New printing and dyeing technologies with environmental effects

Scientists from all countries have made remarkable efforts. Some forward-looking, innovative and practical new technologies and new equipment have been developed, which has greatly improved the environmental protection level of the printing and dyeing industry. The brief introduction is as follows:

Ultrasonic printing technology Ultrasound is an acoustic wave whose frequency exceeds the range of human hearing. It has mechanical, thermal and cavity effects. Elastic vibration of the ultrasonic wave has the functions of dispersion, degassing and diffusion. The use of ultrasonic vibrations in a liquid medium can smash the dye particles in the dye bath, increase the surface activity of the detergent, and improve the stability of the emulsion and colloidal solution, such as desizing, scouring, bleaching, and washing in dyeing and finishing processes. The use of dyeing can increase the diffusion rate of chemical agents, activate and accelerate the reaction.

Nano-coating technology Coating printing is widely used in the dyeing and finishing industry due to its simple process, accurate color dithering, no need of water washing and compliance with environmental protection requirements. The proportion of such products in foreign countries has exceeded 50%. However, paint printing also has drawbacks such as poor pattern definition, low color fastness and low light fastness, and a harder touch. In the paint printing, as long as adding 0.3% nano-scale silicon-based oxide, you can get good results. The thixotropy of the paste is good, the transparency of the paint paste and the clarity of the printed pattern are significantly improved, and the strength, elasticity, abrasion resistance, and water resistance of the film are increased, thereby improving the related color fastness.

Electrochemical Dyeing Drifting Technology Krantz, Germany, has introduced an Electrochemical Reduction Dyeing Equip- ment. When using dyes such as reducing, indigo, and sulphide for dyeing, caustic soda and infu- sion powder used in conventional processes may not be used. Instead of the drug, the dye bath medium is reused by electrochemical means to reduce the dye. The advantage of this method is that it saves 80% of chemicals, water consumption is almost zero, and pollution is greatly reduced.

The electrochemical device invented by the University of California, USA, is mainly used for pollution-free scouring and bleaching. The basic principle is that the cathode of the electrode releases the lye, performs bleaching and mercerizing, and the anode generates acid to neutralize the residual alkali, which can eliminate waste liquid discharge.

Bioenzyme scouring and finishing technology Enzyme is a kind of "biological catalyst", which can be used for scouring and sorting various types of fabrics to obtain good results; at the same time, the enzyme will not produce harmful by-products like traditionally used bases during use. , emissions will not pollute the environment.

Various types of enzymes have different uses: "Amylase" is particularly suitable for desizing of dyed fabrics; "Protease" is suitable for anti-shrinkage finishing of wool and enzyme scouring of silk; "Cellulase" can be used for indigo jeans Enzyme washing and biological finishing of cotton, Tencel, viscose, jute, flax and their blended fabrics; "pectinase" and "cellulase" are used in combination to remove cotton seed hulls on cotton fabrics and improve whiteness.

Plasma Pretreatment Technology Plasma processing technology is a direct reaction between solids and gases. It is a dry process that does not require water or chemicals. It can save water, save energy, and reduce environmental pollution. Selecting the appropriate gas type and processing conditions for the plasma treatment and physical etching of the fabric surface can change the surface properties of the fabric, such as hydrophilicity, surface roughness, and the like. The KPR type industrial plasma processing equipment developed and introduced by Mezzera of Italy has entered the pilot production stage. It is used in the desizing of fabrics and can effectively cut off the molecular chain of the fabric slurry, making the slurry easy to wash away, not only improving the fabric's Dyeing rate and color fastness can also greatly shorten the pre-treatment washing process and reduce waste liquid discharge.

Natural Printing Paste Technology Printing paste is the key to the quality of printing. Using good paste can not only make the outline of the pattern clear and non-permeating, but also can increase the depth and vividness, thus saving dyes and reducing the cost. Some foreign printing and dyeing factories actively use natural pastes to develop natural printing pastes that use less water, are easy to clean, are easy to degrade, and are conducive to reducing energy consumption and pollution.

Microwave Far Infrared Dyeing Technology Microwave is an extremely short-wavelength electromagnetic wave, which, like radio waves, infrared rays, and visible light, belongs to electromagnetic waves. Microwave heating uses microwaves as a power source. When the microwave interacts with the molecules of the material, polarization, orientation, friction, and absorption of microwave energy are generated to generate a heating effect. Microwave heating is the self-heating of an object after it absorbs microwaves. Heating starts from the inside of the object and can be heated simultaneously inside and outside.

The microwave energy technology is suitable for the dyeing of polyester fabrics, polyester-cotton fabrics, acrylic fabrics, and polyester nitrile fabrics. The traditional dyeing method lasted for several hours, resulting in a lot of heat loss and poor working conditions. Under the irradiation of microwave, the movement of the dyeing liquor is intensified, and dye molecules that dissolve in water are diffused and dyed in the fiber of the fabric, so the dyeing time is short, generally 1-10 minutes, which saves much energy compared with the traditional dyeing. The color fastness, color and other indexes of the dyed fabrics are all improved compared with the traditional techniques.