The hottest screen printing and screen printing

2022-08-14
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Silk printing and silk printing (Part 2)

4. The difference between printing materials is simply water-based and solvent-based (commonly known as oily)

1) textile printing is generally dominated by dyes, especially on silk fabrics, corresponding dyes should be used according to different fiber properties. The technical process and supporting equipment are relatively complex. Pigment printing paste is used for printing, which is called "water-based ink". Due to the need of practicality, the color and luster of textile silk printing must have a certain firmness (not easy to fade), and its color and luster change greatly, so the size and color material should generally be sold and stored separately, and the printing paste should be prepared according to the requirements when using. In addition, there are many special functional pigment printing pastes, which are often not limited by the properties of fabric fibers, so pigment silk printing occupies a certain position

2) non textile printing ink. This kind of ink is almost solvent-based, and its biggest feature is "specificity", that is, what materials are printed and what ink is used; Secondly, most of the colors of ink are sold in finished products, such as four-color ink. In addition, there are some special functional inks, such as foaming ink, bright ink, fluorescent ink, etc. In recent years, the variety of printing inks has been increasing, so we won't comment

5. post press processing

in the textile silk printing process, post press processing is very important. It must be steamed or baked at high temperature to fix the color, so that the dye can be combined with the textile fiber to ensure the color fastness. After fixing the color, wash it with water to remove the carrier and unfixed dye in the printing paste, so as to make the color bright. Even if the coating process is adopted, it should be baked at high temperature, but it can be washed without water. The post-processing of non textile printing is generally relatively simple, but it is also necessary to take some necessary treatments according to the quality requirements of printed products, such as UV ink curing treatment

flag and banner production technology

these two products belong to textile silk printing. Because most of its substrates are all kinds of textiles, its technical process is basically carried out according to the textile silk printing process

1. the development of flags and their production technology

flags occupy an important position in people's minds at all times and in all countries. The flag production technology in all periods is very exquisite, which is briefly introduced below

1) history of flag making. The first national flag raised in Tiananmen Square on October 1st, 1949 was made of red silk cloth sewn with yellow five pointed stars. Therefore, for a period of time, the production of flags is limited to sewing, splicing, patching, embroidery and other processes, but the speed is slow and the output is small. In the early 1950s, when industries were divided into centralized management, flag making belonged to industry. Several printing and dyeing enterprises are designated by the state to produce the national flag. As for a small number of flag, some also use silk screen printing technology, but the technology is relatively backward. In the sixties and seventies, man-made fibers and other textiles began to be used in the flag industry, but the process technology is still relatively primitive. The national flag and party flag are made by first using discharge technology to pull out the white five pointed star or party emblem, and then using basic dyes to dye yellow, so its color fastness is very poor. In 1990, the national flag law was promulgated, and the people's governments of all provinces, cities and autonomous regions approved a number of designated production enterprises, and formulated national standards for the national flag and its color. With the development of market economy, the number of flag categories has increased, which has brought a development opportunity to the flag industry. The international influence of China's plastic machinery industry has been continuously improved. At present, the flag industry in large and medium-sized cities is still developing at a deep level, which can meet the market needs in terms of scale and product quality

2) technology and evolution of flag making. At present, the scale of flag making enterprises is relatively small, and their equipment is not perfect. Compared with regular silk printing enterprises, the gap is not small. Generally, there are not many relatively perfect flag making enterprises that do it themselves or process it externally as the needs change. As the asset liability ratio of the flag making company will be further lowered, the materials are all kinds of textiles, and their performance specifications are constantly changing, so the technical process of flag making also changes. The printing materials of silk printed flag fabrics are different from pure cotton, real silk and man-made fiber fabrics used in the early days to polyester fabrics widely used at present. The printing processes are divided into direct printing and discharge dyeing. For example, the national flag, party flag, regimental flag and military flag of our country all have red background and yellow emblem, and discharge dyeing process is adopted. There are also some enterprises that use pigment direct printing process, and enterprises with good conditions have adopted disperse dye direct printing process. Because the main feature of the flag is that the front and back sides of the pattern color should be consistent, and at the same time, it has drapability and elegance, so the fabric should not be too thick, and the color of paint direct printing should not be consistent

2. Types of flags

there are quite a few types of flags, with different shapes and colors. Their uses are targeted to a certain extent, which can be roughly divided into the following types

① political flags: there are national flags, Party flags, regimental flags, military flags, and flags of nearly 200 countries, international organizations, and regional flags in the world. Their graphic colors are relatively complex and it is difficult to make

② logographic flags: flags with eye-catching words or emblems of units, groups, schools, etc., can display their own images

③ publicity flag: such as the special flag for large-scale advertising activities, in order to achieve the purpose of publicity and encouragement

④ ceremonial flags: flags for protocol in international exchanges, team flags for sports teams and brocade flags for rewards, etc

⑤ flags used at sea: such as communication flags, communication flags, command flags, etc. for ships

3. specification and production method of flag

1) specification of flag. In addition to special requirements, the flags we see in daily life are used to indicate their specifications by size. The specific dimensions are as follows:

1 flag 288cm × 192cm; 2 # flag 240cm × 16. If there is dirt 0cm between the force measuring cylinder and the force measuring piston; 3 flag 192cm × 128cm; 4 # flag 144cm × 96cm; 5 # flag 96cm × 64cm; 6 flag 30cm × 20cm; 7 flag 21cm × 14cm; 8 flag 15cm × 10cm。 long × The high ratio is 3:2. The national flag of Tiananmen Square is 500cm × 333cm, the flag hanging generally cannot exceed this specification. In all kinds of large-scale activities, the entrance leading flag is determined according to its size, which is generally 15m × About 10m, no matter how big the flag is, it can only be made by sewing and splicing. The specifications of flag and commercial flag are basically selected according to this standard. Strip shaped propaganda materials with a ratio of less than 3:2 belong to banners or special flags

2) flag making process. The production process of the flag is relatively complex. First, the logo and text must be adapted to the size of the flag. Therefore, the first step is to enlarge or reduce the graphics and text, and then draw a black-and-white manuscript by color separation, or make a printing plate by drawing and carving. In the process of silk screen printing, it involves the width setting of the printing board, the preparation of printing paste, the selection of scraper, and the post-treatment of color fixation, washing, ironing and leveling. It also needs to be sewn after printing. While ensuring the specification and size of the flag, we should pay more attention to the firmness of the suture to prevent it from being damaged by the wind during hanging. The flag pole cover (also known as Qiyong) is the symbol of the appearance of the flag. Without it, it can't be called a flag, so its width should match the size of the flag

3) flag material. In recent years, the textiles used for flag making have basically replaced pure cotton from model to bonding mechanism with polyester Chunya (thin) and Oxford (thick) fabrics, as well as man-made fiber fabrics and real silk. Therefore, the printing pastes used are also changed, among which the coating printing pastes are generally understood and familiar. Therefore, here is a brief introduction to the basic points of direct printing and discharge of some disperse dyes, because it is the development direction of silk printing flags in the future. The pigment printing process will gradually be reduced or eliminated

4) direct printing process with disperse dyes. It is a special dye for polyester fabric. It has complete chromatography, firm color and bright face. Thousands of varieties are produced at home and abroad recently, and there is a wide choice. Direct printing with disperse dyes is a common process. As the name suggests, it is made by mixing disperse dyes into the printing paste with the required color and directly printing it on the white or light colored polyester fabric, fixing the color at high temperature after drying, washing, soaping, drying and finishing. The process flow is:

color matching paste → screen printing → high temperature fixation → washing → soaping → drying and finishing. When matching colors, the dosage of disperse dyes depends on the color depth, generally not more than 5%. The slurry used as the carrier accounts for 60% - 70%. According to different conditions, 1% ammonium sulfate and 5% urea are added appropriately, and the rest is synthesized with water. The color paste should have good fluidity and stability. The printed board should be heated appropriately to prevent infiltration and improve production efficiency

there are three ways to fix the color at high temperature: first, high temperature and high pressure steaming, 135 ℃/min. The second is high temperature and atmospheric pressure steaming, 175 ~ 185 ℃/min, and the other is dry and hot baking, ℃/min. It can be determined according to their respective conditions. Water washing is to wash the slurry and unfixed dyes at room temperature, and soap washing is to wash with 2G/L caustic soda solution, ℃/10 ~ 15 minutes

5) silk screen discharge process. Disperse dyes are more difficult to discharge than other dyes. The key is the supply of high-temperature equipment and heat energy. At the same time, the technical requirements for preparing color paste are high, and the use of additives should be accurate. Discharge dyeing is to hydrolyze the color of the printing part into white under high temperature by using dark medium color polyester fabric and the auxiliary agent in the printing pulp. Discharge dyeing is divided into white and color. For example, the Hong Kong SAR flag is white, and the Chinese flag is color. In white pulling printing, the slurry used for the carrier must be resistant to various chemical additives, with the dosage of about 70%, stannous chloride (white pulling agent) 6%-8%, citric acid 0.5%-1%, brightener 1%-2%, urea 3%-5%, and water added to synthesize 100%. The printing paste of Seba is basically made by adding reducing agent resistant disperse dyes according to the white extraction prescription. Of course, there are many requirements in the specific operation. The fixation conditions of high temperature are basically similar to those of direct printing, and the best conditions can be selected according to local conditions

there are many ways to make flags by silk screen printing, because it is not limited by chromaticity, with rich colors and bright colors, which lays a good foundation for the production of promotional banners

4. the rise of banners

① banners are rising in the reform and opening up. If people want to gain public awareness in commercial and social public welfare publicity in an economic way, one of the best ways is to print hanging banners. Therefore, banners have become a method used by many enterprises for advertising. They are hung above and below commercial buildings. In its heyday, they can be seen everywhere on all kinds of buildings in the streets and lanes. Necessary provisions have been made in the rectification of the city appearance, making the publicity method more standardized

② the technology of making banners is relatively simple, which can be implemented by those who have a little knowledge of silk printing. First of all, it does not need formal equipment, and the printed platens can be selected according to local conditions, equipped with some frames of different specifications and stretched with silk for use. The preparation of paint white and paint color is also convenient. When there is no computer engraving machine, the required words or graphics are generally written or designed manually. The key to design is to calculate the area of words or patterns and the distance between them. Because the printing volume of banners is not large, the bottom plate is used for printing banners. Generally, there is no need to take photos to make plates. Materials such as paper, polyester film or red film can be used to carve words, and some use instant stickers to carve words, which can be used for plate drying. Nowadays, computer engraving is widely used, and its effect and efficiency are much better than manual engraving

③ the textiles used for banners include pure cotton fabric, polyester silk,

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