JPS6271589A - Treatment of waste water of cleaning of roller for wiping intaglio printing plate - Google Patents

Abstract

PURPOSE:To contrive safe and efficient treatment of the titled waste liquid of cleaning by resting said waste liquid to separate the liquid to settled sludge and supernatant liquid, adding an oil product to the supernatant liquid and heating the liquid to separate the liquid to floating sludge and separated liquid, then mixing and incinerating the floating sludge and the settled sludge. CONSTITUTION:The waste liquid of cleaning contg. ink scum, surface active agent and builder, etc., is rested and is allowed to separate to the settled sludge and the supernatant liquid. After 2.5-3.0wt% oil product (e.g., heavy oil among petroleum products) is added to the supernatant liquid, the liquid is heated to the cloud point of the surface active agent or above (about 90 deg.C) to float the sludge-component to the upper layer and to form the separated liquid in the lower layer. The floating sludge and settled sludge are mixed and the mixture is subjected to an incineration treatment. The components necessary as the cleaning soln. are replenished to the separated liquid which is then recovered as the regenerated cleaning soln. As a result, the solid-liquid sepn. of the waste liquid of cleaning the roller for wiping the intaglio printing plate is safely and efficiently treated and the recycling of the separated liq. generated in the lower layer in this stage and the ease of the incineration treatment are made possible.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for treating intaglio wiping roller cleaning waste liquid. More specifically, the present invention relates to a method for efficiently treating waste liquid after cleaning used for wiping off excess ink in intaglio printing, and to recycling the separated liquid.

Conventional technology In intaglio printing, the waste liquid treatment method after washing the cleaning solution used to wipe off excess ink is to dispose of the entire waste liquid in an incinerator or other
For example, incineration has been done using a rotary kiln (rotary kiln, etc.), but this method is dangerous because it generates high heat during incineration, and requires high costs because it requires multiple plates of incineration fuel. Furthermore, there is a limit to the processing capacity due to the amount of waste liquid generated, and it cannot be said to be a safe and efficient processing method.

Purpose of the Invention The present invention aims to safely and efficiently process the solid-liquid separation of waste liquid after cleaning with a cleaning solution used in intaglio printing of securities, and also to separate the separated liquid generated in the lower layer at the same time. The purpose is to recycle and reduce the need for incineration.

Summary of the Invention The present invention provides a solid-liquid separation method for efficiently treating post-cleaning waste liquid (including ink scum, surfactants, builders, etc.) containing a large amount of intaglio ink generated during intaglio printing using a cleaning solution. The present invention relates to the method and the recycling of the separated liquid.

A feature of intaglio printing that is not found in other abdominal printing methods is that, with respect to the intaglio ink supplied to the entire intaglio plate surface, excess ink other than the ink for the pattern area is removed immediately before printing.
For this purpose, an intaglio wiping roller is brought into reverse contact with the printing plate surface to perform wiping. In this case, the ink on the surface of the roller is washed off while being brought into contact with a brush or the like in a wiping cleaning solution (containing water, surfactant, and builder) bath. This is repeated every time you print, so
The cleaning solution in the tank becomes a suspension containing a large amount of intaglio ink and is discharged at the end of the working day.Such a suspension is
It had little cleaning effect (it could not be reused and was discarded).

The present invention efficiently processes and reuses this suspension by collecting it in a tank of a predetermined size, letting it stand for a while, and separating the ink scum that naturally settles due to gravity as settled sludge. After that, 2.5 to 3.0% by weight of oil products (for example, heavy oils or vegetable oils in petroleum products, hereinafter simply referred to as heavy oil, etc.) are added to the upper supernatant liquid. In this case, using heavy oils with low specific gravity and low cost has the role of increasing the floating effect of sludge and accelerating the combustion rate during incineration. After addition, the cloud point of the surfactant or higher (
Heat to approx. 90°C). As a result, ink scum and surfactant float to the surface as sludge along with heavy oil and the like. The solid content (
Approximately 40% of the total amount of waste liquid is disposed of by incineration.

On the other hand, about 6096 of the total amount of waste liquid is separated and recovered in the lower layer. The specific gravity of the collected separated liquid is measured as it is,
After adding the missing builder and replenishing a predetermined amount of surfactant, it is reused as a regenerated cleaning solution.

Example An example of the waste liquid treatment process is shown in FIG.

The generated waste liquid is collected in a settling tank 1, and the settled sludge is sent to a storage tank 4. On the other hand, the supernatant liquid is transferred to the separation tank 2, a predetermined amount of heavy oil etc. is added from the heavy oil etc. tank and heated to about 90°C.

The sludge that floats is collected in advance in a service tank at 90%
The separated liquid heated to a temperature higher than 0.degree. C. is supplied to the separation tank 2 and discharged to the outside of the system as an overflow. The discharged floating sludge is transferred to a heating tank 5, then sent to a mixing tank 6, mixed with settled sludge and stirred, and then sent to an incinerator 7 to be incinerated.

The separated liquid in the lower layer of the separation tank 2 is sent to the regeneration tank 3, supplemented with missing additives, etc., and reused as a regenerated cleaning solution.

Effects of the Invention As explained above, the present invention can remove the solid content of waste liquid without requiring a large amount of energy, and can also reuse the recovered alkaline water and reduce the amount of incineration. Efficient processing can be performed.

In addition, the regenerated cleaning solution recovered from the waste liquid had exactly the same cleaning effect as the new solution, contributing to economic efficiency and resource conservation.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a process for treating intaglio wiping roller cleaning waste liquid according to the present invention. l... Sedimentation tank, 2... Separation tank, 3... Regeneration tank, 4
... Storage tank, 5... Warming tank, 6... Mixing tank, 7.
...Incinerator.

Claims (1)

[Claims] In waste liquid treatment after cleaning of cleaning solutions used for monochrome or multicolor engraving intaglio printing, the cleaning waste liquid containing ink scum, surfactants, builders, etc. is left to stand naturally and separated into settled sludge and supernatant liquid. A step of adding 2.5 to 3.0% by weight of oil products to the supernatant liquid and then heating it above the clouding point of the surfactant to float the sludge to the upper layer to form a separated liquid in the lower layer; A step of mixing the floating sludge from the process with the settled sludge and incinerating it, and a step of replenishing the separated liquid with components necessary as a cleaning solution and recovering it as a regenerated cleaning solution are performed in sequence. A method for processing intaglio wiping roller cleaning waste liquid.