Talking about inkjet CTS system

Since contact screen printing, screen printing process and film are inseparable. The process, in brief, is to place the film, which has been made according to the requirements of screen printing, on a screen plate that has been coated with photoresist and dried, and expose it to ultraviolet light using a printing table. Spots that are not hardened can be rinsed with water. After the exposure is completed, the version is printed with water, which means that the graphic to be printed is displayed. A screen version is ready.

This process has been used for many years, suddenly broke into a few letters of the alphabet, what CTP, CTS, a little bit turned to God, can be a little analysis, the principle is not difficult to understand.

The basic principle of CTS

In recent years, the CTP in the field of offset printing can be described as infinite. The new technology without film direct printing has brought about a digital revolution in the printing industry. In fact, in the world of screen printing. In foreign countries, the direct platemaking technology in screen printing is called CTS, Computer To Screen.

The development of this new technology depends on the development of inkjet printers. The inkjet imaging technology has been developed by transplanting inkjet printing technology onto screen printing plates. The working principle is as follows: the screen is coated with a photo resist and dried, and the light-blocking ink is printed on the photosensitive layer through an ink-jet system. After the ink is dried, the screen is fully exposed with ultraviolet light. See the ink-free place. Light-cured, ink-resistant landlords can be washed away. After the exposure is completed, the inked landowner is rinsed with a developer (usually water) to form a graphic portion of the screen plate. With reference to the plate making process described in the opening paragraph of the article, it is easy to see what the function of the film is and how the ink jet is replaced.

Inkjet system classification

According to the ink jet principle, the ink jet image forming system is classified into a heated thermal ink system and a piezoelectric ink jet system.

In the former nozzle, there is a heating device. During heating, the temperature in the nozzle rises, and a gas is formed. Under the bubble pressure, ink droplets are formed, and ink droplets are ejected from the nozzle, and new ink droplets are added. As for the heating device switch, it is controlled by the computer according to the desired pattern. The nozzles are either arranged in a row or arranged in a matrix, and the whole screen is completed by moving.

As for the latter, the heating device in the nozzle is replaced with a piezoelectric crystal. When the current passes through, the crystal is deformed, and pressure is generated to push the ink droplet out. The passage of current is also controlled by the computer according to the desired pattern.

Compared with the two, the heated inkjet system will produce ink squirting when printing, resulting in the appearance of fine ink droplets at the edges of the image, affecting the quality of the screen. In addition, this device requires the ink viscosity, and only water-based ink can be used. The piezoelectric ink jet system does not produce ink splashes, and there is no requirement for the ink to be viscous. Wax inks are generally used. They are ejected from nozzles in a semi-cured state and immediately dried on a screen. This is what some people call a waxing system.

Precautions

1. Just as we have noticed the light-blocking property of the film before, in the CTS system, we must pay attention to the light-blocking property of the printing ink. Usually we require ink density greater than 3.0.

2. The resolution of the inkjet imaging system is not too high, typically only 600 to 720 dpi. This is because higher resolution causes the dots to be too small, which reduces the UV blocking power.

3. The nozzle may be blocked and the ink cannot be sprayed. Pay attention to the cleaning of the nozzle. There are also some CTS systems that can set their own print heads that cannot be ink jetted.

4. The computer directly plate-making, once made into the rediscovery error re-plate, compared to the previous loss may be large, so proofing is not only essential, but must be refined and detailed.

Features of CTS Direct Plate Making

1. Reduces the plate making process and saves time.

2. Get rid of the film, printing information is easy to save, easy to modify. The folds, traces, and dimensions of the film caused by improper placement of the film are avoided.

3. Digital screen positioning during multi-version printing reduces human error.

4. There is no requirement on the number of screen meshes, and there is no special requirement on the screen frame. Photosensitive adhesives do not need special photosensitive adhesives. There is no special darkroom requirement.

5. Print information can be exchanged with customers via the Internet, saving time and effort.

6. Dot shape and dot size can be set.

Given the CTS system and its many advantages, it is bound to open up a broader market for screen printing. Especially in large-format screen printing, digitization of the CTS system minimizes many human errors and its role is self-evident.