Using Digital Technology to Make Large Format Screens and Printing

With China's accession to the WTO, the 2008 Olympic Games will be held again, the country will be more open, China will go global, and the world will have to understand China. Screen printing images are one of the very best media tools and will be able to take on the important tasks of communication and interaction between East and West culture, economy, politics, and science and technology. The origin of screen printing originated from the Qin and Han Dynasty in China. With the progress of the historical society, the screen printing technology has also been continuously innovated. From the earliest stamp printing products to modern instrument dials, commodity trademarks, and electronic circuit boards, computers, aerospace industries, laser photocopying Other high-tech applications have also made screen printing technology capable of high-efficiency, high-quality color printing over full-color images. As the screen printing process has the effect of ink layer thickness, dot protrusion and vivid colors, it also has a mature and complete substrate and anti-UV ink, low production cost and high efficiency, so it is most suitable for outdoor large-format color screen printing. The production of image advertisements, such as the application in the emerging media and media industry, such as mall light boxes, bus stations, subways, car bodies, POP licensing, etc. To this end, here we introduce the method of using digital technology to produce large format color screen printing plates and inkjet images at the 2002 Beijing International Printing Equipment and Equipment Exhibition.

First, use digital technology to produce large format color screen printing plate

1. Directly making screen printing plates using digital technology

The digital printing technology developed by Gerber Technology Inc. in the United States is used to directly make a screenless printing plate without a film. It is a method that uses a digital camera or a digital camera to capture landscape images or computer-designed images and graphics in a computer. To make the screen printing plate, through the contrast of the screen, edit the processing and processing instructions. The laser ink jet printer prints the images and graphics directly to the screen printing plate coated with the photoresist. The ink layer image is used as a screen printing film master, and then the full-exposure printing of the screen printing plate is performed with ultraviolet light. During the development and processing, the photo-resist layer of the ink-jet-covered impermeable ultraviolet portion does not undergo photochemical reaction and can be dissolved. Water; Photosensitive adhesive without ink-jet cover is photochemically changed by ultraviolet light and cannot be dissolved in water. In this way, a screen printing plate with an image is formed after the water is developed and dried.

In the process of making a screen printing plate directly by a computer, the photoresist used for screen printing a presensitized printing plate can be a conventionally used photoresist. The requirements for laser ink-jet printing inks are that the ink density and the spray volume are based on the final image optical density of 3.0 or more, and the ink is alcohol-solvent, so that the screen printing plate can be completely removed during the water developing and rinsing, without affecting the screen printing. The use of the edition.

Advantages of digitally making screen printing plates directly: (1) Films are saved and platemaking costs are reduced. Since no film is required, the quality problems due to abrasion of film and loss of network layer levels are prevented; (2) Reducing the plate making process and improving Plate speed, time-saving; (3) Automatic screen positioning for multi-color screen printing; (4) Suitable for making various mesh screen versions; (5) Suitable for various frames, such as aluminum alloys Box, wooden frame; (6) The size of the plate can reach up to 66cm×96.5cm.

2. Using Digital Technology to Make Large Format Color Screen Printing Films

This is a software RIP developed by a PC computer and Beijing Yunyuan Digital Technology Co., Ltd., and a method of manufacturing a MIMAKI inkjet printer. It uses a 2 megapixel digital camera or a video camera, or an A4 format graphic image, etc. It is entered into a PC and edited using RIP software. The entire image can be enhanced during processing. For local enhancement or just curve adjustment, to enhance contrast or eliminate background interference color, the processed image is demonstrated on the computer screen, check to confirm that the image color is acceptable, no need to adjust, the image is divided into yellow, product, blue, Black 4 color images, respectively, adjust the dot angle, enter the large-format color inkjet printer; at the same time, set up a dedicated transparent film, adjust the printer, print black and white ink with a black ink to print out 4 black and white film bottom (ie yellow , product, blue, black one each).

The yellow, black, black, and black black and white films are used to cover the four screens that have been coated with common photoresist. The screens are fully exposed by ultraviolet light on the plate, and are developed and dried by water. , that is made for the yellow color black color image screen printing plate. The four editions of the Internet printing station were overprinted with yellow product blue paste. From the perspective of image quality, screen printing 45 line images are rich in texture and high in resolution, and can meet the requirements of large-format and four-color high-precision screen printing plates, and their accuracy is much higher than the traditional way of magnifying film plate making, three-dimensional Strong.

According to reports, the advantages of using digital format for large-format color screen printing software are:

(1) Small investment and low cost. The use of laser photolithography to produce a 1m2 four-color color separation plus mesh is about 600 yuan, while the use of digital inkjet printing plate a set of four-color film costs only 100 yuan, the import of full-laser imagesetter over 1 million yuan , And importing a set of 1.62m width inkjet printing platesetter less than 200,000 yuan.

(2) Save time, labor, and materials. It doesn't have the time-consuming process of developing and flushing like the traditional version. It can directly design, edit, typeset, and separate colors, and print once, with short work flow and high efficiency.

(3) High precision and high definition. The traditional method of making large-format version, photocopying process needs photographic projection amplification film, development, fixing, washing and other processes, optical projection magnification is easy to produce projection distortion outside the optical focus, affect the edge of the picture clarity and quality, loss of precision, and spray Ink printing ink is not lost, which can greatly improve the accuracy and clarity of the dot.

(4) The output format is large. The width of the width of MIMAKI inkjet printer is 1.32m, 1.62m. The most significant by the width of up to 1.87m, the length can be long or short, larger than the laser beam size.

(5) Inkjet printing plate making, bright room operation, no discharge of waste liquid, protection of the environment, while the traditional method requires the operation of the darkroom, development and fixation processes, etc., will produce toxic waste pollution of the environment.

(6) Large-format ink-jet printers have many functions. One machine can be used for multiple purposes. Before the production of four-color separation film baseplates, digital printing can be used to create digital proofing tests.

Second, using digital technology inkjet large format color image

The equipment is a software RIP provided by the computer plus transportation source company and a Japanese MIMAKI JV4 series photo inkjet printer. Similar to the previously described use of digital format for large-format color screen printing, the difference is that printing materials are dedicated. The user's expectations and requirements for the machine's performance and attachment specifications are:

1. It is required to be able to use different ink dots to print out different color screens. From the multiple color gamuts shaded by light columns, color performance can be achieved, which can not only perform low-precision and fast output, but also enable high-precision and high-quality printing.

2. It is required that the height of ink jetting water can be adjusted to a large extent so that it can be used to inject traditional thin materials and KT plates with a thickness of 7 mm can be directly sprayed.

3. Requires 12 ink cartridges, multiple sets of piezoelectric ink jet heads, multiple matching inks, multiple staggered arrays, scientific combination when used, instant switching, high speed printing, and finally becoming a perfect multi-purpose large format color inkjet printer Photo printers.

4. When it is required to make digital large-format color screen printing film bottom plate, its output precision can reach 1440 dpi×1440dpi, and it can produce screen printing film with precision up to 90 lines.

5. Requirements In order to facilitate the operation, improve ergonomics, and accurately understand the running status of the machine, the shortcuts of the three commonly used functions of “test strip”, “cleaning” and “clear data” must be focused on one control panel. Or on the work bench.

6. In order to achieve all-time unattended work and reduce the intensity of work, it is necessary to have a standard automatic delivery machine, which can prevent consumables from deviating, ensure straight-line operation, and automatically rewind consumables.

7. In order to prevent paper or cloth from being curled on either side, or a thick and uneven material lifting up to the inkjet head, an anti-lift pressure plate apparatus must be provided.

8. In order to ensure the application of different consumables and the need for wide-width, long-distance operation, there should be a "multi-point pressure-displacement" roller wheel equipment.

9. MIMAKI JV4 series printer specifications: maximum paper feed width 1.910m, maximum actual spray width 1.870 m, inkjet accuracy 720dpi×720 dpi, input interface 1 IEEE1394, power supply AC100-240 V, <400 VA, machine weight < 140 kg, size 2740 mm (W) × 730 mm (D) × 1220 mm (H).



Source: Screen Printing