Causes and Solutions of Over-spray Problem in Process of UV Printing

When doing UV printing, sometimes you will find that the pattern on the printed product will have blurred edges, disordered spots, and broken lines. The reason for these phenomena is the over-spray of the machine nozzle. After this problem occurs, it is necessary to suspend the operation of the equipment. Please refer to the following tips to check the equipment.

  1. The vertical distance between the nozzle and the product is too far

The operating instructions of some UV printers will indicate the vertical distance between the nozzle and the product to be printed. Once the specified value is exceeded, the trouble of over-spray will appear. The specified range of some machines is below 2cm, and that of others is below 5cm. Please operate the machine in strict accordance with the instructions, otherwise, the light ink droplets cannot be ejected on the surface along a straight line, but move in a curve, and the ink dots cannot fall at the originally determined position.

  1. Static electricity

Static electricity has a great influence on UV printing. Static electricity is easily generated when the external working environment is dry and the humidity is low. Due to the influence of the magnetic field, the downward pressure of the ink is reduced, and Over-spray will occur. When this phenomenon occurs, it is necessary to add an electrostatic rod or a ground wire to shield it, or you directly purchase a UV printer with electrostatic elimination equipment.

  1. Nozzle plug

Once the nozzle is blocked, the spraying amount of ink of a certain color will be insufficient, and the printed pattern will have blurred edges and incomplete picture printing. At this time, you can check the working status of the nozzle by printing a test strip. If the test strip is intermittent or incomplete, it is necessary to clean the inside of the nozzle. If the “automatic cleaning” mode is turned on, and the clogging problem of the nozzle is still not solved after 1-2 times of cleaning, the nozzle can be removed, and soaked in the cleaning solution according to the operation flow in the manual.

  1. The voltage of the UV flat-panel printer nozzle is too low or too high

First one: the voltage of the nozzle is too low. The types of ink are different, and the viscosity of the ink is also different. If the fluidity of the ink used by the machine is poor and the voltage of the nozzle is low, Over-spray may occur at this time. In this case, the problem can be generally solved by increasing the voltage of the nozzle.

Second one: the voltage of the nozzle is unstable or too high. At this time, check the voltage to see if the indicator light turns red and gives an alarm. If there are other circuits on the voltage board of the nozzle, it indicates that the UV machine is a modified machine and there is a problem with the circuit. In this case, only replace the circuit board.

  1. Problems with electric control system

If the above four causes are eliminated, then there should be a problem with the electronic control system. At this time, professional technicians should be invited to deal with it. Dismantling the electronic control system by oneself is likely to cause greater losses.

The problem of over-spray in UV printing is a phenomenon often encountered by many novices operating printers. To sum up, there are two main reasons: an oblique spray of nozzle and problems with the circuit board. If it is determined that the nozzle is blocked, and the problem cannot be solved after cleaning the nozzle, the nozzle needs to be replaced. Go to the original manufacturer to buy the nozzle, so as to ensure that it is an original product with guaranteed quality.

If there is a problem with the circuit control system (such as the motherboard), check whether the UV printer uses a modified motherboard. The modified UV printer will have similar problems.

To avoid those troubles, pay attention to the following points when purchasing UV flat-panel printers:


  1. First, understand the reputation of the brand or manufacturer through the network, and investigate the relevant information. 2. Visiting manufacturers and checking their production scale, service attitude, and professional knowledge. 3. Test the printing effect. 4. Pay attention to after-sales service, not just price. 5. When signing the contract, pay attention to such matters as after-sales service, maintenance, warranty scope, and accessories.

There are also three points to pay attention to when operating the UV printer: 1. Check the nozzle, LED lamp, and machine operation when starting up; 2. During operation, people shall not leave the equipment to avoid emergencies; 3. Clean and maintain the equipment after it stops operating.

Now that communication technology is pretty developed, it is convenient to ask merchants for guidance on machine operation and maintenance through remote video. If you are not skilled in operation or do not carefully read the operating instructions, please don’t disassemble the equipment by yourself.

The above is the reason and solution for the problem of over-spray in Process of UV printing. I hope it can help you.

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