Wool Materials Research Articles

Improvement of Sound-Absorbing Wool Material by Laminating Permeable Nonwoven Fabric Sheet and Nonpermeable Membrane

Thin sound-absorbing materials are particularly desired in space-constrained applications, such as in the automotive industry. In this study, we theoretically analyzed the structure of relatively thin glass wool or polyester wool laminated with a nonpermeable polyethylene membrane and a permeable nonwoven fabric sheet. We also measured and compared the sound-absorption coefficients of these samples between experimental and theoretical values. The sound-absorption coefficient was derived using the transfer matrix method. The Rayleigh model was applied to describe the acoustic behavior of glass wool and nonwoven sheet, while the Miki model was used for polyester wool. Mathematical formulas were employed to model an air layer without damping and a vibrating membrane. These acoustic components were integrated into a transfer matrix framework to calculate the sound-absorption coefficient. The sound-absorption coefficients of glass wool and polyester wool were progressively enhanced by sequentially adding suitable nonwoven fabric and PE membranes. A sample approximately 10 mm thick, featuring permeable and nonpermeable membranes as outer layers of porous sound-absorbing material, achieved a sound-absorption coefficient equivalent to that of a sample occupying 20 mm thickness (10 mm of porous sound-absorbing material with a 10 mm back air layer).

Performance Enhancement of PV Module with Cooling Effect using Wet Wicks

Solar energy is one of the most potential sources of power production among all the renewable energies which is eco-friendly and can be much cheaper too. The energy conversion efficiency of the PV module decreases even more due to an increase in operating cell temperature over a certain limit. One way of improving the efficiency of the system is to maintain a low operating temperature by cooling it down during its operational period. This study compares the effects of cooling on the performance of photovoltaic systems. Experiments are performed on the solar panel inclined at a fixed 23.45° angle with the horizontal to the south without active cooling initially to have a set of reference performance parameters for comparison. The polycrystalline PV Module was tested with different cooling methods including Normal water Spray over the front surface, wet jute, and wet woolen material over the back surface of the panel. The cooling of the panels combined with the soiling effect enhances solar efficiency. The wet woolen material results in the most significant efficiency improvement, followed closely by wet jute and normal water spray.

Влияние длительного естественного старения теплоизоляционных минераловатных материалов на физико-химические и термические превращения

Purpose. The article studies physico-chemical and thermal transformations of mineral wool thermal insulation of natural ageing. The subject of the study is thermal insulation materials of natural ageing, and the object of the study is their physicochemical and thermal characteristics. The aim of the work is to establish physicochemical and thermal transformations of mineral thermal insulation of natural ageing. The research is aimed at identifying features of physico-chemical and thermal transformations of thermal insulation based on mineral fibers and organic binders in the ageing process. Methods. A set of precision physicochemical methods such as X-ray phase analysis (XRF), infrared spectroscopy and thermal analysis methods (TG, DTG, DSC) was used. Findings. The results of studying mineral thermal insulation (service life of 60 years) revealed characteristic changes in the structure of the material. The XRF method established that the ageing process of mineral wool materials is caused by occurring microdefects and disruption of material fibers structure organization. Changes in thermal insulation phase state have thermal fluctuation of kinetic nature of material mechanical destruction. The IR spectroscopy method identified changes in the areas of characteristic absorption bands: 2 800–2 200, 2 000–1 600 and 1 295–1 005 cm–1 caused by chemical destruction of organic binder in mineral thermal insulation. The nature of thermal transformations of the material was established, a tendency towards a decrease in the threshold temperatures for mass loss start due to destructing polymer binder was revealed. It is noted that natural ageing may result in loss of fire resistance of thermal insulation systems, as well as in intensificating smoldering combustion of thermal insulation. Research application field. The results are of interest to builders, designers, fire safety engineers and can be used in regulatory and technical as well as in reference literature on fire safety. Conclusions. During the ageing process irreversible physical and chemical changes occur in the structure of thermal insulation, leading to loss of thermal stability of the material and to a possible increase in the intensity of latent smoldering combustion. Technical obsolescence of the material leads to decreasing fire resistance limits of various thermal insulation systems due to loss of thermal insulation capacity and integrity.

Synthesis and Structural Views on New Azo Ligand and Its Metal Complexes with Some of their Application

In this work, we presented a study of the structural formula for a new series of complexes with Ag(I), Cu(II), Zn(II), and Cd(II) derived from the guanine azo dye ligand 2-amino-8-((3-hydroxyphenyl)diazinyl)-1,7-dihydro-6H-purin-6-one (HAG), which is investigated using various physicochemical analyses, spectroscopic techniques (FT-IR, U.V-VIS, and 1H NMR), thermogravimetric analysis (TGA). In addition, elemental analyses, magnetic susceptibility, and molar conductance measurements were all stabilized. As well as the mole ratio, stability constant, and Gibbs free energy were studied for all complexes, where they showed high stability and spontaneous synthesis. The Cu(II) complex was suggested to have octahedral stereochemistry, while the Ag(I), Zn(II), and Cd(II) complexes were suggested to have tetrahedral stereochemistry. The ligand has been demonstrated to be a useful acid-base indicator, and it has been shown that the ligand (HAG) and its complexes exhibit high photostability and have various colors that can be used to dye wool materials.

Structural, mechanical, electronic and thermodynamic analysis of calcium aluminum silicate crystalline phases in stone wool insulation materials: A first-principles study

Stone wool materials have gained considerable attention due to their effectiveness as thermal and acoustic insulation solutions. The comprehension of crystal structure properties is pivotal in determining the overall performance of these materials, as it enables us to optimize their composition for enhanced insulating capabilities. Crucial factors such as structural, mechanical, and thermodynamic characteristics of crystalline phases within stone wool are vital for evaluating its thermal and acoustic insulation properties. This study investigates the properties of calcium aluminum silicate crystal phases commonly present in stone wool, including anorthite, svyatoslavite, scolecite, and dehydrated scolecite using density functional theory (DFT) calculations. In comparison to previous works, this study provides a more comprehensive analysis using advanced DFT calculations. Our analysis reveals the complex interplay between the crystal structures and mechanical behavior of these phases. The calculated bulk modulus of the phases varies significantly, ranging from 38 to 83 GPa. We have compared the calculated elastic properties with available experimental data and found excellent agreement, confirming the accuracy of the computational approach. Moreover, we find that polymorphism has a significant impact on the mechanical strength, with anorthite exhibiting higher strength compared to svyatoslavite. Furthermore, dehydration is found to cause a reduction in unit volume and mechanical strength. The thermodynamic properties of dehydrated scolecite, including entropy and heat capacity, are significantly lower due to the absence of water molecules. These findings highlight the importance of understanding the structural and mechanical characteristics of calcium aluminum silicate phases in stone wool materials. Additionally, our findings have broader implications in various industries requiring effective insulation solutions such as to develop new materials or to enhance the energy efficiency of existing insulating products.

Sound insulation of slabs in dwellings

The well-being and sleeping quality of people in dwellings depends on appropriate sound insulation efficiency of building structures. In individual apartments, airborne sound is produced by people talking and music playing, and impact sound is produced by people walking and falling of various objects on the floor. The inter floor slab separating the individual dwellings is intended for airborne and impact noise insulation, so special attention is paid to its design and installation. Since the composition of this structure is primarily determined by the structural requirements, the improvement of the sound insulation performance is mainly carried out by developing the damping interlayer materials. The stone wool plate has been modified reducing the fiber intertwining to obtain a more uniform fiber directivity, thus reducing its dynamic stiffness. Therefore, the aim of this study was to investigate the sound insulation efficiency of inter floor slabs with a new modification of stone wool damping interlayer in comparison with currently used mineral wool products. The experimental measurements in 50-5000 Hz frequency range were performed in construction site (real structures), the single-number quantities – weighted standardized level difference (DnTw) and weighted normalized impact sound pressure level (L‘nW) with living adaption term (C) were determined and compared. The research results demonstrated that the modified stone wool with reduced fiber intertwining and lover organic content used for damping interlayer enables to improve living sound insulation of inter floor slab comparing with existing stone wool materials.

Enhancing the hydrophobicity of the mineral wool through surface modification with organo-silane

Mineral wool materials are consistently preferred material to be used for building thermal insulation because of their low heat conductivity, making energy-efficient structures impossible to construct without highly insulating thermal envelopes. A mineral wool with a hydrophobic external surface could be used for several applications where hydrophobicity would be helpful. Organo-silanes are one of the most promising materials to impart hydrophobic character to varied surfaces to achieve performance properties such as dust-resistant coatings on building glass, solar panels with self-cleaning surfaces, biofouling resistant paints, self-cleaning car windshields etc. In this study, mineral wool was treated with methyltrimethoxysilane (MTMS) to achieve hydrophobic surfaces.A Fourier Transform Infrared Spectrometer is used to confirm the successful deposition of organosilane/siloxane networks on glass wool fibre surfaces. The hydrophobicity of treated wool was assessed and quantified using a contact angle measurement. Contact angle measurement was used to quantify the hydrophobicity of treated wool. The thermal conductivity of treated mineral wool fiber was calculated using the portable Lee's disc method. To determine the thermal stability and crystallinity of the treated wool, X-ray diffraction spectroscopy and thermogravimetric analysis were used, respectively. The treated mineral wool exhibited excellent thermal stability up to 800 °C, and wettability tests proved the treated surface highly hydrophobic, allowing water droplets to roll off with contact angles up to 134.9°. Surface modification reduced thermal conductivity by 20%, showing good thermal resistance. Here, we show easy and sustainable methods of treating mineral wool surfaces, which can serve as a thermal insulation option under humid conditions.

Not all screens are created equal: examination of surface features and other physical properties of commonly used screen materials for smoking drugs

BackgroundBrass screens are considered an essential part of the safer drug smoking/inhalation supplies and are widely distributed by harm reduction programs in Canada. However, the use of commercially available steel wools as screens for smoking crack cocaine remains a common practice among people who smoke drugs in Canada. Use of these steel wool materials is associated with different adverse effects on health. This study aims to determine what changes folding and heating have on several filter materials, including brass screens and commercially available steel wool products, and examine the implications of these changes on health of people who smoke drugs.MethodsThis study investigated the microscopic differences, studied by optical and scanning electron microscopy, between four screen and four steel wool filter materials used in a simulated drug consumption process. New materials were manipulated, compacted into its own Pyrex® straight stem using a push stick and then heated with a butane lighter simulating a common method in preparing drugs for consumption. The materials were studied in the as-received (new), as-pressed (compressed and inserted into the stem tube but without heating) and as-heated (compressed and inserted into the stem tube and heated with a butane lighter) conditions.ResultsThe steel wool materials with the smallest wire thicknesses were found to be the easiest to prepare for pipe use, but degrade significantly during shaping and heating, making them wholly unsuitable as a safe filter material. In contrast the brass and stainless steel screen materials remain mostly unchanged by the simulated drug consumption process. After the stainless steel pellet screen, the Brass Impact 2.0 screen material had the best characteristics of the materials tested due to its mesh wire diameter, pitch, alloy choice and its pre-strained state.ConclusionCommonly used steel wool alternatives degrade during the handling and stem insertion, and heating the screens in the stem. Debris is generated by wool deformation on insertion and after heating that easily separates from the screen and can be inhaled during drug consumption. The brass and stainless steel screen materials are safer to use as they remain mostly stable during the simulated drug consumption process.

Testing the Greenhouse Emission Model (GEM) for Pesticides Applied via Drip Irrigation to Stone Wool Mats Growing Sweet Pepper in a Recirculation System

Pesticide emissions to surface water from greenhouses with crops grown on substrates in open or closed systems may be significant. It is important, therefore, to test models such as the Greenhouse Emission Model (GEM), which was developed to assess these emissions as part of the Dutch authorization procedure for use of plant protection products in greenhouses. GEM was tested using an experiment in which imidacloprid and pymetrozine were applied via drip irrigation to stone wool mats growing sweet pepper. The irrigation system in such greenhouses consists of a mixing tank to prepare the nutrient solution and a series of tanks to treat and recirculate the drain water back to the mixing tank. Emissions may occur because (part of) this recirculation water may be discharged or leached to the surface water. GEM assumes that all tanks are perfectly mixed. GEM further assumes that the water in these mats is perfectly mixed and that the pesticide behavior can be simulated by assuming one perfectly mixed reservoir. The model predicted breakthrough of both pesticides out of the mats earlier than measured, and the measured maximum concentrations were approximately two times lower than predicted. We considered a series of possible causes, including a smaller water volume in the mats, a higher plant uptake factor, and sorption to the stone wool. The model performance improved by representing the mats as a sequence of two equally large tanks with plant uptake restricted to the first tank. We recommend to study the solute transport process and the distribution of plant roots in the mats in more detail to further underpin the hypothesis used and improve the model. After this first validation, the GEM model might also be used in other countries to forecast emissions of PPPs to surface water.

Assessment of acute and chronic ecotoxicological effects of aqueous eluates of stone wool insulation materials

BackgroundStone wool is an inorganic mineral insulation material increasingly used to reduce the climate impact of buildings. The acute and chronic ecotoxicological potential of stone wool eluates have been studied in a battery of standardized laboratory ecotoxicological tests. The experiments were conducted with stone wool test materials in fibrous and milled form, with and without the presence of organic binder. For the preparation of eluates, the OECD protocol on the transformation/dissolution of metals and metal compounds was applied. The resulting eluates were used in acute tests, i.e., bioluminescence test with Aliivibrio fischeri (DIN EN ISO 11348-1:2009), algae growth test with Desmodesmus subspicatus (OECD No. 201) and immobilization test with Daphnia magna (OECD No. 202), as well as chronic tests, i.e., the Daphnia magna reproduction test (OECD No. 211) and the nematode growth and reproduction test with Caenorhabditis elegans (ISO 10872:2010).ResultsWhile no acute or chronic ecotoxicological effects of the eluates were observed for fibrous stone wool material, the milled test materials showed some chronic effects on aquatic invertebrates. Depending on the test materials and concentrations of milled stone wool used in the eluate preparation, these chronic effects included significant stimulation or inhibition of daphnid reproduction and nematode growth. The chemical analysis conducted in parallel to the ecotoxicological assessment indicated no leaching of organic substances from the applied binder or mineral oils and no formation of nanoparticles by the milling of stone wool. Furthermore, ICP-MS and ICP-OES analysis of eighteen elements revealed that only aluminum and nickel could be quantified in the eluates, at concentrations of approximately 750 µg/L and 7 µg/L, respectively.ConclusionsBased on the present ecotoxicological assessment, eluates from stone wool fibers cannot be considered as chemically hazardous to the aquatic environment. However, additional investigations of the ecotoxicological potential of the milled material and the environmental exposure of stone wool products are necessary for a complete evaluation of potentially negative effects of stone wool insulation materials.

Experimental study on affordable thermal insulation of exhaust manifolds using modified sheep wool waste

Internal Combustion (I.C.) engines generate lot of heat during high-speed operations. In order to prevent this heat loss, thermal insulation is mandatory to prevent heat transfer from the exhaust to the adjacent parts. The main aim of this work is to develop a thermally insulating material placed inside the catalytic converter to block the withdrawal of heat from the converter. This insulating material is usually placed between the heat shields for better heat dissipation. Comparison studies is executed between two different types of insulation material such as conventional Z-mat and super wool at various temperatures ranging from 200 °C to 800 °C for a period of 60 min and distortion results are noted at each temperature. Muffler furnace is used for the heat treatment analysis of the fabricated super wool. The composition of the novel fabricated super wool material can withstand all temperature levels between 200 °C and 800 °C, but the conventional Z-mat is suitable only up to 600 °C, where the Z-mat structure lost its capacity of insulation. Hence, the fabricated super wool material is more suitable for insulating catalytic converters and thereby it enhances the performance of engine with longer durability. In addition, hot vibration test is conducted for a duration of 50 h to check the thermal resistance capability of the super wool material. It is found that the thermal insulation is intact in position with absence of cracks or failures, inlet face erosion and retention losses. The fabricated thermal insulation mats from sheep wool waste also passed thermal shock test performed for 1500 thermal cycles. Thereby, this sort of sheep wool based affordable thermal insulation can be used for applications associated with larger thermal gradients to control the thermal-related errors such as shrinkage, warpage and distortion, which can also be extended to acoustic absorption.

Marine Biodegradability and Ecotoxicity of MWool® Recycled Wool Fibers: A Circular-Economy-Based Material

Pollution of the marine environment by microfibers is considered a problem for ecosystem conservation. The amount of microplastic, localization of sources, and associated ecotoxicity are well known in the literature. Wastewater from washing machines is the main source of microplastic fibers in the aquatic environment, and fabrics made from recycled plastic are widely reused. The circular economy also promotes recycling of dyed natural wool materials as a basis for making new clothing, but in this case, less research has been conducted on the behaviour and effects of recycled wool microfibers in marine ecosystems. MWool® (MW) and MWool® carded (MWc) products made from recycled wool fibers were tested in mesocosms to investigate the biodegradation of wool fibers over a 260-day period and the effects of this process on marine ecosystems in terms of microfiber inputs and the ecotoxicological effects of by-products and chemicals released during degradation. The early degradation process was associated with the loss of artificial pigments from the dyed wool, particularly pink and red, which occurred within 30–90 days of exposure. Mean release of microparticles into contact water is significantly different from control (T0, p < 0.01) at 90 days MWc (36.6 mg/L) and 180 days MW (42.9 mg/L). The biodegradation process is accompanied by swelling of wool fibers, which is associated with a significant increase in mean wool thickness (p < 0.05, 18.8 ± 2.1 µm at T0 vs. 24.0 ± 7.1 µm). In both cases, the contact water was not associated with signs of ecotoxicity for the marine species tested in this study (Phaeodactylum tricornutum, Brachionus plicatilis, and Paracentrotus lividus).

Influence of Sheep’s Wool Vegetation Mats on the Plant Growth of Perennials

Vegetation mats for horticulture and landscaping usually consist of coconut fibre and straw. They have hardly any available nutrients and serve only as a carrier material for plant growth. Water capacity is low. By incorporating raw sheep‘s wool, nutrients, such as nitrogen, potassium, and sulphur can positively influence the nutrient content of the carrier material. Water storage and water holding capacity are increased by the wool. In this study, three different thick-layered vegetation mats with different proportions of sheep’s wool and coir fibres were developed for the pre-cultivation of perennials. The focus is on the evaluation of sheep’s wool as a carrier material compared to pure coconut fibre as well as the plant growth of the eight perennial species used (Achillea clypeolata ‘Moonshine’, Achnatherum calamagrostis ‘Algäu’, Anaphalis triplinervis, Aster dumosus ‘Prof. Anton Kippenberg’, Aster dumosus ‘Silberball’, Centranthus ruber ‘Coccineus’, Coreopsis verticillata, Salvia nemorosa ‘Rosakönigin’). The vegetation mats with sheep’s wool (V1–V3) contained 192.6, 154.0, and 283.5 g nitrogen (N)/m2 and the coir mats (V4) contained 7.5 g N/m2. The water content ranged from 16.0 to 22.1 vol% for the sheep’s wool mats and 12.6 vol% for the coir mat at pF1 (is equal to matrix potential at −10 hPa). The air content ranged from 71.9 to 77.0 vol% for the sheep’s wool mat and 79.4 vol% for the coir mat at pF1. On all vegetation mats containing sheep’s wool, the overall impression of the perennials was better than in the control. Especially good were Asters. At the end of the trial, the assessment scores of Asters on the sheep’s wool mats were two scores higher than on the coir mat. Aster dumosus ‘Prof. Anton Kippenberg’ achieved an average plant height between 35.8, 35.8, and 36.5 cm on the sheep’s wool mats and 14.4 cm on the coir mat. Aster dumosus ‘Silberball’ yielded 41.3, 42.3, and 44 cm on the sheep’s wool mats and 26.7 cm on the coir mat. No significant differences regarding plant height between the different variants of sheep’s wool mats emerged. Therefore, these mats can be used as alternative planting concepts for landscaping.

Evaluation of Sheep Wool as a Substrate for Hydroponic Cucumber Cultivation

The problem of the use and disposal of horticultural substrates is an important element of the optimization of plastic greenhouse production in terms of economic and environmental efficiency. The production of mineral substrates is associated with a high energy expenditure, which generates costs and greenhouse gas (GHG) emissions. An important factor is also the transport of professional substrates over long distances. The research objective was to evaluate the possibility of using sheep wool to create horticultural substrates in the hydroponic production of cucumber. The modifier of production technology was the use of substrates of various origins. The experiment was based on the use of two substrates: one was a conventional substrate, made of mineral wool, and the other was made of greasy Gissar sheep wool, which is considered waste or a nuisance byproduct of sheep farming today. The adopted functional unit was 1 ton of commercial cucumber yield. The boundaries of the system were soil formation, fertilization, irrigation, and harvesting. The amount of GHG emissions was calculated in accordance with the ISO 14040 and ISO 14044 standards. The results of the experiment show that the use of sheep wool as a substrate in the hydroponic cultivation of cucumbers reduced yield by approximately 8%, but it allowed for a higher efficiency of water and mineral fertilizer use per crop mass unit. Within the adopted system boundary, the value of the carbon footprint in the object with the conventional substrate was 276.9 kg CO2 eq · Mg−1. The value of this parameter for the object with the sheep wool was 193.9 kg CO2 eq · Mg−1. The use of sheep wool did not increase the phytosanitary risk of the cultivated plants. An important goal for achieving sustainability, especially in food production, is to use materials that are easily recyclable and renewable, locally available, and environmentally friendly. The use of sheep wool as a substrate for soilless plastic greenhouse cultivation is a rational solution, as this material consists of 60% animal protein fibers, 10% fat, 15% moisture, 10% sheep sweat, and an average of 5% impurities. This makes it an easily recyclable, easily renewable, and environmentally friendly source of raw material for hydroponic substrates in food production, contrary to rockwool, which produces waste that is difficult to manage and a nuisance to the natural environment. In the countries of Central Asia, the sheep population is over 20 million; therefore, the potential for using sheep wool material for agricultural production is significant.

Mathematical Modeling, Prediction and Research on Heat and Moisture Transfer of a Kind of Textile Materials

The structure, layers, and mix of a particular type of textile material affects how warm and permeable to moisture a piece of clothing is. The microclimate region between the human body and clothes also has an impact on it. Designing warm clothing and choosing materials can be guided by the inverse problem of the heat and moisture transfer model and its parameter determination in winter clothing. This paper investigates the mathematical modeling of heat and moisture transfer of a class of textile materials based on PSO (abbreviation: PSO). Under the two categories of temperature and humidity combinations mentioned above, the three materials exhibit extreme values and are one of a kind. The disturbance function of polypropylene fiber material at 5% is 10, the disturbance function of polyester material at 5% is 8, and the disturbance function of wool material at 5% is 18 when the fabric thickness reaches 0.012. PSO was used in this experiment to calculate the thickness inversion results for fabrics made of polypropylene, polyester, and wool. The results are consistent with those in the figure. In order to solve the inverse problem of functional design, it is necessary to mathematically study the transfer of heat and moisture through textile materials.

Surface Temperature Reduction of Porous Concrete Pavers Using a Water Retention Layer

Porous pavements are now used to reduce urban heat even though previously it was designed specifically to reduce stormwater runoff. To qualify the pavement as a cold pavement, the pavement needs to be modified either as evaporative pavement, reflective pavement, and heat storage pavement. This study used porous concrete pavers as evaporative pavement by adding wetted retention layer underneath the pavers and investigated the temperature reduced. Three materials of water retention layers were investigated and material with higher water retention was selected. The pavement temperature changes are studied using selected water retention material with different layer thicknesses. The result shows that felt wool material absorbed more water compared to palm oil fiber and geotextile. While as for the selection of the thickness, water retention layer with 8 mm thick was selected due to its optimal evaporation rate and gives higher temperature reduction on the block pavers compared to 4 mm thick and 12 mm thick.

Hybrid composite board produced from wood and mineral stone wool fibers

Wood fiberboards are used extensively, mainly in the fields of furniture production, interior fittings, construction, etc. Mineral stone wool materials are used for heat and sound insulation in the construction industry. This study aimed to produce a new hybrid-based composite material by mixing fibers obtained from wood and mineral stone wool. For this purpose, hybrid fiberboards with 50, 40, 30, and 20% stone wool addition and a fiberboard group consisting of 100% pine and beech fibers (control sample) were produced in a hot press using thermoset-based urea formaldehyde and phenol formaldehyde resins. Statistical comparisons of the results were made for values of density, thickness swelling, and water absorption extents after 24 h immersion, bending strength and modulus of elasticity in bending, tensile strength perpendicular to the board surface (internal bond strength), and time to ignition (TTI) analysis. Additionally, percentage of mass loss (PML), average heat release rate (A-HRR), average effective heat of combustion (A-EHC), and mass loss rate (MLR) were studied. The results showed that as the stone wool content in the produced boards increased, the mechanical properties and thickness swelling decreased. The combustion results showed that the combustion resistance of the boards increased with increasing stone wool ratio.

Synthesis, Application, and Antibacterial Activity of New Direct Dyes based on Chromene Derivatives.

This study aimed at synthesizing, analyzing, and utilizing two new direct dyes based on chromene derivatives as the chromophoric moiety in dyeing wool, silk, and cotton, with good color strength, light fastness, and other desirable features. New direct dyes with antimicrobial activities for Gram-positive, Gram-negative bacteria, and fungus are being developed. These dyes are used on cotton, silk, and wool materials, which have excellent light fastness, washing, rubbing, and perspiration fastness. All dyeing fabrics were tested for antibacterial activity. As a part of the experiment, parent structure 1 was previously synthesized. Then, diazotization and coupling reactions were used to prepare these dyes. P-Aminobenzenesulfonic acid (C1) and 4-Aminoazobenzene-3,4'-disulfonic acid (C2) were diazotized in hydrochloric acid with sodium nitrite and then coupled with compound 1 in a molar ratio of 1:1 at 25 °C until the pH was fixed at 5. Finally, the monoazo and diazo direct dyes (D1 and D2) were prepared. Wool, silk, and cotton materials benefit from the increased antibacterial activities and dyeing qualities (exhaustion and fixing) of synthetic dyes. Furthermore, they offer excellent fastness qualities (light, rubbing, and perspiration).

Techniques for Creating Wool Carpets and Some Methods of Improvingthe Quality of Decorative Wool Mats

Techniques for Creating Wool Carpets and Some Methods of Improvingthe Quality of Decorative Wool Mats

Potential of Bamboo as Car Roof Material

An effort to achieve SDGs 12# responsible for consumption and production is by optimizing the application of natural recycled materials, such as bamboo, in the automotive industry. Bamboo is a potential insulating material because it has low thermal conductivity. This study used Gigantochloa Atroviolacea as a thermal insulator projected as a car roof. Experiments were performed to identify the effective thermal conductivity. There were two shapes tested: slab and box. The first specimen is a laminated bamboo slab, and the second is a combined slab of laminated bamboo, glass wool, and aluminum foil. Based on the heat transfer calculation, the effective thermal conductivity is 0.21 W/mK and 0.14 W/mK for the laminated bamboo slab and combined slab, respectively. The thermal flow characteristic was analyzed in two box models with different material arrangements. The first box is laminated bamboo and fiber, and the second is laminated bamboo and glass wool. The results show that the first box can insulate heat better than the second. It was concluded that laminated bamboo and bamboo fiber can be used as a substitute for glass wool material. The bending test of laminated bamboo with three different layers was performed according to ASTM D 790. The maximum load was 616 kg for five layers. The bending test showed that laminated bamboo is insufficient as a car roof. Steel plates are still necessary to comply with the requirements of the FMVSS 216 standard.