A new type of hydrophobic natural wax fabric coating developed by the University of Alto, a top university in Finland

Researchers at Aalto University, Finland's top university, have developed an environmentally friendly hydrophobic wax coating for textile and lignocellulosic fiber substrates, which not only improves the hydrophobicity of the fabric, but also retains its original air permeability and natural feel Due to the use of waterproof products in the production process of textiles, and many waterproof products use toxic chemicals, resulting in environmental impact problems, there is an urgent need for environmentally friendly alternatives, but the production of non-toxic, breathable and waterproof textiles, and environmentally sound and economic thinking is still a challenge at present Under the condition of water, wax was melted and decomposed into anionic wax particles with negative charge In order to make the wax particles adhere to the surface of cellulose well, some positively charged cations are needed as buffers, because the particles with opposite charges will attract each other In the previous study, a natural protein of polylysine was used Dr Forsman of the University of Alto pointed out that "polylysine is more expensive, so in our study, cationic starch with lower cost is used as an alternative Although cationic starch is not as effective as poly-L-lysine, the water-proof property of fabric surface can be realized by mixing starch and wax particles in a certain proportion The researchers also compared the air permeability between the fabrics treated with natural wax and the fabrics treated with the same kind of commercial products The results showed that the natural wax particles improved the water resistance of the fabrics while retaining the air permeability, while the fabrics treated with commercial products reduced the air permeability The research team of the project consists of multidisciplinary members, such as Matilda tuure, a designer from the school of art design and architecture of the University of Alto Wax coating can be applied to the surface of fabric by dip coating, spraying or brushing, and three coating methods are analyzed and tested respectively The results show that dip coating is suitable for smaller size fabrics, while spray or brush coating is more suitable for larger size fabrics In the process of industrial production, as a part of fabric surface treatment process, wax treatment can be carried out simultaneously with coloring The research team pointed out that at present, the detergent resistance of wax coating needs to be further improved, and the new coating is more suitable for coats such as jackets that do not need to be washed frequently The research team also studied the effect of the drying temperature after wax treatment on the water resistance The results showed that when the drying temperature is lower than the melting temperature of wax, the water resistance is the best Dr Forsman pointed out that "we have tested the coating on different fabric materials, such as viscose fiber, silk, cotton, hemp, cotton knitwear, etc The results show that the surface roughness of the fabric will affect its hydrophobicity, and the rougher the surface, the better This is because on a rough surface, the contact area between the water drop and the fabric surface is smaller "