JPH10175284A - Damping water filtering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the apparatus low in equipment cost and running cost and capable of almost perfectly removing impurities such as coarse dispersed particles, fine dispersed particles or colloidal particles by providing a first filter means containing a natural oil absorbing material as a filter material. SOLUTION: Containers 10a, 10b house bag-shaped filters 9a, 9b housing natural oil absorbing materials 8a, 8b and a large number of small holes are provided to bottom plates 11a, 11b. Damping water supplied by a pump 6b is injected into the natural oil absorbing materials 8a, 8b from the upper opening parts of the bag-shaped filters 9a, 9b when valves 7a, 7b are opened to pass through the gaps thereof under gravity and gathered to the container 12 from a large number of holes of the bottom plates 11a, 11b. As the natural oil absorbing materials 8a, 8b, barks of a cedar or a hinoki to which water repelling processing is applied or kapok fibers being cotton like fibers collected from fruit of kapok are used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention belongs to the technical field of a filtration device. In particular, the present invention relates to a dampening solution filtering device for removing stains such as ink, paper powder, oil, etc. mixed into a dampening solution of an offset printing press.

[0002]

2. Description of the Related Art As is well known, the main purpose of using dampening solution in offset printing is to selectively apply dampening solution only to the non-image area of the printing plate, and to use the dampening solution due to the presence of the dampening solution. The purpose is to prevent ink from being applied to the image area.
The non-image area is surface-coated with, for example, a gum arabic, which is a hydrophilic polymer, as a desensitizer. Even after washing the gum arabic just before printing, it remains slightly,
Generally absorbs water well and repels oil well. However, it is necessary to make the dampening solution itself wet well, and thus the surface tension is reduced. As additives for this purpose, IPA (isopropyl alcohol), a non-alcohol etch liquid (hydrophilic liquid), or the like, which does not cause harm such as emulsifying the ink even when the surface tension is reduced, is used. Further, an additive for adjusting pH to prevent a delay in drying of the ink, an additive for preventing rusting of a printing machine, and the like are used.

The flow characteristics of ink are thixotropy, and the viscosity of the ink is reduced to an appropriate value by being kneaded by an ink kneading roller. At that time, the temperature of the ink also increases. One of the many purposes of the dampening solution is to reduce the temperature of the ink, which has risen too high, and to cool the plate so that it is at the proper temperature at the plate. Therefore, various devices for properly managing dampening water are attached to the dampening water device. A device that automatically controls the concentration of IPA (the concentration of the etchant) and the pH (for example, 4.5 to 6.0) in the dampening solution, and detects the temperature of the dampening solution (for example, 17 ° C. on the dampening roller). And automatic cooling.

[0004] In addition, various impurities are mixed into the dampening solution during printing. Ink mist is generated from the ink mixing roller or the like, and is mixed into the dampening solution. The ink or the components of the ink are mixed into the fountain solution by emulsification or the like, albeit slightly, on the plate surface. Paper dust generated from printing paper is also mixed into the dampening solution. Mixing of machine oil cannot be completely prevented. For this reason, the dampening device is provided with a filter for filtering and purifying the dampening solution. The dampening solution is constantly circulating in the printing unit between the portion of the applicator that supplies the dampening solution to the plate surface and a dampening solution management tank that appropriately manages the dampening solution. The dampening solution overflowed in the applicator of each color printing unit is collected by a pipe, passed through a filter by a circulating pump to remove impurities mixed in, and further passed through a control tank to adjust components, physical properties, liquid temperature, etc. And returned to each applicator by piping.

[0005]

However, the filter used in the conventional dampening solution apparatus uses a filter to physically capture the impurity particles that are going to pass through the gap. Therefore, it is necessary to replace the filter before clogging occurs. It is necessary to separately install a filter in each offset printing machine in order to save the time for replacing the filter about once a day and not increase the size of the filter. Therefore, the equipment cost is high, and the running cost is high because a large amount of relatively expensive filters are disposable. In addition, since the system is physically filtered, coarse dispersed particles (up to several tens of μm) and fine dispersed particles (several tens μm to 0.1 μm) are used.
Impurities such as several μm) and colloids (0.1 μm or more) cannot be completely removed, and dirt adheres to the walls of applicators, management tanks, pipes and the like. To remove it, it is necessary to periodically clean the dampening device, during which the offset printing machine cannot be operated. In addition, due to the impurities remaining in the dampening solution, thickening of the image area and background stains occur on the printed matter, resulting in poor print quality. In particular, when the dirt attached to the wall surface is peeled off, it causes a serious print quality defect.

Therefore, an object of the present invention is to reduce equipment costs and running costs, to remove impurities such as coarsely dispersed particles, finely dispersed particles and colloids almost completely, and to apply them to wall surfaces of applicators, management tanks, pipes and the like. Provided is a dampening water filtration device capable of obtaining a high-quality printed matter with extremely little adhered dirt, without causing defects such as thickening of image lines, background dirt, uneven printing, dust on a printing plate, and the like. It is in.

[0007]

SUMMARY OF THE INVENTION The present invention provides a dampening water filtration device for filtering dampening water of an offset printing press, wherein the dampening device has a first filtering means containing a natural oil absorbing material as a filter medium. Water filtration device ". According to the present invention, lipophilic impurities such as ink and machine oil contained in the fountain solution are adsorbed by the natural oil-absorbing material and removed from the fountain solution. Paper powder is also physically captured in the gaps existing in the natural oil-absorbing material. On the other hand, the dampening solution itself passes through the gap. Therefore, the dampening solution is purified, and a high-quality printed matter can be obtained without causing defects such as thickening of the image, background stain, uneven printing, dust on the plate surface, and the like. In addition, equipment costs and running costs are low because low-priced natural oil-absorbing materials are used. Further, the present invention is a "fountain solution filtering device using a water-repellent bark as the natural lipophilic material". According to the present invention, the water-repellent bark absorbs lipophilic impurities such as ink and machine oil contained in the dampening solution, and purifies the dampening solution. The reason is that dried natural bark contains lipophilic lignin (Lignin) etc. and basically adsorbs lipophilic impurities such as ink and machine oil, but if dampening water is present on the surface of the bark, Adsorption is inhibited. By performing the water repellent treatment on the bark, the surface of the bark is hardly wetted by the dampening solution, and it is considered that lipophilic impurities such as ink and machine oil contained in the dampening solution are adsorbed.

[0008] The present invention is also a "fountain solution filtering device having a second filtering means for capturing particles passing through the gap and disposed downstream of the first filtering means". In the case where all the impurities contained in the dampening solution are removed only by the first filtration means, the first filtration means needs to have a considerably large capacity. According to the present invention, on the other hand, by providing the second filtering means having a relatively narrow gap downstream, the capacity of the first filtering means can be significantly reduced. Also, the first
Most of the large-size impurity particles and oily particles are removed by the filtering means, so that the second filtering means is unlikely to cause clogging, and the combined use thereof greatly increases the replacement period.

Further, the present invention is a "fountain solution filtering device having third filtering means for filtering a substance by adsorption and disposed downstream of the second filtering means". According to the present invention, the characteristics of each filter including the first filtering means and the second filtering means are effectively exhibited for the same reason as described above, and particularly, finely dispersed particles, colloids and the like are effectively removed. Can be removed.
Further, the present invention is a "fountain solution filtration device wherein the third filtration means contains activated carbon as a filter medium". According to the present invention, finely dispersed particles, colloids, and the like can be particularly effectively removed by the action of activated carbon of the filter medium.

[0010] The present invention also provides a collecting means for collecting overflowing dampening water in an applicator for supplying dampening water to each color plate surface of the offset printing press, and introducing the dampening water to the filtering means; A dampening water filtration device having a dampening water management tank for controlling the composition, physical properties, temperature, etc. of the dampening water, and supply means for supplying dampening water from the dampening water management tank to the applicator. '' . According to the present invention, the dampening solution that overflows in the applicator that supplies dampening water to each color plate surface of the offset printing press by the collecting unit is collected and introduced into the filtering unit, and is passed through the filtering unit by the dampening water management tank. The components, physical properties, temperature, etc. of the dampening water are controlled, and dampening water is supplied from the dampening water management tank to the applicator by the supply means. Therefore, a circulating path of the dampening solution is formed, and impurities are removed by the above-described filtering means provided in the path, so that the purified dampening solution is always supplied to each color plate surface.

The present invention also provides "a dampening solution filtering device comprising a pair of the filtering means, and having a selecting means for individually selecting an operating state and a stopped state for the pair of filtering means".
It is. ADVANTAGE OF THE INVENTION According to this invention, even if one of a pair of filtration means is a stop state, if the other is an operation state, a dampening solution can be purified. Therefore, a filter medium such as a filter can be replaced while the purification of the dampening solution is continued. Further, the present invention is a "fountain solution filtering device for recovering dampening water from the plurality of offset printing presses, and the supply unit supplying dampening water to the plurality of offset printing presses". ADVANTAGE OF THE INVENTION According to this invention, the number of installation of a dampening-water filtration apparatus decreases by centralized processing, and equipment cost and running cost decrease.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to embodiments. FIG. 1 is a diagram schematically showing the configuration of the dampening solution filtration device of the present invention. In FIG. 1, reference numeral 1 denotes a dampening fountain roller, 2 denotes a dampening fountain, 3 denotes dampening water of the dampening fountain 2, and 4 denotes a plate cylinder. Although only one of each is shown in FIG. 1, there are a plurality of sets of components attached to each printing unit of each color in the offset printing press. Reference numeral 5 denotes a dampening water management tank, 6a denotes a pump for supplying dampening water in the dampening water management tank 5 to the dampening basin 2, and 6b supplies dampening water overflowing the dampening basin 2 to the filtration system. The pumps 7a and 7b are valves for opening and closing piping to the filtration system.

Next, in the filtration system, 8a and 8b are natural oil-absorbing materials, and 9a and 9b are natural oil-absorbing materials 8a and 8
a bag-shaped filter made of a nonwoven fabric or the like for storing b, 1
0a and 10b are containers of bag-shaped filters 9a and 9b, 11
a and 11b are containers 10a and 10 having many small holes.
The bottom plate 12b is a container for storing dampening water that has passed through the bottom plates 11a and 11b. These constitute the first filtering means. Reference numeral 6c denotes a pump for supplying the dampening water stored in the container 12 to the second and third filtering means on the downstream side, and 7c and 7d denote valves for opening and closing pipes to the pair of second and third filtering means. It is. 13a and 13b are second filtration means, 14a and 1
4b is a third filtering means. Third filtering means 14a,
The dampening solution that has passed through 14b is returned to the dampening solution management tank 5, and circulates along the above-described route.

Next, the operation of the dampening water filtration device of the present invention and its peripheral devices in the above configuration will be described. The dampening water management tank 5 is provided with a detector that detects the concentration of IPA and / or the concentration of etchant (hydrophilic liquid), pH, water temperature, and the like in the dampening solution. Further, a controller is provided for automatically controlling components, physical properties, liquid temperature, liquid replenishment and the like based on the detected data. The pH is usually between 4.5 and
The temperature is adjusted to about 6.0 and the temperature is adjusted to, for example, about 17 ° C. on a dampening roller. The dampening water in the dampening water management tank 5 is supplied by a pump 6a to the dampening water fountain 2 of the printing unit of the offset printing machine via a pipe. In the case of a four-sided four-color offset printing press, there are eight dampening fountains 2 in one offset printing press. The dampening water 3 of this dampening basin 2
Is supplied to the plate surface of the plate cylinder 4 by the dampening fountain roller 1 and a plurality of rollers subsequent thereto, is absorbed by the hydrophilic non-image portion of the plate surface, and prevents ink from adhering to the non-image portion.

By the way, ink adheres to the lipophilic image portion of the plate surface, and the roller for supplying the dampening solution in contact with the plate surface also comes into contact with the ink of the image portion. Since the surface of the roller is wet by the fountain solution, the adhesion of ink to the surface of the roller is not a simple theory. However, in practice, the ink or the components of the ink enter the dampening solution 3 of the dampening fountain 2 via a plurality of rollers for supplying the dampening solution to the plate surface. It is considered that this is mainly because the ink or the components of the ink are slightly dissolved in the fountain solution, and the ink or the components of the ink are dispersed in the fountain solution as an emulsion.

An ink kneading roller and an inking roller are provided near the plate cylinder 4, and an ink mist is generated when the ink film is divided by the roller and the roller. The printing paper is transported near the plate cylinder 4, and paper dust is generated from the printing paper. Impurities such as ink mist, paper powder, and other mechanical oil adhere to a plurality of rollers that supply dampening water to the plate surface, and enter the dampening water 3 of the dampening fountain 2 via these rollers. There are also impurities that directly enter the dampening solution 3 of the dampening basin 2. As a result, the dampening solution overflowing the dampening basin 2 contains impurities.

The dampening solution that overflows the dampening fountains 2 in the offset printing press is collected at one location, and is supplied to a filtration system by a pump 6b to remove the above-mentioned impurities mixed therein. As shown in FIG. 1, the first filter means looks like a single container, but the containers 10a, 10b,
The container 12 is divided into three containers. Container 10a,
10b accommodates bag-shaped filters 9a, 9b accommodating the natural oil absorbing materials 8a, 8b. Many small holes are provided in the bottom plates 11a and 11b of the containers 10a and 10b. Therefore, when the valves 7a and 7b are open, the dampening water supplied by the pump 6b passes from the opening above the bag-shaped filters 9a and 9b to the natural oil-absorbing material stored under the opening. 8a and 8b. The poured fountain solution is gravity-driven so that the natural oil absorbing material 8a,
8b, and is collected in the container 12 from a number of holes provided in the lower bottom plates 11a and 11b. Container 12
Pool the dampening water.

Lipophilic impurities such as ink and machine oil contained in the fountain solution are adsorbed by the natural oil-absorbing materials 8a and 8b and removed from the fountain solution. Also, paper powder is physically captured in the gaps existing in the natural oil-absorbing materials 8a and 8b. Specifically, for example, as a natural oil-absorbing material 8a, 8b, a water-repellent bark can be used. The reason that it adsorbs lipophilic impurities is that dried natural bark basically contains lipophilic impurities such as ink and machine oil, including lipophilic lignin. on the other hand,
The presence of dampening water on the surface of the bark inhibits its adsorption. It is considered that the surface of the bark is hardly wetted by the dampening water by applying the water repellent treatment to the bark, and lipophilic impurities such as ink and machine oil contained in the dampening water are considered to be adsorbed.

The dampening water stored in the container 12 is supplied to the valve 7
When c and 7d are open, the pump 6c causes the second
And the third filtering means 14a and 14b downstream of the filtering means 13a and 13b. Second filtering means 13
a and 13b capture particles that are going to pass through the gap.
The second filtering means 13a and 13b have a relatively narrow gap as compared with the first filtering means. In the case where all impurities contained in the dampening solution are removed only by the first filtration means, the first filtration means needs to have a considerably large capacity.
The second filtering means 13a and 13b can reduce the size of the first filtering means. Further, since the first filtering means removes most of the large-sized impurity particles and oily particles, the second filtering means is less likely to be clogged, and when used together, the replacement period is greatly lengthened and the running cost is reduced. To save.

The third filtering means 14a, 14b downstream thereof
Filters the material by adsorption. As the filter medium, a filter medium containing activated carbon can be used. The third filtering means 14a, 14b is provided with the second filtering means 13a, 13
For the same reason as in b, the characteristics of each filter including the first filtration means and the second filtration means are effectively exhibited, and in particular, finely dispersed particles, colloids and the like can be effectively removed.

The dampening solution which has passed through the third filtering means 14a and 14b and which has been purified by removing impurities is returned to the dampening solution management tank 5, where components, physical properties, liquid temperature, liquid replenishment and the like are adjusted. Will be
The dampening solution stored in the dampening solution management tank 5 is again supplied to the dampening fountain 2 of the printing unit of the offset printing machine via a pipe by the pump 6a, and circulates in the above-described circulation path.

In FIG. 1, the filtration system is constituted by a pair of filtration means. Even if one of them is in a stopped state, if the other is in operation, the dampening solution can be purified. Therefore, it is possible to replace the filter material such as a natural oil-absorbing material and a filter while purifying the dampening solution. By opening and closing the valves 7a, 7b, 7c, 7d, the filtering means can be brought into an operating state or a stopped state. Although not shown in FIG. 1, the dampening solution can be recovered from a plurality of offset printing presses and supplied to the plurality of offset printing presses in the dampening solution filtering device of the present invention. By intensively treating the dampening water in this way, the number of dampening water filtration devices to be installed is reduced, and equipment costs and running costs can be reduced.

Next, a filter medium that can be used in the dampening solution filtration device of the present invention will be described. As the natural oil-absorbing material that can be used for the first filtering means, the above-mentioned water-repellent bark can be used. There is no particular limitation on the type of tree from which the bark is collected.However, when using the bark of architectural wood such as cedar and cypress, it is originally inexpensive because it is originally waste material. It is easy to obtain.

Further, Kapok fiber, which is a flocculent fiber obtained from the fruit of Kapok tree, can be used. Kapok fibers are rich in oil absorbency and have the property of not absorbing water as it is without water repellency treatment. The amount of oil absorption per unit weight is about three times higher than that of a polypropylene-based oil-absorbing material, which is a typical synthetic oil-absorbing material. These natural oil-absorbing materials can be disposed of by incineration after they have been used in a fountain solution filter. Moreover, it has a feature that it burns well and does not generate toxic gas when incinerated.

The filter media usable for the second filtration means include cotton, synthetic fiber, glass fiber, stainless cloth, and the like.
A woven fabric made of iron cloth or the like, or a non-woven fabric such as filter paper, synthetic resin products, felt, and asbestos can be used. As the synthetic fiber, a fiber of vinyl acetate type, polyamide type, vinyl chloride type, acrylic type, ethylene type, propylene type or the like can be used. These turret materials are usually used after being formed into a cartridge filter or the like so as to improve performance and handleability. The activated carbon described above can be used as a filter medium that can be used for the third filtration means. The activated carbon is used in the form of granules filled in a filtration container or formed into a cartridge filter or the like together with other materials. In addition to activated carbon, anthracite, magnetite, sand, silica sand and the like can be used.

[0026]

As described above, according to the present invention, equipment costs and running costs are low, impurities such as coarsely dispersed particles, finely dispersed particles, and colloids can be almost completely removed. Very little dirt adhering to the walls of pipes, etc., dampening water filtration that can produce high quality printed matter without defects due to thickening of image lines, background stain, uneven printing, dust on plate surface, etc. An apparatus is provided.
According to the present invention in which the water-repellent bark is used as the natural lipophilic material, the water-repellent bark is contained in the fountain solution, and the lipophilic impurities such as the machine oil are removed. Adsorb and purify dampening water. Further, according to the present invention, which has a second filtering means for capturing particles that are going to pass through the gap, and is disposed downstream of the first filtering means, the capacity of the first filtering means is greatly reduced. In addition, since the first filtering means has largely removed large-sized impurity particles and oily particles, the second filtering means is less likely to cause clogging, and the replacement period is greatly reduced by the combined use. Can be longer. Further, according to the present invention, which has a third filtration means for filtering a substance by adsorption and is disposed downstream of the second filtration means, the first filtration means and the second filtration means are provided for the same reason as described above. The characteristics of each filter including the means are effectively exhibited, and particularly, coarsely dispersed particles, finely dispersed particles, colloids and the like can be effectively removed. According to the present invention, the third filtering means includes activated carbon as a tower material. According to the present invention, in particular, coarse dispersed particles, fine dispersed particles,
Colloids and the like can be effectively removed.

A collecting means for collecting overflowing dampening water in the applicator for supplying dampening water to each color plate surface of the offset printing press and introducing the dampening water to the filtering means; and a component of the dampening water passing through the filtering means. According to the present invention, a dampening solution management tank for managing physical properties, temperature, and the like, and a supply unit that supplies dampening water from the dampening solution management tank to the applicator, Is formed, and impurities are removed by the above-mentioned filtering means provided in the path, so that the purified fountain solution is always supplied to each color plate surface. Further, according to the present invention, the filtering means is constituted by a pair, and has a selecting means for individually selecting an operating state and a stopped state for the pair of filtering means. The material can be replaced. According to the present invention, the collection means collects the dampening solution from the plurality of offset printing presses, and the supply means supplies the dampening solution to the plurality of offset printing presses. The number of installed filtration devices is reduced, and equipment costs and running costs are reduced.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a dampening solution filtration device of the present invention.

[Explanation of symbols]

 1 dampening fountain roller 2 dampening fountain 3 dampening water 4 plate cylinder 5 dampening water management tank 6a, 6b, 6c pump 7a, 7b, 7c, 7d valve 8a, 8b natural oil absorbing material 9a, 9b bag filter 10a, 10b, 12 Container 11a, 11b Bottom plate 13a, 13b Second filtering means 14a, 14b Third filtering means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 29/36 Z

Claims (8)

[Claims] 1. A dampening water filtration device for filtering dampening water of an offset printing press, comprising a first filtration means containing a natural oil absorbing material as a filter medium. . 2. The fountain solution filtering device according to claim 1, wherein a water-repellent bark is used as the natural lipophilic material. 3. A dampening device according to claim 1, further comprising a second filtering means for trapping particles passing through the gap, and being disposed downstream of the first filtering means. Water filtration device. 4. The dampening solution filtration according to claim 1, further comprising a third filtering means for filtering a substance by adsorption, and being disposed downstream of said second filtering means. apparatus. 5. The fountain solution filtering device according to claim 4, wherein said third filtering means includes activated carbon as a filter medium. 6. A collecting means for collecting overflowing dampening water in an applicator for supplying dampening water to each color plate surface of the offset printing press and introducing the dampening water to the filtering means, and dampening water passing through the filtering means. 6. A dampening solution management tank for controlling components, physical properties, temperature, and the like, and supply means for supplying dampening water from the dampening solution management tank to the applicator, wherein The fountain solution filtration device according to any one of the above. 7. The filter device according to claim 1, wherein said filter means comprises a pair, and said filter means has a selection means for individually selecting an operation state and a stop state for said pair of filter means. The fountain solution filtration device as described in the above. 8. The apparatus according to claim 6, wherein said recovery means recovers dampening water from a plurality of offset printing presses, and said supply means supplies dampening water to said plurality of offset printing presses. The fountain solution filtration device according to 7.