Modifizierung von Wolle durch Enzyme mit dem Ziel der Griffverbesserung und Filzfreiausrüstung
This study investigates the effect of different enzymes on wool top. Wool top was incubated with proteases SP 655, SP 656, SP 490 as well as with lipase SP 398. The changes in wool morphology that occurred as a result of the enzyme treatment were shown by means of scanning electron microscopy and transmission electron microscopy. On the basis of the morphological results protease SP 655 was chosen for further experiments to improve the wool properties like handle, dyeing, shrink resistance and whiteness. Wool cortex and cuticle are not significantly changed after treatment with protease SP 655 over a period of 1 h. This was confirmed by gel electrophoresis. By contrast, the densitogram of merino wool treated with protease SP 655 over a period of 6 h, showed no more peaks in the area of the low sulfur proteins with a molecular weight of 45-50 kD, but an increase of peak number in the area of the low molecular weight proteins. The handle of merino wool was improved by enzyme treatment with a protease concentration of 0,2 % over a period of 1 h at 57 °C. Moreover 72 % of the testing persons found that the softness of crossbred wool increased after this enzyme treatment compared to the reference sample. The felting of merino wool top is not reduced by the enzyme treatment described above. The felting of crossbred wool, however, was significantly reduced after enzyme treatment in comparison to the reference fibres and untreated crossbred wool. The shrink resistance of merino wool is significantly improved only after treatment with a protease concentration of 0,6 %. A further decrease of felting was achieved by enzyme treatment in sodium borate/HCl-buffer. The felt density of the wool fibres treated in borate/HCl-buffer is significantly lower in comparison to the felt density of the wool fibres treated in borate/acetate-buffer. The felting results of merino wool after different treatment times showed that the felt density decreases with treatment time. Non-extracted wool felts significantly more compared to extracted wool top after enzyme treatment. The modification of merino wool fibres is very high after increasing the enzyme concentration and the treatment time. The modification of non-extracted wool top after enzyme treatment is distinctly smaller compared to wool top, which was extracted before. The degree of whiteness of enzyme treated wool top, such as merino and crossbred wool, is generally higher than that of the respective reference samples and of untreated wool top. After enzyme treatment, the whiteness of non-extracted wool top is significantly higher than the whiteness of extracted wool top. A higher protease SP 655 concentration on wool top does not cause a further improvement of the degree of whiteness. The tensile strength of merino and crossbred wool is not influenced by treatment with a protease concentration of 0,2 owf in borate/acetate buffer. The tensile strength of merino wool decreases significantly after treatment with a protease concentration of 0,6 owf compared to untreated wool top. The results of a new test method developed for measuring the buckling force of fibre bundles showed that significant differences in the buckling force of wool bundles with varying fibre diameter can be measured. By contrast, the values obtained when using this test method on enzyme-treated wool samples varied widely. Dyeing tests with Lanasol Blue 8 G at 98 °C and 50 °C showed that the enzyme treated wool samples are darker stained in comparison to the reference samples. The dye uptake of the enzyme treated samples is higher and faster than that of the reference samples. Using the dyestuffs Acid Red 88-II and Food Red 5 with a smaller molecular weight in comparison to Lanasol Blue 8 G no significant difference is found between the dye uptake of the enzyme treated wool fibres and the reference fibres.
info:eu-repo/classification/ddc/540, Wolle, Modifizierung, Proteasen, Filzfreiausrüstung, Griffigkeit, Stoffeigenschaft, Chemie, Enzyme, Griffverbesserung
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