In the current work, the performance properties of natural-fibre-based thermal insulation materials were examined. For this purpose, three different compositions of natural fibres were prepared: pure sheep wool (SW), wool and industrial hemp (SW/HF) fibres, and pure industrial hemp (HF) fibres. Low-melt bicomponent polylactide (PLA) fibres were used as a binding material. For specimens prepared from natural fibres, the dependence of the thermal conductivity, the tensile strength along and across the direction of product formation, and the short-term water absorption on the density of the specimens and the flammability parameters were determined. In addition, to reduce the water absorption and flammability, the specimens were coated with hydrophobic agents and flame retardants. The obtained research results were also statistically processed. The analysis of the results showed that the thermal conductivity of natural-fibre-based thermal insulation materials varied within the range of 0.0333 ÷ 0.0438 W/(m·K), the tensile strength varied from 2.5 to 130 kPa, the short-term water absorption varied from 0.5 to 8.5 kg/m², and the water vapour diffusion resistance factor varied from 2.537 to 2.667. It was additionally determined that all the studied products were flammable. The water absorption and flammability values were significantly reduced by the use of hydrophobic agents and flame retardants.

Textile waste is formed in various stages, from the preparation of raw materials to the utilisation of textile products. One of the sources of textile waste is the production of woollen yarns. During the production of woollen yarns, waste is generated during the mixing, carding, roving, and spinning processes. This waste is disposed of in landfills or cogeneration plants. However, there are many examples of textile waste being recycled and new products being produced. This work deals with acoustic boards made from waste from the production of woollen yarns. This waste was generated in various yarn production processes up to the spinning stage. Due to the parameters, this waste was not suitable for further use in the production of yarns. During the work, the composition of waste from the production of woollen yarns was examined–namely, the amount of fibrous and nonfibrous materials, the composition of impurities, and the parameters of the fibres themselves. It was determined that about 74% of the waste is suitable for the production of acoustic boards. Four series of boards with different densities and different thicknesses were made with waste from the production of woollen yarns. The boards were made in a nonwoven line using carding technology to obtain semi-finished products from the individual layers of combed fibres and thermal treatment of the prepared semi-finished product. The sound absorption coefficients in the sound frequency range between 125 and 2000 Hz were determined for the manufactured boards, and the sound reduction coefficients were calculated. It was found that the acoustic characteristics of soft boards made from woollen yarn waste are very similar to those of classic boards or sound insulation products made from renewable resources. At a board density of 40 kg/m³, the value of the sound absorption coefficient varied from 0.4 to 0.9, and the noise reduction coefficient reached 0.65.

In the current study, high-strength boards for the construction industry were developed from renewable natural resources, fibrous hemp shives, and corn starch. During the research, the influence of the composition of the mixture, the processing of raw materials, and technological parameters on the operational properties of the board were evaluated. The influence of the binding material and the water content on the properties of the molded boards was evaluated. It was established that the rational amount of starch is 15% of the mass of the shives, and the amount of water is 10%. It has been established that with the proper selection of the forming parameters of the board, it is possible to avoid internal disintegration of the structure due to the water vapor pressure, increase the bending strength, and ensure uniform sintering of the board throughout the entire volume. It was found that additional processing of hemp shives can increase bending strength by more than 40%. Furthermore, during the processing of shives by chemical means, soluble substances are washed out, which reduces the density and thermal conductivity of the shives. Selection of a rational level of compression allowed us to increase the bending strength of the boards by 40%. The assessment of all factors made it possible to obtain boards with a bending strength of 40 MPa. The additives used made it possible to reduce the water absorption of the boards up to 16 times and obtain non-flammable boards. The thermal conductivity of the resulting boards varied from 0.07 to 0.095 W/(m·K). The analysis of macrostructure and microstructure allowed us to evaluate the process of the formation of bonds between hemp shives.

In the current research, waste from woollen yarn production was analysed. Woollen yarn waste as raw material was used for the production of soft thermal insulation mats. Two types of mats were produced in a textile plant: thermally untreated and thermally treated. Properties such as the fibre composition, structure, and thermal conductivity of the thermally untreated and thermally treated mats were studied. During the composition analysis of the woollen yarn waste, the quantity of long, medium length, and short fibres was determined. The content of fats, salts, and other organic and synthetic impurities was investigated. The micro and macrostructures and contact zones between the fibres and the binding material were analysed. The dependences of the thermal conductivity on the density of the thermally untreated and thermally treated composites were obtained.

Fiber hemp shives and biopolyurethane binder were used to create an engineered wood composite due to the synergistic properties of these materials. This study created engineered wood specimens using different ratios of biopolyurethane binder and hemp shives, which varied from 0.5 to 1.5. Different pressure levels were used when preparing the specimens, which were 1.5, 3.0, and 4.5 MPa. The formed engineered wood specimens showed that both the amount of binder and the level of pressure significantly influence the strength and moisture indicators, and different processes occur when increasing the amount of binder and the level of pressure. The research showed that the developed engineered wood composites had reached bending strength equal to 17 MPa, tensile strength equal to 7 MPa, and compressive stress equal to 11 MPa. In most cases, the strength index values were higher than those of various industrial-engineered wood products. Engineered wood was characterized by water absorption from 35 to 10%, and swelling in water varied from 26 to 10%. The flammability of the specimens, determined by the low-flame method, indicated that the specimens were flammable, but the expanded graphite used allowed for the creation of non-flammable specimens.