Screen printing techniques for the most popular la

2022-07-23
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Plate making skills for large-area screen printing the absolute size of large-scale silk is a major step in making large-scale plates - eye preparation, coating, exposure and recycling - is also the main challenge. However, now we use several solutions to simplify the process of making versions. For example, manual silk making has been replaced by automatic equipment in many factories, and silk coating has also been replaced by automatic coating machines. Let's discuss each step and introduce some techniques and tools that can be used to simplify the production of large format silk plate

silk preparation

polyester silk is a kind of synthetic fiber with precise design. This material has excellent barrier properties and moisture resistance, which is why it is used in soda bottles and film packaging. To be exact, it is an inert plastic product that is not easy to bond

direct coated photosensitive emulsions are somewhat like water-based coatings. These emulsions are not easy to adhere to plastics and have poor adhesion characteristics. I) batch experiment: sample properties of the same parameters. To produce a high-quality version with a long printing life, the silk must be properly prepared so that the emulsion will stick to the silk well. Good adhesion is very important when using abrasive or water-based inks, such as printing on glass or textiles. This is also very important when some areas of an image are covered or blocked by adhesive tape and then uncovered during the next stage of printing. It can avoid damage to the version

the silk must be cleaned to remove oil or pollutants, which can prevent the emulsion from wetting the surface of the plate. The fiber also needs to be treated with wetting agent. This can increase the level of surface tension, or the energy on the surface of polyester fiber, to an acceptable level, so that the emulsion will adhere to it. This principle is very familiar to printing plants that print on low-energy plastics, such as polyethylene. These substrates need surface treatment to make the surface tension reach a certain level and achieve the best ink adhesion effect. A well degreased and pretreated silk will form a uniform and complete water film after rinsing. When the adhesion of the plate is improved, the exposure tolerance and resolution can reach the highest value

gluing

in order to achieve a stable effect, we strongly recommend that you use the automatic silk coating machine on the large format silk printing machine. If manual coating technology is not possible in this size of the wire to ensure uniform coating thickness. If your arm is not enough, 3. Keep the equipment and computer clean and long, and balance the weight of the whole wide coating liquid tank, it is almost impossible to manually coat large-scale silk

emulsion with high solid content shall be used for gluing. This can avoid shrinkage in the drying process, and help you use simple coating technology to produce high-quality templates. The current coater also has a built-in drying device, which can perform very well when using large-scale silk with high mesh number. Silk with medium to small mesh counts uses a wetter emulsion to dry faster and more efficiently on the coater

drying

wire drying is usually carried out in a pollution-free environment in the isolation area, and it should be carried out in a place illuminated by a safety lamp. Warm and dry hot air of about 100 ° f (40 ° C) can circulate freely in the dry area to remove moisture

during drying and storage, photosensitive polymer emulsion is not affected by residual moisture and high temperature. They can be exposed without completely drying out. However, diazo and double cured emulsions must be dried thoroughly before exposure, and the exposure shall be carried out when the water content is less than 4%. You can use a contact gauge to accurately measure the residual water content in the emulsion

The technological progress in the field of

exposure

template making has challenged the traditional large format imagesetter and other similar methods in terms of cost and efficiency. The computer direct silk imaging system has brought efficiency to the digital process of silk plate making. The film has been canceled, and the exposure process and silk processing process have been simplified. The original large format vacuum printer is no longer needed. Finally, the time spent on repairing the pinholes on the printing plate has been greatly shortened, because there is no more film or glass surface to attract dust

although the large format inkjet printers are different from the computer direct silk system, their output quality is much better for the printing plants that often have to wait for films from other companies. Many silk printing plants use large format inkjet printers to produce large-scale positive films in their factories

the projection exposure unit greatly reduces the film cost. For a photo used for making large format silk plate, if the magnification is 10 times, the size of the film is only 1% of the final product. A special emulsion allows the exposure time to be controlled within one minute. Since there is no need for a vacuum printer, the silk processing is simplified again

it is not necessary to consider how you expose your printing plate. The most important thing is to make the exposure time long enough to ensure that the emulsion is completely cured and produce a durable printing plate with good adhesion and resistance to chemical corrosion and abrasion. A color conversion exposure calculator is used to determine the correct exposure time of diazo and double curing emulsion. This method, as the last point of color conversion processing, indicates the correct exposure time. For example, yellow diazo is bleached during exposure, which can change the color of the exposed template. Usually the color changes from green to blue or from brown to purple

a tool to judge whether the exposure value is good or bad is to use the 21 grade gray ladder exposure calculator, which can be used in photosensitive polymerization emulsion, diazo emulsion and double curing emulsion. The ideal exposure depends on the time required to cure the 7 gray levels after the silk is made

exposure is a major problem when exposing high-quality surface templates that greatly meet customers' needs. In order to maximize the exposure tolerance when exposing large format silk, the most important thing is to select an emulsion that supports high resolution, improve the coating process, reduce the uneven thickness of the coating layer, and improve the adhesion of the version through appropriate pretreatment of the silk

development

in order to achieve the best resolution, both sides of the silk must be spray developed with high-pressure and evenly distributed developer. This is easy to do in small screen printing plates, but difficult in large screen printing plates. Because it has certain requirements for processing process and space. The effective solution is to use automatic cleaning equipment that can also develop. This requires less space and does not need to be designed. There is a nozzle in the developing tower. The best manual option is to use a pressure water gun with a fan-shaped spray with a minimum speed of 1000PSI and a flow rate of gallons per minute

recycling

manual cleaning of large format silk requires workers to pay special attention and use tools correctly, so as to ensure work efficiency and safety. The tools used mainly include a brush with a long handle, which can reach the far corner of the silk, and protective clothing - glasses, gloves, boots, etc. Each step of cleaning requires the use of a separate brush to avoid cross contamination between chemical containers. Please do not underestimate the importance of a good pressure water gun. Buy the biggest and best washer you can afford. It won't disappoint you

automatic silk recovery equipment can do many difficult jobs and reduce the possibility of workers being injured by chemical agents. The combined and on-line equipment can systematically remove the oil stains on the silk. The removal of ghosting is still a difficult problem, because this kind of machine can not completely do so. So even if you use an automated system, you still have many opportunities to clean it yourself

the emergence of large-scale silk plates on large screen printing machines is closely related to people's pursuit of printing larger and better images on different substrates. Only by constantly innovating in materials and technologies can we ensure the prosperity of the cause and ensure that silk printing is always at the center of the large-scale imaging field

source: Wuzhou search

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