JP2004001561A - Plate cylinder and ink retaining member of stencil printing equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plate cylinder and an ink retaining member for a stencil printing equipment, which can effectively prevent offset from occurring. <P>SOLUTION: The outer surface of the plate cylinder 1, which has an outer peripheral surface with the ink retaining member 15 wound thereon by a master 27 made of only a thermoplastic resin film, of the stencil printing equipment has a surface roughness of 5 to 45 μm Rz. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a plate cylinder and an ink holding member used in a stencil printing machine.

Conventionally used stencil masters have a porous support made of a thin thermoplastic resin film (about 1-2 μm thick) made of Japanese paper fiber, synthetic fiber, or a mixture of Japanese paper fiber and synthetic fiber. It has a laminated structure. The surface of the thermoplastic resin film of the master was subjected to heat perforation plate making, and the plate was formed on a rotatable plate cylinder having an ink holding layer formed of a mesh screen or the like made of resin fibers or metal fibers on a porous support cylinder. The master is wound, ink is supplied from ink supply means provided inside the plate cylinder, and the printing paper is continuously pressed by pressing means such as a press roller. 2. Description of the Related Art Thermal digital stencil printing apparatuses that perform printing by exuding ink are well known.

Japanese Utility Model Publication No. 5-41026 JP-B-63-59393

Generally, in the above-described stencil printing machine, when the printing machine is left for a certain period of time or when printing is restarted after stopping printing, the problem of poor printing caused by evaporation of the ink is eliminated. To prevent this, oil-based inks and water-in-oil emulsion inks, which are difficult to evaporate, are used.

However, since this ink is difficult to dry, at the time of printing, the ink transferred to the printing paper penetrates into the printing paper and does not stain even when rubbed with a finger or the like. Need time.

In a stencil printing machine, printed printing paper is continuously discharged and stacked on a paper output tray.At this time, if the next printing paper is immediately loaded on the previous printing paper, the drying time of the ink is reduced. This causes a problem of so-called set-off, in which the image ink of the previous printing paper is short and adheres to the back surface of the next printing paper and becomes dirty. This set-off is likely to occur when printing an image with a large amount of ink transfer, particularly an image with a thick ink layer (high ink transfer height) when transferred to the printing paper surface.

Further, in the master or plate cylinder used in the conventional stencil printing machine, the opening diameter (gap) of the porous support or the ink holding layer is configured to be larger than the perforation diameter of the master, and the transfer is performed. The effect of preventing set-off by reducing the amount of ink to be performed could hardly be expected.

Also, in a conventional porous support or a mesh screen, there are many parts that flow out without changing the flow direction of the inflowing ink. In this part, the outflow amount of the ink becomes large, causing a set-off. There is a problem that it is.

The present invention provides a master, a plate cylinder of a stencil printing apparatus, and an ink holding member capable of effectively preventing set-off.

The invention according to claim 1 is a plate cylinder of a stencil printing machine having an ink holding member on an outer peripheral surface and winding a master made of only a thermoplastic resin film on the ink holding member, wherein the ink holding member is provided. Has a surface roughness of 5 to 45 μmRz.

The invention according to claim 2 is a plate cylinder of a stencil printing machine that has an ink holding member on an outer peripheral surface and winds a master on which a thermoplastic resin film and a porous support are bonded on the ink holding member. The sum of the surface roughness of the ink holding member on the side in contact with the porous support and the thickness of the porous support is 5 μm or more and 45 μm or less.

According to a third aspect of the present invention, in the plate cylinder of the stencil printing apparatus according to the first or second aspect, the ink holding member is made of two or more types of fibers having different fiber diameters. .

According to a fourth aspect of the present invention, in the plate cylinder of the stencil printing apparatus according to the first or second aspect, the ink holding member is configured such that a gap decreases toward an outer surface. Features.

According to a fifth aspect of the present invention, in the plate cylinder of the stencil printing apparatus according to any one of the first to fourth aspects, at least the surface of the ink holding member is made of metal. It is characterized.

According to a sixth aspect of the present invention, in the plate cylinder of the stencil printing apparatus according to any one of the first to fifth aspects, the ink holding member further includes an ink inlet side hole and an ink outlet side hole. The ink holding member has an ink passage through which the ink flowing from the ink inflow side hole deviates at least once from a perpendicular to the outer peripheral surface of the plate cylinder and then flows out of the ink outflow side hole. It is characterized by doing.

According to a seventh aspect of the present invention, there is provided an ink holding member constituting an outer peripheral surface of a plate cylinder, wherein the surface roughness is 5 to 45 μmRz.

According to an eighth aspect of the present invention, in the ink holding member according to the seventh aspect, the ink holding member further includes two or more types of fibers having different fiber diameters.

According to a ninth aspect of the present invention, in the ink holding member according to the seventh aspect, the gap is further reduced toward the outer surface.

According to a tenth aspect of the present invention, in the ink holding member according to any one of the seventh to ninth aspects, at least the surface thereof is made of a metal.

According to an eleventh aspect of the present invention, in the ink holding member according to any one of the seventh to tenth aspects, the ink holding member further has an ink inflow side hole and an ink outflow side hole. An ink passage flowing out of the ink outflow side hole after the ink flowing from the ink outflow side hole deviates at least once from a perpendicular to a surface having the opening of the ink outflow side hole.

According to a twelfth aspect of the present invention, there is provided a plate cylinder of a stencil printing machine having an ink holding member made of fiber on an outer peripheral surface, and a master made of only a thermoplastic resin film wound on the ink holding member. The fiber diameter of the outer surface of the ink holding member is 1 μm or more and 20 μm or less.

According to a thirteenth aspect of the present invention, in the plate cylinder of the stencil printing machine according to the twelfth aspect, the ink holding member is made of two or more types having different fiber diameters.

The invention according to claim 14 is a plate cylinder for a stencil printing machine in which a plurality of ink holding members made of fibers are provided on the outer peripheral surface, and a master made of only a thermoplastic resin film is wound on the ink holding members. Wherein the plurality of ink holding members are arranged such that a gap becomes smaller toward an outermost shell layer, and a fiber diameter of an outer surface of the ink holding member is 1 μm or more and 20 μm or less. I do.

The invention according to claim 15 is a plate of a stencil printing machine in which the outer peripheral surface has only one layer of an ink holding member made of fiber, and a master made of only a thermoplastic resin film is wound on the ink holding member. A cylinder, wherein the ink holding member is configured such that a gap becomes smaller toward an outer surface, and a fiber diameter of an outer surface of the ink holding member is 1 μm or more and 20 μm or less.

According to a sixteenth aspect of the present invention, in the plate cylinder of the stencil printing machine according to any one of the twelfth to fifteenth aspects, at least the surface of the ink holding member is made of metal. It is characterized by.

According to a seventeenth aspect of the present invention, in the plate cylinder of the stencil printing machine according to any one of the twelfth to sixteenth aspects, the ink holding member further includes an ink inlet side hole and an ink outlet side hole. And the ink holding member has an ink passage that flows out of the ink outflow side hole after the ink flowing from the ink inflow side hole deviates at least once from a perpendicular to the outer peripheral surface of the plate cylinder. It is characterized by having.

According to an eighteenth aspect of the present invention, there is provided an ink holding member comprising a fiber constituting an outer peripheral surface of a plate cylinder, wherein the outer surface has a fiber diameter of 1 μm or more and 20 μm or less.

The invention according to claim 19 is characterized in that, in the ink holding member according to claim 18, the ink holding member further comprises two or more types having different fiber diameters.

According to a twentieth aspect of the present invention, in the ink holding member according to the eighteenth aspect, the ink holding member is configured such that a gap becomes smaller toward an outer surface.

According to a twenty-first aspect of the present invention, in the ink holding member according to any one of the eighteenth to twentieth aspects, at least the surface thereof is made of metal.

According to a twenty-second aspect of the present invention, in the ink holding member according to any one of the eighteenth to twenty-first aspects, the ink holding member further includes a hole on an ink inflow side and a hole on an ink outflow side. An ink passage flowing out of the ink outflow side hole after the ink flowing from the ink outflow side hole deviates at least once from a perpendicular to a surface having the opening of the ink outflow side hole.

According to the first aspect of the present invention, the surface roughness of the ink holding member provided on the outer peripheral surface on the side in contact with the master made of only the thermoplastic resin film is 5 to 45 μmRz, preferably 5 to 35 μmRz, more preferably. By using a plate cylinder having a thickness of 5 to 25 μm Rz, the gap of the ink holding member above the perforated portion of the thermoplastic resin film is reduced, and the ink is pulled out from the ink holding member through the perforated portion. The amount of ink has been reduced. Thereby, the amount of ink drawn out from the inside of the ink holding member through the perforated portion of the thermoplastic resin film at the time of printing becomes an appropriate amount, the time required for permeation drying is reduced, and the master made of only the thermoplastic resin film is used. When printing is performed by using this method, occurrence of set-off can be prevented and a good image can be obtained.

According to the second aspect of the present invention, the sum of the surface roughness of the ink holding member provided on the outer peripheral surface and the thickness of the porous support on the side in contact with the porous support is 5 μm or more and 45 μm or less, preferably By using a plate cylinder having a size of 5 μm or more and 35 μm or less, more preferably 5 μm or more and 25 μm or less, the amount of ink drawn out from the inside of the ink holding member and the porous support through the perforated portion of the thermoplastic resin film during printing. Is an appropriate amount, the time required for penetration drying is reduced, and when printing is performed using a master having a porous support, set-off can be prevented and a good image can be obtained.

According to the third aspect of the present invention, by using a plate cylinder having an ink holding member in which two or more types of fibers having different fiber diameters are combined, the surface roughness of the ink holding member is filled by filling thick fibers with thin fibers. In printing, the amount of ink drawn out from the inside of the ink holding member or the ink holding member and the porous support through the perforated portion of the thermoplastic resin film becomes an appropriate amount, and The time required is shortened, and when printing is performed using a master made of only a thermoplastic resin film or a master having a porous support, occurrence of set-off can be prevented and a good image can be obtained. Further, by mixing thick fibers and thin fibers, the durability of the plate cylinder can be improved without increasing the cost.

According to the fourth aspect of the present invention, by using the plate cylinder having the ink holding member configured such that the gap becomes smaller toward the outer surface, it is possible to initially supply and supply the ink along the ink passage. By using a master consisting of only a thermoplastic resin film or a master having a porous support, diffusion can be performed well, the amount of ink drawn out can be optimized at the end, and the time required for osmotic drying can be shortened. When printing is performed, it is possible to prevent the occurrence of set-off and obtain a good image.

According to the fifth aspect of the present invention, by using a plate cylinder having an ink holding member having at least its surface made of metal, the ink holding member having its surface made of metal having a high energy surface is Adhesive strength with ink is increased, making it difficult for ink to be pulled out from the inside of the ink holding member. In addition, the ink holding member is highly elastic, and the ink holding member is compressed when the pressing member presses to discharge ink. When the pressure is released, the ink holding member is restored, so that the ink is sucked back into the ink holding member, so that excess ink is prevented from being transferred to the printing paper, and the master made of only the thermoplastic resin film is used. Or, when printing using a master having a porous support, prevent the occurrence of set-off and obtain a good image. It can be. Further, since the strength of the ink holding member is high, there is little settling due to long-time use, and it is possible to prevent corrosion due to ink, and to provide a plate cylinder of a stencil printing machine which is durable and suitable for mass printing. can do.

According to the sixth aspect of the present invention, there is formed an ink passage in which the ink that has flowed in from the hole on the ink inflow side deviates at least once from a perpendicular to the outer peripheral surface of the plate cylinder and then flows out from the hole on the ink outflow side. By using the plate cylinder having the holding member, the amount of ink drawn out from the inside of the ink holding member becomes small, so that the ink transferred to the printing paper is permeated and dried in a short time, and the set-off is reduced.

According to the invention of claim 7, the surface roughness of the ink holding member is set to 5 to 45 μmRz, preferably 5 to 35 μmRz, more preferably 5 to 25 μmRz, so that the ink is Can be reduced, so that the amount of ink drawn out from the inside of the ink holding member at the time of printing becomes an appropriate amount, the time required for penetration drying becomes shorter, and the set-off It is possible to prevent the occurrence and to obtain a good image.

According to the eighth aspect of the present invention, by using an ink holding member in which two or more kinds of fibers having different fiber diameters are combined, the surface roughness of the ink holding member is reduced by filling thick fibers with thin fibers. During printing, the amount of ink drawn out from the inside of the ink holding member becomes an appropriate amount, so that the time required for osmotic drying can be shortened, and the occurrence of set-off can be prevented, and a good image can be obtained. In addition, by mixing thick fibers and thin fibers, the durability of the ink holding member can be improved without increasing the cost.

According to the ninth aspect of the present invention, by using the ink holding member configured so that the gap becomes smaller toward the outer surface, the supply and diffusion of the ink can be improved at first along the ink passage. At the end, the amount of ink to be drawn out can be optimized, and the time required for penetrating and drying at the time of printing can be shortened, so that set-off can be prevented and a good image can be obtained.

According to the tenth aspect of the present invention, by using the ink holding member having at least its surface made of metal, the ink holding member having its surface made of metal having a high energy surface has an adhesive force with ink. And the ink is difficult to be pulled out from the inside of the ink holding member, and the ink holding member is highly elastic and the ink holding member is compressed to discharge the ink when pressurized by the pressing member, and the pressure is released. Occasionally, when the ink holding member is restored, the ink is sucked back into the ink holding member, so that the excess ink is prevented from being transferred to the printing paper during printing, and the occurrence of set-off is prevented and a good image is formed. Can be obtained. Furthermore, since the strength is high, there is little settling due to long-time use, and corrosion due to ink can be prevented, and an ink holding member having good durability and suitable for mass printing can be provided.

According to the eleventh aspect of the present invention, the ink flowing from the ink inflow-side hole is at least once deviated from the perpendicular to the surface having the ink-outflow-side hole opening, and then flows out of the ink outflow-side hole. By using the ink holding member formed with the ink, the amount of ink drawn out from the inside of the ink holding member becomes small, so that the ink transferred to the printing paper during printing is permeated and dried in a short time, and set-off is reduced. .

According to the twelfth aspect of the present invention, the fiber diameter of the ink holding member provided on the outer peripheral surface on the side in contact with the master made of only the thermoplastic resin film is 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably. By using a plate cylinder having a size of 1 μm or more and 8 μm or less, the gap of the ink holding member above the perforated portion of the thermoplastic resin film and in which ink is present is reduced, and is drawn out of the ink holding member through the perforated portion. The amount of ink has been reduced. Thereby, the amount of ink drawn out from the inside of the ink holding member through the perforated portion of the thermoplastic resin film at the time of printing becomes an appropriate amount, the time required for permeation drying is reduced, and the master made of only the thermoplastic resin film is used. When printing is performed by using this method, occurrence of set-off can be prevented and a good image can be obtained.

According to the invention as set forth in claim 13, by using a plate cylinder having an ink holding member in which two or more kinds of fibers having different fiber diameters are combined, the surface roughness of the ink holding member is filled by filling thick fibers with thin fibers. The amount of ink drawn out from the inside of the ink holding member through the perforated portion of the thermoplastic resin film at the time of printing becomes an appropriate amount, the time required for permeation drying is shortened, and the thermoplastic resin film When printing is performed using a master including only the master, it is possible to prevent occurrence of set-off and obtain a good image. Further, by mixing thick fibers and thin fibers, the durability of the plate cylinder can be improved without increasing the cost.

According to the fourteenth aspect of the present invention, by using a plate cylinder having a plurality of layers of ink holding members arranged such that the gap becomes smaller as going from the plate cylinder side to the master side, firstly along the ink passage. By supplying and diffusing the ink satisfactorily and further adjusting the fiber diameter of the outer surface of the ink holding member to 1 μm to 20 μm, preferably 1 μm to 15 μm, more preferably 1 μm to 8 μm, the thermoplastic resin film The gap of the ink holding member above the perforated portion where the ink is present is reduced, and the amount of ink drawn from the ink holding member through the perforated portion is reduced. As a result, the amount of ink drawn out can be optimized at the end, and the time required for the penetrating drying can be shortened, so that when printing is performed using a master made of only a thermoplastic resin film, set-off occurs. In addition, a good image can be obtained.

According to the invention as set forth in claim 15, a plurality of layers of ink holding members are used by using a plate cylinder having only one ink holding member configured such that the gap becomes smaller from the plate cylinder side toward the master side. Can prevent the occurrence of printing defects due to the displacement between the ink holding members during printing or the like, which occurs when printing is performed, and at the beginning, improve the supply and diffusion of ink along the ink path. Further, by making the fiber diameter of the outer surface of the ink holding member 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less, the ink above the perforated portion of the thermoplastic resin film The gap of the ink holding member in which is present is reduced, and the amount of ink drawn from the ink holding member through the perforated portion is reduced. As a result, the amount of ink to be drawn out at the end can be optimized and the time required for immersion drying can be shortened. Therefore, when printing is performed using a master made of only a thermoplastic resin film, occurrence of set-off can be prevented. And a good image can be obtained.

According to the sixteenth aspect of the present invention, by using a plate cylinder having an ink holding member having at least the surface thereof made of metal, the ink holding member having the surface made of metal having a high energy surface can be made of ink. And the ink is hardly pulled out from the inside of the ink holding member, and the ink holding member is highly elastic. When the ink is released, the ink holding member is restored, so that the ink is sucked back into the ink holding member, so that the transfer of excess ink to the printing paper is prevented, and a master made of only a thermoplastic resin film is used. When printing is performed, it is possible to prevent the occurrence of set-off and obtain a good image. Furthermore, since the strength of the ink holding member is high, there is little settling due to long-term use, and it is possible to prevent corrosion due to ink, and to provide a plate cylinder of a stencil printing machine which is durable and suitable for mass printing. it can.

According to the seventeenth aspect of the present invention, there is provided an ink holding device in which the ink flowing from the hole on the ink inflow side is displaced at least once from the perpendicular to the outer peripheral surface of the plate cylinder and then flows out of the hole on the ink outflow side. By using the plate cylinder having the member, the amount of ink drawn out from the inside of the ink holding member becomes small, so that the ink transferred to the printing paper is permeated and dried in a short time, and the set-off is reduced.

According to the invention of claim 18, by setting the fiber diameter of the ink holding member to 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less, The gap of the ink holding member where ink is present can be reduced, so that the amount of ink drawn out from the inside of the ink holding member at the time of printing becomes an appropriate amount, the time required for osmotic drying is reduced, and set-off occurs. And a good image can be obtained.

According to the nineteenth aspect, by using an ink holding member in which two or more kinds of fibers having different fiber diameters are combined, the surface roughness of the ink holding member is reduced by filling the space between the thick fibers with the thin fibers. The amount of ink drawn out from the inside of the ink holding member at the time of printing becomes an appropriate amount, the time required for the penetration drying is reduced, and the occurrence of set-off can be prevented and a good image can be obtained. In addition, by mixing thick fibers and thin fibers, the durability of the ink holding member can be improved without increasing the cost.

According to the twentieth aspect of the present invention, by using the ink holding member configured so that the gap becomes smaller toward the outer surface, the supply and diffusion of the ink can be improved at first along the ink passage. At the final stage, the amount of ink to be drawn out can be optimized, and the time required for permeation drying during printing can be shortened, thereby preventing occurrence of set-off and obtaining a good image.

According to the twenty-first aspect, by using the ink holding member whose surface is made of metal at least, the ink holding member whose surface is made of metal which is a high-energy surface has an adhesive force with ink. And the ink is difficult to be pulled out from the inside of the ink holding member, and the ink holding member is highly elastic and the ink holding member is compressed to discharge the ink when pressurized by the pressing member, and the pressure is released. Occasionally, when the ink holding member is restored, the ink is sucked back into the ink holding member, so that the excess ink is prevented from being transferred to the printing paper during printing, and the occurrence of set-off is prevented and a good image is formed. Can be obtained. Furthermore, since the strength is high, there is little settling due to long-time use, and corrosion due to ink can be prevented, and an ink holding member having good durability and suitable for mass printing can be provided.

According to the twenty-second aspect of the present invention, the ink passage flowing out of the ink outflow side hole after the ink flowing from the ink inflow side hole deviates at least once from a perpendicular to a surface having the opening of the ink outflow side hole. By using the formed ink holding member, the amount of ink drawn out from the inside of the ink holding member becomes small, so that the ink transferred to the printing paper during printing is permeated and dried in a short time, and the set-off is reduced.

FIG. 1 shows a main part of a stencil printing machine used in the first embodiment of the present invention. In FIG. 1, a plate cylinder 1 rotatably supported and rotationally driven by a plate cylinder driving means (not shown) has an ink pipe 2, an ink roller 3, and a doctor roller 4 therein.

As shown in FIG. 2, the plate cylinder 1 is composed of a porous support plate 1b having an opening 1a, and an ink holding layer 15 wound on the outer surface of the porous support plate 1b. The ink holding layer 15 is formed of a mesh screen formed by meshing synthetic resin fibers such as Tetron (trade name) or nylon or stainless steel fibers in a mesh shape, has an ink passage for passing ink, and has an ink passage. It works like diffusion, retention, and extrusion. The ink holding layer 15 may be provided with a plurality of layers, may be provided with only one layer, or may not be provided.

An ink pipe 2 also serving as a support shaft of the plate cylinder 1 is fixed to a casing side plate (not shown), and a plurality of small holes for supplying ink to the inside of the plate cylinder 1 are formed on the surface thereof. . The ink pipe 2 supplies ink pumped by a pump (not shown) from inside an ink pack (not shown) provided outside the plate cylinder 1 to the inside of the plate cylinder 1.

イ ン キ Below the ink pipe 2, an ink roller 3 and a doctor roller 4 are disposed. An ink roller 3 rotatably supported by a side plate (not shown) in the plate cylinder 1 is installed such that its outer peripheral surface is close to the inner peripheral surface of the plate cylinder 1, and the ink roller 3 supplies ink supplied from the ink pipe 2. It is supplied to the plate cylinder 1. The ink roller 3 is transmitted with a rotational force from a plate cylinder driving unit by a driving force transmitting unit such as a gear or a belt (not shown), and is rotated clockwise in FIG.

In the vicinity of the ink roller 3, a rotatable doctor roller 4 is provided. The doctor roller 4 is disposed so that a slight gap is formed between the outer peripheral surface of the doctor roller 4 and the outer peripheral surface of the ink roller 3, and forms a wedge-shaped ink reservoir 5 in the vicinity of the outer peripheral surface of the ink roller 3. are doing.
The ink supplied from the ink pipe 2 to the ink reservoir 5 passes through the gap between the ink roller 3 and the doctor roller 4 and is supplied to the surface of the ink roller 3 while forming a uniform layer.

A stage portion 6 extending in the axial direction is provided on the surface of the non-opening portion of the plate cylinder 1. A clamper 7 having a magnet pivotally attached to and detachable from the stage 6 is disposed on the stage 6 made of a magnetic material. The clamper 7 is rotated by opening / closing means (not shown). You.
A master roll 9 formed by winding a master 8 into a roll, a thermal head 10 and a platen roller 11, a master transport roller pair 12, a cutting unit 13, a master guide plate 14 And are arranged.

As shown in FIG. 3, the master 8 used in the first embodiment is an ink passage for allowing ink to pass through natural fibers such as Japanese paper fibers or synthetic resin fibers 8a such as Tetron (trade name) or nylon. And a thermoplastic resin film 8b, such as a polyester film, bonded together by bonding or the like. The porous support 8c is made of a porous thin paper made of natural fibers such as mulberry, mitsumata, manila hemp, flax, or the like, a nonwoven fabric made of synthetic resin fibers such as rayon, vinylon, fluororesin, polyester, or a combination of natural fibers and synthetic resin. It may be composed of a nonwoven fabric obtained by mixing fibers.

The porous support 8c preferably has a high density. For example, when the porous support 8c is made of a natural fiber or a synthetic resin fiber, the density is 0.1 to 0.6 g / cm ³ , more preferably 0.2 to 0 g / cm ³ . It is about 0.6 g / cm ³ . In the case where the porous support 8c is made of metal fibers, the density of stainless steel or iron is 0.7 to 3.0 g / cm ³ , more preferably 0.9 to 3.0 g / cm ³ . was 0 g / cm ³ or so, the density in the case of titanium 0.4~1.7g / cm ^3, more preferably 0.5~1.7g / cm ^3, the density in the case of aluminum 0.2 0.0 g / cm ³ , more preferably about 0.3 to 1.0 g / cm ³ .

The master roll 9 has its core 9a rotatably supported by holder means (not shown).
The thermal head 10 and the platen roller 11 are attached to a side plate of a stencil printing machine (not shown). The thermal head 10 having a large number of heating elements is urged to the platen roller 11 by urging means (not shown). The platen roller 11 is rotatably provided, and is driven to rotate clockwise in the figure by a stepping motor (not shown). The master 8 is pushed out of the master roll 9 by the rotation of the platen roller 11 while the thermoplastic resin film 8b is pressed by the thermal head 10 and the platen roller 11 is rotated by the thermal head 10 to make a plate by hot-melt perforation.

The master transport roller pair 12 is disposed downstream of the position where the thermal head 10 and the platen roller 11 are disposed in the master transport direction. The master transport roller pair 12 rotatably supported by a side plate of a stencil printing machine (not shown) is driven to rotate at a peripheral speed slightly higher than the peripheral speed of the platen roller 11 by a driving means (not shown). A torque limiter (not shown) is attached to the master transport roller pair 12 so that a preset tension acts on the master 8 transported between the platen roller 11 and the master transport roller pair 12 at a constant level. It is configured to

切断 A cutting means 13 including a movable blade 13a and a fixed blade 13b and a master guide plate 14 are disposed downstream of the position where the pair of master transport rollers 12 is disposed in the master transport direction. The cutting means 13 has a well-known configuration in which the movable blade 13a rotates or moves up and down with respect to the fixed blade 13b to cut the master 8. The master guide plate 14 is fixed to a side plate of a stencil printing machine (not shown) and guides the conveyed master 8.

プ レ ス A press roller 16 as a pressing means is disposed below the plate cylinder 1. The rotatably supported press roller 16 is selectively rocked by a rocking means (not shown) between a position where its outer peripheral surface is separated from the outer peripheral surface of the plate cylinder 1 and a position where it comes into contact with the outer peripheral surface of the plate cylinder 1. Is done.

レ ジ ス ト A registration roller pair 17 is provided on the right side of the press roller 16. The registration roller pair 17 picks up the leading edge of the printing paper 18 fed from paper feeding means (not shown), and synchronizes the printing paper 18 with the printing drum 1 in synchronization with the timing at which the press roller 16 contacts the printing drum 1. The paper is fed toward the space between the press roller 16. In place of the press roller 16, an impression cylinder having substantially the same diameter as the plate cylinder 1 may be provided.

The operation will be described below based on the above configuration.
When a document is set on a document reading unit (not shown) and a plate making start key (not shown) is pressed, the plate cylinder 1 is rotated, and a used master wound around the outer peripheral surface of the plate cylinder 1 is peeled off by a plate discharging device (not shown). The plate cylinder 1 is discarded, and stops at the plate feeding standby position where the clamper 7 is located almost directly above. When the rotation of the plate cylinder 1 is stopped, the opening / closing means (not shown) is operated to open the clamper 7, and the plate cylinder 1 enters a plate feeding standby state shown in FIG.

(4) When the plate discharging operation is completed, the plate making operation is performed subsequently. The read document image is converted into an electric signal by a CCD or the like of the document reading unit, and is sent as image data to a plate making control device via an A / D converter. The plate-making control device performs pulse-like energization on the heating elements of the thermal head 10 based on the sent image data, and the thermal head 10 performs hot-melt perforation on the thermoplastic resin film 8b of the master 8. . Prior to the operation of the thermal head 10, the platen roller 11 is driven to rotate by a stepping motor (not shown), and the master 8 is pulled out from the master roll 9.

The master 8 on which the plate making image is formed is transported to the clamper 7 by the master transport roller pair 12 while being guided by the master guide plate 14. When it is determined from the number of steps of the stepping motor for driving the platen roller 11 that the leading end of the master 8 has reached a predetermined position between the clamper 7 and the stage section 6, the opening / closing means (not shown) operates to operate the clamper 7. After rotating the counterclockwise direction and holding the leading end of the master 8 between the stage section 6 and the clamper 7, the plate cylinder 1 starts rotating clockwise at a peripheral speed substantially equal to the master transport speed. Of the plate cylinder 1 is started.

When it is determined from the number of steps of the stepping motor for driving the platen roller 11 that plate making for one plate has been completed, the rotating operations of the platen roller 11 and the master transport roller pair 12 are stopped, and the cutting means 13 8 is cut. The cut master 8 is pulled out by the rotation of the plate cylinder 1, and the winding operation is completed.

Subsequent to the winding operation, a plate attaching operation is performed.
The printing paper 18 fed from paper feeding means (not shown) enters the registration roller pair 17. The registration roller pair 17 moves the printing paper 18 between the plate cylinder 1 and the press roller 16 when the image area of the master 8 wound around the plate cylinder 1 rotating at a low speed reaches a position corresponding to the press roller 16. Feed between. The fed printing paper 18 is pressed by the press roller 16 against the master 8 wound around the plate cylinder 1. Due to this pressing operation, the press roller 16, the printing paper 18, the master 8, and the outer peripheral surface of the plate cylinder 1 are pressed against each other, and the ink supplied to the inner peripheral surface of the plate cylinder 1 by the ink roller 3 is moved to the opening 1 a. After oozing out of the open area of the ink holding layer 15 and filling the open area of the ink holding layer 15 and the void 8e of the porous support 8c constituting the master 8, it passes through the perforated portion of the thermoplastic resin film 8b. Is transferred to the printing paper 18.

The printing paper 18 to which the ink has been transferred is peeled off from the outer peripheral surface of the plate cylinder 1 by a peeling claw (not shown), and is discharged outside the machine by a paper discharging means (not shown) to complete the printing operation.

When the printing start key (not shown) is pressed after the completion of the printing operation, the printing paper 18 is continuously fed from a paper feeding means (not shown), and the printing drum 1 is rotated at a high speed to perform a printing operation.

When the printing paper 18 is peeled off from the surface of the plate cylinder 1 during the printing operation or the printing operation described above, as shown in FIGS. 4, 5 and 6, the ink on the surface of the master 8 and the printing paper 18 are removed. The ink 19 is drawn out from the perforated portion 8d of the thermoplastic resin film 8b due to the adhesive force with the ink. The amount of the ink 19 drawn out is related to the structure of the porous support 8c, and the unevenness of the surface of the porous support 8c. The larger the L (surface roughness), the thicker the ink layer in the gap 8e above the perforated portion 8d, and the greater the amount of ink drawn out, that is, the ink transfer height l.

As shown in FIG. 4 and FIG. 5, the larger the unevenness L on the surface, the larger the gap 8e above the perforated portion 8d where the ink is present, so that the gap between the porous support 8c and the perforated portion 8d is increased. A large amount of the ink 19 is drawn out. Therefore, as shown in FIG. 6, the smaller the fiber diameter of the synthetic resin fiber 8a, the smaller the unevenness L and the amount of ink drawn out (ink transfer height 1) are reduced. If it is performed too much, the amount of ink drawn out is too small to obtain a satisfactory image. Therefore, in the porous support 8c having a thickness of 100 μm and a density of 0.4 g / cm ³ , the unevenness L is adjusted by changing the fiber diameter of the synthetic resin fiber 8a, and printing is performed. did.

In the experiment, printing was performed using a digital stencil printing machine Preport VT3820 (manufactured by Ricoh Co., Ltd.), and the roughness L of the porous support 8c was measured using a surface roughness meter SEF-30D (manufactured by Kosaka Laboratories). (Surface roughness) was measured. The surface roughness was measured at a feed rate of 0.1 mm / sec and a measurement length of 0.8 mm using a head having a radius of 7 μm, and a ten-point average roughness in this range was determined. The unevenness L (surface roughness Rz) was calculated from the average. The measurement of the surface roughness is performed on the surface of the porous support 8c on the side in contact with the thermoplastic resin film 8b before the porous support 8c is bonded to the thermoplastic resin film 8b. The master 8 is obtained by applying a thin adhesive to the surface of the support 8c and bonding the thermoplastic resin film 8b. The measurement of the surface roughness is performed similarly in the second to sixth embodiments described later. The thickness of the thermoplastic resin film 8b is 1.5 μm. Table 1 shows the results of the experiment.

As is clear from Table 1, when the surface roughness is 45 μmRz or less, set-off is reduced as indicated by triangles in the table, and when the surface roughness is 35 μmRz or less, set-off is almost eliminated as indicated by circles in the table, When the value was 25 μmRz or less, the result that no set-off occurred as shown by the star in the table was obtained. It was also found that satisfactory images could not be obtained if the surface roughness was less than 5 μmRz.

Further, when the fiber diameter of the synthetic resin fiber 8a is set to 20 μm or less, set-off decreases as indicated by a triangle in the table, and when set to 15 μm or less, set-off hardly occurs as indicated by a circle in the table, and 8 μm or less As a result, no set-off occurred as shown by the star in the table. It was also found that a satisfactory image could not be obtained if the fiber diameter was less than 1 μm.

From the above, the porous support 8c is set to have a surface roughness of 5 to 45 μmRz, preferably 5 to 35 μmRz, more preferably 5 to 25 μmRz on the side in contact with the thermoplastic resin film 8b. The porous support 8c has a fiber diameter of 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less, on the surface in contact with the thermoplastic resin film 8b.

と Also, if the density of the porous support 8c is low, the voids 8e between the fibers become wide, and even if thin fibers or the like are used, the unevenness L becomes large, and the set-off becomes severe. Further, if the density is too high, the gap 8e between the fibers becomes narrow, and it becomes difficult for the ink to pass through at a portion where many fibers intersect, so that a white spot (fiber lump) is observed in the image, and a satisfactory image cannot be obtained. . Therefore, the relationship between the density of the porous support 8c and set-off was investigated.

As a result, when the porous support 8c is made of natural or synthetic resin fibers, the density is 0.1 g / cm ^{3 to} 0.6 g / cm ³ , more preferably 0.2 g / cm ³ to 0.6 g / cm ³ , which is made of metal-based fiber. The density of stainless steel or iron is 0.7 g / cm ^{3 to} 3.0 g / cm ³ , more preferably 0.9 g / cm ³ . cm ³ ~3.0g / cm ^3, the density in the case of titanium ^{0.4g / cm 3 ~1.7g / cm 3} , more preferably ^{0.5g / cm 3 ~1.7g / cm 3} , in the case of aluminum the density of ^{0.2g / cm 3 ~1.0g / cm 3} , more preferably became ^{0.3g / cm 3 ~1.0g / cm 3} .

From the above, the preferable density range Dw of the porous support 8c is represented by the following equation.
Dw = 0.09ρ-0.38ρ (g / cm ³ )
ρ: density of the substance (g / cm ³ )
The above equation can be applied to the density of each porous support or ink holding member in the second to fifteenth embodiments described later.

In the above embodiment, the porous support 8c is made of a non-woven fabric. However, natural fibers such as Manila hemp and flax, synthetic resin fibers such as Tetron (trade name) and nylon, or stainless steel, iron, copper, nickel and aluminum , A mesh screen formed by crossing fibers such as titanium in a mesh, a synthetic resin fiber such as Tetron (trade name) or nylon, a nonwoven fabric made of stainless steel, iron, copper, nickel, aluminum, titanium fiber, etc., Tetron (trademark) Sintered sheet made by sintering synthetic resin fibers such as Nichia) and nylon, a porous elastic body having open cells of polyvinyl acetal or polyvinyl alcohol, a porous body having open cells mixed with hard particles and rubber Elastic body, porous elastic body obtained by sintering synthetic resin such as polyethylene or inorganic fine powder, liquid such as polyurethane Porous elastic bodies by sintering, or may be made of a porous elastic body such as cellular rubber.

Further, in the above-described mesh screen, non-woven fabric, sintered sheet, and porous support such as various porous elastic bodies, at least a surface of the side in contact with the thermoplastic resin film is dispersed with a fine powder of a metal or a resin, Welding or bonding may be used to reduce the surface roughness of the porous support.

FIG. 7 shows a master 20 used in the second embodiment of the present invention, and FIG. 8 shows a master 21 used in a modification of the second embodiment. The second embodiment and the modified example are different from the first embodiment only in that a master 20 or a master 21 is used instead of the master 8, and other configurations are the same.

The master 20 is formed by bonding a thermoplastic resin film 8b to a porous support 20b made of a sintered sheet of a metal fiber 20a of stainless steel, iron, copper, nickel, aluminum, titanium or the like. The master 21 heats a porous support 21c made of a sintered sheet in which a metal 21b such as stainless steel, iron, copper, nickel, aluminum or titanium is coated on a surface of a synthetic resin fiber 21a such as Tetron (trade name) or nylon. It is configured by bonding a plastic resin film 8b. The porous supports 20b and 21c have a surface roughness of 5 to 45 μmRz, preferably 5 to 35 μmRz, and more preferably 5 to 25 μmRz, respectively, on the side in contact with the thermoplastic resin film 8b.

In addition, the porous supports 20b and 21c each have a fiber diameter of 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less of the fiber diameter on the surface in contact with the thermoplastic resin film 8b. Is set. The porous supports 20b and 21c are obtained by sintering a non-woven fabric made of the metal fiber 20a or a non-woven fabric made of the synthetic resin fiber 21a whose surface is coated with the metal 21b.

As described above, the master 20 or the master 21 having the porous support 20b formed of the sintered sheet of the metal fiber 20a or the porous support 21c formed of the sintered sheet obtained by coating the surface of the synthetic resin fiber 21a with the metal 21b is used. Accordingly, the porous supports 20b and 21c, which have a high energy surface and are made of a metal member having good wettability, have a high adhesive force with the ink, and the ink is difficult to be pulled out from the inside of the porous supports 20b and 21c. Thus, occurrence of set-off can be prevented.

Further, since the porous supports 20b and 21c have higher elasticity than the porous supports made of a natural fiber member or a synthetic resin member, the porous supports 20b and 21b are pressed when pressed by a pressing member such as a press roller. , 21c are compressed to eject ink, and when the pressure is released, the porous supports 20b, 21c are restored, so that the ink is sucked back into the porous supports 20b, 21c, and excess ink is obtained. Is prevented from being transferred to printing paper, and a good image with less set-off can be obtained.

Further, since the strength of the porous supports 20b and 21c is higher than that of the porous supports made of a natural fiber member or a synthetic resin member, there is less settling due to long-time use. It is possible to provide a product having good durability and suitable for mass printing.

In the above-described embodiment and the modified examples, the porous supports 20b and 21c are configured by the sintered sheet made of the metal fiber 20a or the sintered sheet made by coating the surface of the synthetic resin fiber 21a with the metal 21b. The non-woven fabric made of a metal fiber, a non-woven fabric made of a synthetic resin fiber coated with a metal, a mesh screen formed by intersecting metal fibers in a mesh, a metal Any material may be used as long as at least its surface is made of a metal and has a passage through which ink passes, such as a porous body obtained by sintering fine powder of the above. It should be noted that the sintered sheet has a higher tensile strength than a nonwoven fabric and is lower in cost than a mesh screen, and thus is particularly suitable for use as a porous support.

FIG. 9 shows a master 22 used in the third embodiment of the present invention, and FIG. 10 shows a master 23 used in a modification of the third embodiment. The third embodiment and the modified example are different from the first embodiment only in that a master 22 or a master 23 is used in place of the master 8, and other configurations are the same.

The master 22 is a nonwoven fabric in which two types of synthetic resin fibers 22a and 22b having different fiber diameters are provided, and two rows of the synthetic resin fibers 22a are arranged between the synthetic resin fibers 22b. The master 23 has different fiber diameters. Each of the porous supports 22c and 23c is made of a nonwoven fabric composed of two types of synthetic resin fibers 23a and 23b, and the synthetic resin fibers 23a are arranged in a row between the synthetic resin fibers 23b. , 23c are bonded to the thermoplastic resin film 8b to form a master 22 and a master 23, respectively.

In this embodiment and the modified example, the fiber diameters of the synthetic resin fibers 22a and 23a are set to 4 μm, and the fiber diameters of the synthetic resin fibers 22b and 23b are set to 8 μm, respectively. In the mixing ratio, the masters 22 and 23 have a surface roughness of 5 to 45 μmRz, preferably 5 to 35 μmRz, and more preferably 5 to 25 μmRz on the side of the porous supports 22 c and 23 c that are in contact with the thermoplastic resin film 8 b. It is selected from those that can be set within the range.

Further, as the synthetic resin fiber used, the fiber diameter of the surface on the side in contact with the thermoplastic resin film 8b is 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less. Selected. In this embodiment and the modification, two types of synthetic resin fibers are combined, but three or more types may be used.

(4) By using the above-mentioned master 22 or master 23, the space between the thick fibers can be filled with thin fibers, and the irregularities L (surface roughness Rz) on the surfaces of the porous supports 22c and 23c can be reduced.

In the above embodiment and the modified examples, the porous support 22c is constituted by the nonwoven fabric composed of the synthetic resin fibers 22a and 22b, and the porous support 23c is constituted by the nonwoven fabric composed of the synthetic resin fibers 23a and 23b. Instead of the nonwoven fabric composed of the fibers 22a, 22b, 23a and 23b, the sintered sheet made of the metal fiber shown in the second embodiment, the sintered sheet made of a synthetic resin fiber coated with a metal surface, the metal fiber A nonwoven fabric or a mesh screen made of synthetic resin fibers having a metal-coated surface, or a sintered sheet, a nonwoven fabric, a metal fiber of a mesh screen, or a fine metal or resin material between metal surface fibers. A material obtained by dispersing a powder, welding or bonding the powder, or the like may be used.

Further, as another modified example of the above embodiment, as shown in FIG. 31, a porous support body 56c made of a nonwoven fabric in which thick synthetic resin fibers 56a and thin synthetic resin fibers 56b are arranged in a staggered manner, and a thermoplastic resin A master 56 to which the film 8b is attached may be used.

FIGS. 11 and 12 show a master 24 used in the fourth embodiment of the present invention and a master 25 used in the fifth embodiment of the present invention, respectively. The fourth and fifth embodiments differ from the first embodiment only in that a master 24 or a master 25 is used in place of the master 8, and the other configurations are the same.

The master 24 is configured by forming a porous support 24b by a nonwoven fabric in which a plurality of the same synthetic resin fibers 24a are laminated, and laminating the porous support 24b with the thermoplastic resin film 8b. The porous support 24b is formed so that the density of the synthetic resin fibers 24a decreases as the layers of the synthetic resin fibers 24a formed in a plurality of layers move from the outermost shell layer bonded to the thermoplastic resin film 8b to the inner layer. Is formed.

The master 25 is formed by laminating synthetic resin fibers 25a, 25b, and 25c having different fiber diameters in layers to form a porous support 25d, and bonding the porous support 25d to the thermoplastic resin film 8b. Have been. In the porous support 25d, the outermost shell layer bonded to the thermoplastic resin film 8b is composed of a layer of the synthetic resin fiber 25a having the smallest fiber diameter, and a layer of the synthetic resin fiber 25b toward the inner layer; It is configured to be a layer of 25c and a layer of synthetic resin fiber having a gradually increasing fiber diameter.

That is, the porous supports 24b and 25d are configured such that the gap becomes smaller from the side not in contact with the thermoplastic resin film 8b to the side in contact with the thermoplastic resin film 8b.

In the masters 24 and 25 used in the above-described fourth and fifth embodiments, the surface roughness of the porous supports 24b and 25d on the side in contact with the thermoplastic resin film 8b is preferably 5 to 45 µmRz, and more preferably 5 to 45 µmRz. Is in the range of 5 to 35 μmRz, more preferably 5 to 25 μmRz.

In addition, each synthetic resin fiber 24a, 25a has a fiber diameter of at least 1 μm to 20 μm, preferably 1 μm to 15 μm, more preferably 1 μm to 8 μm in a surface in contact with the thermoplastic resin film 8 b. Are used.

Further, in each of the above embodiments, the number of layers of each of the synthetic resin fibers 24a, 25a, 25b, and 25c constituting each of the porous supports 24b and 25d is three, but any number of layers may be used as long as it is two or more.

By using the master 24 or the master 25 described above, the porous support members 24b and 25b have a large gap at the beginning along the ink flow path and good supply and diffusion of the ink, and have a small gap and a small unevenness L at the end. It can be.

In each of the above embodiments, the porous support 24b is formed of the nonwoven fabric of the synthetic resin fiber 24a, and the porous support 25d is formed of the nonwoven fabric of the synthetic resin fibers 25a, 25b, and 25c. , 25a, 25b, 25c, the sintered sheet made of metal fibers shown in the second embodiment, the sintered sheet made of synthetic resin fibers coated with metal, and metal fibers Non-woven fabrics and mesh screens, non-woven fabrics and mesh screens made of synthetic resin fibers coated with metal on the surface, these sintered sheets, non-woven fabrics, metal fibers of mesh screens, and fine powder of metal and resin dispersed between metal surface fibers , Welded or bonded, porous body of sintered metal fine powder, etc. A porous support composed of a metal may be used. Further, as the porous support, the porous elastic body having open cells described in the first embodiment, the porous elastic body formed by liquid sintering, or the like may be used.

FIG. 13 shows a master 36 used in the sixth embodiment of the present invention. The sixth embodiment differs from the first embodiment only in that a master 36 is used in place of the master 8, and the other configuration is the same.

The porous support 36a made of a nonwoven fabric constituting the master 36 is mainly composed of a fiber member 36f, and the ink flowing from the hole 36b on the ink inflow side is filled with a thermoplastic resin in the porous support 36a. After at least one shift from the perpendicular S to the contact surface of the film 8b with the porous support 36a, there is formed an ink passage 36d flowing out of the hole 36c on the ink outflow side.

The ink passage 36d is configured such that substantially the entire amount of the ink flowing from the hole 36b on the ink inflow side is prevented from flowing down by the fiber member 36f existing on the perpendicular S, and does not flow down along the perpendicular S. . In other words, the ink passage 36d is formed such that substantially the entire amount of the ink that has flowed in from the hole 36b on the ink inflow side is prevented from flowing down by the fiber member 36f. And then flows down toward the hole 36c on the ink outflow side.

When the printing paper 18 is peeled off from the surface of the master 36, the adhesive force of the ink 19 acts between the ceiling 36e of the hole 36c and the ink 19, and the amount of the ink 19 pulled out from the porous support 36a is reduced. Reduced.

Here, a method for determining whether or not the above-described ink passage 36d is formed in the porous support 36a will be described.
First, as shown in FIG. 14, a paper 37 of a color different from that of the porous support 36a is attached to the back surface of the porous support 36a. Next, while irradiating light from the side of the porous support 36a, the microscope 37 is observed at a magnification of 50 times with a microscope. If the paper 37 is not visible between the fiber members 36f, it can be determined that the ink passage 36d is formed.

Further, as shown in FIG. 15, a vertical parallel light beam 54 is emitted from one surface of the porous support 36a to the porous support 36a, and light 55 reaching the other surface of the porous support 36a. Can be determined by measuring the light intensity with a light meter (for example, a laser type discrimination sensor LX2-100 manufactured by Keyence Corporation). The irradiated parallel light beam 54 is reflected in the ink passage 36d and does not reach the other surface. Therefore, if the light 55 is not measured by the light meter, it can be determined that the ink passage 36d is formed.

As a modification of the above embodiment, as shown in FIG. 16, instead of the master 36, a master 39 having a porous support 39a in which three or more fiber members 39b similar to the fiber member 36f are stacked may be used.

In the above Examples and Modifications, the porous supports 36a and 39a are set to have a surface roughness of 5 to 45 μmRz, preferably 5 to 35 μmRz, more preferably 5 to 25 μmRz on the side in contact with the thermoplastic resin film 8b. ing. Further, as the fiber members 36f and 39b, the fiber diameter on the surface in contact with the thermoplastic resin film 8b is 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less. Things are used. Further, in the above-described embodiment and modified examples, two or more types of fiber members having different fiber diameters may be used instead of the fiber members 36f and 39b.

Further, in the above-described embodiment and the modified examples, similarly to the fourth or fifth embodiment, the density of the porous supports 36a and 39a or the fiber diameter of the fiber members 36f and 39b is changed to change the heat. The masters 36, 39 in which the gaps between the porous supports 36a, 39a are reduced toward the side in contact with the plastic resin film 8b may be formed. Instead of the porous supports 36a, 39a, the masters 36, 39 are made of metal. A porous support made of a fiber member or a metal-coated fiber member, a porous body obtained by sintering a fine metal powder, or the like may be used. Further, as the porous support, the porous elastic body having open cells described in the first embodiment, the porous elastic body formed by liquid sintering, or the like may be used.

FIG. 17 shows a plate cylinder 43 and a master 27 made of only a thermoplastic resin film used in the seventh embodiment of the present invention. The seventh embodiment differs from the first embodiment only in that a plate cylinder 43 and a master 27 are used instead of the plate cylinder 1 and the master 8, and the other configuration is the same. The plate cylinder 43 mainly includes a porous support plate 1b having an opening 1a and the ink holding member 26.

The ink holding member 26 is made of a non-woven fabric in which an ink passage for passing ink is formed by synthetic resin fibers 26a such as Tetron (trade name) or nylon.

It is preferable that the ink holding member 26 has a higher density. For the same reason as described in the first embodiment, for example, when the ink holding member 26 is made of synthetic resin fiber or natural fiber, the density is 0.1%. 1 to 0.6 g / cm ³ , more preferably about 0.2 to 0.6 g / cm ³ , and when the ink holding member 26 is made of a metal-based fiber and is made of stainless steel or iron. density 0.7~3.0g / cm ^3, more preferably 0.9 to 3.0 g / cm ³ or so, the density in the case of titanium, 0.4~1.7g / cm ^3, more preferably 0 The density is about 0.5 to 1.7 g / cm ³ , and the density of aluminum is about 0.2 to 1.0 g / cm ³ , more preferably about 0.3 to 1.0 g / cm ³ .

In this embodiment, as in the first embodiment, the preferred density range Dw of the ink holding member 26 is expressed by the following equation.
Dw = 0.09ρ-0.38ρ (g / cm ³ )
ρ: density of the substance (g / cm ³ )
In this embodiment, since the master 27 used does not have the porous support, the ink holding member 26 prevents the extra ink from being drawn out instead of the porous support 8c in the first embodiment. are doing. However, on the surface of the ink holding member 26, the unevenness L1 due to the dent shown in FIG. 18A, the unevenness L2 due to the undulation shown in FIG. 18B, and the synthetic resin fiber 26a shown in FIG. There are irregularities L such as irregularities L3 caused by the fiber diameter.

Therefore, similarly to the first embodiment, in the ink holding member 26 having a thickness of 100 μm and a density of 0.4 g / cm ³ , the unevenness L of the ink holding member 26 is adjusted by changing the fiber diameter of the synthetic resin fiber 26 a. Printing was performed, and set-off at that time was investigated.

In the experiment, as in the first embodiment, printing was performed using a digital stencil printing machine Preport VT3820 (manufactured by Ricoh Co., Ltd.), and a surface roughness meter SEF-30D (manufactured by Kosaka Laboratories) was used. The unevenness L (surface roughness) of the ink holding member 26 was measured. The surface roughness was measured at a feed rate of 0.1 mm / sec and a measurement length of 0.8 mm using a head having a radius of 7 μm, and a ten-point average roughness in this range was determined. The unevenness L (surface roughness Rz) was calculated from the average. The thickness of the master 27 is 1.5 μm. Table 2 shows the results of the experiment.

As is clear from Table 2, when the surface roughness is 45 μmRz or less, set-off is reduced as indicated by a triangle in the table, and when the surface roughness is 35 μmRz or less, set-off is almost eliminated as indicated by a circle in the table, When the value was 25 μm Rz or less, the result that no set-off occurred as shown by the star in the table was obtained. It was also found that satisfactory images could not be obtained if the surface roughness was less than 5 μmRz.

Further, when the fiber diameter of the synthetic resin fiber 26a is 20 μm or less, set-off is reduced as indicated by a triangle in the table, and when the fiber diameter is 15 μm or less, set-off is almost eliminated as indicated by a circle in the table, and 8 μm or less. As a result, no set-off occurred as shown by the star in the table. It was also found that a satisfactory image could not be obtained if the fiber diameter was less than 1 μm.

From the above, the surface roughness of the outer surface of the ink holding member 26 around which the master 27 is wound is set to 5 to 45 μmRz, preferably 5 to 35 μmRz, and more preferably 5 to 25 μmRz. The fiber diameter of the outer surface of the ink holding member 26 around which the master 27 is wound is set to 1 μm to 20 μm, preferably 1 μm to 15 μm, more preferably 1 μm to 8 μm.

In the seventh embodiment, the ink holding member 26 is made of a non-woven fabric. However, the ink holding member 26 may be made of natural fibers such as manila hemp or flax, synthetic resin fibers such as Tetron (trade name) or nylon, stainless steel, iron, or the like. Mesh screens formed by cross-linking fibers of copper, nickel, aluminum, titanium, etc. in a mesh form, synthetic resin fibers such as Tetron (trade name) or nylon, stainless steel, iron, copper, nickel, aluminum, titanium fibers, etc. Nonwoven fabric, sintered sheet made by sintering synthetic resin fibers such as Tetron (trade name) and nylon, porous elastic body having open cells of polyvinyl acetal or polyvinyl alcohol, continuous mixture of hard particles and rubber Porous elastic body made by sintering a porous elastic body with air bubbles, synthetic resin such as polyethylene, or inorganic fine powder Body may be constituted by a porous elastic body by liquid sintering, such as polyurethane, or those made of a porous elastic body of porous rubber or the like.

In the above-described ink holding member such as a mesh screen, a nonwoven fabric, a sintered sheet, and various kinds of porous elastic materials, at least a fine powder of a metal, a resin, or the like is dispersed on the outer surface on which the master is wound, and is welded or bonded. Thus, the surface roughness of the ink holding member may be reduced.

FIG. 19 shows a plate cylinder 45 used in the eighth embodiment of the present invention, and FIG. 20 shows a plate cylinder 46 used in a modification of the eighth embodiment. The eighth embodiment and the modified example are different from the seventh embodiment only in that a plate cylinder 45 or a plate cylinder 46 is used instead of the plate cylinder 43, and other configurations are the same.

The plate cylinder 45 mainly includes a porous support plate 1b and an ink holding member 28. The ink holding member 28 includes a sintered sheet of a metal fiber 28a such as stainless steel, iron, copper, nickel, titanium, and aluminum. Have been. The plate cylinder 46 is mainly composed of a porous support plate 1b and an ink holding member 29. The ink holding member 29 is made of stainless steel, iron, copper, or the like on the surface of a synthetic resin fiber 29a such as Tetron (trade name) or nylon. It is formed of a sintered sheet formed by coating a metal 29b such as nickel, titanium, and aluminum. In each of the ink holding members 28 and 29, the surface roughness of the outer surface around which the master is wound is set to 5 to 45 μmRz, preferably 5 to 35 μmRz, and more preferably 5 to 25 μmRz.

In addition, each of the ink holding members 28 and 29 has a fiber diameter on the outer surface around which the master 27 is wound around the same diameter of 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less. Have been. The ink holding members 28 and 29 are obtained by sintering a nonwoven fabric made of a metal fiber 28a or a nonwoven fabric made of a synthetic resin fiber 29a whose surface is coated with a metal 29b.

As described above, by using the ink holding member 28 made of a sintered sheet of the metal fiber 28a or the ink holding member 29 made of the sintered sheet formed by coating the surface of the synthetic resin fiber 29a with the metal 29b, high energy can be obtained. The ink holding members 28 and 29 made of a metal member on the surface have good wettability and a high adhesive force with the ink, so that it is difficult for the ink to be pulled out from the inside of the ink holding members 28 and 29 and set-off occurs. Can be prevented.

Further, since the ink holding members 28 and 29 have higher elasticity than the ink holding members formed of a natural fiber member or a synthetic resin member, the ink holding members 28 and 29 are pressed when pressed by a pressing member such as a press roller. The ink is compressed and ejected, and when the pressure is released, the ink holding members 28 and 29 are restored, so that an effect of sucking the ink back into the ink holding members 28 and 29 is obtained. The transfer to the surface is prevented, and a good image with little set-off can be obtained.

Further, since the ink holding members 28 and 29 are higher in strength than the ink holding members made of a natural fiber member or a synthetic resin member, there is little settling due to long-time use, and the durability is good and suitable for mass printing. Stencil printing apparatus can be provided.

In the above-described embodiment, the ink holding members 28 and 29 are formed by the sintered sheet made of the metal fiber 28a or the sintered sheet formed by coating the surface of the synthetic resin fiber 29a with the metal 29b. Not limited to this, non-woven fabric made of metal fiber, non-woven fabric made of synthetic resin fiber coated with metal, mesh screen formed by crossing metal fibers in a mesh, and fine metal powder Any material such as a tied porous body may be used as long as at least its surface is made of metal and has a passage through which ink passes.
It should be noted that the sintered sheet has a higher tensile strength than a nonwoven fabric and is lower in cost than a mesh screen, and is therefore particularly suitable for use as an ink holding member.

FIG. 21 shows a plate cylinder 47 used in the ninth embodiment of the present invention, and FIG. 22 shows a plate cylinder 48 used in a modification of the ninth embodiment. The ninth embodiment and the modified example are different from the seventh embodiment only in that a plate cylinder 47 or a plate cylinder 48 is used instead of the plate cylinder 43, and other configurations are the same.

The plate cylinder 47 is mainly composed of the porous support plate 1b and the ink holding member 30, and the plate cylinder 48 is mainly composed of the porous support plate 1b and the ink holding member 31.

The ink holding member 30 is composed of two types of synthetic resin fibers 30a and 30b having different fiber diameters, and is a nonwoven fabric in which the synthetic resin fibers 30a are arranged in two rows between the synthetic resin fibers 30b. It is composed of two types of synthetic resin fibers 31a and 31b having different fiber diameters, respectively, and is constituted by a nonwoven fabric in which the synthetic resin fibers 31a are arranged in a row between the synthetic resin fibers 31b. In this embodiment and the modified example, the fiber diameters of the synthetic resin fibers 30a and 31a are set to 4 μm, respectively, and the fiber diameters of the synthetic resin fibers 30b and 31b are set to 8 μm. The mixing ratio is such that the surface roughness of the outer surfaces of the ink holding members 30 and 31 around which the master 27 is wound can be set within a range of 5 to 45 μmRz, preferably 5 to 35 μmRz, and more preferably 5 to 25 μmRz. More choice.

As the synthetic resin fibers used, the fiber diameter of the outer surfaces of the ink holding members 30 and 31 around which the master 27 is wound is 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less. Is selected from those within the range. In this embodiment and the modification, two types of synthetic resin fibers are combined, but three or more types may be used.

By using the ink holding member 30 or the ink holding member 31 described above, the space between the thick fibers can be filled with the thin fibers, and the unevenness L (surface roughness Rz) on the surfaces of the plate cylinders 47 and 48 can be reduced. .

In the above-described embodiment and modified examples, the ink holding member 30 is formed of the nonwoven fabric of the synthetic resin fibers 30a and 30b, and the ink holding member 31 is formed of the nonwoven fabric of the synthetic resin fibers 31a and 31b. , 30b, 31a, 31b, the sintered sheet made of metal fibers shown in the eighth embodiment, the sintered sheet made of synthetic resin fibers coated with metal, and metal fibers Non-woven fabrics and mesh screens, non-woven fabrics and mesh screens made of synthetic resin fibers coated with metal on the surface, or fine powders of metals and resins between these sintered sheets, non-woven fabrics, mesh screen metal fibers and metal surface fibers What is dispersed, welded or adhered, or the like may be used.

Further, as another modified example of the above embodiment, as shown in FIG. 32, an ink holding member 57 made of a nonwoven fabric in which thick synthetic resin fibers 57a and thin synthetic resin fibers 57b are arranged in a staggered manner, and a porous support plate 1b may be used.

FIGS. 23 and 24 show a plate cylinder 49 used in the tenth embodiment of the present invention and a plate cylinder 50 used in the eleventh embodiment of the present invention, respectively. The tenth and eleventh embodiments differ from the seventh embodiment only in that a plate cylinder 49 or a plate cylinder 50 is used instead of the plate cylinder 43, and the other configurations are the same.

The plate cylinder 49 is mainly composed of the porous support plate 1b and the ink holding member 34. The ink holding member 34 is made of a nonwoven fabric in which the same synthetic resin fibers 34a are laminated in a plurality of layers.

The ink holding member 34 is formed such that the density of the synthetic resin fibers 34a decreases as the layers of the synthetic resin fibers 34a formed in a plurality of layers move from the master 27 made of only a thermoplastic resin film toward the porous support plate 1b. Is formed.

The plate cylinder 50 is mainly composed of a porous support plate 1b and an ink holding member 35, and the ink holding member 35 is a nonwoven fabric in which synthetic resin fibers 35a, 35b, and 35c having different fiber diameters are laminated in layers. It is configured.

The ink holding member 35 is composed of a layer of synthetic resin fiber 35a having the smallest fiber diameter on the master 27 side, and a layer of synthetic resin fiber 35b and a layer of synthetic resin fiber 35c gradually increasing in diameter toward the inside. It is configured to be a layer of fibers. That is, the ink holding members 34 and 35 are configured such that the gap becomes smaller toward the outer surface on which the master 27 is wound.

The ink holding members 34 and 35 used in the tenth and eleventh embodiments have a surface roughness of 5 to 45 μmRz, preferably 5 to 35 μmRz on each outer surface of the side on which the master 27 is wound. More preferably, those having a range of 5 to 25 μm Rz are used.

As the synthetic resin fibers 34a and 35a used, at least the fiber diameter of the outer surface of the ink holding members 34 and 35 around which the master 27 is wound is 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably. Is used in a range of 1 μm to 8 μm.

In each of the above embodiments, the three layers of the synthetic resin fibers 34a, 35a, 35b, 35c constituting the ink holding members 34, 35 are three layers. Further, each layer of the synthetic resin fibers 34a, 35a, 35b, 35c constituting each of the ink holding members 34, 35 may have an integral structure or a laminated structure (a structure in which individual layers are superimposed). In this manner, a plurality of ink holding members having gaps of different sizes are prepared, and these are stacked and arranged so that the gap becomes smaller toward the outer peripheral surface of the plate cylinder, and this is used as an ink holding member. be able to.

By using the ink holding member 34 or the ink holding member 35 described above, an ink holding member having a large gap at the beginning and good supply and diffusion of ink along the ink flow path, and having a small gap and a small unevenness L at the end. 34, 35.

In each of the above embodiments, the ink holding member 34 is made of a nonwoven fabric made of synthetic resin fibers 34a, and the ink holding member 35 is made of a nonwoven fabric made of synthetic resin fibers 35a, 35b, 35c. , 35b, 35c, the sintered sheet made of metal fibers shown in the eighth embodiment, the sintered sheet made of synthetic resin fibers coated with metal, the nonwoven fabric made of metal fibers, Mesh screens, nonwoven fabrics and mesh screens made of synthetic resin fibers whose surfaces are coated with metal, and fine powders of metals and resins are dispersed and welded between these sintered sheets, nonwoven fabrics, metal fibers of the mesh screens, and metal surface fibers. Or at least a surface such as a bonded body, a porous body obtained by sintering a fine metal powder, etc. A porous support composed of a metal may be used. Further, as the porous support, the porous elastic body having open cells described in the first embodiment, the porous elastic body formed by liquid sintering, or the like may be used.

FIG. 25 shows a plate cylinder 53 used in the twelfth embodiment of the present invention. The twelfth embodiment differs from the seventh embodiment only in that a plate cylinder 53 is used in place of the plate cylinder 43, and the other configuration is the same.

The plate cylinder 53 is mainly composed of the porous support plate 1b and the ink retaining member 38, and the ink retaining member 38 is mainly composed of the fiber member 38c. In the ink holding member 38, the ink 19 flowing from the ink inflow side hole 38 a and the ink outflow side hole 38 b and the ink 19 flowing from the ink inflow side hole 38 a are perpendicular to the outer peripheral surface of the plate cylinder 53, that is, the ink outflow side. An ink passage 38d that flows out of the hole 38b on the ink outflow side after at least one shift from the perpendicular S to the surface having the opening of the hole 38b is formed.

The ink passage 38d is configured such that substantially the entire amount of the ink flowing from the hole 38a on the ink inflow side is prevented from flowing down by the fiber member 38c existing on the perpendicular S, and does not flow down along the perpendicular S. . In other words, the ink passage 38d is formed such that substantially the entire amount of the ink that has flowed in from the hole 38a on the ink inflow side is prevented from flowing down by the fiber member 38c. And then flows down toward the hole 38b on the ink outflow side.

When the printing paper 18 is peeled off from the surface of the master 27, the adhesive force of the ink 19 acts between the ceiling 38e of the hole 38b and the ink 19, and the amount of the ink 19 pulled out from the ink holding member 38 is reduced. Is done.

Here, a method for determining whether or not the above-described ink passage 38d is formed in the ink holding member 38 will be described.
First, as shown in FIG. 26, a sheet 37 of a color different from that of the ink holding member 38 is attached to the back surface of the ink holding member 38. Next, while irradiating light from the ink holding member 38 side, the microscope 37 is observed at a magnification of 50 times with a microscope. If the paper 37 cannot be seen from between the fiber members 38c, it can be determined that the ink passage 38d is formed.

Further, similarly to the porous support member 36a in the sixth embodiment, a parallel light beam perpendicular to the ink holding member 38 is irradiated from one surface of the ink holding member 38 to the other surface of the ink holding member 38. Judgment can also be made by measuring the arriving light with a light meter.

As a modification of the above embodiment, as shown in FIG. 27, an ink holding member 42 having three or more layers of fiber members 42a similar to the fiber member 38c may be used instead of the ink holding member 38.

In the above embodiments and modifications, the ink holding members 38 and 42 have a surface roughness of 5 to 45 μmRz, preferably 5 to 35 μmRz, on the outer surface on the side on which the master 27 made of only a thermoplastic resin film is wound. Preferably, it is set to 5 to 25 μmRz. Further, as the fiber members 38c and 42a, the fiber diameter of the outer surface of the ink holding members 38 and 42 on which the master 27 is wound is 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less. Those that are within the range are used. Further, in the above-described embodiment and modified examples, two or more types of fiber members having different fiber diameters may be used instead of the fiber members 38c and 42a.

Further, in the above-described embodiment and the modified examples, similarly to the tenth embodiment or the eleventh embodiment, the density of the ink holding members 38 and 42 or the fiber diameter of the fiber members 38c and 42a is changed to change the master 27. The gap between the ink holding members 38 and 42 may be reduced toward the outer surface to be wound, and a nonwoven fabric, a sintered sheet, and a mesh screen made of a metal fiber member or a metal coated fiber member may be used. Alternatively, an ink holding member whose surface is formed of at least a metal, such as a porous body obtained by sintering a fine metal powder, may be used. Further, as the ink holding member, the porous elastic body having open cells described in the first embodiment, the porous elastic body formed by liquid sintering, or the like may be used.

FIG. 28 shows the plate cylinder 44 and the master 41 used in the thirteenth embodiment of the present invention. The thirteenth embodiment differs from the seventh embodiment in that a master 41 made of a porous support 41a and a thermoplastic resin film 41b is used instead of the master 27, and that the plate cylinder 43 is used instead of the plate cylinder 43. The only difference is that the plate cylinder 44 is used, and the other configuration is the same.

The plate cylinder 44 is mainly composed of a porous support plate 1b and an ink holding member 40. The ink holding member 40, like the ink holding member 26, includes a nonwoven fabric, a mesh screen, a sintered sheet, and a porous elastic member. It is composed of a body and the like.

The master 41 used in this embodiment includes a porous support 41a formed of a nonwoven fabric made of synthetic resin fibers 41c such as Tetron (trade name), nylon, rayon, vinylon, and polyester, and a thermoplastic resin film such as a polyester film. 41b with an adhesive or the like. The porous support 41a is made of porous thin paper made of natural fibers such as mulberry, mitsumata, manila hemp, flax, etc .; A mesh screen made of resin fibers, a sintered sheet made of synthetic resin fibers or metal fibers, or the like may be used.

It can be seen from the seventh embodiment that prevention of set-off is related to the surface roughness of the ink holding member. This is the case where the porous support 41a is interposed between the ink holding member 40 and the thermoplastic resin film 41b, and the porous support 41a is straightened without changing the flow direction of the ink on the porous support 41a as described later. If there are many outflow portions and the size of the opening diameter 41d of the straight outflow portion is larger than the perforated portion 8d (see FIG. 4) formed in the thermoplastic resin film 41b, the ink holding member is used. The surface roughness of 40 can be considered as a distance L ′ from the inner surface of the thermoplastic resin film 41b to the concave portion on the outer surface of the ink holding member 40. Therefore, in order to prevent set-off, the distance L 'needs to be 5 μm or more and 45 μm or less.

In this embodiment, a porous support 41a is interposed between the thermoplastic resin film 41b and the ink holding member 40. Therefore, in order to prevent the occurrence of set-off, the sum of the thickness of the porous support 41a and the surface roughness of the ink holding member 40 needs to be 5 μm or more and 45 μm or less. For example, if the thickness of the porous support 41a is 20 μm, the surface roughness of the ink holding member 40 is 25 μmRz or less. The sum of the thickness of the porous support 41a and the surface roughness of the ink holding member 40 is preferably in the range of 5 μm to 35 μm, and more preferably in the range of 5 μm to 25 μm.

Comparing the porous support 41a of the present embodiment with the porous support 8c of the first embodiment, the porous support 41a has many portions that flow straight out without changing the ink flow direction. Present, furthermore, since the size of the opening diameter 41d of the portion that flows straight out is larger than the perforated portion 8d formed in the thermoplastic resin film 41b, the ink easily passes through the inside of the porous support 41a, While the ink is cut on the surface of the ink holding member 40, the porous support 8c has many channels for changing the flow direction of the ink, so that the ink is cut on the surface of the porous support 8c. Therefore, in the first embodiment, the occurrence of set-off is related to the surface roughness of the porous support 8c, but in the present embodiment, the set-off is caused by the thickness of the porous support 41a and the surface roughness of the ink holding member 40. It is related to the sum of

In the above embodiment, instead of the ink holding member 40, an ink holding member formed of a nonwoven fabric made of two or more kinds of fiber members having different fiber diameters may be used. Further, the density of the ink holding member 40 or the fiber diameter of the fiber member constituting the ink holding member 40 is changed to reduce the gap of the ink holding member 40 toward the outer peripheral surface on which the master 41 is wound. Alternatively, instead of the ink holding member 40, the surface of a nonwoven fabric, a sintered sheet and a mesh screen made of a metal member or a metal member coated with a metal, a sintered sheet and a mesh screen, or a porous body obtained by sintering a fine metal powder, etc. May be used an ink holding member formed of at least a metal. Further, instead of the ink holding member 40, an ink holding member having the same ink passage as the ink holding members 38 and 42 shown in the twelfth embodiment and its modifications may be used. As the ink holding member, the porous elastic body having open cells described in the first embodiment, the porous elastic body formed by liquid sintering, or the like may be used.

FIGS. 29 and 30 show a plate cylinder 51 used in the fourteenth embodiment of the present invention and a plate cylinder 52 used in the fifteenth embodiment of the present invention, respectively. The fourteenth and fifteenth embodiments are different from the seventh embodiment only in that a plate cylinder 51 or a plate cylinder 52 is used instead of the plate cylinder 43, and the other configurations are the same.

The plate cylinder 51 mainly includes a porous support plate 1b and an ink holding member 32. The ink holding member 32 includes an ink holding member 32b made of a nonwoven fabric in which a plurality of the same synthetic resin fibers 32a are stacked. It is configured by superposing two layers.

The ink holding member 32b is formed such that the density of the synthetic resin fibers 32a decreases as the plurality of layers of the synthetic resin fibers 32a are formed from the master 27 toward the porous support plate 1b.

The plate cylinder 52 is mainly composed of a porous support plate 1b and an ink holding member 33. The ink holding member 33 is formed by laminating synthetic resin fibers 33a, 33b, and 33c having different fiber diameters in layers. The ink holding member 33d is formed by superposing two layers of the ink holding member 33d.

The ink holding member 33d is composed of a layer of synthetic resin fiber 33a having the smallest fiber diameter on the master 27 side, and a layer of synthetic resin fiber 33b and a layer of synthetic resin fiber 33c gradually increasing in diameter toward the inside. It is configured to be a layer of fibers. That is, the ink holding members 32b and 33d are configured such that the gap becomes smaller toward the outer surface on which the master 27 is wound.

The synthetic resin fibers 32a, 33a constituting the ink holding members 32b, 33d used in the above-described fourteenth and fifteenth embodiments include at least the outer surfaces of the ink holding members 32b, 33d around which the master 27 is wound. Fibers having a fiber diameter of 1 μm or more and 20 μm or less, preferably 1 μm or more and 15 μm or less, more preferably 1 μm or more and 8 μm or less are used.

In the above embodiment, the number of layers of the synthetic resin fibers 32a, 33a, 33b, and 33c constituting each of the ink holding members 32b and 33d is three. In each of the above embodiments, the ink holding members 32b and 33d are formed by superposing two layers of the ink holding members 32b and 33d, respectively. However, if the ink holding members 32b and 33d are two or more layers, any number of layers are superposed. To form the ink holding members 32 and 33.

Further, in the ink holding members 32 and 33, as in the twelfth embodiment, the ink flowing out of the holes on the ink inflow side deviates at least once from the perpendicular to the outer peripheral surfaces of the plate cylinders 51 and 52, and then the ink flows out. An ink passage flowing out of the side hole may be formed.

By using the above-described ink holding member 32 or the ink holding member 33, an ink layer having a large gap at first and good supply and diffusion of the ink along the flow path of the ink, and finally having a small gap and a small unevenness L is formed. The holding members 32 and 33 can be used.

In each of the above embodiments, the ink holding member 32 is made of a nonwoven fabric made of synthetic resin fibers 32a, and the ink holding member 33 is made of a nonwoven fabric made of synthetic resin fibers 33a, 33b, and 33c. Instead of the nonwoven fabrics 33b and 33c, the sintered sheet made of metal fibers shown in the eighth embodiment, the sintered sheet made of synthetic resin fibers coated with metal, the nonwoven fabric or mesh made of metal fibers Screens, nonwoven fabrics and mesh screens made of synthetic resin fibers coated with metal on the surface, and fine powders of metals and resins dispersed and welded or bonded between metal fibers and metal surface fibers of these sintered sheets, nonwoven fabrics and mesh screens The surface of the material, such as a porous body obtained by sintering fine metal powder, A porous support composed of a metal may be used. Further, as the porous support, the porous elastic body having open cells described in the first embodiment, the porous elastic body formed by liquid sintering, or the like may be used.

Each plate cylinder used in the seventh to fifteenth embodiments is composed of a porous support plate 1b and each ink holding member. For example, Japanese Patent Application Laid-Open No. As disclosed in Japanese Patent Publication No. 218889, a porous support plate 1b may be omitted and only a cylindrical ink holding member may be provided. In this case, a cylinder formed in a cylindrical shape and housed inside the stencil printing apparatus is called a plate cylinder, and a sheet-shaped thing is called an ink holding member.

In the seventh to fifteenth embodiments, an ink holding layer such as a mesh screen or a nonwoven fabric may be interposed between the porous support 1b of each plate cylinder and the ink holding member.

In addition, the master composed of only the thermoplastic resin film used in each of the above-mentioned examples refers to a master composed of only a thermoplastic resin film, and a thermoplastic resin film containing a trace component such as an antistatic agent. Further, a thermoplastic resin film includes one or more thin film layers such as an overcoat layer formed on at least one of the front surface and the back surface of the thermoplastic resin film.

FIG. 1 is a schematic front view of a main part of a stencil printing apparatus employing a first embodiment of the present invention. FIG. 9 is a partial sectional view showing a plate cylinder and an ink holding member used in the first to sixth embodiments of the present invention. FIG. 2 is a partial sectional view showing a master used in the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view for explaining a state of transfer of ink to printing paper in the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view for explaining a state of transfer of ink to printing paper in the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view for explaining a state of transfer of ink to printing paper in the first embodiment of the present invention. FIG. 9 is a partial cross-sectional view illustrating a master used in a second embodiment of the present invention. FIG. 13 is a partial cross-sectional view illustrating a master used in a modification of the second embodiment of the present invention. FIG. 13 is a partial cross-sectional view illustrating a master used in a third embodiment of the present invention. FIG. 14 is a partial cross-sectional view illustrating a master used in a modification of the third embodiment of the present invention. FIG. 14 is a partial sectional view showing a master used in a fourth embodiment of the present invention. It is a partial sectional view showing a master used for a 5th example of the present invention. FIG. 14 is a partial sectional view showing a master used in a sixth embodiment of the present invention. FIG. 14 is a partial sectional view illustrating a master used in a sixth embodiment of the present invention. FIG. 14 is a partial sectional view illustrating a master used in a sixth embodiment of the present invention. FIG. 15 is a partial cross-sectional view illustrating a master used in a modification of the sixth embodiment of the present invention. FIG. 14 is a partial cross-sectional view illustrating a plate cylinder and an ink holding member used in a seventh embodiment of the present invention. It is a partial sectional view showing (a) unevenness due to a dent, (b) unevenness due to undulation, and (c) unevenness due to the fiber diameter of a synthetic resin fiber on the surface of an ink holding layer in a seventh embodiment of the present invention. It is a partial sectional view showing a plate cylinder and an ink holding member used in an eighth embodiment of the present invention. It is a partial sectional view showing a plate cylinder and an ink holding member used in a modification of the eighth embodiment of the present invention. It is a partial sectional view showing a plate cylinder and an ink holding member used in a ninth embodiment of the present invention. It is a partial sectional view showing a plate cylinder and an ink holding member used in a modification of the ninth embodiment of the present invention. FIG. 21 is a partial sectional view showing a plate cylinder and an ink holding member used in a tenth embodiment of the present invention. FIG. 21 is a partial sectional view showing a plate cylinder and an ink holding member used in an eleventh embodiment of the present invention. FIG. 21 is a partial sectional view showing a plate cylinder and an ink holding member used in a twelfth embodiment of the present invention. FIG. 21 is a partial sectional view illustrating an ink holding member used in a twelfth embodiment of the present invention. FIG. 21 is a partial sectional view showing an ink holding member used in a modification of the twelfth embodiment of the present invention. It is a partial sectional view showing a plate cylinder and an ink holding member used in a thirteenth embodiment of the present invention. FIG. 21 is a partial sectional view showing a plate cylinder and an ink holding member used in a fourteenth embodiment of the present invention. FIG. 21 is a partial sectional view showing a plate cylinder and an ink holding member used in a fifteenth embodiment of the present invention. FIG. 15 is a partial cross-sectional view illustrating a master used in another modification of the third embodiment of the present invention. FIG. 21 is a partial sectional view showing a plate cylinder and an ink holding member used in another modification of the ninth embodiment of the present invention.

Explanation of reference numerals

1,43,44,45,46,47,48,49,50,51,52,53,58 Plate cylinders 8,20,21,22,23,24,25,27,36,39,41,56 Master 8b, 41b Thermoplastic resin film 8c, 20b, 21c, 22c, 23c, 24b, 25d, 36a, 39a, 41a, 56c Porous support 26, 28, 29, 30, 31, 32, 32b, 33, 33d , 34,35,38,40,42,57 Ink holding member 20a, 21b, 29b Metal (metal fiber)

Claims (22)

A plate cylinder of a stencil printing machine having an ink holding member on an outer peripheral surface and winding a master made of only a thermoplastic resin film on the ink holding member,
A plate cylinder of a stencil printing machine, characterized in that the outer surface of said ink holding member has a surface roughness of 5 to 45 mRz. A plate cylinder of a stencil printing machine that has an ink holding member on an outer peripheral surface and winds a master in which a thermoplastic resin film and a porous support are bonded on the ink holding member,
A plate cylinder of a stencil printing machine, wherein the sum of the surface roughness of the ink holding member on the side in contact with the porous support and the thickness of the porous support is 5 μm or more and 45 μm or less. 3. The plate cylinder of a stencil printing apparatus according to claim 1, wherein the ink holding member is made of two or more kinds of fibers having different fiber diameters. 3. The plate cylinder of a stencil printing apparatus according to claim 1, wherein the ink holding member is configured such that a gap becomes smaller toward an outer surface. The plate cylinder of a stencil printing apparatus according to any one of claims 1 to 4, wherein at least a surface of the ink holding member is made of metal. The ink holding member has a hole on the ink inflow side and a hole on the ink outflow side, and the ink holding member is configured such that the ink flowing from the hole on the ink inflow side is at least from a perpendicular to the outer peripheral surface of the plate cylinder. The plate cylinder of a stencil printing apparatus according to any one of claims 1 to 5, further comprising an ink passage that flows out of the ink outflow side hole after being shifted once. (4) An ink holding member constituting an outer peripheral surface of a plate cylinder, wherein the surface roughness of the ink holding member is 5 to 45 μmRz. 8. The ink holding member according to claim 7, wherein the ink holding member is composed of two or more types of fibers having different fiber diameters. (8) The ink holding member according to (7), wherein the gap is reduced toward the outer surface. (10) The ink holding member according to any one of (7) to (9), wherein at least the surface is made of metal. The ink having a hole on the ink inflow side and a hole on the ink outflow side, wherein the ink that has flowed in from the hole on the ink inflow side at least once deviates from a perpendicular to a surface having the opening of the hole on the ink outflow side. The ink holding member according to any one of claims 7 to 10, wherein the ink holding member has an ink passage that flows out of a hole on an outflow side. A plate cylinder of a stencil printing machine having an ink holding member composed of fibers on an outer peripheral surface, and a master made of only a thermoplastic resin film wound on the ink holding member,
A plate cylinder of a stencil printing machine, wherein a fiber diameter of an outer surface of the ink holding member is 1 μm or more and 20 μm or less. The plate cylinder of a stencil printing apparatus according to claim 12, wherein the ink holding member is made of two or more kinds having different fiber diameters. A plate cylinder of a stencil printing machine having a plurality of layers of an ink holding member formed of fibers on an outer peripheral surface, and a master including only a thermoplastic resin film wound on the ink holding member,
The plurality of ink holding members are arranged so that the gap becomes smaller toward the outermost shell layer,
A plate cylinder of a stencil printing machine, wherein a fiber diameter of an outer surface of the ink holding member is 1 μm or more and 20 μm or less. A plate cylinder of a stencil printing machine having only one layer of an ink holding member made of fibers on an outer peripheral surface, and a master made of only a thermoplastic resin film wound on the ink holding member,
The ink holding member is configured such that the gap decreases toward the outer surface,
A plate cylinder of a stencil printing machine, wherein a fiber diameter of an outer surface of the ink holding member is 1 μm or more and 20 μm or less. The plate cylinder of a stencil printing apparatus according to any one of claims 12 to 15, wherein at least a surface of the ink holding member is made of metal. The ink holding member has a hole on the ink inflow side and a hole on the ink outflow side, and the ink holding member is configured such that the ink flowing from the hole on the ink inflow side is at least from a perpendicular to the outer peripheral surface of the plate cylinder. The plate cylinder of a stencil printing apparatus according to any one of claims 12 to 16, further comprising an ink passage that flows out of the ink outflow side hole after being shifted once. An ink holding member composed of fibers constituting the outer peripheral surface of the plate cylinder,
An ink holding member, wherein the outer surface has a fiber diameter of 1 μm or more and 20 μm or less. 19. The ink holding member according to claim 18, wherein the ink holding member is composed of two or more types having different fiber diameters. 19. The ink holding member according to claim 18, wherein the ink holding member is configured such that a gap becomes smaller toward an outer surface. 21. The ink holding member according to claim 18, wherein at least the surface is made of a metal. The ink having a hole on the ink inflow side and a hole on the ink outflow side, wherein the ink that has flowed in from the hole on the ink inflow side at least once deviates from a perpendicular to a surface having the opening of the hole on the ink outflow side. 22. The ink holding member according to claim 18, wherein the ink holding member has an ink passage flowing out of a hole on an outflow side.

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