Screen printing workshop environment

For the screen printing workshop, clean and tidy environment is very favorable for production. However, most screen printing workshops are arranged in one corner of the building. For many people, there is a mysterious place, and there are always people there doing something strange with high pressure water guns.

When we enter a screenmaking workshop, what does it usually feel like? The first thing you might feel is noise, moisture, and dust. There may be some strained screens that have been sun dried and some are not stencils. We will also find that many screen frames are bent under great pressure. If we measure with a pressure gauge, we will find that their pressure range is 0-16N/cm.

We may well find that there are still many cured coating solutions on the tank containing the coating solution, and the screen to be dried is blown against the wall by a hot air blower.

Next, we can not help but see many of the ill-treated pictures of Yang, some on the table, some in the cupboard, and some not on the ground. There will be a large footprint on it. There is a layer of dust on the glass plate of the vacuum frame, and there are some random scratches on it, and some cover material is stuck on the blanket of the vacuum frame. We will also find that the exposure lamp has already exceeded the service life, the light source monitoring device has been broken, and the entire device does not have a device that blocks the UV light.

After exposure, the screen also undergoes a development phase. Here, the untrained worker flushes the non-graphical part of the template with a high-pressure water gun. The screen was then leaned against the wall, facing the dusty wind blown by the hot air fan.

There is another horrible scene in the screen-making workshop. The screen and the frame continue to be abused. This will continue to be discussed later. The only instrument that works in the room is the clock on the wall.

Fortunately, most screen printing workshops are not as scary as described above. Most people realize that the stencil is the basis of screen printing, and it is very important to use various measuring instruments and other quality control methods throughout the entire process. The cleanliness and maintenance of the workshop environment and the proper use of platemaking and recycling equipment are all important for production.

Mentioned in front of the bending of the screen box. Let's take a closer look at this issue. Although the net frame was once carefully selected, and the method of operation is correct, it can withstand some pressure. However, if the network is removed improperly, it will reduce the pressure resistance of the frame.

For example, some companies use very hard metal frames. Then, after the screen is removed, the workers are likely to remove the remaining substances stuck to them by sanding. After the screen frame is polished, it will become very thin, and the strength will be reduced. The screen will be deformed under the action of the pulling force, making the pressure of the screen difficult to control and sagging during the printing process.

The simplest solution is to use a relatively thin wire mesh and a quick-drying acrylic cyanide. However, this type of glue requires a very clean, very flat surface to firmly adhere the screen to the screen frame, so care must be taken when handling the screen frame.

Each time the screen frame is polished, the thickness will be reduced by 30 microns, which is also the case when using acrylic cyanide. After many times of dismantling the screen, the pressure that the frame can withstand must be reduced. It is also for this reason that we usually say that the life of the screen box is about 20 times.

In order to fully understand this situation, you can refer to the following example. Suppose we have a 60 x 40-inch metal mesh frame. The pressure of this frame is preferably below 25N/cm. Now suppose the price of this box is 1,000 yuan. A 305 mesh screen for this frame is $450. After 20 times of wire mesh disassembly, the money spent on the frame was still 1,000 yuan, but it had cost 9,000 yuan on the screen. That is, the cost of the frame is 10% of the cost of the screen.

In the screen printing company that has done a good job in management, each screen box has a number, and it also records the type of wire mesh and the degree of pressure resistance to which it is applicable. The screen frame was used correctly from the beginning, and its compression error was limited to about 2N/cm.

In the process of using screens, one must establish the concept of data tolerance, and the other is to measure frequently. For example, it is necessary to control the amount of ink and the defined range of variation, to constantly measure, maintain the standard template thickness, and maintain the stability of relevant factors (such as Rz values). To understand the exposure characteristics of the new batch of photopolymer, to ensure proper exposure. Make sure the function of the exposure light source is normal, the light source monitor is normal, and the light source lighting is uniform.

In addition, regular drying equipment should also be used. One of them is used to dry the newly coated wire mesh and the other is used to dry the developed stencil. Wet and dry vacuum equipment should also be purchased. Using this type of vacuum equipment with a fishtail tank is useful for cleaning and degreasing, and it can be used to remove sticky and excess moisture from the screen. However, we do not encourage using this device to suck the water on the developed stencil. In this way, the water on the stencil should be cleaned, white paper with no scratches or dust, or white newspaper without ink marks should be used.

Compared to past emulsions, the quality of the current emulsions has greatly improved. However, once formulated, no matter how good the coating solution is, there is a certain time limit for use. However, in the actual production process, the sensitized emulsion should be used up as soon as possible because the longer the sensitizing emulsion is placed, the easier it is to change its exposure characteristics. Usually should be configured to use up to 24 hours. It should be noted that after removing the emulsion, the lid of the can should be covered immediately. Do not pour the unused emulsion from the tank back into the tank. Instead, use another container to hold the used coating solution. Also the storage temperature of the coating solution.

Excessive humidity is a potential hazard in screen-printing shops. The humidity in the workshop should be stable below 55%. Manufacturers of coating fluids will try to increase the moisture tolerance of emulsions, but there is no single standard here. If the humidity changes too much during the process of screen printing, the exposure time will be seriously affected. In general, the higher the humidity, the longer the exposure time.

The stencil making process is a wet and dry process. Separate the coated wire mesh from the already dried wire mesh and do not place it in the platemaking and dismantling areas. The workshop temperature should be maintained between 20-25°C. In a workshop using a vertical projection screen exposure system, moisture should be avoided. The cleanliness of its work environment is also very important.

In short, we should pay attention to the cleanliness and cleanness of the workshop. The operators should wear overalls and wear hats, and they should not eat in the workshop. Do not brush, aspirate, and mop the floor during screen printing. In addition, dust from the flow of indoor air should also be avoided.