RU1839151C - Method for transferring pictures - Google Patents

Description

The invention relates to an electron-droplet inkjet technology and may find application in printing, marking, microdosing, obtaining a topological pattern in the electronic industry, etc.

As a prototype, the method of electro-inkjet printing (marking) 1 was selected, which includes the emission of a stream of monodisperse drops from a liquid representing a suspension (e.g., nitro-paint) under the influence of a controlled capillary effect (emission of drops under the action of high constant pressure with ultrasonic synchronization of crushing jets for drops). Further, the droplets of the suspension are selectively charged in a deflecting electric field in the summer, either linearly or along a displaced path. Thus, droplet synthesis of prints on the substrate (symbols, lines, topologies, etc.) is provided.

However, this method has the following disadvantages; In the process of droplet deposition of images, the solid phase of the sprayed suspension is enveloped on the walls of the die of the droplet generator, which ultimately leads to clogging of the die and loss of operability of the droplet device. The suspension used as a working fluid has a limited lifetime, since over time, colloidal particles suspended in the liquid precipitate, which leads to the separation of the solid and liquid phases. This also leads to the inoperability of the droplet device, requiring the suspension to be replaced at regular intervals, and flushing of pipelines and containers to place and transport the suspension. In order to ensure sedimentation and coagulation stability of the working fluid, it is necessary to add various surface-active substances (SAS) to the system, introduce dispersing blocks into the device, etc. The presence of solid particles in the liquid during crushing of the jet impairs droplet formation and print quality. These drawbacks limit the scope of the droplet device, since the components of the working substance that are not always required by the technology correspond to the necessary parameters of the droplet device.

The aim of the invention is to improve the usability, print quality and reliability of ink jet devices.

This is achieved by the fact that in the method of droplet deposition of images, including the emission of monodisperse drops of liquid and their sequential deposition

to the surface, droplets are passed through a region of fluidized fine powder before precipitation. A comparative analysis of the claimed solution with the prototype shows that the claimed

The method is characterized in that only monodispersed drops of liquid are emitted, and its mixing with the solid phase occurs at a subsequent stage - before application to the working surface.

5 Obtaining a jet of monodisperse drops can be realized in various ways: under the action of a strong electric field (electrodispersion), under the action of a high constant pressure

-0 with ultrasonic synchronization (capillary monodispersion) or under pulsed pressure (droplets on request).

Common in all cases is the introduction of a solid phase in the form of a powder into droplets when droplets pass through a fluidized region. Fluidization, as is known, can be implemented in different ways (vibrational, ultrasonic, electrodynamic). With electrodynamic fluidization, finely dispersed powders of various materials can be weighed, including metals (copper, molybdenum, tungsten, etc.) with sizes from fractions of a micron to hundreds of micrometers.

The introduction of a solid phase into droplets (into the liquid phase) by fluidization eliminates the drop-jet method from a number of disadvantages. Reduced requirements

0 filtration and fluid stability. It is possible to use small diameter nozzles (units and tens of micrometers), which increases the resolution, the solid phase ceases to affect the droplet quality and liquid properties, for example viscosity. All this improves print quality, reliability of the device and expands the scope of the method.

0 Thus, the claimed method meets the criteria of the invention of novelty. In the study of other known technical solutions in this technical field, the features distinguishing the claimed

5 of the invention from the prototype, were not identified, and therefore they provide the claimed method with the criterion of significant differences.

Figure 1 shows a device that implements the proposed method: in figure 2, the electrodes of the zone of electrodynamic fluidization of a solid phase; on ir.3 - diagram of the feeder,

The device contains a generator 1 of mono-1 dispersed drops 2 of a liquid, a pair of electrodes 3, a feeder h of finely dispersed electrically conductive powder, a zone 5 of electrodynamic fluidization of a solid phase 1, a sealing surface 6, the finished suspension slurry 7, control unit 8: , The electrodes 3 contain a channel 9 of the sub- and solid phase, zone A of the fluidization ring locking zones In the region of an inhomogeneous field, position 10 indicates the capacity, 11 powder, 12, 13 electrodes (14, section of the channel, 15 - plug, 16 — elastic fluidization of the feeder, 17 — dielectric body.

The control unit 8 acts on the transmitter 4. which, through channel 9, feeds 5 pairs of electrodes 3 finely dispersed electroconductive powder of the applied suspension, the particle size of the powder in one embodiment was 10-15 microns, and the volume concentration of the powder in the 5 pore zone was 1%.

Rotationally opposite voltage potentials of the same magnitude are supplied to the pairs of electrodes 3 of the system in order to create an electrostatic electric field with a strength of 4 to V / cm in the zone A of fluidization.

Particles of the solid phase, entering through knew 9 to the lower electrode 3 of the electrode system, acquire, due to their electrical conductivity, an electric charge q.

If the force of interaction of such a mycosis and the electric field is significant. If it exceeds the particle weight and the adhesion force to the electrode, then the microparticle will begin to move the electrode of opposite polarity - iBepx.

As a result of the collision with the electrode of the opposite polarity, the sign of the micro-ar is reversed, and the direction of its interaction with the electric field changes. Consequently, the mikusar d starts moving again to the lower electrode, etc. In other words, the self-oscillating regime of microprobe movement in the electrostatic ole of the interelectrode region, a known electrodynamic fluidization by the verde phase, is indicated. A droplet during the passage of a fluidized bed captures particles. In this case, its task remains practically unchanged due to the equilibrium of the process.

To solve the spatial problem

tabulation of particle oscillations in zone A

the electrode gap of the pair of electrodes 3

create a closed annular zone B of the inhomogeneous floor by drawing the ends of the pairs of electrodes closer, in contrast to zone A, in which the sections of the pair of electrodes 3 are plane 5 parallel. As a result of the presence of converging portions of zone B, a field is formed in the latter with an increased intensity compared to a uniform field in zone A. As a result, particles of finely dispersed fluidized electrically conductive powder are pushed into zone A and do not leave the interelectrode gap.

Generator 1 emits monodispersed droplets (charged or uncharged) in one of the above ways. A bicomponent liquid or molecular solution is used. The droplet size is controlled from 1 µm to 1 mm. Into device

0, charge and deflect systems can be driven (before fluidization or after).

When moving through zone 5, the droplets of the liquid phase are orthogonally oscillated by particles of an electrically conductive powder

5 capture particles of the solid phase, and the resulting droplets of suspension 7 are sealed to surface 6 during their further flight.

Therefore, the droplet process

0 printing is combined with the process of slurry formation after ejection of liquid from the nozzle. The amount of fluidized particles in zone A is statically stable and depends on the field strength in zone A and on the radius 5 RO of this zone.

The main elements of the feeder 4 are the capacitance 10 and the system of two electrodes 12, 13, which are supplied with a high voltage, capacity 10 in its lower part

0 has a conical section and ends with a tube. It is made of a dielectric with a low relative permittivity and high dielectric strength. Into this container and

5, the powder 11 to be metered is poured. The electrode 12, through which the tube passes, is made with low taper from the side of the interelectrode region. Angle at the top of the cone - angle

0 close to 180 °. The lower electrode 13 is flat and has a channel 9. For electrical safety reasons, the structure is enclosed in a dielectric housing 17. The section of the tube is separated from the lower electrode 5 by a certain distance h. The size of this gap can be changed by changing the distance between the electrodes or moving the tube relative to the electrode 12. The tube section is selected so that the powder

11 freely woke up to the surface of electrode 13. The appearance of a conical plug of powder 11 on the electrode stops its further entry into the interelectrode region.

When the potential difference U is applied to the electrodes, the powder particles 11 lying on the surface of the conical plug will acquire a certain charge, and their disruption from this surface by electric field forces will begin. Torn particles will enter the self-oscillation regime and create in the interelectrode region a countable concentration of the solid phase close to the limiting one. The presence of a gradient electric field shifts the trajectories of the oscillating particles toward channel 9, through which the outflow of solid particles from the interelectrode region of the feeder takes place.

The decrease in the calculated concentration of particles of the solid phase in the interelectrode region is continuously replenished due to the separation of particles from the surface of the cone and the entry into the last powder 11 from the container 10.

The capacity of the feeder can be adjusted by varying the magnitude of the applied voltage and the magnitude of the gap h. This feeder is characterized by high productivity stability: instability does not exceed several percent.

The control unit 8 contains controllable sources of high and other voltages necessary for the operation of the device and has no special features. Unit 8 also controls the operation of the droplet emitter and, if necessary, the processes of droplet charging and their deflection.

Parameters of one experimentally implemented setup: drop emitter with

Claims (1)

The claims  METHOD FOR APPLYING IMAGES, including the emission of monodisperse drops of liquid and their 1 sequential deposition on the surface, characterized in that, in order to improve usability, capillary monodispersion of ethyl alcohol; nozzle diameter 50 μm; the flight speed of droplets with a diameter of 100 μm was 15 m / s; monodispersity of the order of 0.1%; pressure in the droplet generator in the range of 0.5-1 atm; the droplet charge was controlled in the range of 0 to 5 pC; fluidized ash extended from 5 to 50 mm; the bulk density of molybdenum with a diameter of granules of 1 to 7 microns was ". 1%; The fluidization voltage at an interelectrode distance of 10 mm was 7-15 kV; the width of the layer (pattern) on the substrate was adjustable from 0.2 to 0.5 mm. At No nozzle clogging was observed experimentally. Thus, this method of ink jet printing has high reliability due to the fact that only the liquid phase passes through the die of the droplet generator. The creation of a suspension at the stage of the kalletnyj deposition process and the separate storage of the solid and liquid phases eliminates the very problem of the suspension's lifetime. The method allows to expand the scope, since it allows the use of a wider range of solid and liquid phases of the applied substance. The method is characterized by high economy in the flow rate of the working substance and low power consumption, since the power consumed by electrodynamic fluidization is largely determined by leakage currents in the structural elements. (56) 1. Copyright certificate No. 1818941, cl. B 41 J 3/04, 11/19/85. print quality and reliability in the path of passing monodisperse drops liquids electrodynamically form a region of fluidized fine powder of a dye or an applied substance, and drops form from a solvent or a transporting liquid. V Specialized movements of 41 drops of liquid Phpch 1 1/ Fig i fip b