Browsing by Author "Kultalahti, Ella"

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  • Analytical and testing methods for assessing pulp performance in Lyocell fiber production
    (2025-01-30) Kultalahti, Ella
     School of Chemical Engineering | Master's thesis
    Cellulose is an abundant and renewable biopolymer found in the cell walls of plants. It is used for producing man-made cellulosic fibers (MMCFs) which are a sustainable alternative to synthetic textile fibers. Different types of MMCFs include for example viscose, cuprammonium rayon and Lyocell. Among these, Lyocell is considered as an environmentally friendly process, as it recycles chemicals and water within the process. The global generation of textile waste continues to rise, yet only 1% of it is currently recycled into new textile fibers. The majority is either incinerated or sent to landfills. Utilizing this waste as a raw material for textile fiber production would support circular economy and reduce the reliance on virgin materials in the textile industry. The goal of this thesis is to identify which pulp and Lyocell dope properties can be used to evaluate the suitability of pulp for Lyocell fiber production. Four different pulps, including commercially used dissolving pulps and recycled textiles, are characterized and Lyocell fibers are produced from them. Fiber and spinning dope properties are studied, and a connection between them and the pulp properties is formed. The results show that intrinsic viscosity and degree of polymerization of the pulp greatly influence spinning dope properties. These, in turn, impact the properties of the Lyocell fibers and efficiency of the fiber production process. When the intrinsic viscosity of the pulp was within the range of 350--450 ml/g, the fiber properties were comparable to commercial Lyocell. The results of this study are valuable for expanding the raw material selection for Lyocell fiber production. The characterization methods used in this work provide a strong foundation for assessing the potential of new types of recycled cellulosic materials as raw material for Lyocell fibers.
  • Safiirin mikrokuviointi laserilla
    (2021-09-17) Kultalahti, Ella
     Kemiantekniikan korkeakoulu | Bachelor's thesis