JPS63176153A - Printing ink viewing device - Google Patents

Abstract

PURPOSE:To enable observation of an emulsified condition of printing ink precisely and with time by providing a transparent roller incorporating an illumination device which rotates in contact with a plurality of rollers rotating in contact with each other, and an enlargement viewing device which permits observation of an enlargement image of printing ink on a rotating roller as a stationary image. CONSTITUTION:An offset printing device is composed of a pressure cylinder 1, a blanket cylinder 2, a plate cylinder 3, an inking device 4 and a wetting water device 5. A transparent roller 7 of a viewing device rotates in contact with the first inking roller 6 of the offset printing device. The emulsified condition of an emulsified ink on the transparent roller 7 is observed with the help of an optical microscope and a camera of an enlargement viewing device 8 using a fast flashing stroboscopic beam emitted by an illumination device in the transparent roller 7. The transparent roller 7 uses an oleophilic light permeable material 10 of transparent acrylic resin, and the part of light permeable material 10 rotates freely. A beam 17 emitted from an optical fiber cable 14, which is an illumination device, has its light path changed by a mirror 15 to a light axis direction of an objective lens of the optical microscope.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a device for observing printing ink on a roller making one revolution. More specifically, the present invention relates to a device capable of dynamically observing the emulsification behavior of ink and dampening water on a roller such as offset printing ink.

(Prior art) In offset printing, etc., a printing plate is used that is composed of a lipophilic image area that accepts printing ink and a hydrophilic non-image area that accepts dampening water and repels printing ink. Since it is a printing method, printing ink and dampening water are both supplied onto the printing plate surface during printing.

As printing progresses, the ink deposit passes from the ink fountain to the mixing rollers, and the dampening water gradually emulsifies into the printing ink that is supplied to the printing area on the printing plate by the rollers. The ink buildup progresses not only to the printing ink but also to the printing ink on the rollers and kneading rollers. This emulsification behavior depends on the surface chemical or rheological properties of the printing ink, or the relative amounts of the printing ink and dampening solution.
Furthermore, it is greatly influenced by the dampening water OpH value 1 surface tension, etc.

In addition, there are many printing problems caused by emulsification9, such as stains, roll accumulation, baldness of the base roll, roll stripping, ghosting, delays in setting and drying, deterioration of gloss, and deterioration of halftone dot reproducibility. All of these phenomena occur when the printing ink and dampening water are not properly emulsified.

Therefore, for those involved in related industries such as offset printing, especially in the printing ink manufacturing industry, it is important to know how to control the physical properties of the printing ink that affect this in order to maintain proper emulsification between the printing ink and the dampening solution. It is no exaggeration to say that this is the biggest challenge.

Conventionally, the conventional test method for emulsification of printing ink and dampening water9 is to forcibly stir a certain amount of printing ink and dampening water with a high-speed mixer to emulsify, and then Remove excess dampening water and measure the amount of dampening water emulsified using the xylene reflux method.

After supplying a certain amount of printing ink to a group of rollers that rotate in contact with each other, such as a lip leak tester (manufactured by THWING-ALBERT), dampening water is brought into contact with the roller at the end for a certain period of time, and the roller After the printing ink above is emulsified, the emulsified ink is scraped off from the roller, and the amount of emulsified dampening water is quantitatively measured using the Karl Fischer method.

That's what it was.

However, to grasp the essence of emulsification behavior.

As in the above test method, not only the amount of dampening water that can be emulsified in the printing ink, but also the state of emulsification, that is, the size distribution state of water droplets of emulsified dampening water and the emulsification state during the emulsification process. It is difficult to accurately confirm changes in .

Conventionally, the only equipment available to confirm the emulsification state was an optical microscope or an electron microscope. When using these devices, first scrape the emulsified ink directly onto the rollers of the printing press to obtain an emulsified sample, or scrape the emulsified ink from the rollers of an emulsification tester such as the Tri-Tub Break Tester. First, these samples were observed using an optical microscope, or the samples were frozen and their cut surfaces were observed using an electron microscope. However, when using these devices, the emulsified ink is subjected to shearing forces due to scraping during sample collection.

There was a major drawback in that the emulsified state changed and the emulsified state was different from that of the emulsified ink on the roller that was originally supposed to be observed. In addition, the optical microscope has the disadvantage that the emulsified state changes further due to pressurization of the cover glass when preparing the preparation. Electron microscopes have the disadvantage that it takes time to prepare a measurement sample and that information on only one cut plane can be obtained. Also,
In any of the above devices, it is impossible to know in detail the continuous change in the emulsified state on the roller over time.

Also, as in Japanese Patent Application Laid-Open No. 57-35113.

Devices for monitoring the equilibrium state of fountain solution and printing ink in offset printing devices are also known. With this device, it is possible to know the amounts of dampening water and printing ink during printing. However, it does not know even seven states of emulsion (it only measures the amounts of dampening water and printing ink with a receiver (sensor)).

(Problems to be Solved by the Invention) The present invention improves the drawbacks of conventionally known devices, and improves various drawbacks related to devices for observing the emulsification state of emulsified ink. The object of the present invention is to provide an excellent device for accurately observing or measuring the state on a rotating roller and easily observing or measuring detailed continuous changes in the emulsified state over time.

[Structure of the invention]

(Means for Solving the Problems) According to the present invention, five or more rotors contact each other and rotate. Printing ink that has been emulsified with dampening water contacts and rotates the roller on its surface. A transparent roller has an illumination device inside and transmits the light from the vi illumination device, and the magnified image of the printing ink on the rotating roller can be observed as a still image using the light from the illumination device as an observation light source. The printing ink observation device is equipped with a magnifying observation device that can be used, and the illumination device has a light source that is a high-speed flashing xenon lamp, or the illumination device is a high-speed flashing This is a printing ink observation device in which light is guided from a lamp into a transparent roller by an optical fiber cable. Moreover, it is a printing ink observation device in which the surface of the transparent roller is lipophilic.

Note that the apparatus of the present invention can of course be installed in an actual printing machine, but also in a printing ink testing machine.

The transparent roller of the present invention usually has a hollow shape, and a lighting device can be installed inside. The transparent roller is made of a material that can transmit light from the illumination device, such as (meth)acrylic resin.

Lipophilic light-transmitting materials such as styrene resin and urethane resin are preferred. That is, in the case of a hydrophilic material such as glass, the dampening water wets the roller surface, and the printing ink does not adhere to it, making it impossible to obtain an emulsified state on the roller, which is not preferable. Note that the roller may be made of glass, and the surface of the glass may be covered with a lipophilic light-transmitting material.

Are the equipment used for the magnifying observation device and illumination device capable of recording a still image of the object to be observed on the one-rotation roller?

There is no particular limitation as long as it can be observed with the naked eye, but
A commonly used optical microscope is preferable as the magnifying observation device, and a photographic camera can also be attached to the optical microscope for recording. In addition, C
It is also possible to use a CD camera as a magnifying observation device; in this case, a CCD camera and CRT, or a CC
The emulsified state can be observed by a combination of a D camera and a VTR, and furthermore, the emulsified state can be analyzed by counting by combining these with an image analysis circuit.

The illumination device is a light source device, and it is preferable to use a high-speed flash xenon lamp as the light source.

The required flash duration varies depending on the circumferential speed of the two-rotation roller, the magnification of the magnifying observation device, and the size of the object to be observed, but a high-speed flash duration with a half-width of around 1/1 millionth of a second has the highest resolution. Suitable for obtaining good still images. However, if the roller rotation is relatively slow, an ordinary tungsten lamp or halogen tungsten lamp that generates continuous light can also be used as the illumination light source. In this case, the shutter of a photo camera attached to a magnifying observation device can be used. By increasing the speed, a still image can be recorded. The light source of these lighting devices may be installed inside the transparent roller, but
A light source is installed outside the roller, and the light is guided by a projection optical system using an optical lens or an optical fiber cable inside the acid roller, and the optical path is changed to the optical axis direction of the magnifying observation device using an optical path changer such as a mirror. It is preferable.

Further, it is preferable that the lighting device includes a holding structure that allows the lighting device to stand still within the transparent roller without rotating together with the rotation of the transparent roller.

It goes without saying that the observation device of the present invention can also observe the fine state of the ink film on the roller when it is not emulsified and no dampening water is supplied. Therefore, it can also be used to check ink kneading dust on a three-roll mill during printing ink production. It can also be used for quality control during the production of emulsions or dispersions for paints, cosmetics, etc.

Next, the present invention will be explained with reference to the drawings. Note that the two drawings are one embodiment of the present invention.

FIG. 1 is a schematic side view showing an embodiment in which an observation device of the present invention is attached to an offset printing device.

The offset printing device includes an impression cylinder 1. Blanket cylinder 2, plate cylinder 3. It consists of an inking device 4 and a dampening water device 5, and the transparent roller 7 of the observation device is rotating in contact with the roller 6 where the first ink is deposited in the offset printing device.
The emulsified state of the above emulsified ink is observed using a combination of an optical microscope and a camera of the magnifying observation device 8, using a high-speed flashing strobe light emitted from the illumination device in the transparent roller 7 as an observation light source.

In FIG. 1, the observation device is brought into contact with the roller 6 for the first ink deposit, but it may be brought into contact with the second, etc. roller depending on the case.

FIG. 2 shows a partial cross section of the transparent roller rough in FIG. 1 rotating in contact with the ink roller 6. The transparent roller 7 uses a lipophilic light-transmitting material 10 made of transparent acrylic resin, and the hollow shaft 11 is fixed to the main body of the printing apparatus. A bearing 12 is interposed between the light transmitting material 10 and the hollow shaft 11.

Although the hollow shaft 11 is fixed, the light transmitting material 100 portion on the surface of the transparent roller rotates freely. Further, inside the hollow shaft 11, an optical fiber cable 14, which is a lighting device. A holding member 13 and a mirror 15 of an optical path changer are provided, and an optical fiber cable 14 that guides a light beam from a separately installed high-speed flash flash light source is attached to the holding member 13.
The light beam 17 emitted from the optical fiber cable 14 is held and fixed to the hollow shaft 11 by the mirror 1.
5, the optical path is changed in the optical axis direction of the objective lens 16 of the optical microscope. By using the holding material 13, the light beam 17 is always kept in the optical axis direction of the S:1 lens 16.

In the above manner, the transparent roller 7 and the ink are deposited on the roller 6.
The emulsified state of the emulsified ink 9 on top is observed as a still image even though it is rotating.

FIG. 3 is a schematic side view showing an embodiment in which the observation device of the present invention is incorporated into an emulsification test device for checking the emulsification state in a table test. The roller group consists of a vibration roller 18 for leveling, a drive roller 19, and a transparent roller 20, and dampening water supplied from a water supply pump 25 is applied to the ink applied onto the roller group that rotates in contact with each other. is dropped onto the surface of the vibration roller 18, and the vibration roller 18 and drive roller 19. The emulsification progresses as shearing force is applied between each nip between the drive roller 19 and the transparent roller 20. Also,
The light emitted from the light source lamp 23 by the high-speed flash strobe device 24 is transmitted to the transparent roller 2 using the optical fiber cable 22.
Using this as an observation light source, the emulsified state of the emulsified ink on the transparent roller 20 is received by a CCD camera 26 equipped with an optical system for magnification, observed by a CRT 27, and simultaneously recorded on a VTR 28. We were able to.

[Brief explanation of the drawing]

The drawings show two embodiments of the present invention. FIG. 1 is a schematic side view of a printing ink observation device attached to an offset printing device, FIG. 2 is a partial sectional view of FIG. 1, and FIG. 3 is a schematic side view of an emulsification test device with an observation device attached. are shown respectively. The symbols in the figure are 1-impression cylinder, 2-blanket cylinder. 3-plate cylinder, 4-ink device, 5-dampening water device, 6-ink roller, 7.20-transparent roller, 8-4 wide observation device, 9-emulsified ink, 10-light transmitting material, 11 - hollow shaft 12 - bearing, 13 - holding material, 14.
22-optical fiber cable, 15-mirror, 16-objective lens, 17-light beam, 18-vibration roller, 19-driving roller, 21-illumination device, 23-light source lamp, 24-high-speed flash flash device, 25-water bomb, 26-CCD camera. 27-CRT and 28-VTR are respectively shown.

Claims (1)

[Scope of Claims] 1. A plurality of rollers that rotate in contact with each other and have printing ink emulsified with dampening water on their surfaces, and have an illumination device inside; A transparent roller that transmits the light beam from the illumination device, and a magnifying observation device that can use the light beam from the illumination device as an observation light source to observe an enlarged image of the printing ink on the rotating roller as a still image. A printing ink observation device characterized by: 2. The printing ink observation device according to claim 1, wherein the light source of the illumination device is a high-speed flash xenon lamp. 3. The printing ink observation device according to claim 2, wherein the illumination device is a device in which light is guided into the transparent roller by an optical fiber cable from a high-speed flash xenon lamp located outside the transparent roller. 4. The printing ink observation device according to any one of claims 1 to 3, wherein the surface of the transparent roller is lipophilic.