JP2003291307A - Apparatus and method for printing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control dispersion of a print thickness caused by cohesion and drying of ink when printing using the ink which is high in cohesion and a quick drying property, is carried out. <P>SOLUTION: Ink is fed to an anillox roller 4 from an ink feed opening 12 while vibration is applied with an ultrasonic vibrator 17. Vibration is applied to the remaining ink 20c cohered in a cell 4a, which is dispersed again to the ink 20d to be newly fed. A feed quantity of the ink 20a under an uncohesive state to the anillox roller 4 is kept constant independent of generation of ink cohesion, and a quantity of the ink 20b to be transferred to a flexographic plate 7 from the cell 4a of the anillox roller 4 is kept constant. Then, when printing is carried out by using the ink which is high in cohesion and quick drying property, dispersion in a print thickness to be caused by the cohesion and drying of ink is controlled, and precise printing can be continuously carried out. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus and a printing method using an ink having high cohesiveness and quick drying property.

[0002]

2. Description of the Related Art Conventionally, various printing methods have been used in order to flexibly meet requirements such as product shape and printing quality. One of the printing methods is flexo printing (Flexograph).
y) is widely used. FIG. 3 shows an example of a conventional flexographic printing apparatus. The flexographic printing device 1 is
Ink is supplied from the ink pan 2 to the anilox roll 4 using the fountain roll 3. The anilox roll 4 is formed with a fine concave engraving (cell) for obtaining a desired printed figure, and holds the ink supplied from the fountain roll 3 in the cell. The excess ink attached to the anilox roll 4 is scraped off by the doctor blade 5, and only the ink held in the cells is transferred to the flexographic plate 7 attached to the surface of the plate cylinder roll 6. The plate cylinder roll 6 is formed by inserting the material 9 to be printed together with the impression cylinder roll 8 into a flexographic plate 7.
The ink transferred to (1) is further transferred to the material 9 to be printed, and continuous printing is performed.

[0003]

However, the following problems have been pointed out when printing is performed on the flexographic printing apparatus 1 using an ink having high cohesiveness and quick drying property. That is, in the ink having high cohesiveness and quick drying property, the coagulation and drying of the ink will proceed in the cells of the anilox roll 4. Then, the cells become clogged, the volume of the cells gradually decreases, the amount of ink newly supplied into the cells decreases, and it becomes impossible to ensure the uniformity of the printing thickness. Regarding such a problem, as a conventional countermeasure, for example, an ink supply roll group such as an anilox roll 4 and a plate cylinder roll 6 is placed in a closed casing, and the closed casing is filled with a solvent gas,
A method to prevent ink from drying, a method to wash the residual ink after the ink transfer with a cleaning liquid sprayed from a cleaning nozzle, a method to wash the residual ink after the ink transfer with an ink scraping blade, and a regular ink supply For example, a method of removing the roll group from the flexographic printing apparatus 1 and washing the roll group may be used.

However, the method for filling the solvent gas into the container in which the ink supply roll group is closed should be adopted in consideration of safety in the case of an ink using an organic solvent or an alcohol solvent as the solvent. Since the method of cleaning with the cleaning nozzle is not possible, it is difficult to perform reliable cleaning, and foreign matter may remain on the cell bottom.Therefore, it is necessary to ensure sufficient printing thickness uniformity. I can't
The method of cleaning with the ink scraping blade of, there is a possibility that foreign matter may be mixed in the ink, the method of disassembling and cleaning is not realistic, because continuous printing becomes impossible with ink that agglomerates and dry in a few minutes, There was such a problem.

Moreover, the precision of flexographic printing is determined by the "number of lines" of the anilox roll 4, which is the number of cells per inch, and today, 200, 300, 400, 500, 600, 700
Wires are generally used, and 800 or 1000 wires have been commercialized. As described above, as the cells of the anilox roll 4 are further miniaturized, the aggregation and drying of the ink in the cells become more remarkable, so that a more effective solution has been desired. The above problem is not limited to the anilox roll 4 of the flexographic printing apparatus. For example, even in the case of a plate cylinder roll for gravure printing, the amount of ink newly supplied due to aggregation and drying of ink is As a result, there arises a problem that it becomes impossible to ensure the uniformity of the printing thickness.

In addition, when an expensive ink is used, an increase in the amount of ink that does not contribute to printing due to ink agglomeration and washing removal causes an increase in printing cost, which is not preferable. The present invention has been made in view of the above problems, and an object thereof is to agglomerate ink when performing printing using an ink having high aggregating property and fast drying property,
It is intended to suppress variations in printing thickness due to drying and enable continuous precision printing. It is also an object of the present invention to reduce the maintenance man-hours of the printing apparatus and prevent the printing cost from increasing due to the deterioration of the ink yield.

[0007]

In order to solve the above-mentioned problems, a printing apparatus according to a first aspect of the present invention is an ink which remains on the rolls constituting an ink supply roll group and agglomerates after the ink transfer. Is provided on the roll with a mixing means for mixing with ink newly supplied to the roll. According to the present invention, by the mixing means, the ink that remains after the transfer of the ink and agglomerates (including a part of agglomerates) is formed on the rolls forming the ink supply roll group, and then the ink is transferred to the rolls. By mixing with newly supplied ink, it becomes possible to keep the amount of ink in the non-aggregated state supplied to the roll constant regardless of the occurrence of ink aggregation. In addition, the aggregated ink can be used as a part of the ink for the next printing process without waste, instead of being removed.

Further, according to a second aspect of the present invention, in the printing apparatus according to the first aspect, the mixing means applies vibration to the agglomerated ink to newly supply the ink to the roll. And a vibration applying means for redispersing According to the present invention, on the rolls constituting the ink supply roll group, vibration is applied by the vibration applying means to the ink remaining and agglomerated after the ink is transferred, and the ink is newly supplied to the rolls. For ink
Redisperse the agglomerated ink (disperse the agglomerated ink in the solvent of the newly supplied ink),
It is possible to keep the amount of ink in the non-aggregated state supplied to the roll constant regardless of the occurrence of ink aggregation.

According to a third aspect of the present invention, in the printing apparatus according to the second aspect, the vibration applying means includes an ink supply port that faces the roll and extends in the longitudinal direction of the roll. , And is provided inside an ink supply means including an ink storage means for holding ink. According to the present invention, when ink is supplied to the roll, the ink applied to the ink held in the ink storing means inside the ink supplying means while being vibrated by the vibration applying means is used. By supplying the ink from the supply port to the roll, vibration is applied to the residual ink aggregated on the roll over the longitudinal direction of the roll to redisperse it to the newly supplied ink, and to the roll. It is possible to keep the supply amount of the ink in the non-aggregated state constant over the entire length of the roll irrespective of the occurrence of ink aggregation.

Further, in order to solve the above-mentioned problems, a printing method according to a fourth aspect of the present invention is a printing apparatus having an ink supply roll group, in which ink is transferred onto a roll constituting the ink supply roll group. The ink that remains and agglomerates is mixed on the roll with the ink newly supplied to the roll, and continuous printing is performed. According to the present invention, on the rolls forming the ink supply roll group, the ink that remains and aggregates after the ink transfer is mixed on the rolls with the ink newly supplied to the rolls, When performing continuous printing, it is possible to keep the amount of ink in an unaggregated state supplied to the roll constant regardless of the occurrence of ink aggregation. In addition, the aggregated ink can be used as a part of the ink for the next printing process without waste, instead of being removed.

The printing method according to a fifth aspect of the present invention is the printing method according to the fourth aspect, wherein when the agglomerated ink is mixed with the ink newly supplied to the roll, the agglomerated ink is vibrated. Is applied to re-disperse the agglomerated ink in the ink newly supplied to the roll. According to the present invention, on the rolls constituting the ink supply roll group, vibration is applied by the vibration applying means to the ink remaining and agglomerated after the ink is transferred, and the ink is newly supplied to the rolls. When the aggregated ink is redispersed in the ink and continuous printing is performed, the supply amount of the ink in the non-aggregated state to the roll can be kept constant regardless of the occurrence of the aggregation of the ink.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, parts that are the same as or equivalent to those of the conventional technique are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 1 shows a schematic diagram of a flexographic printing apparatus 11 according to an embodiment of the present invention. The flexographic printing apparatus 11 is an ink supply means for supplying ink to the anilox roll 4, and is an ink supply port that extends in the longitudinal direction of the anilox roll 4 (direction orthogonal to the paper surface of FIG. 1) facing the anilox roll 4. The ink chamber 14 is provided with 12 and an ink storage portion 13 (ink storage means) that holds ink. An ink agitator 16 is provided in an ink tank 15 that supplies ink to the ink chamber 14. Also, the ink chamber
The ink supply port 12 of 14 is provided with a doctor blade 5 as a means for adjusting the amount of ink deposited on the surface of the anilox roll 4. Further, inside the ink chamber 14, an ultrasonic vibrator 17 is provided as a vibration applying means.
The ultrasonic oscillator 17 can freely adjust the distance to the anilox roll 4 and the oscillation frequency according to the state of ink aggregation and the state of ink dispersion in the cells 4a of the anilox roll 4 described later. It can be carried out. In addition, although not shown in the drawing, the ink chamber 14 is provided with an ink temperature adjusting means for adjusting the temperature of the ink held in the ink reservoir 13. On the other hand, in the anilox roll 4 and the plate cylinder roll 6, a temperature adjusting path 18 for circulating a cooling medium to adjust the temperature of the roller surface,
19 are provided.

The operation and effect obtained by the embodiment of the present invention having the above structure will be described with reference to FIG. Ink 20 held in the ink reservoir 13 of the ink chamber 14
Is supplied from the ink supply port 12 of the ink chamber 14 to the cells 4a on the surface of the anilox roll 4. With respect to the excess ink of the ink supplied to the cells 4a, the anilox roll 4 rotates so that the ink chamber
It is scraped off by the doctor blade 5 provided in the ink supply port 12 of 14. The non-aggregated ink 20a in the cells 4a is transferred to the convex surface of the flexographic plate 7 at the rotary contact portion with the flexographic plate 7 fixed to the plate cylinder roll 6. Then, the convex ink 20 transferred to the flexographic plate 7
b is transferred to the printing object 9 (FIG. 1) backed up by the impression cylinder roll 8 (FIG. 1), and the printing proceeds.

Generally, the amount of the ink 20b transferred from the cell 4a of the anilox roll 4 to the flexographic plate 7 is about 70% of the volume of the cell 4a. Therefore, even after the ink 20a in the cell is transferred to the flexographic plate 7, the residual ink 20c of about 30% of the volume of the cell 4a remains in the cell 4a. When the ink 20 having high cohesiveness and quick drying property is used, the residual ink 20c is dried and solidified in the cell 4a before the new ink is supplied, and the substantial volume of the cell 4a is reduced. I will let you. Therefore, if the supply of new ink is repeated on the solidified residual ink 20c, the amount of newly supplied ink 20d gradually decreases, which leads to a decrease in printing thickness.

Therefore, in the embodiment of the present invention, when the ink 20 is supplied to the anilox roll 4, ultrasonic vibration is applied to the ink 20 held in the ink reservoir 13 inside the ink chamber 14. By supplying the ink 20 from the ink supply port 12 to the anilox roll 4 while applying vibration by the child 17, the anilox roll 4 is placed over the anilox roll 4 (in the cell 4a).
Vibration can be applied to the residual ink 20c that has been agglomerated in step 1 to redisperse it into the newly supplied ink 20d. Therefore, the supply amount of the ink 20a in the non-aggregated state to the anilox roll 4 is kept constant irrespective of the occurrence of ink aggregation, and the amount of the ink 20b transferred from the cell 4a of the anilox roll 4 to the flexographic plate 7 is It becomes possible to keep it constant at about 70% of the volume of the cell 4a. Therefore, when printing is performed using an ink having high cohesiveness and quick-drying property, it is possible to suppress variations in the printing thickness due to the coagulation and drying of the ink and to perform precision printing continuously. Therefore, even when an expensive ink is used, it is possible to suppress an increase in printing cost by significantly reducing the amount of ink that does not contribute to printing due to ink aggregation and washing.

Further, since the ink tank 15 for supplying the ink to the ink chamber 14 is provided with the ink agitator 16, a step before the ink agitator 16 supplies the ink to the anilox roll 4. Therefore, it is possible to prevent in advance the agglomeration of the ink that is supplied to the anilox roll 4 by stirring the ink 20 in the ink tank 15. Furthermore, since the ink chamber 14 is provided with the ink temperature adjusting means, even when heat is generated by applying vibration to the ink 20 from the ultrasonic vibrator 17,
The ink temperature can be optimized in the stage before the ink 20 is supplied to the anilox roll 4 and the aggregation of the ink can be prevented in advance. In addition, the anilox roll 4 also has a temperature adjusting path 18 as a temperature adjusting means for adjusting the temperature of the roller surface by circulating a cooling medium.
The cell 4 of the anilox roll 4 is provided.
Even after transferring to the inside of a, the temperature of the ink is optimized, the coagulation speed of the residual ink 20c is slowed, and the work of re-dispersing the solidified ink into the newly supplied ink 20d is facilitated. I am trying.

The ink 20c solidified in the cell 4a
The re-dispersion of the ink into the newly supplied ink 20d may be completed before the transfer of the ink from the anilox roll 4 to the flexographic plate 7 of the plate cylinder roll 6, so that the ultrasonic transducer 17 The installation place is not limited to the inside of the ink chamber 14 as long as the vibration can be applied to the ink in the cell 4a before the transfer of the ink. In addition, a plurality of ultrasonic vibrators 17 may be provided in order to reliably redisperse the ink depending on the aggregation speed of the ink, the roll diameter, and the like. Further, the ultrasonic transducer 17 may be any one that applies vibration over the entire length of the anilox roll 4, so that, for example, a plurality of ultrasonic transducers 17 are arranged at appropriate intervals over the entire length of the anilox roll 4, Alternatively, one ultrasonic transducer 17 is reciprocally moved over the entire length of the anilox roll 4, or
A diaphragm extending over the entire length of the anilox roll 4 may be attached to the tip of the ultrasonic vibrator 17 so as to satisfy the above requirements.

Further, the ink transferred from the anilox roll 4 to the flexographic plate 7 fixed on the plate cylinder roll 6.
After transferring 20b to the printing object 9, the flexo plate 7
The ink remaining on the upper surface may also solidify as described above. Even in such a case, since the amount of ink newly transferred from the anilox roll 4 to the flexographic plate 7 is reduced, the cooling medium is also circulated in the plate cylinder roll 6 to adjust the temperature of the roller surface. Temperature control path
By providing 19, the aggregation speed on the flexographic plate 7 is slowed down. Further, similarly to the case of the anilox roll 4, the ink solidified on the flexographic plate 7 is newly supplied from the time when the new ink is supplied to the time when the ink is transferred to the printing material 9. It is also possible to further prevent the decrease in printing thickness more reliably by providing an ultrasonic transducer for re-dispersion to the plate cylinder roll 6 at a position facing the plate cylinder roll 6.

That is, in the flexographic printing apparatus according to the embodiment of the present invention, on the anilox roll 4 and the plate cylinder roll 6 which constitute the ink supply roll group, the ink that remains and agglomerates after the ink is transferred is rolled. The mixing means (the ultrasonic vibrator 17 in the present embodiment) for mixing with the ink newly supplied to the rolls is provided above, and the mixing means causes the aggregation to remain on the rolls 4 and 6. The prepared ink is mixed with the newly supplied ink, and each roll 4, 6
It is possible to keep the amount of ink in a non-aggregated state supplied to the ink supply constant regardless of the occurrence of ink aggregation.
In addition, the aggregated ink is not removed but used as a part of the ink for the next printing process without waste, preventing foreign substances from adhering to each roll and reducing the number of washing steps. It is intended to prevent the yield from deteriorating.

Further, in the embodiment of the present invention, by supplying the roll cleaning liquid to the ink chamber 14 and supplying the roll cleaning liquid to the anilox roll 4 from the ink supply port 12, the ink chamber 14 supplies the roll cleaning liquid. It can function as a means. Moreover, vibration is applied to the roll cleaning liquid by the ultrasonic vibrator 17 and is supplied to the anilox roll 4, so that vibration is applied to the residual ink 20c aggregated in the cells 4a of the anilox roll 4 to be supplied. The cleaning ability of the cleaning liquid can be improved. Therefore, when the flexographic printing apparatus 11 is overhauled, the anilox roll 4 can be reliably washed while the anilox roll 4 is attached to the printing apparatus 11, and the number of maintenance steps can be reduced.

Although detailed description is omitted, even when the fountain roll 3 described in FIG. 3 is used as the ink supply means for supplying ink to the anilox roll, the flexo from the anilox roll 4 to the plate cylinder roll 6 is used. A mixing means for mixing the solidified ink with the newly supplied ink is provided on the anilox roll 4 at a position where the solidified ink can be redispersed into the newly supplied ink before the transfer of the ink to the plate 7. By providing the same function and effect can be obtained. In addition, it can be similarly applied to a plate cylinder roll of a gravure printing device.

[0023]

EFFECTS OF THE INVENTION Since the present invention is constituted in this way, when printing with an ink having high cohesiveness and quick drying property,
It is possible to suppress the variation in the printing thickness due to the aggregation and drying of the ink and continuously perform precision printing. Also,
It is possible to reduce the maintenance man-hours of the printing apparatus and prevent the printing cost from rising due to the deterioration of the ink yield.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a flexographic printing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining the function of the flexographic printing apparatus shown in FIG.

FIG. 3 is a schematic view showing an example of a conventional flexographic printing apparatus.

[Explanation of symbols]

4 Anilox roll 5 doctor blade 6 plate cylinder roll 7 Flexo version 8 impression cylinder roll 9 Printed matter 11 flexographic printing equipment 12 Ink supply port 13 Ink storage section 14 Ink chamber 15 ink tank 16 Ink stirrer 17 Ultrasonic transducer 18, 19 Temperature control path 20 ink 20a Ink in non-aggregated state 20b Convex ink transferred to flexographic plate 20c residual ink 20d Newly supplied ink

Claims (5)

[Claims] 1. A mixing unit is provided on a roll that constitutes an ink supply roll group, for mixing the ink that remains and aggregates after the ink transfer with the ink that is newly supplied to the roll on the roll. A printing device characterized by the above. 2. The vibration applying means for applying a vibration to the agglomerated ink to re-disperse it to the ink newly supplied to the roll, wherein the mixing means includes a vibration applying means. Printing device. 3. The vibration applying unit includes an ink supply port that faces the roll and extends in the longitudinal direction of the roll.
3. An ink supply means provided with an ink storage means for holding ink, the ink supply means being provided inside.
The printing device described. 4. In a printing device having an ink supply roll group, ink that remains and agglomerates after the ink is transferred is newly added to the roll that constitutes the ink supply roll group on the roll. A printing method characterized in that continuous printing is performed by mixing with supplied ink. 5. When mixing the agglomerated ink with the ink newly supplied to the roll, vibration is applied to the agglomerated ink so that the ink newly supplied to the roll has
The printing method according to claim 4, wherein the aggregated ink is redispersed.