Technical application principle II of the hottest

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The technical application principle of inkjet printer II

bubble printing

bubble printing technology is an updated technology, which is still widely used in the office field

a voltage is applied to the two terminals. Due to the impedance between the terminals, the ink is heated, forming a vapor bubble. Due to the expansion of the chlorine bubble, a drop of ink is sprayed out of the nozzle When the voltage between the terminals is removed, the bubbles disappear, and new ink is filled into the row nozzle due to the effect of surface tension Like the piezoelectric jet printing technology, if a series of nozzles are arranged together, a larger jet printing range will be obtained The resolution is largely determined by the dense arrangement of nozzles

ink characteristics are particularly important for the normal operation of bubble printing system In the office, you can control the surface of the print to match the ink, but in the production environment, it is completely another matter For this reason, the influence of bubble printing technology in the field of product coding is limited However, in the application of bubble inkjet printing, we can get excellent inkjet printing effect Continuous inkjet coding has a wide range of applications, and it is perhaps the most diverse technology From the mid-1970s to the late 1970s, the early continuous inkjet coders had complex operations and frequent failures This impression still exists, but the situation has changed. Many of the experimental machines sold in Jinan have changed, just like the car no longer leaks oil when we drive The latest continuous inkjet coding system only requires the operator to press the on/off key and do routine maintenance once a week, and the maintenance is much less than that of some other ill fated equipment There are two different but related continuous inkjet coding technologies: deflection inkjet printing, binary inkjet printing

deflection inkjet printing

deflection inkjet printing technology has been commercialized since the early 1970s. It may be the most developed technology applied in the production environment Although the principle is quite simple, for many years, a large number of control circuits have been combined to ensure reliability and simple use

the ink is pressurized and sent to the nozzle, forming an ink flow of about 20m/s There is a piezoelectric device behind the nozzle. When the voltage is applied, the device will produce displacement, which will disturb the ink flow. If the frequency of the electric signal applied to the piezoelectric device resonates with the ink jet frequency, the ink flow will break into ink droplets of the same size and spacing At the position where the continuous ink flow breaks into a series of ink drops, there is a charging electrode If the frequency of the pulse voltage on the charging electrode is the same as the frequency of the ink flow breaking, each ink drop will carry a corresponding charge The ink drops continue to move forward, passing a pair of deflection plates The voltage on the deflection plate is a fixed value (for example, +/-5kv), forming an electrostatic field. Under the action of this electrostatic field, the charged ink drops will deflect towards one of the deflection plates according to their own charged amount Finally, the ink drops pass through the air and fall on the surface of the printed object passing through the nozzle The uncharged ink droplets do not deflect and are recycled in the recovery tank at the bottom of the nozzle, and finally recycled to the nozzle through an ink reservoir

continuous inkjet printing

in this way, approximately, the mode of ink drop inkjet printing corresponds to the pulse voltage applied to the charging electrode The actual process is not so simple We must synchronize the breaking of ink drops with the charging of the charging plate, and we must consider the mutual repulsion between charged ink drops, and even the aerodynamic problems of ink drops in flight Users of continuous inkjet coders will not feel these problems, but it is these problems that make the design of continuous inkjet coders interesting

because the ink jet is continuous, the continuous inkjet coder can use many types of inks, especially those with very fast drying speed (within 1 second) Therefore, continuous inkjet coding technology is very ideal for the printing of products with impermeable surfaces (such as cans and plastics) that need to be processed quickly after printing In addition, you can also use pigment inks with brighter colors

due to the relatively high spraying speed of continuous printing, the printing distance of continuous printing is usually much farther than that of pulse printing (generally more than 10mm), but the printing quality will not decline, so the placement of nozzle position can have a larger choice

binary spray printing

binary continuous spray printing technology the concept of digital constant temperature water tank is as old as deflection spray printing technology. This technology developed towards the commercial field of high-speed (high cost) and large-scale spray printing in the early stage With the progress of technology, binary printing will be applied in a very short time

the ink is sprayed from a series of closely arranged nozzles, and the printing resolution is 4 - 8 points/mm. The ink flow is broken into ink drops by the piezoelectric device. The breaking mode is similar to the deflection printing (but the binary printing has more ink flow) Ink dots that do not need to be sprayed are charged, deflected, and then recycled by the recycling tank The ink dots that need to be sprayed are not charged and deflected, but directly hit the surface of the object to be sprayed In order to establish and improve the comprehensive evaluation criteria and industry standards for plastic granulator equipment, the width of the spray printing pattern is determined by the number of nozzles or ink flow Of course, we can also use charged ink droplets for printing and recycle the uncharged ink droplets

the printing distance of binary printing is smaller than that of deflection printing, but it is still much larger than that of valve printing In principle, all kinds of inks used in deflection printing can be used in binary printing In the future, whether to use binary printing or deflection printing will depend on whether printing focuses on the number of information lines or speed and cost When printing more than 3 lines of information at the same time, binary printing is undoubtedly faster than deflection printing However, binary inkjet printing is more expensive and requires more manual operations in early applications - especially when different heterogeneous inks are used Basically, binary printing and deflection printing will coexist, because at present, they provide customers with the most diverse and effective solutions in the field of printing

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