JP3844027B2 - Web adsorption method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a web adsorbing method, and more particularly to a web adsorbing method for electrostatically adsorbing a metal web such as a photosensitive lithographic printing plate transferred in the longitudinal direction and an interleaf web.
[0002]
[Prior art]
For example, a thin plate such as an aluminum plate is used as a support for a PS plate for lithographic printing, and a photosensitive composition is provided in a layer form on the support. In general, products that are shipped in a cardboard box are electrostatically adsorbed with a slip sheet to protect the photosensitive composition.
[0003]
The PS plate is processed by laminating a pair of upper and lower rollers while transferring the interleaving web to a metal web provided with a photosensitive composition in layers, and further charging the entire surface of the interleaving web negatively to form a metal web. The interleaf paper web is electrostatically adsorbed. At this time, at least one of the pair of upper and lower rollers used is a crown roller. The electrostatically attracted web is nipped and transferred to a cutting device by a feed roller and cut into a sheet. The cut sheets are conveyed by a conveyor and accumulated while being slid by an accumulation unit.
[0004]
By the way, when the metal web and the interleaf paper web are overlapped with each other with a pair of rollers as described above, a lump of air enters between the metal web and the interleaf paper web and is conveyed together with the overlap web. As shown in FIGS. 3A to 3E, when the overlapping web passes through the feed roller portion, only the web passes and the air mass is stagnated, and the air mass transported later is absorbed. , Grow big. Grown air mass collapses when it reaches the limit. When the air mass is crushed, the interleaving web is folded and partially overlaps and passes through the feed roller.
[0005]
[Problems to be solved by the invention]
However, the creases in the interleaving web cause scratches on the PS plate when stacked and cause product defects. Furthermore, when a product defect occurs, the yield decreases and waste is generated, and the operation is lowered by stopping the line to remove the defective product.
[0006]
The present invention has been made in view of such circumstances, and even if the electrostatically adsorbed metal web and the interleaf paper web are nipped and transported by a pair of transport rollers, the interleaf web does not fold. Therefore, an object of the present invention is to provide a web suction method and apparatus that can eliminate product defects.
[0007]
[Means for Solving the Problems ]
In order to achieve the above object, the present invention sandwiches and conveys a laminated web in which a metal web and an interleaf paper web are overlapped by a pair of conveying rollers, and at the upstream side of the conveying roller, charging means is provided on the overlapping web. In a web adsorbing apparatus that adsorbs the metal web and the interleaf paper web by electrostatic attraction by charging, a flat roller having a smooth surface is provided below the charging means, and the overlapping web is charged by the charging means. In this case, the overlap web is pressed and conveyed to the flat roller so that the contact angle is 2 to 30 degrees with respect to a horizontal tangent on the upper surface of the flat roller.
[0009]
Further, in order to achieve the above object, the present invention is configured to sandwich and convey a laminated web in which a metal web and a slip sheet web are overlapped with each other by a pair of conveying rollers, and to charge the overlapping web with a charging means during transportation. In the web adsorbing method in which the metal web and the interleaf paper web are adsorbed by electrostatic attraction force, the metal web and the interleaf paper web are overlapped by a flat roller having a smooth surface and a pressure contact with the flat roller. It is carried out by sandwiching the interleaf paper web with the conveyed metal web.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The outline of a preferred embodiment of a web adsorbing method and apparatus according to the present invention will be described in detail below with reference to the accompanying drawings.
FIG. 1 is a basic configuration diagram of a web cutting apparatus to which the present invention is applied. This apparatus processes a PS plate, and includes a rewinding device 16 having a winding shaft 14 around which a metal web 10 is wound, a rewinding device 24 having a winding shaft 22 around which an interleaf paper 20 is wound, and a metal. A nip roller 32 as an apparatus for superimposing the web 10 and the interleaf web 20, a charging device 34 for electrostatically adsorbing the metal web 10 and the interleaf web 20, and adsorbing the metal web 10 and the interleaf web 20 The cutting device 40 for cutting the web into a predetermined length and processing it into a sheet material, and three conveyors 70, 70, 70 for conveying the sheet to the laminating device 76 are provided.
[0014]
The rewinding device 16 for the metal web 10 includes a rotation drive source (not shown) for rotating the winding shaft 14 in the direction of the arrow and feeding the metal web 10, and a roller 18 is disposed in the vicinity of the rewinding device 16. Established. The decurling device 30 disposed close to the roller 18 includes a plurality of decurling rollers. On the other hand, the unwinding device 24 for the interleaf web 20 includes a rotation drive source (not shown) for rotating the winding shaft 22 in the direction of the arrow and feeding the interleaf web 20 in the same manner as the unwinding device 16. A roller 26 is disposed adjacent to the rewinding device 24.
[0015]
A drying device 28 for the slip sheet web 20 is provided between the rewinding device 24 for the slip sheet web 20 and the nip roller 32. On the downstream side of the nip roller 32, a charging device 34 for electrostatically adsorbing the overlapped metal web 10 and interleaf paper web 20 is disposed. A pair of feed rollers 36 are disposed on the downstream side of the charging device 34, and the feed rollers 36 are rotated by a drive motor (not shown) to sandwich and convey both webs 10 and 20. A slitter 38 disposed on the downstream side of the feed roller 36 includes a pair of slitter blades for cutting the webs 10 and 20 into a predetermined width.
[0016]
The cutting device 40 includes an upper blade and a lower blade, and cuts both the webs 10 and 20 to a predetermined length while moving forward and backward in the transport direction via a drive unit including a motor (not shown). The cut webs 10 and 20 are formed into a sheet shape, conveyed by the conveyor 70, and stacked on the stacking device 76.
The stacking device 76 stacks the sheets 12 sequentially fed from the conveyors 70, 70, 70 on the stacking device 76 by aligning the side surfaces of the sheets with a side stopper (not shown). A shock absorber 80 that shocks and a sheet rear end stopper 78 that includes means for blowing air in the loading direction.
[0017]
The charging device 34 is installed between the nip roller 32 and the feed roller 36 and electrostatically adsorbs the overlapped metal web 10 and interleaf web 20.
As shown in FIG. 2, the charging device 34 includes a high-voltage power source 92, a charging electrode 90, and a high-voltage cable 94 that connects them. The charging electrode 90 includes a charging needle 96 and an insulator 98. The charging needle 96 is made of stainless steel having a diameter of 3 mm and a length of 15 mm with one pointed tip. The charging needle 96 is arranged in the width direction of both the webs 10 and 20 at a pitch of 20 mm with the pointed end of the insulator 98 facing the interleaf paper web.
[0018]
When a high voltage is applied to the charging electrode 90, electrons are emitted from the electrode needle 96, the interleaf web 20 is negatively charged, and is electrostatically adsorbed to the metal web 10. The charging voltage 34 controls charging by a charging current command generated by the charging control device 42.
Specific examples of materials and processing conditions in the above basic configuration are as follows.
[Explanation of materials]
A PS plate for planographic printing is used as the metal web 10. The PS plate uses a thin aluminum plate (JIS alloy number 1050), width 1310, thickness 0.2 mm, and length 5000 m as a support. The PS plate is provided with a photosensitive composition on this support. As the interleaving paper, 100% natural pulp, the same width as the metal web, thickness 0.05 mm, length 10,000 m, basis weight 35 g / m ² are used.
〔Processing conditions〕
As the processing conditions, the interval between the slitter blades is set so that the diameter of the decurling roller constituting the decurling device 30 is 60 mm and the width of the web 10 after being cut by the slitting device 38 is 1300 mm. The cutting length of the sheet material 12 cut by the cutting device 40 is set to 1120 mm, and the conveying speed of the conveyor is set to 100 m / min.
[0019]
Further, the diameter of the nip roller 32 on the downstream side of the decurling device is 250 mm, and the charging electrode 90 is attached at a position of 500 mm on the upstream side of the cutting device 40. The height from the web to the tip of the electrode needle 96 of the charging device 34 is set to 25 mm. The moisture content of the interleaving web is 3% to 4.8%, and the humidity around the interleaving web is 30% to 45%. The moving speed of the web is 5 m / min to 70 m / min.
[0020]
In the above basic configuration, as shown in FIGS. 3A to 3E, the air that has entered the space between the metal web 10 and the interleaf paper web 20 by overlapping the metal web 10 and the interleaf paper web 20 is shown. The lumps 50 stagnate when passing through the feed roller 36 and cause creases in the interleaf paper web 20, and the folds cause damage to the PS plate.
[0021]
Therefore, in the first embodiment of the present invention, when the overlapping web is nipped and conveyed by the feed roller 36 as the charging strength of the charging device 34 described in the basic configuration, the interleaf web 20 is separated from the metal web 10. Charging stronger than the normal strength for obtaining an electrostatic attraction force that does not peel off or shift is performed on the overlapping web for a short time. That is, the air mass 50 that has entered between the metal web 10 and the interleaf web 20 due to the superposition can pass through the feed roller 36 without stagnation at the position of the feed roller 36. 50 is a charging strength for obtaining an electrostatic attraction force that can be fixed between the metal web 10 and the interleaf web 20. For example, the charging current for obtaining the normal charging strength is 0.6 mA, but in the first embodiment of the present invention, a charging current of 3 mA, which is five times the normal charging current, is set for 10 seconds. To be charged.
[0022]
According to the first embodiment configured as described above, a strong suction force that is greater than the suction force required for the processing of the web works, so that the air mass 50 interposed between the two webs has this strong suction force. Fixed between the webs. As a result, the air mass 50 is conveyed downstream together with the web as shown in FIGS. Therefore, the interleaf paper web does not form a fold. The reason why the charging time is set to a short time of 10 seconds or less is that if the strong charging is continued as it is, a brake is generated when accumulating while sliding on the accumulating portion, and a trouble occurs in the accumulating portion.
[0023]
The charging device 34 is preferably disposed immediately after the nip roller 32 that overlaps the metal web 10 and the interleaf web 20. That is, the air mass 50 is formed by gathering air intervening between the two webs immediately after the webs are overlapped. Therefore, if the charging device 34 is installed immediately downstream of the nip roller 32 and electrostatically adsorbed immediately after the two webs are overlapped, the air intervening between the webs becomes a small mass before the two masses remain between the two webs. This is because the effect of becoming more difficult to stay is obtained.
[0024]
FIG. 5 is a side view showing the main part of the second embodiment of the present invention. That is, a flat roller 82 having a smooth surface is provided below the charging electrode 90 described in the basic configuration, and the overlapping web is conveyed while being pressed against the flat roller 82 when the charging device charges the overlapping web. I did it. In order to press the overlapping web against the flat roller 82, as shown in FIG. 5, the contact angle θ of the web contacting the upper surface of the flat roller 82 is 2-30 with respect to the horizontal tangent on the upper surface of the flat roller 82. It is preferable to adjust the degree.
[0025]
According to the second embodiment configured as described above, the air mass 50 interposed between the overlapped metal web 10 and the interleaf web 20 is caused by the tension of the interleaf web 20 on the flat roller 82. Thus, the feed roller 36 is crushed to a size that does not stagnate. In this state, the interleaf paper web 20 is charged and adsorbed to the metal web 10, so that a lump of air is fixed between both webs with a fine size and passes through the feed roller 36 without stagnation. Therefore, the interleaf paper web 20 does not form a fold. The contact angle θ is set to 2 to 30 degrees when the contact angle θ is 2 degrees or less so that the tension of the interleaf paper web 20 is too weak so that the air mass 50 does not stagnate with the feed roller 36. This is because when the contact angle θ is 30 degrees or more, the tension of the metal web 10 increases and the metal web 10 is damaged.
[0026]
FIG. 6 is a side view showing the main part of the third embodiment of the present invention. In other words, a single flat roller 84 is provided on the interleaf web side instead of the nip roller 32 as the overlapping device described in the basic configuration. The metal web and the interleaf paper web were overlapped by sandwiching the interleaf paper 20 between the flat roller 84 and the metal web 10 brought into pressure contact with the flat roller 84. In order to press the metal web 10 against the flat roller 84, the contact angle γ of the metal web contacting the lower surface of the flat roller 84 is 10 degrees with respect to the horizontal tangent on the lower surface of the flat roller 84 as shown in FIG. It is preferable to make it above.
[0027]
According to the third embodiment configured as described above, the interleaf paper 20 is superimposed on the metal web 10 while being sandwiched between the metal web 10 and the flat roller 84 by the metal web 10. When the contact angle γ of the metal web increases, the area where the pressure acts on the metal web 10 toward the center of the flat roller 84 increases, and the force for sandwiching the interleaf paper 20 increases, so that it is difficult for air to intervene between both webs. Become. Therefore, it is possible to prevent the generation of the air lump 50 that stagnates at the feed roller 36, and the interleaf paper web 20 does not fold.
[0028]
FIG. 7 is a side view showing the main part of the fourth embodiment of the present invention. In other words, a flat roller 86 having a smooth surface is arranged between the charging electrode 90 and the nip roller 32 described in the basic configuration, and charging is performed after the overlapping webs are handled by the flat roller 86.
[0029]
According to the fourth embodiment configured as described above, the overlapped metal web 10 and the interleaf paper web 20 are handled and adhered by the flat roller 86, and the air mass 50 interposed between the two webs is flat. It is driven out of the web by the roller 86 and disappears. And since it charges in the state where air does not intervene between both webs, stable charge can be performed. Therefore, the interleaf paper web 20 does not fold at the feed roller 36 portion.
[0030]
FIG. 8 is a side view showing the main part of the fifth embodiment of the present invention, and FIG. 9 is a top view of the grooved roller in the fifth embodiment. At the front stage of the feed roller 36, a grooved roller 88 having a spiral groove from the center toward the side is provided on the surface, and the grooved roller 88 causes the interleaf web 10 side surface of the overlapped web from the center to the side. This is an example in which a grooved roller 88 is provided between the charging electrode 90 and the nip roller 32.
[0031]
According to the fifth embodiment configured as described above, the air mass 50 interposed between the overlapped webs is efficiently driven out of the web by the spiral groove of the grooved roller 88. It disappears. Therefore, the interleaf paper web 20 does not fold at the feed roller 36 portion.
FIG. 10 is a top view showing the main part of the sixth embodiment of the present invention. That is, the shape of the charging electrode 90 of the charging device 34 described in the basic configuration is a V-shape as shown in FIG.
[0032]
According to the sixth embodiment configured as described above, the superposed metal web 10 and interleaf web 20 are charged and adsorbed from the center toward the side in accordance with the shape of the charging electrode 90. As a result, the air mass 50 interposed between the two webs gradually moves outward, and is expelled from the overlapped web and disappears. Therefore, the interleaf paper web 20 does not fold at the feed roller 36 portion.
[0033]
The six embodiments described above are effective in preventing the folding of the interleaf paper web 20 at the feed roller 36 part, but a higher effect is obtained by combining a plurality of embodiments. be able to.
[0034]
【The invention's effect】
As described above, according to the web adsorbing method and apparatus of the present invention, the air mass generated when the metal web and the interleaf web are overlapped is not driven out between the two webs or does not move between the two webs. By preventing the air from entering between the two webs when they are fixed or overlapped, it is possible to suppress the folding of the interleaf paper web, and thus prevent the occurrence of product defects.
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram of a web cutting device to which the present invention is applied. FIG. 2 is a configuration diagram of a charging device applied to the web cutting device shown in FIG. 1. FIG. FIG. 4 is an explanatory diagram for explaining an aspect of an air mass in the first embodiment of the present invention. FIG. 5 is a side view showing a main part of the second embodiment of the present invention. FIG. 6 is a side view showing the main part of the third embodiment of the present invention. FIG. 7 is a side view showing the main part of the fourth embodiment of the present invention. FIG. 9 is a side view showing the main part of the embodiment of the present invention. FIG. 9 is a top view of the grooved roller in the fifth embodiment of the invention. FIG. 10 is an upper view showing the main part of the sixth embodiment of the invention. Figure [Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Metal web 20 ... Interleaf web 32 ... Nip roller 34 ... Charging device 36 ... Feed roller 50 ... Air lump 90 ... Charging electrode

Claims (2)

The metal web and the slip sheet web are sandwiched and transported by a pair of transport rollers, and the metal web and the slip sheet are charged by a charging unit on the upstream side of the transport roller. In the web adsorption device that adsorbs the web with electrostatic adsorption force,
When a flat roller having a smooth surface is provided below the charging unit, and the charging unit is charged on the overlapping web, the contact angle is 2 to 30 degrees with respect to a horizontal tangent on the upper surface of the flat roller. The web adsorbing device, wherein the overlapped web is conveyed in pressure contact with the flat roller. The overlapping web in which the metal web and the slip sheet web are overlapped is transported by being sandwiched by a pair of transport rollers, and the transporting of the metal web and the slip sheet web is performed by charging the overlapping web with a charging unit. In the web adsorption method,
The superposition of the metal web and the slip sheet web is performed by sandwiching the slip sheet web between a flat roller having a smooth surface and the metal web pressed and conveyed to the flat roller. A characteristic web adsorption method.

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