Purpose The purpose of this paper is to analyse the properties of bacterial cellulose (BC) film, obtained through Kombucha tea fermentation. Design/methodology/approach Kombucha fungus was used to produce BC film under static cultivation conditions. Physical and mechanical properties under the influence of drying temperature and durability of BC material were investigated. Tensile properties were estimated by TINIUS OLSEN H10 KT test machine according to ISO 3376:2011, thickness was measured by DPT 60. BC structure was analysed by Scanning Electron Microscopy Quanta 200 FEG. Findings BC material with excellent deformation properties in wet state were obtained by fermenting Kombucha tea. Due to the presence of fermentation residues, Kombucha film is sensitive to drying temperature. The best deformation properties retain when BC material is dried at low temperature (about 25°C). BC material becomes stiffer and ruptures at lower deformations due to rapid water evaporation at higher drying temperature. It is confirmed that during time, the properties of BC film changes significantly and there may be problems with the durability of products from this material. BC film has an interesting set of properties, therefore its application to fashion industry without further preparation is limited. Originality/value A new approach is based on the evaluation of Kombucha material properties and investigation of BC as new type of material for fashion industry. Some recommendations for Kombucha BC film production are provided, basing on gained experience, experimental results and analysed literature. The advantages and disadvantages of material are discussed in the paper, in order to search for the ways to adapt the new type of material to fashion business.

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The article presents an experimental study of mechanical properties of cellulose biofilm produced by bacterial fermentation process. Naturally derived biomaterial has great current and potential applications therefore the conditions of material preparation as well as control and prediction of mechanical properties is still a relevant issue. Bacterial cellulose was obtained as a secondary product from Kombucha drink. Presented technique for material preparation and drying is particularly simple and easy to access. The influence of drying temperature (25 °C, 50 °C and 75 °C) on the sample size (thickness and planar dimensions) and mechanical properties (tensile and bursting strength) of cellulose biofilm has been evaluated. It was estimated that during drying biofilm specimens lost up to 92 % of weight and up to 87 % of thickness therefore planar specimen dimensions varied insignificantly. The study showed that the drying temperature is important for optimum strength properties of bacterial cellulose biofilm. The maximum tensile strength (27.91 MPa) was recorded for the samples dried at temperature of 25 °C, when the moisture from the biomaterial is removed gradually and good deformation properties are ensured (respectively tensile extension 18.8 %). Under higher drying temperature biomaterial shows lower values of tensile strength and higher values of bursting strength. The maximum bursting strength (57.2 MPa) was recorded for samples dried at 75 °C when punch displacement changes were insignificant for all tested samples (from 17.8 mm to 21.7 mm). DOI: http://dx.doi.org/10.5755/j01.ms.25.3.20764

The aim of this study was to estimate the influence of purification and treatment with textile finishing agent procedures on structural, mechanical, and water barrier properties of bacterial cellulose (BC) in order to predict the end-use properties. Kombucha fungus generated by Komagataeibacter xylinus species, formerly known as Gluconacetobacter xylinus, was used to produce the BC material. The BC was purified with 0.5% sodium hydroxide (NaOH) solution and treated with 5%, 10%, and 20% concentration of N, N-dimethylol 4,5-dihydroxy-ethylene urea (DMDHEU). By Fourier transform spectroscopy (FTIR) and X-ray diffractometer (XRD) was estimated, that the purification with a weak alkali solution was effective to remove amorphous matter of the BC material. Scanning electron microscope (SEM) images demonstrated the BC structure, similar to a non-woven textile fabric with clearly visible three-dimensional networks of fine cellulose fibers. After the purification process, the BC material tensile strength increased by 52%; however, the strain decreased by 93%. BC material after treatment with 20% DMDHEU regained deformability and tensile properties analogous to untreated samples. Water vapor permeability (WVP) values increased and water absorption capacity (WAC) decreased in BC material with increasing DMDHEU concentration. According to the FTIR results, the crosslinking reaction of DMDHEU and adjacent BC molecules was proved. The treatment with DMDHEU restores the amorphous properties of BC material, and therefore blocks water absorption, and the decrease in the water absorption parameter might be determined.