JPH0661935B2 - Printing ink observation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to an apparatus for observing printing ink between roller nips rotating in contact with each other. More specifically, the present invention relates to an apparatus capable of observing the emulsification behavior of the fountain solution and ink between rotary roller nips such as offset printing ink.

(Prior Art) In planographic ink such as offset printing, a printing plate composed of an oleophilic image area that receives the printing ink and a hydrophilic non-image area that receives the dampening water and repels the printing ink. Since the printing method uses a printing ink, both the printing ink and the dampening water are supplied onto the printing plate surface during printing. As the printing progresses, the dampening water gradually emulsifies into the printing ink supplied from the ink fountain through the kneading roller group to the image area on the plate surface by the inking roller. Not only ink, but also printing ink on inking rollers and kneading rollers. This emulsification phenomenon is
In both cases, the printing ink and the dampening water are subjected to pressure and shear deformation at the nip between the rubber roller and the metal roller, which rotate in contact with each other, or the nip between the plate surface and the inking roller, and are agitated and agitated. Furthermore, this emulsification behavior is
Surface chemical or rheological properties of printing ink,
Alternatively, it is greatly affected by the relative amounts of the printing ink and the dampening water, the pH value of the dampening water, the surface tension, and the like.

In addition, there are many printing problems due to the emulsification phenomenon, such as dirt, roll accumulation, pot peeling, roll stripping, ghost, delay in setting / drying, deterioration of gloss, and deterioration of dot reproducibility. Both phenomena occur when the emulsification between the printing ink and the fountain solution is not proper.

Therefore, for those involved in offset printing and other related industries, especially printing ink manufacturing industry, in order to properly maintain the emulsification of printing ink and fountain solution, how to control the physical properties of printing ink It is no exaggeration to say that this is the biggest issue.

Conventionally, the conventional test method for emulsification of printing ink and fountain solution is that a certain amount of printing ink and fountain solution are forcibly stirred by a high-speed mixer to emulsify and then a constant shear rate is applied. Excess fountain solution is removed with, and the amount of fountain solution emulsified by the xylene reflux method is measured, or it is fixed to a group of rollers that rotate in contact with each other such as a litho break tester (made by THWING-ALBERT). After supplying a certain amount of printing ink, contact the roller at the end with dampening water for a certain period of time to emulsify the printing ink on the roller, scrape the emulsified ink from the roller, and wet it by the Karl Fischer method. It was to quantitatively measure the amount of water.

However, in order to understand the essence of the emulsification behavior, not only the amount of dampening water that can be emulsified in the printing ink but also the emulsification behavior, that is, the printing ink and the dampening water between the roller nip, can be determined as in the above test method. It is essential to know exactly how to emulsify.

Despite the strong demand in the industry, there has been no apparatus or method capable of observing the emulsified state between roller nips.

In addition, as a conventional device for confirming the emulsified state, only an optical microscope or an electron microscope was used. When using these devices, first scrape the emulsified ink directly from the roller of the printing machine to obtain an emulsified sample, or scrape the emulsified ink from the roller of an emulsifying tester such as a litho break tester. Next, these samples were observed with an optical microscope, or the samples were frozen and the cut surface was observed with an electron microscope. However, with these devices, it is not possible to observe the emulsification behavior occurring in the actual printing device.

There is also known a device for monitoring the equilibrium state of dampening water and printing ink in an offset printing device, as in Japanese Patent Publication No. 57-35113. With this device, it is possible to know the amounts of dampening water and printing ink during printing. However, it does not know even the emulsified state, but measures the amount of dampening water and printing ink with a receiver (sensor). Furthermore, the observation between the roller nips is not performed.

(Problems to be Solved by the Invention) The present invention provides an apparatus excellent in observing the emulsified state of printing ink and fountain solution between rotating roller nips, which has not been conventionally performed.

[Structure of Invention]

(Means for Solving Problems) The present invention has an internal illumination device, a transparent rotating illumination roller that passes a light beam from the illumination device, and a transparent rotating roller that contacts and rotates the illumination roller. The magnifying observation comprises an observation roller and a magnifying observation device or a light receiving part of the magnifying observation device inside the observation roller, and passes the light beam of the illumination device through a roller nip between the illumination roller and the observation roller. It is a printing ink observation device for observing a magnified image of the printing ink between the roller nip as a static image by reaching the device or the light receiving part.It is an observation device suitable for lithographic ink emulsified by fountain solution. is there. Further, the light source of the illumination device is a printing ink observation device in which a high-speed flash xenon lamp is used, or the illumination device is a device in which a high-speed flash xenon lamp outside the transparent roller is guided into the transparent roller by an optical fiber cable. It is an ink observation device. In addition, it is a printing ink observation device in which the surface of the transparent roller is lipophilic.

The apparatus of the present invention can be installed not only in an actual printing machine but also in a printing ink testing machine or the like.

As the transparent illumination roller or observation roller of the present invention,
Usually, it is hollow, and the material of this transparent roller is one that can transmit the light rays from the illuminating device, and is preferably a lipophilic light transmitting material such as (meth) acrylic resin, styrene resin, urethane resin. That is, in the case of a hydrophilic material such as glass, dampening water wets the roller surface, printing ink does not adhere, and the emulsified state on the roller cannot be obtained, which is not preferable. It should be noted that it is also possible to use a glass which is used as the roller and whose glass surface is covered with a lipophilic light-transmitting material.

Whether the equipment used for magnifying and illuminating devices can record a static image of the observation object in the nip between the rotating rollers,
There is no particular limitation as long as it can be observed with the naked eye. An optical microscope, which is a commonly used magnifying optical system, is preferable as the magnifying observation device, and a photographic camera may be attached to the optical microscope for recording. A CCD camera having a magnifying optical system can also be used as a magnifying observation device. In this case, the CCD camera and CR
The emulsified state can be observed with a combination of a T or CCD camera and a VTR, and the emulsified state can be counted and analyzed by combining these with an image analysis circuit. Further, a photographic camera or a CCD camera is used as the recording device for the observation image.

Although a magnifying observation device can be provided in the observation roller, only a light receiving portion such as a lens and an optical fiber cable is provided in the observation roller, and an image received by this light receiving portion is transmitted to the outside of the observation roller to be enlarged. You can also

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 time depends on the peripheral speed of the rotating roller, the magnifying power of the magnifying observation device, and the size of the observation object. Although different, one having a high-speed flash time with a half-width of about one millionth of a second is suitable for obtaining a still image with good resolution. However, if the roller rotation is relatively slow, a normal tungsten lamp or halogen tungsten lamp that generates continuous light can be used as the light source of the illumination device. In this case, the shutter speed of the photographic camera attached to the magnifying observation device can be used. By raising it, a still image can be recorded. The light source of these illuminating devices may be installed in a 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 in the roller, and a mirror is used. It is preferable to change the optical path in the optical axis direction of the magnifying observation apparatus by using an optical path changing device such as. In addition, the illumination device and the magnifying observation device do not rotate together with the rotation of the illumination roller and the transparent roller which is the observation roller, and the optical axis of the light beam from the illumination device and the optical axis of the magnifying observation device are always in the roller. It is preferable to provide a holding structure so as to match.

Needless to say, the observing device of the present invention can also observe the fine state of the ink film on the roller at the time of non-emulsification to which the fountain solution is not supplied. Therefore, it can also be used to check the degree of ink kneading on a roll mill during the production of printing ink. It can also be used for quality control during the production of emulsions or dispersions such as paints and cosmetics.

Next, the present invention will be described with reference to the drawings. The drawing is an embodiment of the present invention.

FIG. 1 is a schematic side view showing a test apparatus for observing emulsification behavior between roller nips according to the present invention.
The observation roller 1, the illumination roller 2 and the drive roller 5 are provided. The observation roller 1 is provided with a magnifying observation device 3 and the illumination roller 2 is provided with an illumination device 4. The dampening water supplied from the water supply pump 6 is dripped on the surface of the observation roller 1 to the printing ink provided on the rotating roller group in contact with each other, and the observation roller 1 and the illumination roller 2, Further, the nip between the illuminating roller 2 and the driving roller 5 receives a shearing force respectively, and the emulsification of the printing ink and the dampening water occurs. Further, the light beam emitted from the light source lamp 12 by the high-speed flash strobe device 13 is guided to the illumination device 4 in the illumination roller 2 by the optical fiber cable 11, and this is used as an observation light source.
The emulsification behavior of the printing ink and the dampening water generated at the nip between the observation roller and the illumination roller is captured by the magnifying observation device 3 as a still image. This still image is transmitted to the CCD camera 8 by the optical fiber image guide 7 and is recorded on the VTR 10 while being observed by the CRT 9.

FIG. 2 shows the observation roller 1 and the illumination roller 2 in FIG.
FIG. Both the observing roller 1 and the illuminating roller 2 use a transparent acrylic resin lipophilic light transmitting material 16, and the hollow shafts 17 and 17 'are fixed to the main frame of the test apparatus. Light transmitting material 16 and hollow shaft 17,
A bearing 15 is interposed between 17 'and the hollow shaft is fixed, but the light transmitting material 16 on the surfaces of the observation roller 1 and the illumination roller 2 is freely rotatable. The hollow shaft 17 of the illuminating roller 2 is provided with an optical fiber cable 11 which is an illuminating device, a holding member 18 and a mirror 20 of an optical path changing device, and the optical fiber cable 11 which guides a light beam from a separately installed high speed flash strobe light source.
Is held and fixed in the hollow shaft by a holding member 18, and the light beam 2 emitted from the optical fiber cable 11
The mirror 1 changes the optical path in the optical axis direction of the lens 22 of the magnifying observation device in the observation roller 1. Further, inside the hollow shaft 17 'of the observation roller 1, there is provided a light receiving portion of the magnifying observation device composed of the optical fiber image guide 7 and the lens 22 and a holding member 19, and the holding material allows the observation light of the magnifying observation device to be observed. The axis is the direction of the light ray 21,
The roller group is fixed to the hollow shaft 17 'so that the roller group is always aligned during rotation. As described above, the emulsification behavior of the emulsified ink 14 on the roller group rotating in contact with each other between the observation roller 1 and the illumination roller can be obtained as a static image.

FIG. 3 is a partial sectional view of a test apparatus showing another embodiment according to the present invention.

The same illumination roller as that shown in FIG. 2 is used. The observing roller 1'is made of a transparent acrylic resin lipophilic light-transmitting material 1
6 ', the hollow shaft 23 is fixed to the body frame of the test apparatus. A bearing 15 'is interposed between the light transmitting material 16' and the hollow shaft 23, and the hollow shaft 23 is fixed. However, the light transmitting material 16 'on the surface of the observation roller 1'is not illuminated. Rotates with the light transmitting material 16 on the surface of the. Further, inside the hollow shaft 23 of the observing roller 1, there is provided a tip portion of a lens barrel 25 of an optical microscope which is a magnifying observation device and a mirror 20 'of an optical path changing device. The lens barrel 25 and the mirror 20' are holding materials. It is held by a hollow shaft. The mirror 20 'changes the optical path of the light beam from the illuminating roller in the optical axis direction of the lens barrel 25, and is held and fixed by the holding member so that the optical path of the light beam is always constant during rotation of the roller. Note that focusing during observation is performed by rotating the lens barrel by a screw mechanism 26 provided on each of the lens barrel 25 and the holding member 24. In this way, the emulsification behavior of the emulsified ink 14 between the nip between the observing roller 1'and the illuminating roller 2 rotating in contact with each other is observed as an enlarged still image by the optical microscope.

[Brief description of drawings]

The drawings show one embodiment of the present invention. 1 is a schematic side view of a test apparatus for observing the emulsification behavior between roller nips, FIG. 2 is a partial sectional view of FIG. 1,
FIG. 3 is a partial sectional view of a test apparatus showing another embodiment, respectively. Reference numerals in the figure are 1, 1 '... observation roller, 2 ... illumination roller, 3 ... magnifying observation device, 4 ... illumination device, 5 ... drive roller, 6 ... water pump, 7 ... optical fiber Image guide, 8 ... CCD camera, 9 ... CRT, 10
…… VTR, 11 …… Optical fiber cable, 12 ……
Light source lamp, 13 ... High-speed flash strobe, 14, 14 '
... Emulsified ink, 15, 15 '... Bearing, 16,
16 '... Light transmitting material, 17, 17' ... Hollow shaft,
18, 19, 24 ... Holding material, 20, 20 '... Mirror, 21, 21' ... Ray, 22 ... Lens, 23 ...
Hollow shaft, 25 ... Lens barrel, 26 ... Screw mechanism, respectively.

Claims (5)

[Claims] 1. An illuminating device inside, a transparent rotating illuminating roller that passes a light beam from the illuminating device, a transparent observing roller rotating in contact with the illuminating roller, and an inside of the observing roller. By a magnifying observation device or a light receiving part of the magnifying observation device, and by causing the light beam of the illuminating device to reach the magnifying observation device or the light receiving part through a roller nip between the illumination roller and the observation roller. A printing ink observation device for observing a magnified image of the printing ink between the roller nips as a static image. 2. The printing ink observing device according to claim 1, wherein the printing ink to be observed is a lithographic ink emulsified with a fountain solution. 3. The printing ink observing device according to claim 1, wherein the light source of the illuminating device is a high-speed flash xenon lamp. 4. The illumination device is a device in which a high-speed flash xenon lamp outside the transparent roller is guided into the transparent roller by an optical fiber cable.
The printing ink observation device according to the item. 5. The printing ink observation device according to claim 1, wherein the surface of the transparent roller is lipophilic.