JP2019093605A - Regeneration method and regeneration device of blanket for newspaper offset printing - Google Patents

Abstract

To regenerate a used blanket for newspaper offset printing thickness of which is reduced by use, and extend a life.SOLUTION: A mounting thickness when a liquid resin is applied to a rear face of a used blanket for newspaper offset printing and the blanket for newspaper offset printing is mounted on a blanket cylinder is equal to a mounting thickness of the used blanket for newspaper offset printing when it is brand-new.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and an apparatus for regenerating a newspaper offset printing blanket for regenerating a used newspaper offset printing blanket. In the present specification, "newsprint offset printing blanket" is also referred to simply as "blanket".

  In an offset printing press (a rotary press) for printing newspapers and the like, printing is usually performed by sandwiching a sheet between two blanket cylinders wound and attached with a blanket and applying printing pressure. At this time, the interval between the two blanket cylinders is set so as to obtain an appropriate printing circumferential length when an appropriate printing pressure is applied to the blanket cylinders.

  However, since the blanket has a structure in which a rubber layer (resin layer) is laminated on a sheet-like substrate (cloth layer) (see, for example, Patent Document 1), it is particularly fragile on the substrate (cloth layer) by printing pressure during use. Occurs and the thickness decreases. If the reduction in thickness exceeds a predetermined limit, a proper printing pressure will not be applied at the time of printing, and it is necessary to replace it with a new blanket.

  Conventionally, there has been a method of affixing a backing sheet (resin sheet) to the back of the blanket to increase the thickness (see, for example, Patent Document 2), but it is not easy to affix thin sheets uniformly on the entire surface The In addition, the resin sheet is apt to be creased because it is bent when attached to a blanket cylinder when attached in a flat surface, and even if attached in a bent state, the resin sheet is stretched to a flat surface during storage or wrinkled for storage with a smaller curvature. It was happening. on the other hand. Although the woven fabric is unlikely to be creased even if it is bent and stretched after pasting, there has been a problem that it is difficult to produce a thin woven fabric having a uniform thickness.

  Furthermore, in a commercial offset rotary press (which is also rarely carried out by a newspaper offset rotary press), when the thickness of the blanket becomes thinner, the sheet is attached to the blanket cylinder side instead of the back side of the blanket to increase the thickness. Although there are cases in which work to make printing pressure easy to apply is also performed, there is a problem that the work becomes complicated.

JP, 2015-171779, A JP, 2011-83985, A

  The problem to be solved by the present invention is to provide a method and an apparatus for regenerating a newspaper offset printing blanket capable of regenerating a used newspaper offset printing blanket whose thickness has been reduced by use to extend the life. .

According to one aspect of the present invention, the following newspaper offset printing blanket recycling method is provided.
“A method of recycling a newspaper offset printing blanket that reproduces a used newspaper offset printing blanket,
Apply a one-component RTV silicone resin that is a liquid resin with a viscosity of 50 Pa · s or less and a hardness after curing of 30 or less with a durometer A on the back of a newspaper offset printing blanket that has been used A method for recycling a newspaper offset printing blanket, wherein the mounting thickness when the blanket is mounted on the blanket cylinder is equal to the mounting thickness of the used newspaper offset printing blanket at the time of new product. "

According to another aspect of the present invention, there is provided a reproduction device for the following newspaper offset printing blanket.
"It is a reproduction device for a newspaper offset printing blanket that reproduces a used newspaper offset printing blanket,
Blanket mounting means having a suction table for mounting and suction-holding the surface of a used newspaper offset printing blanket;
A gantry-type orthogonal robot disposed above the blanket mounting means;
Liquid resin application means for applying liquid resin to the back surface of the used newspaper offset printing blanket provided on the gantry-type orthogonal robot and held by suction on the suction table;
Leveling means for leveling the liquid resin provided on the gantry-type orthogonal robot and applied to the back surface of the used newspaper offset printing blanket;
Securing means for securing a mounting member mounted at one longitudinal end of the used newspaper offset printing blanket to the blanket mounting means;
A fixing tension means for fixing a mounting member attached to the other end of the used newspaper offset printing blanket in the longitudinal direction to the blanket mounting means and applying tension in the longitudinal direction;
Reproduction device for a newspaper offset printing blanket comprising: "

  Here, in the present invention, “mounting thickness” is used as a reference for the thickness of the blanket. The attachment thickness is the thickness when the blanket is attached to the blanket cylinder. Since the blanket is mounted by being wound around the blanket cylinder while applying tension, the mounting thickness is smaller than the initial thickness before mounting, but since the actual printing thickness is the mounting thickness, the present invention is based on the mounting thickness And

According to the recycling method of the present invention, since the thickness of the used blanket is regenerated to be equal to the thickness of the new blanket, when the recycled blanket is used in an offset printing machine, it is as good as in the new blanket. Printing, and as a result, the life of the blanket can be extended. That is, in the present invention, the technical significance of "making the thickness equal to the mounting thickness at the time of the new product" is that when the recycled blanket is used in the offset printing machine, good printing can be performed as in the case of the new product. In this respect, "to make it equal to the mounting thickness at the time of new product" should not be interpreted strictly, and the above-mentioned technical significance including the error of the mounting thickness (slight fluctuation) "To be substantially (approximately) equal to the mounting thickness at the time of new product" to the extent that can be achieved.
Further, according to the reproduction apparatus of the present invention, the above-described reproduction method of the present invention can be implemented easily and reliably.

FIG. 1 is a plan view showing an embodiment of a reproduction apparatus of the present invention. The front view which expands and shows the fixing means in the reproducing | regenerating apparatus of FIG. The fixed tension means in the reproducing | regenerating apparatus of FIG. 1 is expanded and shown, (a) is a top view, (b) is a front view.

  The structure itself of the blanket to be regenerated in the present invention is the same as the conventional one, having a structure in which a rubber layer (resin layer) is laminated on a sheet-like substrate. And at the time of reproduction | regeneration, liquid resin is uniformly apply | coated to the back surface (back surface of a sheet-like base material) of the used blanket. At this time, select and adjust the material, thickness (coating amount), etc. of the liquid resin so that the mounting thickness of the used blanket coated with the liquid resin is equal to the mounting thickness at the time of the new used blanket. Do.

  Examples of usable liquid resins include epoxy resins, urethane resins, silicone resins, etc. In the regeneration method of the present invention, the one-pack type having good workability, low viscosity, and uniformity by leveling after coating That it is easy to become thick, it is difficult for the back surface (base material (cloth layer)) of the blanket that is the coated surface to penetrate, and that the hardness after curing is apt to absorb local changes in thickness. From the conditions such as this, a one-part RTV (room temperature vulcanization) silicone resin which is a liquid resin having a viscosity of 50 Pa · s or less and a hardness after curing of durometer A of 30 or less is used.

  After printing is completed, the blanket surface is cleaned to remove the deposited ink and paper dust, but the cleaning solution enters the back surface from the end face of the blanket and penetrates the back surface of the blanket, causing the substrate on the back surface of the blanket to swell or There is a risk of deterioration. At the time of blanket regeneration, liquid resin with waterproof / oilproof function, such as RTV silicone resin mentioned above, is applied to the entire surface of the blanket back surface that contacts the blanket cylinder surface to prevent penetration of cleaning solution into the blanket back surface. be able to.

Next, one embodiment of the reproducing apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view showing an embodiment of the reproducing apparatus of the present invention. The reproduction apparatus shown in FIG. 1 includes a blanket placement unit 10, a gantry type orthogonal robot 20, a liquid resin application unit 30, a leveling unit 40, a fixing unit 50, and a fixing tension unit 60.

  The blanket mounting means 10 has a suction table 11 on which the surface of the blanket is placed and held by suction. In this embodiment, the suction table 11 has a plurality of suction holes 11 a for vacuum-sucking the surface of the blanket. The diameter (pore diameter) of each suction hole 11a should be 0.5 mm or more and 3 mm or less from the viewpoint of preventing large deformation at the time of vacuum suction on the surface (rubber layer) of the blanket in contact with the paper surface at the time of printing. Preferably, 1 mm or more and 2 mm or less are more preferable. In addition, it is preferable that the respective suction holes 11 a be evenly arranged on the suction table 11.

  The gantry type orthogonal robot 20 is disposed above the blanket mounting means 10. In this embodiment, the gantry-type orthogonal robot 20 has two X-direction beams 21 and one Y-direction beam 22, and the Y-direction beams 22 can move in the X-direction along the X-direction beams 21.

The liquid resin application means 30 is provided in the gantry type orthogonal robot 20. In this embodiment, the liquid resin coating unit 30 is provided on the Y-direction beam 22 side of the gantry-type orthogonal robot 20 and is movable in the Y-direction along the Y-direction beam 22. As a result, the liquid resin coating unit 30 is freely movable in the XY direction (orthogonal direction) above the blanket mounting unit 10.
In this embodiment, the liquid resin application means 30 applies the liquid resin in a straight line with a nozzle that discharges a predetermined amount of liquid resin, but the liquid resin application means 30 applies a wider surface using a spray. It is also possible to adopt a method of applying using a roller or a brush.

The leveling means 40 is provided to the gantry type orthogonal robot 20. In this embodiment, the liquid resin coating means 30 is provided on the Y-direction beam 22 side of the gantry-type orthogonal robot 20 and is movable in the X-direction along the X-direction beam 21 together with the Y-direction beam 22.
In this embodiment, the leveling means 40 is configured to level the liquid resin applied to the back surface of the blanket using a leveling blade which is movable in the vertical direction. However, the leveling means 40 can also be a method of leveling the liquid resin applied on the back surface of the blanket using a roller, a brush or the like.

  The fixing means 50 fixes the mounting member B1 attached to one end of the blanket B in the longitudinal direction to the blanket mounting means 10 (the suction table 11). In this embodiment, the fixing means 50 is a toggle clamp system as shown in FIG. 2, and the mounting member B1 is placed on a blanket with the one end of the mounting member B1 abutting against the step 11b of the end of the suction table 11. It fixes with respect to the placement means 10 (suction table 11). However, the fixing means 50 may be a system other than the toggle clamp system. In short, it is sufficient that the mounting member B1 can be fixed to the blanket mounting means 10 (the suction table 11). The shape of the mounting member B1 may be different from that of FIG. 2, but in this case, the fixing means 50 may be appropriately changed in design according to the shape of the mounting member B1.

The fixing tension means 60 fixes the mounting member B2 attached to the other end in the longitudinal direction of the blanket B to the blanket mounting means 10 and applies tension in the longitudinal direction of the blanket. In this embodiment, the fixing tension means 60 is a toggle clamp method having an elastic body (coil spring) 61 as shown in FIG. 3, and the mounting member B2 is placed on the blanket by hooking the clamp 62 onto the mounting member B2 and pulling it. It fixes with respect to the means 10 (suction table 11). At this time, since the mounting member B1 mounted at one end of the blanket in the longitudinal direction is fixed to the blanket mounting means 10 (the suction table 11), the elastic force of the elastic body 61 of the fixing tension means 60 The blanket is tensioned in the longitudinal direction.
The fixed tension means 60 may be a system other than the toggle clamp system having an elastic body (coil spring) 61 as shown in FIG. 3, or may be a toggle clamp system having no elastic body. It is preferable that the fixing tension means have an elastic body in order to appropriately fix and apply tension to the mounting member B2 while absorbing manufacturing errors in the longitudinal length of the blanket.
The shape of the mounting member B2 may be different from that of FIG. 3, but in this case, the fixing tension means 60 may be appropriately changed in design according to the shape of the mounting member B2.

  Thus, the mounting member B1 mounted on one end of the blanket in the longitudinal direction is fixed to the blanket mounting means 10 (suction table 11), and the mounting member B2 mounted on the other end of the blanket in the longitudinal direction is blanketed By fixing to the mounting means 10 (the suction table 11) and applying tension in the longitudinal direction of the blanket, it is possible to prevent the floating of the bent and curved portion when the blanket is attached to the blanket cylinder. .

Next, a method of regenerating the blanket by the regenerating apparatus of this embodiment will be described.
First, with the surface of the blanket facing downward on the suction table 11 of the blanket mounting means 10, the both ends to which the attachment members B1 and B2 are attached are arranged so as to match the both ends of the suction table 11 in the longitudinal direction. Then, the mounting member B1 on one end side is fixed to the step 11b at the end of the suction table 11 by the fixing means 50 of the clamp method (see FIG. 2), and the mounting member B2 on the other end side is an elastic body (coil spring) 61 The mounting member B2 is hooked and fixed by a clamp type fixed tension means 60, and tension is applied in the longitudinal direction of the blanket. Thereafter, the surface of the blanket is held by suction on the suction table 11.

Subsequently, the liquid resin coating unit 30 is moved to a fixed distance from one end side in the longitudinal direction of the blanket so that the specified coating amount per fixed area is linearly formed in the direction (width direction) perpendicular to the longitudinal direction. Apply liquid resin. Furthermore, application is repeated at a position moved in the longitudinal direction according to the previous application amount so that the target thickness is achieved over the entire application area, and liquid resin is applied linearly at equal intervals over the entire application area.
Here, the total coating amount of the liquid resin is based on the penetration amount of the liquid resin to the back surface (cloth layer) of the used blanket and the data of the shrinkage amount or expansion amount at the time of curing of the liquid resin. The mounting thickness when the recycled blanket is mounted on the blanket cylinder is set to be equal to the mounting thickness of the used blanket when it is new. That is, the data of the above-mentioned amount of penetration, and the amount of contraction or expansion are acquired beforehand by a preliminary test, and the total application amount of liquid resin is set based on these data.

When application of the liquid resin by the liquid resin application means 30 is completed, from the surface of the blanket so that the total thickness of the blanket after regeneration is the desired thickness specified and uniform thickness over the entire surface of the liquid resin application region of the blanket. It is naturally cured after being leveled by leveling means 40 (leveling blade) set to have a constant height. The height of the leveling blade is determined in consideration of the volume change (the data of the amount of contraction or the amount of expansion described above) after curing of the liquid resin.
The used blanket is regenerated by the above.

  As a used blanket, the mounting thickness at the time of a new article was 2.03 mm in average value (the initial thickness before mounting was 2.09 mm), and the result was that printing was continued by mounting on the blanket cylinder and printing pressure A blanket in which the mounting thickness was reduced to 2.00 mm on average due to the occurrence of sagging was regenerated using the regenerator of FIG. Note that the time of occurrence of the occurrence of the blanket setting may vary depending on the degree of printing pressure, the number of copies, and the like.

  Specifically, the used blanket is removed from the blanket cylinder, and the hardness after curing is not less than 50 Pa · s and the durometer A so that the total thickness including the blanket on the back side is 2.05 mm. The liquid resin of RTV silicone resin of not more than 30 was applied and regenerated by the regenerator of FIG. As a result of winding and mounting this regenerated blanket on the blanket cylinder of a newspaper offset printing press, the mounting thickness became equal to the mounting thickness at the time of new article. When this recycled blanket was used in a newspaper offset printing press, good printing could be performed as well as when it was new.

DESCRIPTION OF SYMBOLS 10 Blanket mounting means 11 Suction table 11a Suction hole 20 Gantry type orthogonal robot 21 X direction beam 22 Y direction beam 30 Liquid resin application means 40 Leveling means 50 Fixing means 60 Fixed tension means 61 Elastic body 62 Clamp

Claims (6)

A method for reclaiming a newspaper offset printing blanket that reclaims a used newspaper offset printing blanket, comprising:
Apply a one-component RTV silicone resin that is a liquid resin with a viscosity of 50 Pa · s or less and a hardness after curing of 30 or less with a durometer A on the back of a newspaper offset printing blanket that has been used A method for recycling a newspaper offset printing blanket, wherein the mounting thickness when the blanket is mounted on the blanket cylinder is equal to the mounting thickness of the used newspaper offset printing blanket at the time of new product.   The method for regenerating a newspaper offset printing blanket according to claim 1, wherein the RTV silicone resin is applied to the entire surface of the back surface of the used newspaper offset printing blanket in contact with the blanket cylinder surface. A newspaper offset printing blanket reproducing apparatus for reclaiming a used newspaper offset printing blanket, comprising:
Blanket mounting means having a suction table for mounting and suction-holding the surface of a used newspaper offset printing blanket;
A gantry-type orthogonal robot disposed above the blanket mounting means;
Liquid resin application means for applying liquid resin to the back surface of the used newspaper offset printing blanket provided on the gantry-type orthogonal robot and held by suction on the suction table;
Leveling means for leveling the liquid resin provided on the gantry-type orthogonal robot and applied to the back surface of the used newspaper offset printing blanket;
Securing means for securing a mounting member mounted at one longitudinal end of the used newspaper offset printing blanket to the blanket mounting means;
A fixing tension means for fixing a mounting member attached to the other end of the used newspaper offset printing blanket in the longitudinal direction to the blanket mounting means and applying tension in the longitudinal direction;
Reproduction device for a newspaper offset printing blanket comprising:   The liquid resin application means blankets the newspaper offset printing blanket based on the amount of immersion of the liquid resin into the used newspaper offset printing blanket and the data of shrinkage amount or expansion amount at the time of curing of the liquid resin. The newspaper offset printing blanket according to claim 3, wherein the liquid resin is applied in an amount such that the mounting thickness when loaded on the cylinder is equal to the loading thickness when the used newspaper offset printing blanket is new. Playback device.   The said adsorption | suction table has multiple adsorption holes for vacuum-sucking the surface of the newspaper offset printing blanket which has been used, The diameter of each adsorption hole is 0.5 mm or more and 3 mm or less. Reproduction device for the newspaper offset printing blanket.   The newspaper offset printing blanket reproduction apparatus according to any one of claims 3 to 5, wherein the fixed tension means has an elastic body and applies the tension by the elastic force of the elastic body.

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