How Printing Experience Removes Impurities from Substrates

The printing materials have to achieve an acceptable level of printing, not only to eliminate the electrostatic charge on the surface, but also to remove all the dust and other impurities adsorbed on the surface. After the charge is eliminated, the adsorption capacity of the printing material to dust can disappear immediately, and the dust in the surrounding environment can be prevented from being adsorbed again. However, this does not mean that the dust and other impurities that have been adsorbed on the surface have been removed, and therefore other measures must be used in conjunction with it. .

The easiest way is to remove the electrostatic charge and then use a brush to clean it. However, this method can only remove large particles and incomplete removal.

A more effective method is to use an ultrasonic generator to generate a strong compressed air flow. Through the same width as the paper roll web and very close to the nozzle of the paper roll, the compressed air is blown to the surface of the printing material to produce an air knife-like effect to sweep the dust. . Its function is like a vacuum cleaner, dust will not return to the surface of printing materials. Although the nozzles of different brands have different geometrical profiles, they all use their own proprietary technology to make the air flow reach a very high speed. Some nozzles can generate airflow speeds of more than 560 kilometers per hour, which can effectively remove the adherence. Dust particles on the surface of the printing material.

In addition to the above-mentioned method of removing dust particles by a strong compressed air flow, there are still methods for removing particles using a tape, and the apparatus adopted by this method has a simple structure and is easy to install.

Attached to the more popular dust removal equipment:

1.Shinko UVU Ultrasonic Cleaner

Shinko's UVU Ultrasonic Cleaner consists of two ultrasonic generators, two ultrasonic nozzles, and a large vacuum tank, which produces both air knife and ultrasonic effects.

The air knife effect is to use a high-pressure air knife produced by a double high-pressure nozzle to blow impurity particles larger than 50 μm into a vacuum tank.

A viscous boundary layer (Viscous Boundary Lager) can be formed between the ultrasonic airflow and the substrate at a relative zero speed. After pressurization, the ultrasonic airflow blows the viscous boundary layer and transfers the energy to the boundary layer to be buried in the boundary layer. The tiny dust was released and was blown into a vacuum tank to remove fine dust. At higher operating speeds, it is easier to remove 0.003mm dust.

2. HildeBrand's Model 1000 Jet Surface Cleaner

HildeBrand's Model 1000 Jet Surface Cleaner uses a specially contoured aerodynamic nozzle developed with aerospace technology that ejects extremely high velocity airflow to the substrate surface. The distance between the aerodynamic nozzle and the substrate is very close. The combination of the vacuum force in the cleaning module and the tape speed can generate high-speed airflow (>560km/h). This high-speed airflow passes through the edge of the nozzle, and can break the binding force of the boundary layer on the surface of the printing material on the surface of the printing material at a high pressure, and the impurity particles are sent to the clearance bin.

The Model 1000 jet surface cleaner has the function of monitoring and controlling the system status and pressure parameters, and it can interact with PLC or industrial PC. The cleaner has high production efficiency, compact structure and easy installation, and is applicable to various types of printing machines, so the relative investment is low.

The clearance position is close to the back-up roll (see Figure 2-2), which is necessary to ensure the removal effect. Should have the smallest diameter and wrap angle, in order to prevent the printing material from fluctuating under the high-speed airflow, maintain the constant distance between the printing material and the nozzle, and ensure that most of the dust particles are removed without being influenced by the speed of the vehicle. It can be observed from the microscope that 99.7% of dust particles larger than 40 μm can be removed.

The front of the clearance bin is equipped with an ionization system, so that the electrostatic charge carried on the surface of the printing material disappears, and the dust particles are no longer confined by electric charges. The control unit of the ionizer is equipped with a safety interlock system that can be automatically turned off as required.

3. Device for removing dust with tape

German company BST recently introduced a TEKNEK particle remover with a tape to remove dust and foreign particles.

The device is composed of two elastic rubber rollers and two adhesive rollers covered with adhesive tape, and is equipped with a static elimination bar. When the rubber roller is in operation, it is in direct contact with the printing material, and by the strong adsorption force of the rubber roller, the dust and impurity particles on the surface of the printing material can be rapidly sucked away. Even the particles below the micron level will not be missed. Then, dust and foreign particles adsorbed by the rubber roller are transferred to the tape. When the tape is completely covered with dust and other impurities, you can easily replace the new tape. The tape removed can be used to analyze and evaluate the type and status of dust.

The static elimination rod can eliminate electrostatic charges on the surface of the substrate and prevent it from re-adhering to dust. The features of the device are:

(1) It has the functions of transfer and adhesion and can remove particles below 1μm.

(2) Dust and other foreign particles that have been adsorbed on the substrate can be removed at the same time.

(3) The device is compact in design, easy to install and occupies only a small space.

(4) Adhesive rollers are easy to maintain and do not need to be stopped when cleaning.

(5) Cantilevered bearing structure makes it easy and quick to guide the paper roll.

(6) When the device is running, it does not require the paper roll to run synchronously. It will not slip and it will not scratch the printing material.

BST's TEKNEK particle remover can be combined with the company's corona treatment system and DF frame correction device, enabling three functions to work simultaneously.

The three-in-one multi-use combination system has a compact design and is relatively easy to install on various trademark printers. It can not only improve product quality, reduce auxiliary time, and reduce product loss, but also increase output. It is a narrow-area multi-function flexible version. The best partner for the press.