Browsing by Author "Nygren, Nicole"

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Färgning av cellulosafibrer med naturliga färgämnen
(2023-04-17) Österlund, Sigrid
Kemiantekniikan korkeakoulu | Bachelor's thesis
Ioncell fibres from alternative cellulose sources for nonwovens
(2024-06-11) Hart, Emily
Kemian tekniikan korkeakoulu | Master's thesis
The textile and nonwoven industries are growing rapidly, rely heavily on non-renewable raw materials and have a low rate of recycling. To change this into a more sustainable direction, textile fibres made from renewable and recycled feedstocks must be developed. A potential solution is to increase usage of man-made cellulosic fibres that combine the renewable nature of natural fibres with added benefits related to synthetic fibres. The main raw material used for man-made cellulosic fibres is wood pulp. However, it is important to consider alternative sources of cellulose to avoid putting too much pressure on forest ecosystems and ensuring a wide enough availability of sustainably produced cellulose to fit growing demands. The Ioncell process is an emerging technology for producing regenerated cellulosic fibres using ionic liquids as solvents. A variety of raw materials have successfully been used for production of fibres with the Ioncell process, including wood pulp and cotton, as well as many recycled materials such as cardboard, newsprint, and textile waste. This study examined the possibility of using cellulosic raw materials other than wood to produce regenerated fibres with the Ioncell process for production of nonwovens. The studied raw materials were recycled nonwovens and straw pulp. Both raw materials were successfully processed into regenerated fibres and the fibres could be used to produce new nonwovens. The recycled nonwoven could also be upcycled into yarn and a knitted textile sample was produced. Two chemical pre-treatments were applied to the recycled nonwoven to allow sufficient spinnability and improve fibre properties: NaOH for removing binders, and H2SO4 for removing a TiO2 mattifying agent. Sufficient spinnability for production of fibres for nonwovens could be reached by using only the NaOH-treatment, and the H2SO4-treatment can be added for production of fibres for knitted or woven textiles or ifthinner fibres are required. The produced fibres from both starting materials showed a slightly lowered tenacity compared to standard Ioncell fibres, but still reached competitive values compared to commercially available man-made cellulosic fibres. Thus, it can be concluded that both recycled nonwovens and straw pulp can be processed into regenerated fibres suitable for production of new nonwovens with the Ioncell process.
Kehitteillä olevat kaupalliset värjäystekniikat selluloosapohjaisille tekstiilikuiduille
(2024-12-15) Salovaara, Thea
Kemiantekniikan korkeakoulu | Bachelor's thesis
Tekstiiliteollisuus on merkittävä ympäristökuormittaja, ja perinteiset värjäysprosessit kuluttavat runsaasti vettä, energiaa ja kemikaaleja. Työn tavoitteena on tunnistaa ympäristöystävällisempiä ja resurssitehokkaampia ratkaisuja värjäysprosessien parantamiseksi. Selluloosapohjaiset tekstiilikuidut, kuten viskoosi, modaali ja lyocell, ovat uudelleen käsiteltyjä luonnonmateriaaleja, jotka tarjoavat ekologisemman vaihtoehdon synteettisille kuiduillle. Värjäystekniikoiden haasteina ovat kuitenkin muun muassa runsas veden- ja kemikaalienkulutus sekä ympäristölle haitalliset jätevesipäästöt. Työssä tarkastellaan neljää innovatiivista värjäystekniikkaa: kehruuvärjäystä, entsyymipohjaisia värjäystekniikoita, vedetöntä värjäystä ja digitaalista tekstiilipainatusta. Kehruuvärjäyksen avulla väriaineet lisätään suoraan selluloosaliuokseen ennen kehruuta, mikä säästää vettä ja energiaa huomattavasti. Entsyymipohjaiset menetelmät hyödyntävät luonnon väriaineita ja ultraäänitekniikkaa, parantaen värien kiinnittymistä ja kestävyysominaisuuksia. Vedetön värjäys eliminoi veden käytön lähes kokonaan käyttämällä liuottimia, kuten propanolia, mikä vähentää ympäristön kuormitusta. Digitaalinen tekstiilipainatus puolestaan vähentää merkittävästi kemikaalien, veden ja energian kulutusta, mikä tekee siitä resurssitehokkaan vaihtoehdon perinteiselle painatukselle.
Kehruuvärjätyn kuidun kierrätys
(2022-12-11) Sunikka, Pinja
Kemiantekniikan korkeakoulu | Bachelor's thesis
Olika metoder för proteinmodifiering baserade på styrd evolution
(2017-04-25) Nygren, Nicole
Kemiantekniikan korkeakoulu | Bachelor's thesis
Spin-dyeing of cellulose fibres with vat dyes using the Ioncell process
(2024-12-15) Nygren, Nicole; Schlapp-Hackl, Inge; Heimala, Senni; Sederholm, Helena; Rissanen, Marja; Hummel, Michael
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Estimated 20 % of global clean water pollution is attributed to textile production. Dyeing and finishing processes use an extensive amount of water and chemicals, and most of the effluents and wastewater is released into the environment. In this study, we explore spin-dyeing of man-made cellulosic fibres (MMCFs) with vat dyes using the Ioncell process, circumventing the ubiquitous use of fresh water and potentially reducing effluents streams to a great extent. Spin-dyeing is an established process for synthetic polymers but is not common for MMCFs. Regenerated cellulose fibres were produced through dissolution of dissolving pulp in the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate. The produced fibres were processed into yarn and a jersey fabric was knitted. Mechanical and colour fastness properties were tested. The fibres properties were also assessed through SEM, birefringence, and crystallinity measurements. Fibres with excellent mechanical properties (tenacity higher than 50 cN/tex) and colour fastness were produced, with most samples receiving the highest or next highest performance grade. The spun-dyed fibres also hold great potential to be recycled themselves without colour change or loss in colour intensity. Textiles with colours produced in large quantities such as black or navy blue could be the first market entry point.
Spinneret geometry modulates the mechanical properties of man-made cellulose fibers
(2021-11) Moriam, Kaniz; Sawada, Daisuke; Nieminen, Kaarlo; Ma, Yibo; Rissanen, Marja; Nygren, Nicole; Guizani, Chamseddine; Hummel, Michael; Sixta, Herbert
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
The production of cellulose-based textile fibers with high toughness is vital for extending the longevity and thus developing a sustainable textile industry by reducing the global burden of microplastics. This study presented strategies to improve fiber toughness by tuning spinneret geometries. Experimental studies were conducted by spinning with different spinneret geometries and measuring the mechanical and structural properties of the spun fibers. In addition, numerical simulation tools were used to better understand the effects of spinneret geometry. The altering parameters of the spinneret geometries were the capillary diameters D, the angle of the entry cone into the spinning capillary, and the ratio of capillary length to diameter L/D. The highest fiber toughness could be achieved at a capillary aspect ratio of 1 to 2. The obtained maximum fiber toughness was 93 MPa with a tensile strength of 60 cN/tex and a concomitant elongation of 16.5%. For these fiber properties, a 13 wt% solution of a high-purity pulp with higher viscosity in [DBNH][OAc] was spun into a 1.3 dtex fiber using a D100 spinneret with a capillary of 1:1 length/diameter and an entrance angle of 8°. It was noticeable that the microvoid orientations decreased almost linearly with increasing toughness of the fibers. The morphologies of the fibers were similar regardless of the spinneret geometries and the raw materials used in the spinning process. In summary, by modulating the spinneret geometries, Ioncell fibers obtained high toughness that have the potential to replace synthetic fibers.
Steps towards enzymatic sulfation of cellulose
(2020-06-15) Nygren, Nicole
Kemian tekniikan korkeakoulu | Master's thesis
Cellulose is one of the most abundant polymers on earth and is an important source for raw materials. Sulfated cellulose has many potential applications, but presently the sulfation is done via a chemical route that involves many hazardous and toxic chemicals. Enzymatic sulfation would offer a more environmentally friendly and less dangerous option. This thesis aims to explore the steps towards enzymatic sulfation of cellulose through working up from the simplest building blocks of cellulose. The enzymes aryl sulfotranferase B (ASTB) from Desulfitobacterium hafniense and nodulation protein H (NodH) from Rhizobium meliloti were tested and investigated. Different substrates, such as N-acetylglucosamine, cellobiose, xylose, starch, arabinose, cellulose nanocrystals (CNC) and carboxymethyl cellulose (CMC) were tested. The proteins were expressed in Escherichia coli BL21 (DE3), grown in Terrific Broth and purified with FPLC, and their activity was tested on the different substrates by measuring the OD405. p-nitrophenylsulfate (pNPS) acted as a sulfuryl donor in the process, the release of p-nitrophenyl also caused a colour reaction which was needed to follow the process. The experiments showed that ASTB successfully sulfates simpler saccharides such as glucosamine, N-acetylglucosamine, cellobiose and xylose. At the moment, ASTB is not suitable for sulfation of cellulose. It was not possible to do any further experiments with NodH because the purification was unsuccessful.
Upcycling of cellulosic textile waste with bacterial cellulose via Ioncell® technology
(2024-06) A.G.S. Silva, Francisco; Schlapp-Hackl, Inge; Nygren, Nicole; Heimala, Senni; Leinonen, Anna; Dourado, Fernando; Gama, Miguel; Hummel, Michael
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Currently the textile industry relies strongly on synthetic fibres and cotton, which contribute to many environmental problems. Man-made cellulosic fibres (MMCF) can offer sustainable alternatives. Herein, the development of Lyocell-type MMCF using bacterial cellulose (BC) as alternative raw material in the Ioncell® spinning process was investigated. BC, known for its high degree of polymerization (DP), crystallinity and strength was successfully dissolved in the ionic liquid (IL) 1,5-diazabicyclo[4.3.0]non-5-enium acetate [DBNH][OAc] to produce solutions with excellent spinnability. BC staple fibres displayed good mechanical properties and crystallinity (CI) and were spun into a yarn which was knitted into garments, demonstrating the potential of BC as suitable cellulose source for textile production. BC is also a valuable additive when recycling waste cellulose textiles (viscose fibres). The high DP and Cl of BC enhanced the spinnability in a viscose/BC blend, consequently improving the mechanical performance of the resulting fibres, as compared to neat viscose fibres.