Wet transfer printing of woolen fabrics with reactive dyes and dry transfer printing of woolen fabrics are two innovative processes in the printing and dyeing industry. This process not only has a high authenticity rate, good color fastness, rich pattern layers, exquisiteness and delicateness, The printing effect exceeds that of digital printing products, and this process overcomes the shortcomings of traditional screen printing. It is a clean process with low energy consumption and less pollution, and represents the development direction of wool fabric printing technology.
Keywords Wet transfer printing for reactive dye wool fabrics Dry transfer printing
Wool fabrics, the output of which ranks second among natural fiber fabrics Cotton fabrics have huge market consumption. my country is the world’s largest producer and consumer of wool textiles. However, except for some printed sweaters, consumers can hardly see other printed wool textile products in the domestic market.
This is because the traditional printing process, whether it is flat screen printing or rotary screen printing, requires the fabric to be attached to the guide belt. It is quite difficult to patch woolen fabrics, which often results in poor patching and a large number of defective products.
Secondly, woolen fabric printing is mainly based on small batches and multiple varieties, while traditional printing is mainly suitable for large-volume fabric printing. The batch size is small, uneconomical, and the printing factory has no enthusiasm.
Recently, with the rise of digital printing, some people have gradually begun to try digital printing of woolen fabrics. However, the application of traditional digital printing on woolen fabrics has many shortcomings.
First of all, woolen fabrics have a certain amount of fluff, which brings a lot of inconvenience to digital printing. If the nozzle is too close, it will cause damage to the nozzle. If the nozzle is too far away, the inkjet will slip away, resulting in insufficient fineness of the pattern and poor penetration. Moreover, the gray fabric requires pre-treatment and sizing, which is a cumbersome process. Due to the low speed of digital printing, the delivery time for orders of thousands of meters will be a long process. Digital printing is directly sprayed on the fabric, and it is easy to cause clogging and defective products. It cannot fundamentally solve the waste problem.
In order to solve the printing problems of woolen fabrics, Mr. Wang Yong conducted a lot of research on transfer printing of woolen fabrics and successfully developed transfer printing of acid dyes, reactive dyes and plasma dyes for woolen fabrics, many of which The technology is the company’s original technology, and it has a full set of invention patents on process, formula, and equipment, and has completely independent intellectual property rights.
Introduction to transfer printing on woolen fabrics
1. Wet transfer printing on woolen fabrics
Wet transfer printing on natural fibers, Denmark’s DANSK began research in 1984 and subsequently cooperated with other companies. They jointly developed a reactive dye transfer printing process for cellulose fibers, but this process has certain technical flaws and is not effective when applied to woolen fabrics.
Mr. Wang Yong felt the shortcomings of existing printing technology on woolen fabrics, so he began research on wet transfer printing of woolen fabrics in 2009, and started wet transfer printing of woolen fabrics in 2010. Currently, it has obtained a large number of orders for wool knitted fabrics for export and woolen fabrics for domestic sales, and has successfully developed a new process for woolen fabric printing. This process not only has a high authenticity rate, good color fastness, rich and exquisite patterns, and the printing effect exceeds that of digital printing products, but also is a clean production process with less water and low emissions, which is in line with the energy conservation and emission reduction currently advocated by the country. Policies.
The general process of wet transfer of woolen fabrics
1. Mercerization treatment of woolen fabrics:
There is a layer on the surface of wool fiber Dense scale layer, the existence of this scale layer affects the penetration of dye and the combination with fiber. Therefore, before printing, it is necessary to remove the scale layer of the wool fabric (generally called mercerizing treatment in China).
At present, the main methods for mercerizing wool fabrics in production include: chlorination technology, oxidation technology and biological enzyme technology. Among them, chlorination treatment is the main one. Recently, with the increasing emphasis on environmental protection, biological enzyme technology has also received more and more attention.
2. Selection of dyes:
Theoretically, there are many dyes that can be selected for wet transfer printing of woolen fabrics, as long as they can dye protein fibers. It can be used as a wet transfer dye for woolen fabrics. However, considering factors such as color fastness, environmental protection, and reproducibility, Mr. Wang Yong mainly uses reactive dyes in wet transfer printing of wool fabrics, including reactive dyes for wool and reactive dyes for ordinary cotton. Among them, the wet transfer printing of reactive dyes for wool is the first of its kind in Changzhou Hanyuan. It has a high transfer rate, rich colors, excellent color fastness, and is absolutely machine washable. It represents the highest level of wool fabric printing in the world and is the best choice for wool fabrics. The development direction of printing.
3. Introduction to the wet transfer printing process of woolen fabrics:
The process flow is :
Ink preparation: First select the appropriate dye→ Choose the corresponding solvent→ Dissolve→ Grind→ Prepare printing ink for later use
Plate making: Select pattern→ Computer color separation→ Electro engraving plate making.
Transfer film printing: The printing ink is color-matched → according to the customer’s design→ and then printed on the gravure plate through electroengraving printing press admiralThe � shape is printed on the PET film → to make a wet transfer film → and stored for later use.
Pattern transfer: Wet the wool fabric to be transferred→ and attach it to the transfer film→ Press→ so that the reactive dye on the transfer film is transferred to the woolen fabric.
Post-processing: The transferred fabric undergoes conventional post-processing to become a finished wool fabric printing product.
Among them, Mr. Wang Yong has invention patent protection for the preparation of printing ink, transfer technology and transfer equipment, and has completely independent intellectual property rights.
4. Advantages of wet transfer:
Wet transfer is a printing method suitable for small batches and multiple varieties, because the transfer film is stored It is convenient and quick to replace, so it is suitable for small batch printing of wool textile types.
The use of reactive dyes for printing has good color fastness, rich colors, and does not contain heavy metals, which represents the development direction of printing.
Transfer printing has a high authenticity rate, no need for patching, easy operation, small investment, low energy consumption, and low emissions, which is in line with the national industrial development direction.
2. Dry transfer printing of woolen fabrics
Wet transfer printing is suitable for continuous printing of pieces of woolen fabrics. However, for garment printing on woolen fabrics, the application has certain drawbacks because the humidity is difficult to control.
There is a huge market for sheet printing on woolen fabrics, including woolen sweaters, cashmere sweaters, scarves, shawls, garment pieces, etc. In order to solve the problem of sheet printing on woolen fabrics, Mr. Wang Yong In 2010, we developed a dry thermal transfer process for reactive dyes and acid dyes on wool fabrics.
This technology is Mr. Wang Yong’s original technology worldwide. It not only has all the advantages of wet transfer printing, but is also extremely convenient to use.
This technology is combined with digital printing, that is, a digital printing machine is first used to spray the pattern on the thermal transfer film, and then heat-pressed to transfer the pattern to the wool fabric. After simple post-processing, The reactive printing product is ready. Compared with traditional digital direct printing technology, this process eliminates the need for sizing the fabric and sprays it on the transfer film first, avoiding damage to the nozzle by fluff. Defective printing products can be removed before transfer, improving the authenticity rate. .
The process of using this technology is:
Clothing piece preparation→ Transfer film application Combined→ Hot pressing→ Steamed, washed→ Finished→ Finished product
Among them, The printing of transfer film can be gravure printing or digital inkjet printing.
At present, this technology has attracted the attention of many enterprises in the cashmere industry, embroidery industry, garment printing industry, etc. The promotion of this technology will definitely cause a revolution in woolen fabric printing.
Changzhou Mulongsen Digital Technology Co., Ltd. is the only manufacturer in China that has wet transfer printing technology for reactive dyes on wool fabrics and dry transfer printing technology for reactive dyes on wool fabrics. Its innovative technology enables the transfer printing of wool fabrics. It has become possible and overcomes the shortcomings of traditional screen printing. It is a clean process with low energy consumption and less pollution, which represents the development direction of wool fabric printing process.
