Brief Introduction Of Textile Finishing Technology Abroad

Finishing can improve the aesthetics of textile fabrics, because selling is a selling point.

For the textiles that are widely used in the design and development of high and new technology, the most consideration is not its aesthetics but its functionality.

Functional finishing technology can protect textiles from various adverse conditions, such as ultraviolet radiation, harsh climate, microorganisms or bacteria, high temperature, chemicals such as acid, alkali and organic solvents, and mechanical wear.

The international functional textiles are driven by the growing demand. The profit and high added value of textiles are often achieved through finishing.

Therefore, understanding the commonly used fabric finishing technology is very important for enterprises to develop new products.

Nano sol coating technology

Sol gel technology can produce pparent coating containing metal oxide or silicon oxide thin film, which provides an alternative method for deposition of gas-phase metal oxide layer.

In Sol gel technology, nano sol of silicon oxide or other metal oxides is prepared by acid or alkaline hydrolysis of alkoxides.

The nano sol produced usually contains metal oxide (weight by weight) of 3% to 20%, and the diameter of nanoparticles is less than 10 nm.

The agglomeration and aggregation of nanoparticles will form a three-dimensional network structure. After solvent coating, spray coating and continuous coating, solvent sol-gel layer is formed on the surface of the textile. After drying and heat treatment, the coating solvent containing dry gel layer is removed to form porous oxidation structure.

Modification of nano sol by chemical and physical methods can change the functionality of the coating.

For example, chemical modification of three alkoxyl silyl or perfluorinated alkane can produce hydrophobicity or oil repellent.

Larger molecules such as dyes and bioactive agents can be directly covalently bound after this chemical modification.

Physical modification is by assisting the auxiliaries to be united and fixed on the metal oxide substrate. Therefore, various auxiliaries that can increase the functional properties of textiles can be used to improve the fastness to light, fiber to UV stability, wear resistance, antistatic and flame retardancy.

At present, plasma treatment technology is also used for fiber surface modification, such as changing the chemical properties of fiber surface, improving fiber strength, improving the durability of adhesive bond in finishing and coating, and enhancing lamination and adhesion.

Foam coating technology

Recent advances in foam coating technology have been made.

The latest research in India shows that the heat resistance of textile materials is mainly achieved by a large amount of air trapped in porous structures.

In order to improve the heat resistance of textiles coated with polyvinyl chloride (PVC) and polyurethane (PU), as long as some foaming agents are added to the coating formulation.

The researchers said that the foaming agent used for PVC coating is more effective than PU coating, which is because the foaming agent forms a more effective closed air layer in the PVC coating, and the heat loss on the adjacent surface is reduced by 10% to 15%.

Organosilicon finishing technology

The best silicone coating can increase the tear resistance of the fabric by more than 50%.

Silicone elastomer coating has high flexibility and low elastic modulus, allowing yarn to migrate and form yarn when the fabric is torn.

The tear strength of the ordinary fabric is always lower than the tensile strength.

However, when coated, the yarn can move on the ripping extension point, and two or more yarns push each other to form a yarn bundle, thus significantly improving the tear resistance.

The main supplier of silicone coating is German wick, which modifier liquid silicone rubber with other polymers, such as polyurethane or acrylic ester.

Silicone coating can produce water repellent effect, so that the textile will not absorb too much moisture, in order to prevent the wetting effect and weight increase.

The silicone rubber layer can filter out most of the harmful ultraviolet rays in the sunlight, and the handle is soft.

Silicone coating has been used in air bag fabrics, balloons, paragliders, big sail, tents, sleeping bags, and many high-performance sports casual fabrics.

Waterproof and oil repellent finishing technology

The surface of the lotus leaf is a regular microstructural surface, which prevents the wetting of the droplets from the surface.

The microstructure makes air hidden between the droplet and lotus leaf surfaces.

Lotus leaf has a natural self-cleaning function, that is super protection.

The northwest Textile Research Center in Germany is using the potential generated by pulsed UV laser to try to imitate this surface.

The surface of the fiber is processed by pulsed UV laser (excited state laser) to produce a regular micrometer structure.

If modified in gaseous or liquid active medium, photon treatment can be carried out simultaneously with hydrophobic or oil thinning finishing.

In the presence of perfluoro - 4 - methyl - 2 - ene, irradiation can bind to terminal hydrophobic groups.

The further research work is to improve the surface roughness of the modified fibers as far as possible and to combine the appropriate hydrophobic / hydrophobic groups to obtain super protective properties.

This self-cleaning effect and the characteristics of less maintenance are of great potential in hi-tech fabrics.

Antibacterial finishing technology

Many outdoor textiles such as tents, sun umbrellas, awnings and geotextiles require antibacterial finishing to prevent damage caused by fungi, bacteria, yeast and seaweed, especially in the damp and hot environment where bacteria and fungi are easy to grow.

The existing antibacterial finishing range is very wide, and the way of action with microorganism is: function with cell membrane, in the process of metabolism, or in core material.

Oxidants such as acetaldehyde, halogen and peroxide attack the cell membrane of the microorganism first, or penetrate the cytoplasm, and act on its enzyme.

Fatty alcohol as a coagulant makes the protein structure of microorganisms irreversible.

Deacetylchitin is a cheap and easily available antibacterial agent, and the protonated amino group in chitosan can bind to the surface of negatively charged bacteria and bacteriostatic.

Other compounds, such as halides and ISO three nitroalkoxides, are highly reactive as free radicals because they contain a free electron.

Quaternary ammonium compounds, guanidines and glucosides showed special polycation, porosity and absorbability.

When applied to textile fibers, these antibacterial chemicals combine with the cell membrane of microorganisms, causing the structure of the oil soluble glycosylated compounds to break, resulting in cell membrane puncture and cell breakage.

The use of silver compounds is due to their cooperation in preventing microbial metabolism.

However, Ag is more effective for negative bacteria than positive bacteria, but less effective for fungi.