JP2022106028A - Method of manufacturing printed product and machine temperature control device - Google Patents

Abstract

To appropriately control a surface temperature of a printing plate in balancing ink viscosity and ink fluidity: this is because in order to obtain a printed product having an appropriate color density, it is important to control the amount of ink supplied to the printing plate, and it is generally preferable that the ink fluidity from an inkwell to the printing plate is high, however, ink cooling tends to increase ink viscosity.SOLUTION: Provided is a method of manufacturing a printed product, the method blowing air containing mist with a Sauter average particle size of 1.0 μm or more and 20 μm or less generated from a spray nozzle to a printing machine, and performing printing while controlling the surface temperature of the machine.SELECTED DRAWING: None

Description

The present invention relates to a method for manufacturing a printed matter and an equipment temperature control device. In particular, the present invention relates to a method for producing a printed matter that can be suitably used in offset printing.

In offset printing, which is used for printing in a wide range of applications such as paper, flexible packaging, and beverage cans, in addition to the ambient temperature at which the printing machine is installed, the process of kneading ink, the friction between the inking roller and the printing plate, and the blanket The temperature of the ink and the surface of the printing plate to which the ink is transferred rises due to the friction between the cylinder and the printing plate, the viscosity of the ink applied on the plate surface decreases, and the ink adheres to the non-image area of the printing plate. It is known that it becomes easy to print and causes deterioration of print quality called ground stain. Therefore, in order to maintain print quality in long-time printing and high-speed printing, it is important to keep the viscosity of the ink applied on the plate surface constant.

Therefore, as a method of controlling the temperature of the ink, a method of circulating a temperature-controlled fluid inside the rocking roller of the printing machine, controlling the surface temperature of the roller, and controlling the ink temperature is disclosed (for example,). Patent Document 1). Further, as a method of directly cooling the plate surface temperature of the rising printing plate, a water-cooled method of circulating cold water inside the plate cylinder to cool the plate surface and an air-cooled method of applying cold air to the plate surface are disclosed (for example, Patent Document 2 and 3. 3).

The printing plate used in the offset printing press uses a thin film of water (hereinafter referred to as dampening water) or a silicone resin for ink repulsion in the non-image area. The method using dampening water is called offset printing with water, and the printing plate is cooled by controlling the temperature of the fountain solution. On the other hand, the method of using silicone resin for ink repulsion is called waterless offset printing, and when printing for a long time or high-speed printing, the printing plate tends to store heat due to friction with the inking roller or blanket that comes into contact with the printing plate. , A method of controlling the plate surface temperature by blowing cold air onto the plate surface or cooling the plate cylinder from the inside is adopted.

JP-A-11-105261 (Claims) JP-A-2002-347214 (Claims) Japanese Patent Application Laid-Open No. 64-72846 (Claims)

However, in order to obtain a printed matter having an appropriate color density, it is important to control the amount of ink supplied to the printing plate, and it is generally preferable that the ink fluidity from the ink fountain to the printing plate is high. On the other hand, when the ink is cooled by the rocking roller, the viscosity of the ink tends to increase, so that there is a limit to the cooling in terms of compatibility with the ink fluidity.

In addition, in the water-cooled type that cools the plate cylinder, the flow path of the fluid passing through the inside of the plate cylinder tends to be complicated in order to uniformly cool the plate cylinder surface, which poses a problem in practicality from the viewpoint of manufacturing cost and durability. Was. Further, in the air-cooled type in which cold air is applied to the plate surface, the supplied cold air collides with the air layer (gas boundary layer) on the surface layer of the plate surface, so that there is a problem that the cooling efficiency is low.

That is, in the present invention, in order to control the surface temperature of the printing equipment, air containing a mist having a Sauter mean diameter of 1.0 μm or more and 20 μm or less generated from the spray nozzle is blown to the printing equipment to control the surface temperature of the equipment. It is a method of manufacturing printed matter that prints while printing. Further, it is an equipment temperature control device that ejects the air.

According to the method for manufacturing a printed matter of the present invention, the temperature of the surface of the printing equipment can be easily controlled without modifying the conventional rocking roller and the plate cylinder, and the background stains even in long-time printing and high-speed printing. It is possible to obtain a printed matter with stable quality without causing the occurrence of.

It is a schematic side view which shows the example of the common impression cylinder type offset printing machine which is an example of the manufacturing method of the printed matter of this invention. It is a schematic diagram for demonstrating the structure of the equipment temperature control apparatus used as an example of the manufacturing method of the printed matter of this invention. It is a schematic diagram for demonstrating another equipment temperature control apparatus structure used as an example of the manufacturing method of the printed matter of this invention. It is a schematic diagram for demonstrating yet another equipment temperature control apparatus structure used as an example of the manufacturing method of the printed matter of this invention. It is a schematic diagram for demonstrating yet another equipment temperature control apparatus structure used as an example of the manufacturing method of the printed matter of this invention. It is a schematic side view which shows the example of the air knife structure of the gas supply part used as an example of the manufacturing method of the printed matter of this invention.

Hereinafter, preferred embodiments will be described in detail by taking the method for producing a printed matter of the present invention as an example. However, the present invention is not construed as being limited to the following embodiments, and can be variously modified and implemented according to an object and an application as long as the gist of the present invention is not deviated.

In the method for producing a printed matter of the present invention, air containing at least a mist having a Sauter mean diameter of 1.0 μm or more and 20 μm or less generated from a spray nozzle 11 is blown to a printing device, and the printed matter is manufactured while controlling the surface temperature of the device. do. In the method for producing printed matter of the present invention, mainly in order to minimize the change in ink viscosity on the printing plate in waterless offset printing, the equipment temperature control unit 4 is attached to the printing plate or a blanket in contact with the printing plate. It is installed at a position facing each other, and the air is blown from the control unit to control the surface temperature of the printing equipment.

The method for manufacturing a printed matter and the equipment temperature control device of the present invention will be described with reference to the drawings. However, the present invention is not limited to the examples shown in the drawings.

FIG. 1 shows an example of a method for producing a printed matter of the present invention. In the example of this offset printing machine, a large roller is provided as a common impression cylinder 1, and a printing unit 10 corresponding to each color is arranged around the large roller. This example shows an example of a 6-color printing machine, and 6 printing units 10 are arranged. In this example, the ink is applied from the ink jar 7, the ink is supplied to the plate cylinder 3 in which the printing plate is set, via the rocking roller 8 and the ink-applying roller 9, and the ink is applied on the printing plate. Ink is applied to. In the present invention, the "printing machine plate cylinder" (hereinafter, may be simply referred to as "plate cylinder") includes a mode in which a printing plate is set. Further, a base material (printed matter) is wound along the impression cylinder, and the blanket cylinder 2 is in contact with the surface of the base material. The plate cylinder 3 in which the printing plate is set is in contact with the blanket cylinder 2, and the equipment temperature control unit 4 in the present invention is located in front of the inking roller 9 with respect to the rotation direction of the plate cylinder. It is arranged so as to face the plate cylinder 3. The method for producing a printed matter of the present invention can include a step of irradiating an active energy ray so that the ink after printing can be dried or cured. In this example, the active energy ray irradiating device 6 Is provided. As a specific method for producing a printed matter, a printed matter having an ink curing film is obtained by first applying an active energy ray-curable slab ink on a substrate and then irradiating the substrate with an active energy ray to cure the ink. Examples of the base material include, but are not limited to, art paper, coated paper, cast paper, synthetic paper, newspaper, aluminum vapor-deposited paper, metal, polypropylene, polyethylene, nylon, polyethylene terephthalate, and the like. There are two methods of offset printing, one with water and the other without water, but either method can be used. The thickness of the ink curing film applied on the substrate is preferably 0.1 to 50 μm. The active energy ray is not particularly limited as long as it has the excitation energy required for the curing reaction, but for example, ultraviolet rays or electron beams are preferably used. When curing with an electron beam, an electron beam device having an energy ray of 100 to 500 eV is preferably used. When curing with ultraviolet rays, an ultraviolet irradiation device such as a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, or an LED is preferably used. For example, when a metal halide lamp is used, it is conveyed by a conveyor by a lamp having an illuminance of 80 to 150 W / cm. Curing at a speed of 50 to 150 m / min is preferable from the viewpoint of productivity.

FIG. 2 is a schematic side view for explaining the structure of the equipment temperature control device used in an example of the method for manufacturing a printed matter of the present invention. In this example, the water controlled by the water amount control unit 16 and the pressure reducing valve 15 is sent to the spray nozzle through the water pipe 14, and is sprayed in a mist form from the nozzle. The mist generated from the spray nozzle is mixed with the air sent from the blower 13, is supplied to the equipment temperature control unit 4 through the blower pipe 12, and is blown toward the plate cylinder 3. When the fog contained in the blast comes into contact with the equipment, the fog evaporates instantly, so that the temperature of the surface of the equipment can be efficiently cooled by the heat of vaporization. The particle size of the mist blown from the equipment temperature control unit 4 is preferably 1.0 μm or more and 20 μm or less when evaluated by the Sauter average particle size (D ₃₂ ) measured by the immersion method. More preferably, it is 0.0 μm or more and 10 μm or less. If the particle size of the mist is within the range, the mist evaporates while being conveyed in the air, or comes into contact with the surface of the equipment and evaporates instantly. Therefore, the cooling efficiency can be improved without getting the surface of the equipment wet. As a method for measuring the particle size of the mist by the immersion method, the mist is received on a plate glass coated with a thick layer of silicon oil, an enlarged photograph is taken, and the number of particles is counted for each size from the photograph. Then, the ratio of the total volume of the measured droplets to the total surface area is obtained from Equation 1 and the value (D ₃₂ ) obtained by calculating the Sauter average is used as the particle diameter of the fog.

D ₃₂ = Σ (n × d ³ ) _i / Σ (n × d ² ) _i (Equation 1)
n: number of particles, d: particle diameter.

In this example, the amount of mist sprayed from the spray nozzle 11 is preferably 0.5 L / hour or more and 40 L / hour or less, and 1.0 L / hour or more and 30 L / hour in the case of 6 spray nozzles and a water supply pressure of 6 MPa. The following is more preferable, and 2.0 L / hour or more and 20 L / hour or less are particularly preferable. By keeping it within the above range, it is possible to achieve both improvement of equipment cooling efficiency and prevention of fog aggregation in the blower pipe.

Further, the blower 13 can control the temperature and humidity of the air to be blown to predetermined values, and the temperature is preferably 5 ° C. or higher and 30 ° C. or lower, and more preferably 10 ° C. or higher and 25 ° C. or lower. The preferred surface temperature of the equipment varies depending on factors such as the type of ink used, but by adjusting the temperature within the above range, a printed matter having good print quality can be obtained. The temperature is preferably measured by the step of mixing the mist generated from the spray nozzle 11 and the blower pipe 12 connecting the equipment temperature control unit 4. Further, the relative humidity is preferably 10% RH or more and 60% RH or less, and more preferably 30% RH or more and 50% RH or less. Within the above range, the mist in contact with the surface of the equipment can be efficiently evaporated. The phase humidity is preferably measured between the blower 13 and the step of mixing the mist generated by the spray nozzle.

FIG. 3 is a schematic side view for explaining the structure of the equipment temperature control device used in an example of the method for manufacturing a printed matter of the present invention. In this example, the equipment temperature control unit 4 has a gas boundary layer peeling unit having a gas suction port in which an intake pipe 17 is arranged to separate the air layer (gas boundary layer) on the surface layer of the printing plate that has entered the control unit. A gas supply unit for supplying the air to the gas boundary layer peeling unit is provided. The intake pipe 17 is connected to a forced exhaust means (exhaust pressure applying means) such as an exhaust pump or an exhaust fan (not shown). The other end of the intake pipe 17 is connected to a gas suction port opened facing the printed plate, and has a slit shape along the width direction of the printed plate. Preferably, it has an opening width equal to or greater than the width dimension of the printed matter. The clearance between the equipment temperature control unit and the printing plate is preferably 0.1 mm or more and 2.0 mm or less, and more preferably 0.5 mm or more and 1.5 mm or less. Within the above range, the gas boundary layer can be uniformly and efficiently peeled off in the width direction.

FIG. 4 is a schematic side view for explaining an equipment temperature control device structure in still another example of the method for manufacturing a printed matter of the present invention. In this example, the equipment temperature control unit 4 is a gas boundary layer peeling unit having a gas suction port in which an intake pipe 17 for peeling the air layer (gas boundary layer) of the printing plate surface layer that has entered the control unit is arranged. A gas supply unit for supplying the air to the gas boundary layer peeling unit and an intake unit having an intake pipe 18 for sucking the supplied air are provided. Since the air blown from the equipment temperature control unit 4 contains mist, it may cause rust when it comes into contact with the drive unit of the printing machine or the metal parts of various rollers, and the air is introduced after the gas supply unit. It is preferable to suck and collect. Further, the intake amounts of the intake pipe 17 connected to the gas boundary layer peeling portion and the intake pipe 18 connected to the intake portion can be individually and appropriately adjusted according to the surface temperature of the equipment and the printing speed.

FIG. 5 shows still another example of the method for producing a printed matter of the present invention. In the example of this offset printing machine, the equipment temperature control unit 4 in the present invention is arranged so as to face the blanket cylinder 2 in contact with the plate cylinder. This is because when printing for a long time or high-speed printing is performed, the surface of the blanket cylinder undergoes the storage of frictional heat between the impression cylinder and the plate cylinder in contact with the blanket cylinder and the heat transfer from the temperature-controlled impression cylinder. It may be a factor that raises the temperature of the surface of the printing plate. Therefore, the surface temperature of the blanket cylinder can be controlled by arranging the equipment temperature control unit 4 at a position facing the blanket cylinder 2 and blowing the air, so that the surface temperature of the blanket cylinder can be controlled even in long-time printing or high-speed printing. It is possible to obtain a printed matter with stable quality without causing stains.

FIG. 6 is a schematic side view for explaining three examples of the air knife structure of the gas supply unit in an example of the method for manufacturing a printed matter of the present invention. The end of the gas supply unit has a slit shape along the width direction of the printed matter, has an opening width equal to or greater than the width dimension of the printed matter, and ejects the air uniformly in the width direction without a break. By having an injection port having an air knife structure capable of being capable, the air can be efficiently supplied to the boundary layer peeling portion on the equipment. The air knife structure is provided, for example, by narrowing the inner diameter of the blower pipe connected to the spout over one or two steps so that it becomes narrower as it approaches the spout to increase the air spout pressure and improve the cooling efficiency of the equipment. You can also let it. Further, it is preferable to provide a hemispherical flow path in the blower pipe connected to the ejection port because the pressure adjustment in the width direction of the ejected air becomes efficient and the equipment can be uniformly cooled.

In the method for manufacturing a printed matter of the present invention, a temperature sensor capable of measuring the surface temperature of the printing equipment and the temperature sensor are used in order to appropriately cope with the surface temperature of the printing equipment which changes with time due to the influence of the printing time and the temperature. It is preferable to print while adjusting the temperature of the air by interlocking the mechanism for arithmetically processing the signal from the printer and the mechanism for heating or cooling the air according to the arithmetic processing result.

1 Impressor 2 Blanket cylinder 3 Plate cylinder 4 Equipment temperature control unit 5 Base material (printed matter)
6 Active energy ray irradiation device 7 Ink pot 8 Swing roller 9 Ink application roller
10 printing unit
11 Spray nozzle
12 Blower
13 Blower
14 Water pipe
15 pressure reducing valve
16 Water volume control unit
17 Intake pipe connected to the gas boundary layer peeling part
18 Intake pipe connected to the intake section

Claims (11)

A method for producing printed matter, in which air containing a mist having an average diameter of 1.0 μm or more and 20 μm or less generated from a spray nozzle is blown to a printing device, and printing is performed while controlling the surface temperature of the device. After peeling off the gas boundary layer of the printing equipment using the gas suction port provided in the equipment temperature control unit arranged at a position facing the printing equipment, the air is supplied to the gas boundary peeling unit to supply the equipment. The method for manufacturing a printed matter according to claim 1, wherein the surface temperature is controlled. The method for producing a printed matter according to claim 1 or 2, wherein the relative humidity of the air is 10% RH or more and 60% RH or less. The method for producing a printed matter according to any one of claims 1 to 3, wherein the temperature of the air is 5 ° C. or higher and 30 ° C. or lower. The method for manufacturing a printed matter according to any one of claims 2 to 4, wherein the clearance between the temperature control unit and the printing equipment is 0.1 mm or more and 2.0 mm or less. The method for manufacturing a printed matter according to any one of claims 2 to 5, wherein the air is supplied from an injection port of an air knife structure provided in the temperature control unit. The method for manufacturing a printed matter according to any one of claims 2 to 6, wherein the air blown to the printing equipment is taken in by an intake unit provided in the temperature control unit. The temperature of the air is adjusted by interlocking a temperature sensor capable of measuring the surface temperature of the printing equipment, a mechanism for calculating a signal from the temperature sensor, and a mechanism for heating or cooling according to the calculation processing result. The method for manufacturing a printed matter according to any one of claims 1 to 7, wherein printing is performed while printing. The method for manufacturing a printed matter according to any one of claims 1 to 8, wherein the printing equipment is a printing plate or a blanket. The method for producing a printed matter according to any one of claims 1 to 9, further comprising a step of irradiating with active energy rays. An equipment temperature control device used in the method for manufacturing a printed matter according to any one of claims 1 to 10, wherein the equipment temperature control device ejects the air.

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