The basic causes of blockage of screen printing equipment nozzles

Why is the nozzle of the machine blocked? The nozzles of the machine do not print out ink when they are sprayed, causing the lack of color in the picture content. Usually referred to as “head clogging”, this is the main factor affecting the picture quality and yield. Of course, the reasons for “blocking” are also various. There are roughly the following situations:

1. The ink is blocked on the outside after the nozzle has accumulated to a certain degree. It is the most common plugging method because the solvent in the ink must be evaporated into the air to make the picture dry. Therefore, the ink is a volatile liquid. It is volatile in the air and clarifies solids. When the nozzle sprays paint on the fabric, it will always leave a part of the ink around. This part of the ink will dry out in the air and will gradually make the nozzle smaller or even block the nozzle hole. However, because it is outside the nozzle hole, it is very easy. Clean up, this is why we often clean the nozzle.

2. Piezoelectric crystal damage: It is certain that the nozzle can not spray ink, and the general piezoelectric nozzle can use for about one year. It may be normal for a factory with a lot of printing work to use less than one year.

3, piezoelectric crystal fatigue damage: phenomenon is that the nozzle is sometimes inkjet, sometimes no ink, especially when the amount of ink is large (that is, when spraying dark images) "blockage" phenomenon is obvious, this time the best method is to replace A new nozzle.

4. The nozzle is blocked by the filter inside the nozzle. The ink is not ejected. The nozzle is used for a long time, especially in the factory where the painting task is not full and often stops at night. The ink does not flow in the nozzle for a long time and is easily adsorbed in the internal filter. On the wall of the net or ink channel, making the cross-sectional area of ​​the ink flow smaller will also cause the nozzle not to be out of ink. Now special equipment can help you solve this problem of the nozzle.

5, the viscosity of the ink is too high or too low: the viscosity of the ink is too high to make the ink flow is poor, the amount of ink ejected by the nozzle per unit time is not enough; the viscosity of the ink is too low, which is too thin, easy to press in the nozzle hole When the crystal is drawn back and sucks in air, it can't suck ink, so it blows out air; both can cause the phenomenon that the nozzle is not out of ink. It is very important for the customer to store the ink in this environment. It is better to use the ink for more than 24 hours before using the ink. Because the viscosity of the ink will be very high at low temperatures, and the viscosity will be high at high temperatures. It becomes very low and the viscosity is very different. Once the ink with a large difference in viscosity is used together, it will cause no ink to be sprayed. Institution/organization

6, the failure of the drive circuit: the aging of the electronic components of the drive circuit aging and accumulation of too much dry ink dirt, can affect the voltage to drive the nozzle, resulting in no ink or ink out of the nozzle is not stable.

7, the type of ink: some manufacturers of ink due to improper control of the amount of desiccant, too fast drying, easy to cause ink in the external block, although you can wash, but the cleaning interval is relatively frequent, once the nozzle is not used for a long time and not timely When protecting the nozzle, it may cause permanent damage to the nozzle at the next re-spray.

8. Frequent replacement of ink: In many cases, there may be no protection for the nozzle when changing the ink, and the inkjet status of the nozzle may also be affected.

9, the use of the machine environment temperature and humidity: generally recommended temperature is 22 to 25 degrees, humidity 40 to 70%, high and low temperatures affect the viscosity of the ink, the nozzle will produce ink or paste phenomenon, often mistaken Think of "head clogging."