Printing process preparation

Printing process preparation is more than dyeing, in addition to preparation of prepress semi-finished products, but also preparation of paste, color paste, making nets and playing S/O samples (including preparing swatches) for customer confirmation, the most important of which is Network and S/O-like, these two steps take a long time.

First, printing paste

The original paste used in the printing is selected according to the printing dye used and the printing process used. The original paste has a certain degree of viscosity and rheological properties, and its main function is to overcome the bleeding of the dye in order to obtain a clear pattern. At present, the paste used for reactive dye printing is mainly a raw paste made of sodium alginate, and the paint printing is a synthetic thickener.

Second, printing color paste 丨

Adding the dye solution to the original paste to prepare a paste with a certain consistency is called color paste. In addition to dyes and grass pastes, it is also possible to add co-solvents, hygroscopic agents and other necessary chemical agents as required. In this way, the dye can be favorably transferred from the colorant to the fiber during the deuteration, and the dye is allowed to enter the fiber and thus stain the fabric. Unfixed dyes (known as float colors), pastes and other chemical residues on the fabric after steaming can be removed from the fabric during the washing process.

The pigment paste is printed on the fabric, and the dye is fixed on the fabric by means of a film-forming action of an adhesive and a cross-linking agent, and the principle is the same as that of the paint.

Third, flower net

The preparation cycle of cylinder screen printing is longer, mainly because the flower network is also a more complicated process. Large-scale printing and dyeing plants have their own network-making workshops or network-making sub-factories, equipped with professional network-made complete sets of equipment, and some manufacturers use laser engraving. Network making technology. The printing and dyeing factories that are relatively young may not have the ability or need to make their own nets. They just send the tricks to a professional net making factory. The grid manufacturing factory will process the products based on the pattern designs and printing process design requirements provided by the printing and dyeing plants. Due to the relatively low cost of the system, according to the “cost of materials and the production cost of the system” of the nickel manufacturing network, the cost of each rotary screen is more than 1,000 yuan. If small batch processing is performed, the average processing cost per one yard of printing is also Including the system net fee is very high, from the economic point of view, it is not worthwhile. If it is a very well-received pattern, large production volume or repeated production, you can share the cost of the system, for traders And printing and dyeing plants are more favorable.

The production network is usually made by using a nickel mesh that has been perforated (provided by a professional network manufacturer), coated with photo-resist and then baked at low temperature. The black-and-white sheet obtained by computer separation is coated on the surface of the nickel mesh. , Or the computer separation file is sprayed on the surface of the nickel net through the wax sprayer, and then placed on the photosensitive machine, the photosensitive net after the process of washing and baking the photoresist to make the photosensitive adhesive curing, and finally fitted with bulkheads can be made The net used on the machine.

The process with the highest technological content and the largest workload in the early flower-making process was hand-drafted. Now that the computer color separation system is in place, it is easier and more convenient for the operator to complete the work on the computer. With the advancement of science and technology, there are fewer and fewer manufacturers of black-and-white film coated on the surface of nickel nets with clever black-and-white films. The operation of this type of web-making method is complex and prone to “printing and printing” defects. , Now more is the use of direct spray on the nickel network or inkjet instead of coating black and white film making method. There are also a few manufacturers that use more advanced laser manufacturing technology.

Fourth, printing machine proofing

After the completion of the flower net, the most important link is to directly make a large sample on the printing machine or on the matching proofing machine (commonly known as the large machine S/sample). From the printing sample, you can intuitively see the printing of the design pattern on the fabric. The effect can be judged whether it meets the requirements of pattern design. Printing samples generally only return to the main position, and the other colors of the return color must be manually scraped together for customer confirmation. Many customers will also send out the printing sample to the final customer to confirm the effect of printing before deciding whether it can produce large goods. The customer will also propose amendments to the large S/O sample. From this process, it can be seen that after printing orders are given to printing and dyeing factories, it takes a long period of time for S/O confirmation and production delivery of printing and dyeing plants. However, this is also a work that must be followed to ensure the success of trade in printed fabrics. program.

Large machine S / 0 sample generally go through the following procedures: Design patterns - process review to determine the process plan - computer separation (black and white film) - flower network - big machine proofing - steaming - soaping - After finishing - to confirm the customer

There are also customers who do not require a large S/O sample. They only require the printing factory to provide manual sample scraping. The main proofing process is completed manually and does not occupy the production machine, which is more suitable for the production of some small flowers.