det är enbart en liten del som är baserade på träfibrer. Ett ökande behov av förnyelsebara textilier föreligger. Samtidigt är ett minskade pappersbehov en drivkraft till att använda de existerande pappersmaskinerna till att tillverka icke vävda textilliknande material. Till skillnad från vävda material kan materialet tillverkas direkt istället för att först tillverka trådar från fibrer. Möjligheter att ta fram textillika material av cellulosafibrer undersöktes. Dynamiska ark gjorda av en blandning av barrmassa och en blandning av barr- och lövmassa med 0, 55 och 70 vikt% polymjölksyra, PLA, tillverkades. Arken pressades ihop två och två med ett mellanlager av Expancel mikrosfärer och bindemedel. Mowilith DM 105 och Primal LT-2949 Emulsion användes som bindemedel. En jämförelse gjordes med ark med enbart bindemedel som mellanlager.   En subjektiv utvärdering av vilket förhållande mellan Expancel mikrosfärer och bindemedel som var bäst lämpad gjordes. För utvärderingen ytbehandlades ett standard papper med 70 vikt% PLA. Den sats med högst koncentration av Expancel mikrosfärer som band bra till bindemedelet valdes. Draghållfastheten testades genom dragprovning enligt ISO 1924-2:1994 men med endast 5 prover istället för 10.  Dragprovningen visade att tillsatsen av Expancel mikrosfärer ökade töjningen hos materialet. Materialen med högst koncentration av PLA gav den mjukaste känslan men också lägst styrka. / Today the main parts of textiles are either oil (60 %) or cotton based (30 %). It is only a small portion which is based on wood fibres. An increasing demand of renewable textiles is forthcoming. At the same time a decreasing demand of paper is one of the motivation of using the existing paper machines to produce nonwoven textile-like materials. Unlike woven fabrics the fabric can be manufactured directly rather than first producing yarn from fibres. Possibilities of developing a textile-like material of cellulose fibres were investigated. Dynamic lab sheets made of a mix of softwood pulp and a mix of softwood and birch pulp with 0, 55 and 70 weight % Poly(lactic acid), PLA, were manufactured. The sheets was pressed together two and two with a middle layer of Expancel microspheres and binder. Mowilith DM 105 and Primal LT-2949 emulsion were used as binders. A comparison was made between sheets with only binder as the middle layer.   A subjective evaluation of which ratio between Expancel microspheres and binder material was best suited was made. For the evaluation a paper containing 70 weight% PLA was coated. The batch with highest concentration of Expancel microspheres, which bonded well to the binder, was chosen. The tensile strength was measured according to ISO 1924-2:1994 but with only 5 test samples instead of 10. The tensile tests showed that with Expancel microspheres resulted in increase of elongation of the material. The materials with the highest concentration of PLA had softest feeling but also lowest strength.
4

Expancel mikrosfärernaspåverkan på bestrykningssmetoch bestruken kartong / The impact of Expancel microspheres on coating and coatedpaperboard

Chehade, 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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