The Influence And Solution Of Static Electricity in Label Printing

Have you ever encountered static electricity in the process of printing labels? Does it bother you? So let us introduce the impact of static electricity in label printing and the solutions. I believe that reading this article will be very helpful to you.

In daily production and life, all kinds of objects are likely to generate static electricity due to movement or friction. Similarly, the label printing process contains frequent impacts, frictions, contact and separation links, which makes almost all objects involved in the label printing process carry static electricity, which brings a lot of trouble to the label printing process. This will not only seriously affect the quality of label printing, but also sometimes cause safety accidents, causing unnecessary losses to label printing enterprises. Therefore, eliminating static electricity in printing has become one of the most important issues in the current label printing industry.

The effects of static electricity

1. substrate surface electrostatic easy to affect the printing quality and printing efficiency

Various types of substrates such as paper and film are often used in label printing. After friction and collision, static electricity often accumulates on the surface. These electrostatic adsorption of paper debris and dust floating in the air, impurities, thereby affecting the normal transfer of ink, print production "speckle" and other quality problems. For some printed matter with high surface cleanliness requirements, if there are dirty spots formed by paper debris, dust and impurities, there will be a large number of unqualified products, which will bring huge losses to label printing enterprises.

In addition, in the process of single-sheet label printing, due to the influence of static electricity, several sheets or even a stack of paper are firmly stuck together, which is difficult to separate and put neatly. This often leads to two or even multiple sheets of paper being sucked up during printing, or the phenomenon that paper cannot be sucked up, seriously affecting the printing efficiency.

However, for drum label printing, the printing material runs from the unwinding point to the rewinding point. In the printing process, the printing material is spread out in a large area. If there is static electricity on the surface of the printing material, it will adhere to the dust particles in the air, especially for the label of the protective film, which will seriously affect the quality of the printed matter.

2. Printing ink with static electricity affects printing quality

In mesh printing, if the electrostatic ink is discharged in the transfer, it may form an "electrostatic ink spot" on the print, which looks like the ink's fluidity is not good and the ink is not uniform. In the field printing, the electrostatic ink often discharges at the edge of the printed matter, and the blotting edge is easy to appear burr like "ink whisker", resulting in overprinting deviation.

3. Static electricity may damage the device

Due to the accumulation of a large amount of electrostatic charge on the surface of the printed matter, in the subsequent striping, rewinding and other links, the electrostatic discharge of the printed matter will destroy the photoelectric correction system and electromagnetic control system of the equipment, thereby affecting the quality of the final label product.

4. Static electricity can cause fires and even casualties

In the process of label printing, high-speed and repeated friction and peeling make the surface of the substrate constantly generate static electricity. With the continuous accumulation of static electricity, the final voltage can reach tens of thousands of volts, and the high voltage of tens of thousands of volts will easily breakdown the air, causing electric shock or fire. In addition, when the electrostatic voltage of the ink is very high, it may also ignite the ink, organic solvent fire, live ink will shock the operator, a direct threat to the safety of the operator. Every year, the label printing industry in China will cause many safety accidents caused by static electricity, which causes great losses.

How to Eliminate Static Electricity

In the label printing process, static electricity is extremely easy to generate, and ubiquitous, label printing companies should be how to avoid and eliminate static electricity? The following points are worthy of reference and reference.

1. Printing machine grounding

The simplest way to eliminate static electricity is grounding, that is, the printing machine through the wire and earth contact, so that it is equipotential with the earth, electrostatic charge will be leaked through the earth.

2. Control the temperature and humidity of the printing workshop

Control the temperature and humidity of the printing shop is a simple and effective way to prevent and eliminate static electricity. By adjusting the temperature of the printing shop, increase the relative humidity of the air, you can improve the electrical conductivity of the surface of the substrate, accelerate the leakage of charge. Label printing workshop temperature to 18 ~ 25 ℃ is appropriate, the relative humidity in 60% to 70% of the most appropriate. If the temperature is too high, the relative humidity is too low, the workshop environment will be too dry, can not play a role in eliminating static electricity; if the temperature is too low, the relative humidity is too high, it may lead to substrate water absorption deformation, affecting the final overprint. Therefore, the printing workshop should be installed temperature and humidity control system or humidifier, always monitor the temperature and humidity of the printing workshop, only to control it in a reasonable range, can play an effective role in eliminating static electricity.

3. Add antistatic agent or isopropyl alcohol to the ink

Add antistatic agent or isopropyl alcohol in the ink to reduce the generation and accumulation of static electricity in the ink. I recommend the use of more antistatic agent, because too much isopropyl alcohol will lead to the ink "anti-slag". Many professional books on the addition of isopropyl alcohol do not exceed 2%, but practice has proved that the amount of its addition to far more than this amount will really play the effect of anti-static.

4. Antistatic agent treatment of the substrate

Antistatic agent treatment technology is mainly the antistatic agent (surfactant) through the addition of technology or coating technology, to give the substrate and other charged body surface absorbent ions, so that it has hydrophilic. By absorbing moisture from the air, the substrate reduces resistance and increases conductivity, making it less likely for static charges to accumulate. Among them, additive treatment technology is to add a certain proportion of antistatic agent mixed with thermoplastic resin, and add a variety of additives, by melting, mixing, granulation and other processes to produce antistatic concentrated masterbatch, in the use of the antistatic concentrated masterbatch diluted to the required concentration can be. The coating-type antistatic agent treatment technology is ionic surfactants made of antistatic coatings, coated on the surface of plastic films to prevent the accumulation of static charges. In short, antistatic agent treatment technology is a method to modify the resin or substrate, is a more thorough and perfect antistatic technology recognized.

5. Installation of static electricity eliminator

The ions generated by the electrostatic eliminator can neutralize the charge on the charged body in order to eliminate static electricity. Electrostatic eliminator has an external voltage electrostatic eliminator, self-discharging electrostatic eliminator, radioactive elements of three types of dehumidifiers. Label printing in the use of external voltage electrostatic eliminator, is through the needle or thin wire electrode external application of high voltage, the occurrence of corona discharge to generate ions to eliminate the principle of static electricity.

In short, label printing enterprises should always pay attention to and prevent the harm caused by static electricity, according to the actual situation to do a good job in the prevention and control of static electricity, and by a person responsible for checking, to eliminate the quality of printed matter caused by static electricity and the threat to safe production.

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