Browsing by Subject "luonnonväriaine"
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(2020)Research of natural dyes and more ecofriendly textile materials has been of common interest for years. Research of natural dyes has mostly focused on the dyeing of wool, cotton, silk and regenerated cellulosic fibers. This study expands on this topic by combining natural dyes with the latest regenerated cellulosic fiber Ioncell®. When starting this study there was no previous research about the dyeing of Ioncell® and the most recently published research had only fo-cused on industrial dyes. By varying mordant type, acidity and colorant type, their respective effect on the fiber dye up-take could be studied. The data consisted of color measurements of the dyed samples, which were used to analyze the fiber dye uptake. The mordants used were alum, ferrous sulfate and tannic acid with unmordanted reference samples. Acidities used for the dye baths were pH 4 and pH 8. The colorants were dried skins of yellow onions [Allium cepa] and Cortinarius semisanguineus. Wool was used as a reference material for Ioncell® due to its color taking properties being well known and therefore, the dyeing process could be easily verified by it. A spectrophotometer was used for the color measurements. The color uptaking was evaluated by observing the color of the dyed samples and the differences in color between the undyed and dyed fibers. The color fastness to laundering as well as to artificial light were evaluated according to the standards SFS-ENG ISO-B02 and SFS-ENG ISO-C06 by assessing the col-or change, and fastness to laundering was also assessed by the staining of the multifiber ad-jacent fabrics. For a cellulosic fiber, Ioncell's® color uptake was low in alkaline dye baths. With Cortinarius semisanguineus as the colorant, the color take was low regardless of the acidity and the mor-dant type. With Allium cepa as the colorant, in the acid dye bath the color take was quite good. The color varied depending on the mordant used. However, these strong colors had lower color fastness to laundering than the pale colored samples. During staining differences occurred on the behalf of Allium cepa. Acidity or mordant only had an effect on the staining with alum mordanted samples dyed with Cortinarius semisanguineus. The best color fastness to light had alum and iron mordanted samples dyed with Allium cepa. With the tannin and iron mordants the acidity correlated with the color fastness to light, higher pH giving better results. During staining acidity or mordant only had an effect on alum mordanted samples dyed with Cortinarius semisanguineus. For further studies it would be interesting to see if the surprising results between flavonoid and anthraquinoine could be repeated with other dye source mate-rial and would the color uptake improve with the sodium pretreatment of Ioncell® fibers.
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(2023)Faculty: Faculty of Educational Sciences Degree programme: Master’s Programme in Education Study track: Craft Teacher Education Author: Susanna Kirvesniemi Title: Colour from a weed – Scentless mayweed as a dye source for cellulose and regener-ated cellulose fiber Level: Master’s Thesis Month and year: March 2023 Number of pages: 58 pp. + 9 appendices Keywords: Scentless mayweed, natural colorant, cellulose and regenerated cellulose fi-bers, protein fiber, alum, aluminium compounds Supervisor or supervisors: Riikka Räisänen Where deposited: Helsinki University Library – Helda / E-thesis (theses) Additional information: Abstract: This empirical experimental study investigated the functionality of the scentless mayweed (Tripleurospermum inodorum) as a source of dye for cellulose and regenerated cellulose fi-bers (flax, bamboo viscose) and wool was used as reference fiber, which as a protein fiber, is best for dyeing with natural dyes. Tannin and aluminum compounds were used as mor-dants. This study was part of a larger study by the BioColour project, which aimed to pro-duce information on mordants residues in dyeing baths. With this study, the research data was produced, and the colour fastness was analyzed from the dyed textile materials. The research data was carried out using two different methods, a separate mordanting and dye-ing method (linen, bamboo viscose and wool) and a combined mordanting and dyeing method (bamboo viscose and wool). The colour fastness was determined according to in-ternational ISO standards. The total colour change (∆ELab*) was largest after washing with an alkaline standard deter-gent on linen (∆ELab* 11.77) extracted with aluminum acetate and bamboo viscose mor-danted with alum (∆E Lab*11.36). The overall change in the colour of the bamboo viscose mordanted with alum was largest (∆ELab* 10.17) also with pH-neutral detergent. On pH-neutral detergent washed linens mordanted with tannin and aluminium acetate (∆ELab* 0,85) and aluminium acetate (∆ELab* 1,32) and bamboo viscose which was mordanted with aluminium acetate (∆ELab* 1,57) had a slight change in overall colour. For wool, samples washed with alkaline standard detergent all had a large overall colour change (∆ELab* 18.99–24.98). For wool washed with a pH-neutral standard detergent, the overall colour change was significantly less (∆ELab* 9.49–15.37). The overall colour change of bamboo viscose dyed with the combined mordanting and dyeing method and washed with an alka-line standard detergent was large (∆ELab* 10.77–17.94) and the overall colour change of those washed with pH-neutral standard detergent was minor (∆ELab* 1.38–7.9). Assessing the colour change on the gray-gray scale gave a rating of 1–4 for linen washed with standard detergent, 1–3 for bamboo viscose and 3–4 for wool. After washing the col-our of the wool was visually brighter than the colour of the unwashed dyed wool. Using the combined method mordanting and dyeing method, the assessment of the colour change of the dyed material on the gray-gray scale gave bamboo viscose a rating of 1 and wool a rat-ing of 3–4. When assessing colour staining on a gray-gray scale, the lowest grade (3–4) came from the bleached cotton of multi-fiber fabric and the highest grade from the wool of the multi-fiber fabric (4–5). Light fastness was best in linen mordanted with tannic and alu-minum lactate/acetate (4). Wool received a rating 2–3, it turned brown during the test, bam-boo viscose had the worst lightfastness, and it received a rating 1. The grades were 3–5 for dry rubbing and 2–5 for wet rubbing. As expected, the dye extracted from the scentless mayweed had a lower dyeing ability for the cellulose and regenerated cellulose fiber than wool. Thus, scentless mayweed can be seen to be more suitable for dyeing protein fibers than cellulose and regenerated cellulose fiber.
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(2019)In this study the staining of cellulose fibers with mordant dyeing and disperse dyeing techniques are investigated. Previous studies have shown disperse dyeing gives better staining results than mordant dyeing when using synthetic fibers with natural colorants. This study explores the suitability of the disperse dyeing method for cellulose fibers. The study focuses on four cellulosic fibers: viscose, bamboo viscose, lyocell and Ioncell-F. The reference fiber for testing is merino wool. All samples are knitted. There is a little research on disperse-dyed cellulosic fiber with natural colorants, but no previous research with Ioncell-F fiber at all. Disperse dyeing was tested with and without tannin mordant. Mordant-dyed samples are for comparison. Flavonoid-containing onion skins Allium cepa and anthraquinone-containing fungus Cortinarius semisanguineus were used as sources of dyes. The pH for the dye liquor was adjusted to 8 with sodium hydroxide, except for the dyebath for the merino wool that is poorly resistant to bases. Merinos dye liquor adjusted with hydrochloric acid to pH 4. Different dyeing techniques were used with the same dyebath, except for the extra batch of celluose fibres, for which a separate dyebath was prepared from the onion skins and the pH of the dyebath was kept acidic. The color values of the dyed samples were measured on a spectrophotometer, whereby the dyeing results could be viewed as L*, a* and b* values according to CIELAB. In addition, the color fastness to light and washing were tested according to the ISO standards. The dyeing results of the cellulose fibres were lower than merino wool reference in all dyeing techniques. Ioncell-F fiber dyed very similarly to the other cellulosic fibers. Onion skins gave a darker and more stable color compared to the fungus whose color was light throughout the samples and the color fastness in light and washing tests were low. According to the results of this study Cortinarius semisanguineus is poorly suited for dyeing cellulose fibers. It is preferred to dye with the onion skins with the natural pH of the dyebath, under acidic conditions by the dispersion dyeing technique. In this case, the results of the dyeing are better and more stable even without the mordant.
Now showing items 1-3 of 3