Do alkaline treatments reduce the water absorption capacity of hemp fiber?5 answersAlkaline treatments, such as alkalization and silane binding, have been shown to reduce the water absorption capacity of hemp fiber. Studies have demonstrated that alkaline treatments can lead to a rise in surface roughness and a decrease in water attraction and moisture content of the fibers. Additionally, the surface pretreatment with alkali has been found to improve water resistance in hemp fiber-reinforced composites, resulting in lower overall moisture adsorption levels. Furthermore, both water and alkali treatments of hemp fibers have been shown to greatly decrease water absorption, which is beneficial in improving the UV resistance of plant fiber-reinforced composites. Therefore, alkaline treatments play a crucial role in reducing the water absorption capacity of hemp fiber, making them more suitable for various industrial applications.
What is hemp fiber configuration?5 answersHemp fiber configuration consists of various characteristics based on different parts of the hemp plant. The industry hemp stalks' cortex fibers are long (11-30mm), with a high aspect ratio (310-900) and a low ratio of wall thickness to lumen width (0.11-0.50). In contrast, xylem fibers are shorter (0.41-0.90mm), with a lower aspect ratio (11-50) and a slightly higher ratio of wall thickness to lumen width (0.11-0.40). Hemp fibers are essentially a composite material, with rigid cellulose micro-fibrils embedded in a matrix of lignin and hemicellulose. The fibers can be selectively degraded to produce thin bundles with a high tensile strength (960 MPa). Overall, hemp fibers exhibit diverse configurations depending on their location within the plant and can be utilized in various industries like paper-making and composite materials.
How does the silicone softening process affect the sound absorption of hemp fibers?5 answersThe silicone softening process significantly impacts the properties of hemp fibers. Research shows that the softening finishing of hemp fibers with ultrasonic pretreatment enhances the softness of the fibers, making them feel much softer compared to only softener finishing. Additionally, the efficiency of finishing treatment using a softening agent improves the spinnability of processed hemp fibers, increasing their flexibility, surface friction, and moisture absorption. Moreover, the application of silicon on hemp plants during growth improves and preserves the mechanical properties of fibers, especially when exposed to heavy metal stress, suggesting a potential positive impact on sound absorption due to the maintained fiber quality. These findings collectively indicate that the silicone softening process can enhance the overall quality and properties of hemp fibers, potentially positively affecting their sound absorption capabilities.
How does the silicone softening process affect the structure of cellulosic fibers?5 answersThe silicone softening process significantly impacts the structure of cellulosic fibers. When treated with silicone compounds, cellulosic fabrics experience enhanced properties such as increased softness, elasticity, and reduced friction. The application of silicone softeners on regenerated cellulose fabrics like viscose, modal, and lyocell leads to improvements in pilling resistance and air permeability, while maintaining color fastness. Additionally, the quaternization of silicones and adjustment of pH during treatment result in reduced fabric friction, roughness, and waviness, ultimately lowering fabric strain and altering fiber properties at both macro and molecular levels. Furthermore, a method involving the treatment of cellulose fibers with a swelling solvent and silicone compounds leads to a permanent bonding of silicones, reducing the crystalline constituents in the fibers and improving overall fiber properties.
How does the bleaching process affect the parameters of hemp fiber fabrics?5 answersThe bleaching process has significant effects on the parameters of hemp fiber fabrics. Research shows that bleaching with hydrogen peroxide and biological enzymes improves fabric whiteness and water absorbability, meeting dyeing requirements while reducing fiber damage. Different bleaching agents like peracetic acid can achieve high whiteness values without significant fiber damage, with exhaustion bleachings yielding higher whiteness values. The bleaching process positively impacts the fatty acid profile of hemp oil, reducing saturated fatty acids, increasing polyunsaturated fatty acids, and improving the SFA/PUFA and omega-6/omega-3 ratios. Additionally, a scouring and bleaching process for antibacterial moisture-absorption wet spinning hemp yarn produces high-quality hemp fiber products with strong spinnability, suitable for mass production and popularization.
How chemical treatment increase hydrpphily of hemp fibers and decrese tenacity ?5 answersChemical treatment, specifically alkaline treatment using sodium hydroxide (NaOH) solution, increases the hydrophilicity of hemp fibers and decreases their tenacity. The alkaline treatment process removes impurities from the fibers, such as lignin, wax, and oils, resulting in a higher level of fiber purity. This treatment also transforms some of the alpha cellulose to beta cellulose, which improves the bonding and interfacial adhesion of the fibers. The increase in hydrophilicity is indicated by measurements of contact angle and Fourier transform infrared spectroscopy analysis, which show a decrease in fiber impurities with higher NaOH solution concentrations. However, the decrease in tenacity is not directly caused by the chemical treatment itself, but rather by the structural alterations in the fibers, including the removal of targeted components and rearrangement in the cell wall, which influence the unitary fiber properties.