Banner and banner production technology
These two kinds of products belong to textile screen printing, because most of its substrates are all kinds of textiles, so its technical process is basically carried out according to the textile screen printing process.
1. Development of flags and their production techniques
Regardless of ancient and modern times, the banner plays an important role in people's minds. The banner making process in each period is very elegant. Here is a brief introduction.
1) The history of banner making. On October 1, 1949, the first flag raised at Tiananmen Square was made by sewing a yellow pentagram on a red silk cloth. Therefore, in a period of time, the production of banners is limited to stitching, splicing, excavation, embroidery and other processes, but the speed is slow and the output is small. At the beginning of the 1950s when the division of industries was centralized, the flag was an industry. Several national printing and dyeing enterprises are designated by the country to produce the national flag. As for the small number of flag flags, some screen printing processes are used, but the technology is relatively backward. In the 1960s and 1970s, man-made fibers and other textiles began to be used in the flag-making industry, but the process technology was still relatively primitive. The national flag and the party flag were produced using the discharge technology to pull white pentagrams or party emblems, and then dyed with basic dyes. It is yellow, so its color fastness is poor. In 1990, the national flag law was promulgated. The people's governments of various provinces, municipalities and autonomous regions approved a batch of designated production enterprises and set national standards for the national flag and its colors. With the development of the market economy, the increased number of flags has brought a development opportunity to the flag-making industry. Currently, the flag-making industry in large and medium-sized cities is still developing in-depth, and both the scale and product quality can meet market needs. .
2) Flagging process technology and evolution. At present, the size of the flag-making enterprises is relatively small, and their equipment is not perfect. Compared with the formal screen-printing enterprises, the gap is not small. Generally, with change needs, there are not many flag-making enterprises that are relatively self-made or externally processed. Since the flag-making material is a variety of textiles, its performance specifications are constantly changing, so the technical process of flag-making has also changed. The screen printing banner fabrics from the early use of pure cotton cloth, silk, rayon fabrics to the currently widely used polyester fabric, the printing materials are different, the printing process is divided into direct printing and discharge. For example, the national flag, party flag, regimental flag, and military flag in China are all red-backed yellow emblems. There is also a part of direct paint printing process, and companies with good conditions have used direct dyeing process with disperse dyes. Because the main characteristics of the flag are the same as the color of the pattern, the drape and the airiness, so the fabric should not be too thick, and the color of the direct printing of the paint should not be consistent with the front and back.
2. The type of banner
There are many kinds of flags, their shapes and colors are different, and their uses have certain pertinence. They can be roughly divided into the following types.
1 Political Banner: The national flag, international flag and flag of the national flag, party flag, regimental flag, military flag, and nearly 200 countries in the world, as well as international organizations and regional flags, are more complex in graphic color and more difficult to make.
2 logo (ambition) flag: with units, groups, schools and other prominent text or emblem logo banner, can display their own image.
3 Publicity flag: Such as advertising special banner, in order to achieve the purpose of propaganda and agitation.
4 Etiquette Flags: Concierge flags in international exchanges, team flags for sports teams, banners for rewards, etc.
5 flags at sea: such as the traffic flag, communication flag, and command flag used by ships.
3. Banner specifications and methods of manufacture
1) Flag specifications. The flags we see on a daily basis, except for special requirements, are customarily used to indicate their specifications. The specific dimensions are as follows:
1# flag 288cm × 192cm; 2# flag 240cm × 160cm; 3# flag 192cm × 128cm; 4# flag 144cm × 96cm; 5# flag 96cm × 64cm; 6# flag 30cm × 20cm; 7# flag 21cm × 14cm; 8 # Flag 15cm × 10cm. The length × height ratio is 3:2. The national flag of Tiananmen Square is 500cm × 333cm. The hanging flag cannot exceed this size. In all kinds of large-scale activities, the entry-type pilot banner is determined according to its size, generally about 15m × 10m, and the big banner can only be made by stitching. Flags and commercial flags are basically selected according to this standard. The 3:2 ratio of banner advertisements is a banner or special banner.
2) The production process of the banner. The production process of the banner is relatively complex. Firstly, the logo and text must be adapted to the size of the flag. Therefore, the first step is to enlarge or reduce the graphic and text, and then perform color separation and black-and-white drafting, or make a screen printing and engraving. . In the screen printing production process, it involves the width and width of the printing platen, the preparation of the printing paste, the selection of the scraper, the fixation of the post-treatment, the washing, the ironing and other processes. After sewing, it is necessary to sew. While ensuring the size of the banner, it is also necessary to pay attention to the sturdiness of the sewing thread and prevent the wind from being blown in the suspension. Flag set (also known as flag) is a sign of the appearance of a banner. Without it, it cannot be said to be a flag, so its width should be adapted to the size of the flag.
3) Banner material. In recent years, textiles used for flag-making have basically replaced pure cotton fabrics with polyester fiber-type pongee (thin material) and Oxford cloth (thick material), as well as man-made fiber fabrics and real silk fabrics. Therefore, the used printing ink is also changed. The printing paste is generally known and familiar. Therefore, the basic points of direct printing and dyeing of some disperse dyes are briefly introduced here, because it is the development of screen printing flags in the future. direction. The paint printing process will gradually be reduced or eliminated.
4) Disperse dye direct printing process. It is a special dye for polyester fiber fabrics, with complete chromatogram, bright color and beautiful appearance. Recently, there are thousands of varieties produced at home and abroad, so there is a great deal of choice. Direct printing with disperse dyes is the more common process. As the name implies, the printing paste prepared with the disperse dyes into the desired color is directly printed on white or light-colored polyester fabrics. After being dried, it is fixed at high temperatures, washed with water, soaped, and dried. The process flow is:
Color paste → screen printing → high temperature fixing → washing → soaping → drying finishing. In color matching, the amount of disperse dye is determined according to the color depth, and generally does not exceed 5%. The slurry used as a carrier accounted for 60%-70%. Ammonium sulphate 1% and urea 5% were added according to different conditions, and the remaining water was used to synthesize 100%. The paste must have good fluidity and stability. The printed platen should be properly heated to prevent bleedout and improve the production efficiency.
There are three methods for high temperature fixing: First, high temperature and high pressure steaming, 135°C/20-30 minutes. The second is high-temperature atmospheric pressure steaming, 175 ~ 185 °C / 8-10 minutes, and the other is dry hot baking, 190-195 °C / 2-3 minutes. Can be determined according to their conditions. Washing is to wash the slurry and unfixed dye at room temperature, soaping is washed with 2 g/l caustic soda, 80-85°C/10-15 minutes.
5) screen printing discharge dyeing process. Disperse dyes are more difficult to discharge than other dyes, the key is the supply of high-temperature equipment and thermal energy, while the technical requirements for the preparation of colorants is high, the use of additives to be accurate. Discharge is the use of deep-color polyester fabrics, through the printing paste additives, in the high temperature conditions will be printed parts of the color hydrolysis to white. Drainage is divided into white and colored pull. For example, the flag of Hong Kong Special Administrative Region is white and the Chinese national flag is colored. In white printing, the carrier slurry must be resistant to various chemical additives, the amount is about 70%, stannous chloride (whitening agent) 6%-8%, citric acid 0.5%-1%, whitening Agent 1%-2%, urea 3%-5%, add water to synthesize 100%. The pigmented paste is basically made by adding a dispersion-resistant disperse dye in a white prescription. Of course, there are many requirements in the specific operation. High temperature fixing and direct printing fixing conditions are basically similar, and the best conditions can be selected according to local conditions.
There are many ways to make a banner with screen printing. Because it is not limited by color registration, it has rich colors and bright colors, which lays a good foundation for propagating banners.
4. The rise of banners
1 The banner is rising in the course of reform and opening up. If people want to gain public awareness in commercial and social publicity through economic methods, one of the best ways is to print hanging banners. As a result, the banner has become a method used by many companies for advertising. It hangs above and below the commercial building. During its peak period, various buildings on the streets and lanes can be seen everywhere. In the process of rectifying the appearance of the city, the banner has made necessary provisions. Make the method of propaganda normalization.
2 The technology for making banners is relatively simple, and some screen printing experts can implement it. First, it does not require formal equipment. The printed board can be selected according to local conditions, equipped with a number of different specifications of the frame and stretched on the screen. stand-by. The preparation of paint white and paint colors is also convenient, and the required text or graphics are generally written or designed manually without a computer engraving machine. The key to the design is to calculate the area of ​​words or patterns and the distance between them. Because the banners are not printed in large quantities, the printed banners use the original plate, and generally do not require photolithography. Letters can be printed using paper, polyester film or red film, and some can be printed on a sticky note. Nowadays, computer lettering is used more often than not.
The textiles used for the 3 banners are pure cotton, polyester and silk, Oxford, etc. The color of the paint is generally printed on a colored cloth. It is very simple. The colored banners are also printed in color using a color registration process.
Source: China Printing Network