China is a large country in garment production, and also the largest country in the world. Knitted garments account for 55% of the total clothing output, of which 60-70% needs printing. In 2014, 14 billion 414 million pieces of knitted garments were produced in 2014, up 2.88%, mainly in five provinces of Guangdong, Fujian, Zhejiang, Shandong and Jiangsu, with the output ratio of more than 80%, and 25% of the country's total output in Guangdong. Guangdong is the most developed area of knitted garment printing in China. The production and supply chain conditions are superior, the number of enterprises and the technical level are high. For example, there are more than 3000 clothing factories and nearly 200 printing factories in Shaxi town of Zhongshan City, especially in printing technology innovation ability, and the printing technology, technology and equipment of the leading enterprises. And management in the domestic leading level.
Garment printing is mainly used for printing of T-shirts, which is an important way to beautify and decorate clothes and improve added value. With the development of digital technology, the advanced technology of digital inkjet printing has not been applied and developed as expected. The traditional screen printing enterprises how to apply advanced digital ink-jet printing technology, how to play the advantages of digital and traditional network printing, this paper makes a brief analysis.
Traditional screen printing
The printing of knitted garment is mainly carried out on the cut or garment of the pure cotton weft knitted fabric. The printing process usually avoids the dye and the first choice of the paint printing. Because the dye printing must be steamed, washed and dried, the energy consumption is high and a large amount of sewage is produced. The shrinkage of the cut or garment after water treatment is not easily controlled and determined. It is difficult to form, and after printing, it only needs drying and fixing. The production cycle is short, energy saving, environmental protection, and it is not limited by fiber varieties. At present, the printing of knitted apparel is mainly composed of pigment and paste printing process, accounting for 90% of the total output.
Pigment printing is printed on white or light colored fabrics with transparent water-based resins and pigments. The printing of paste is printed on a variety of colors. Special printing of special visual effects in garment printing is also unparalleled in dye printing, such as foaming, flocking, hot gold, thick film, Several dozens of processes, such as extraction, coloring, discoloration, color change and fragrance, etc., rich and colorful special printing give people a kind of novelty and visual beauty, also improve the cultural, artistic and economic value of clothing. The environmental protection and color fastness of the printing have reached the national standard requirements.
The direct printing of cut pieces or ready-made clothes is entirely flat screen printing. Flat screen printing is divided into two methods: manual and mechanical operation. Manual operation is manual operation on special worktable. The machine is divided into three types: ellipse, disc (eight claw fish) and guide belt type. The oval automatic flat screen printing machine has obvious advantages and many applications. A 16 color device needs only 5 people to operate, and the output per hour is 300-500 pieces.
Advantages and disadvantages of digital ink-jet printing
Digital inkjet printing is also called jet printing or direct injection printing. It is a digital means to input a pattern or image into a computer, and then through the printing and color separation system of the computer, the ink jet system is controlled by a special software drive chip, the ink is applied to the ink, and the ink is ejected to the fabric through the nozzle of the nozzle. One color point, digital technology controls the ink-jet and non spray and XY direction movement of the nozzle, and forms corresponding precise color patterns or images on the fabric. The platform type digital inkjet printer specially used for garment cutting or garment is completely used in coating ink, usually with CMYK four colors plus white.
The process of digital coating inkjet printing on cutting pieces or ready-made garments is as follows:
1, white fabric:
Fabric, printing, printing ink fixing agent CMYK, drying, heat treatment, solid color
2, colored fabric:
Fabric, printing, drying, printing agent, ink jet printing CMYK rendering white ink, drying, heat treatment, solid color
Digital ink jet printing has the following obvious advantages over traditional screen printing.
1, the production cycle is short. Receiving printing patterns or images can be done through various means of digital transmission, such as CD ROM, U disk and E-mail, without preprocessing such as dichroic processing and screen printing. If the appropriate 8 Industrial droplets are sprayed and printed, the printing requirements will be achieved, and the width of the A4 will only take 5 seconds.
2. The color is bright. Inkjet printing almost can reproduce any color in nature, breaking the limitation of screen printing quantity, and color fastness can reach the standard of GB18401 - 2010.
3, the printing accuracy is high, the level sense is rich, the scenery effect is lifelike.
4, green production mode, printing process does not produce sewage, noise is very small. Water consumption decreased by 80%, pigment dosage decreased by 60%, sewage treatment decreased by 90%.
5, adapt to small batch, multi variety and personalized production.
However, an independent digital inkjet printing machine is difficult to carry out large production in the garment printing enterprise. The main obstacle is the white ink. At present, it can not reach the inkjet operation and use requirements. The shortcomings are as follows:
1, the white ink sprayed on the fabric has poor fastness after film formation.
2. The white ink on the colored fabric is usually 2-3 times, the speed of the spray printing is slow, the ink layer is thick, and the hand feel is hard. The output of the white fabric is only 1/3 1/4 of the white fabric.
3, white ink has high viscosity and easy to block nozzle, so it is difficult to clean.
5, white ink price is high, the price of 800-1600 yuan per liter, A4 format needs about 3-6 yuan.
Digital inkjet printing and screen printing is the best way to produce digital inkjet printing at present.