JPS5820453A - Control of ink concentration - Google Patents

Abstract

PURPOSE:To maintain the concentration and viscosity of an ink at an optimum value by adjusting the opening/closing level of a solvent supply value according to the degree of variation of the ink flow rate in a tube for circulation being detected. CONSTITUTION:An ink 1 stored in a tank 2 is circulated with a pump 5. Here, the ink 1 varies in the viscosity depending on the concentration. The variation of the viscosity corresponds to change in the flow rate of the ink 1 in a circulation tube. So, the change of the flow rate is detected with a flowmeter 6 and are converted into a signal with a controller 7 to control the opening/ closing of a control valve 8. This allows a solvent 3 to be fed into an ink tank 2 in an appropriate amount from a tank 4 thereby invariably maintaining an ink at a constant concentration and viscosity.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for managing ink density, for example for a printing machine.

For example, when printing signs or the like on the surface of electric wires, the density of ink used is a major factor in determining the quality of printing.

Conventionally, the concentration of ink has been controlled by relying on the intuition of the operator or by measuring the viscosity with a viscometer while supplying the solvent. However, it is difficult to obtain the correct concentration, and when working for long periods of time, the concentration changes due to evaporation of the solvent, and the solvent must be replenished each time, which requires a lot of effort. was there.

The present invention aims to solve the above-mentioned drawbacks of the prior art, provide a management method for always maintaining an appropriate ink density, and achieve stable printing operations.

In other words, the gist of the present invention is that since changes in ink concentration appear as changes in viscosity, the amount by which the flow rate of ink in the same pipe changes due to viscous resistance is detected, and the opening/closing amount of the control valve is automatically changed based on that signal. , to automatically adjust the supply of solvent and keep the concentration constant.

Next, one embodiment of the method of the present invention will be further described with reference to the accompanying drawings.
A tank 2 for storing the solvent 3, a tank 4 for storing the solvent 3, a pump 5 for circulating the ink, a flow meter 6 for detecting the flow rate, a controller 7 for controlling the opening/closing of the control valve 8 according to the signal from the flow meter, and the supply amount of the solvent. This is carried out using a device consisting of a control valve 8 that controls the

The viscosity of the ink that is circulated by the pump 5 changes depending on the concentration of the ink, so the flow rate changes due to viscous resistance.The change in flow rate is detected by the flow meter 6, and the control valve 8 is opened/closed based on the signal passed through the controller 7. By controlling the amount, solvent 3 is transferred to ink tank 2.
The appropriate amount of ink is supplied within the ink tank, and the ink can always have a constant density.

In this embodiment, the change in concentration was detected as a change in flow rate due to viscous resistance, but it is also possible to detect it as a change in differential pressure before and after the orifice.

The supply of the waste solvent can be performed by ON/OFF control by simply opening and closing the control valve without adjusting the opening/closing amount of the control valve. Use an impeller inside the twisted pipe (something like a water wheel is also acceptable)
However, it is also possible to detect changes in viscosity based on the rotational speed or rotational torque.

Although the present invention is aimed at stable printing operations, it can also be used to control the concentration of liquids using solvents (not necessarily ink).
This is not to be construed as being limited by this example.

As explained above, by using the ink density control method of the present invention, (1) it is possible to stably maintain ink at an accurate density;

■ Able to maintain constant ink density even after a long period of time.

■ The ink circulation creates an agitation effect and the ink in the tank becomes uniform.

It has the advantage that it enables stable printing work by making the ink concentration uniform, and has great industrial value.

[Brief explanation of the drawing]

The accompanying drawing is a flowchart 1 diagram showing one embodiment of the ink density management method of the present invention. 1 2 ink, 2: ink tank, 6: solvent, 4 2 solvent tanks, 5 2 bombs, 6 2 flow meters, 7: con) p--y,
8: Control valve.

Claims (1)

[Claims] 1. In a method of controlling ink concentration by supplying a solvent (diluent) to the ink, changes in the flow rate in the pipe due to changes in the viscosity of the ink are detected, and the opening/closing amount of the solvent supply valve is adjusted based on the change, and the appropriate amount of solvent is supplied. A method for controlling ink density, characterized by controlling the density of ink by supplying.