JP2001277471A - Stencil printing machine - Google Patents

Abstract

(57) [Problem] To provide a stencil printing apparatus capable of preventing ink from leaking from a plate cylinder only by adding a simple element. SOLUTION: An ink impermeable area (1) along each side edge.
b) and a cylindrical plate cylinder (1) having a peripheral wall with an ink-permeable area (1a) defined therebetween, an ink supply roller arranged in the plate cylinder, and arranged outside the plate cylinder A stencil printing machine provided with a set outer roller (6), the width direction length of the ink supply roller is A, the width direction length of the ink passage area of the peripheral wall of the printing drum is B, and the width direction of the outer roller is When C is satisfied, the three members satisfy the relationship of A <B <C, and are arranged so as to be centered with each other, and the peripheral wall has an ink shielding layer extending from a side edge of the ink passage area to the ink supply roller. (8) is provided outside the inner surface of the peripheral wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing machine which prevents ink from leaking from a plate cylinder.

[0002]

2. Description of the Related Art In general, a plate cylinder of a stencil printing machine is formed by rolling a flat plate member made of a perforated plate and a punching metal, a metal screen, or the like processed by a method such as etching or electroforming into a cylindrical shape. A flange is attached to both side edges of a cylinder, or a flange is attached to both side edges of a cylindrical porous member. The area along each side edge of the cylindrical peripheral wall to which the flange is attached is buried with a resin or the like so as to prevent ink from penetrating, and is closed as an ink impervious area. The area defined by this is defined as an ink passage area.

[0003] In this manner, a stencil sheet having a stencil formed thereon is wound around the plate cylinder so as to cover the ink-permeable area, and the plate cylinder is rotated around its own central axis while rotating from the ink supply roller provided inside the plate cylinder. By pressing the printing paper against the outer peripheral surface of the plate cylinder while supplying the ink to the inner peripheral surface of the plate cylinder, the ink is transferred to the printing paper through the ink-permeable area of the plate cylinder and the perforated portion of the stencil sheet to perform printing. Is performed.

In the printing process, the ink supplied from the ink supply roller to the inner peripheral surface of the plate cylinder passes through the perforated portion of the stencil sheet and transfers to the printing paper. In this case, the ink behaves like moving in a plane direction under the base paper or returning to the inner surface of the plate cylinder. At this time, as shown in FIG. 11, the ink is more likely to accumulate near the end of the ink supply roller 4 than in the center, so that in the side edge region of the peripheral wall of the plate cylinder 1, that is, in the ink impermeable region 1b, Ink that has moved in the plane direction between the stencil sheet S and the stencil sheet S protrudes from the side edges of the stencil sheet and stains the inside of the printing press and the printing paper, which may cause so-called “side leakage”. As shown in FIG. 12, when the end of the ink supply roller 4 is located on the ink impermeable area 1b of the plate cylinder, the ink is supplied to the area 1b.
b, and the ink may leak from the gap at the plate cylinder end.

[0005]

In order to suppress this phenomenon, Japanese Patent Laid-Open Publication No. Hei 10-181178 discloses an ink supply roller as shown in FIG. The width of the ink-permeable region 1a is increased so as to be located outside the end of the outer roller 4, and the outer roller 4 is positioned such that the end of the outer roller 6 is located outside the side edge of the ink-permeable region 1a. The ink supply roller 4 is moved toward the center of the plate cylinder under conditions where ink leakage is likely to occur (wide printing paper, thick printing paper, or a high-temperature environment in which ink tends to soften). When the outer cylinder 6 presses the plate cylinder, the vicinity of the side edge of the plate cylinder is deformed in a direction away from the ink supply roller 4 so that the ink supply roller 4
To prevent the accumulation of ink between the end of the plate cylinder and the vicinity of the side edge of the plate cylinder.

Japanese Patent Application Laid-Open No. 8-267949 proposes that an ink stop member such as a weir is provided around the ink passage area on the inner peripheral surface of the plate cylinder to prevent ink leakage.

However, the method disclosed in Japanese Patent Application Laid-Open No. 10-181178 requires a special mechanism and a control device for adjusting the position of the ink supply roller, and in fact, the deformation near the side edge of the plate cylinder can be accurately detected. It is difficult to control. Also, JP-A-8-2679
Providing an ink stopper member in the plate cylinder as in JP-A-49-49 complicates the production and assembly steps of the plate cylinder.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stencil printing machine in which ink leakage from a plate cylinder is prevented only by adding a simple element.

[0009]

According to the present invention, the object is to provide a peripheral wall having an ink impervious area provided along each side edge and an ink impervious area defined therebetween. A cylindrical plate cylinder having an ink supply roller disposed in the plate cylinder adjacent to the inner surface of the peripheral wall, and an outer roller disposed outside the plate cylinder and opposed to the ink supply roller. A stencil sheet having a stencil formed thereon is wound around the outer peripheral wall of the plate cylinder, and the plate cylinder is rotated around its central axis, and the printing paper conveyed in synchronization with the rotation is rotated by the plate cylinder and the outer roller. In the stencil printing apparatus designed to perform printing on the printing paper by sandwiching the ink supply roller between A and B, the width in the width direction of the ink supply roller and the width in the ink passage area of the peripheral wall of the plate cylinder are B. When the length in the width direction of the outer roller is C, the relationship of A <B <C However, the ink supply roller is disposed so as to entirely face the ink-permeable region, the outer roller is disposed such that each end thereof faces each ink-impermeable region, and the peripheral wall is An ink shielding layer disposed so as to protrude beyond a position opposed to an adjacent end of the ink supply roller in a width direction from a side edge of the ink passage area, on an outer side than an inner surface of the peripheral wall. This is achieved by a stencil printing apparatus characterized in that:

In the present invention, the width A of the ink supply roller in the width direction, the width B of the ink passage area of the peripheral wall of the plate cylinder in the width direction, and the width C of the outer roller satisfy the relationship of A <B <C. In this way, the arrangement as shown in FIG. 2 is achieved, so that even if ink accumulates at the end of the ink supply roller, the ink leakage phenomenon shown in FIG. 12 is prevented. Further, in the present invention, since the ink shielding layer provided along the side edge of the ink passage area is disposed outside the inner surface of the peripheral wall of the plate cylinder, the inner surface of the ink passage area near the end of the ink supply roller is provided. It has no substantial effect on the uneven shape. Therefore, even when excessive ink is accumulated at the end of the ink supply roller, the supply and recovery of the ink are repeated only between the uneven portion of the inner surface of the plate cylinder peripheral wall and the ink supply roller. Can be effectively prevented. Accordingly, without adjusting the gap between the ink supply roller and the inner surface of the plate cylinder peripheral wall by the above-described conventional method,
Ink leakage from the plate cylinder can be effectively prevented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a specific example of a stencil printing apparatus according to the present invention will be described with reference to FIG.

The stencil printing apparatus shown in FIG. 1 includes a plate cylinder 1 and an outer roller 6 disposed opposite to the plate cylinder. Plate cylinder 1
Is provided with a peripheral wall formed by rolling a mesh-shaped flat plate member made of a metal screen or the like into a cylindrical shape, and fixing both side edges of the cylindrical peripheral wall to a flange (not shown). A region along both side edges of the peripheral wall adjacent to the flange is filled with a resin or the like and is sealed to be an ink impermeable region 1b (see FIG. 2), and is a region defined by being sandwiched by the region 1a. Constitute the ink passage area 1a (see FIG. 2). As in the conventional case, the plate cylinder 1 may be configured by rolling a perforated plate or punched metal into a cylindrical shape instead of a mesh-shaped flat plate member. Further, a screen layer having a fine mesh structure may be wrapped around the outer surface of the peripheral wall of the plate cylinder 1 as a single layer or a multilayer.

The plate cylinder 1 has a stencil sheet mounting seat 2 on the outer surface of the peripheral wall.
It has. A clamp piece 3 is attached to the mounting seat 2 so as to be swingable. An end of a stencil sheet (not shown) which has been made is sandwiched between the mounting seat 2 and the clamp piece 3 to form a plate cylinder. 1, so that it can be wound and held around the outer surface of the peripheral wall.

The plate cylinder 1 has an ink supply roller 4 therein. The ink supply roller 4 is disposed at a position facing the outer roller 6 so as to be inscribed or adjacent to the inner peripheral surface of the plate cylinder 1 at a slight interval. A doctor roller 5 is disposed obliquely above and so as to face and be adjacent thereto.

When the plate cylinder 1 is rotated around its central axis by driving means (not shown) and the ink supply roller 4 is rotated in the same direction, the ink supplied into the plate cylinder 1 is transferred to the ink supply roller 4 and the doctor. An ink vortex 7 is formed between the roller 5 and a predetermined amount of ink is supplied to the outer peripheral surface of the ink supply roller 4, whereby a constant amount of ink is always supplied to the peripheral wall of the plate cylinder 1. Then, the printing paper P is supplied between the plate cylinder 1 and the outer roller 4 and pressed against the plate cylinder 1 in synchronization with the rotation of the plate cylinder 1, so that the ink pierces the peripheral wall of the plate cylinder 1 and the stencil sheet. The printing paper P is transferred to the printing paper P via the printing section, and printing is performed. In order to press the printing paper P against the plate cylinder 1, the outer roller 6 may be moved in the direction of the plate cylinder 1, or the ink supply roller 4 may be moved in the direction of the outer roller 6, and the peripheral wall of the plate cylinder 1 may be moved. May be deformed so as to bulge in the direction of the outer roller 6, or the entire plate cylinder 1 may be moved in the direction of the outer roller 6.

In the specific example of FIG. 1, as shown in FIG. 2, the ink supply roller 4, the ink-permeable region 1a of the peripheral wall of the plate cylinder 1, and the outer roller 6 in the direction of the center axis of the plate cylinder (this specification). In the book, it is called "width direction")
A, B, and C are designed to satisfy the relationship of A <B <C, and the ink supply roller 4 and the outer roller 6 are arranged at the center of the ink passage area 1a, respectively. ing. As a result, the ink supply roller 4 is disposed above the ink-permeable region 1a of the plate cylinder 1, and both ends thereof do not extend above the ink-impermeable region 1b of the plate cylinder 1, but are outside. Both ends of the roller 6 extend over the ink impermeable area 1b of the plate cylinder 1.

Further, the plate cylinder of FIG. 1 is provided with an ink shielding layer along the side edge of the ink passage area 1a. Details of this configuration will be apparent from the following embodiments shown in FIGS. 3 to 10 show the left half of FIG. 2 in an enlarged manner, and the omitted right half has the same configuration.

[0018]

EXAMPLE 1 As schematically shown in FIG. 3, the thickness was 0.35 (mm) and the wire diameter was 0.23.
(Mm) A 50 mesh stainless steel screen 11 was rounded into a cylindrical shape, and regions along both side edges of the cylinder were filled with a silicone resin (ink impermeable region 1b) to form a substrate of the plate cylinder 1. Here, the length in the width direction of the ink supply roller 4
A is 290 (mm), the length B in the width direction of the ink passage area 1a of the plate cylinder 1 is 300 (mm), and the length C in the width direction of the outer roller 6 is 310 (m).
m).

Further, a length 320 in the width direction is provided on the outer circumference of the plate cylinder 1.
(Mm) 120 mesh polyester screen 12 was wound as an intermediate layer, and a 305 mesh polyester screen 13 was wound as an outermost layer on the screen 9 to form the peripheral wall of the plate cylinder 1.

On the outer peripheral surface of the screen 11, a polyester film having a width of 20 (mm) and a thickness of 10 (μm) is formed as an ink shielding layer 8 from each ink impermeable area 1b to the ink permeable area 1a. And pasted so as to overhang 10 (mm) in the width direction.

Embodiment 2 As shown in FIG. 4, the width of the screen 11 from the ink impervious area 1b to the ink permeable area 1a
The plate cylinder 1 was constructed in the same manner as in Example 1 except that the screen 11 was filled with a silicone resin to a thickness of 0.1 (mm) from the outer peripheral surface so as to protrude to form an ink shielding layer 8. As shown in the figure, since the silicone resin did not reach the inner peripheral surface of the screen 11, the inner peripheral surface of the plate cylinder 1 was kept uneven.

Example 3 As shown in FIG. 5, a polyester film having a width of 20 (mm) and a thickness of 10 (μm) was formed on the outer peripheral surface of the screen 12 as an ink shielding layer 8 from each ink impermeable area 1b. A plate cylinder 1 was constructed in the same manner as in Example 1, except that the plate cylinder 1 was adhered so as to overhang the ink-permeable region 1a by 10 (mm) in the width direction.

Embodiment 4 As shown in FIG. 6, the screen 1 has a width of 10 (mm) (processing width 20 mm) inside and outside from each side edge of the ink passage area 1a.
The plate cylinder 1 was constructed in the same manner as in Example 1 except that the ink-shielding layer 8 was formed by filling 2 with a silicone resin.

Example 5 As shown in FIG. 7, a polyester film having a width of 20 (mm) and a thickness of 10 (μm) was formed on the outer peripheral surface of the screen 13 as an ink shielding layer 8 from each ink impermeable area 1b. A plate cylinder 1 was constructed in the same manner as in Example 1, except that the plate cylinder 1 was adhered so as to overhang the ink-permeable region 1a by 10 (mm) in the width direction.

Embodiment 6 As shown in FIG. 8, the screen 1 has a width of 10 (mm) (processing width 20 mm) from inside and outside from each side edge of the ink passage area 1a.
The plate cylinder 1 was constructed in the same manner as in Example 1 except that No. 3 was filled with a silicone resin to form an ink shielding layer 8.

Comparative Example 1 As shown in FIG. 9, a plate cylinder 1 was constructed in the same manner as in Example 1 except that the ink shielding layer 8 was not provided.

Comparative Example 2 As shown in FIG. 10, the screen 11 has the same width as that of FIG.
Was filled with a silicone resin to form a plate cylinder in the same manner as in Example 2. In this case, since the silicone resin has reached the inner peripheral surface of the screen 11, the inner peripheral surface of the plate cylinder with which both ends of the ink supply roller 4 are in contact is in a smooth state.

Test Example The plate cylinders obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were used with a stencil printing machine RISOGRAPH (registered trademark) SR74 manufactured by Riso Kagaku Corporation.
The print was carried out by attaching to 00. The test was performed at 23 ° C.
Unstenciled stencil paper is wrapped around a drum.
This was performed by performing a continuous printing operation on 00 sheets. After printing, the state of ink accumulation and side leakage between the side edge of the stencil sheet and the plate cylinder was visually observed. Table 1 shows the test results.

[0029]

[Table 1]

The symbols in Table 1 mean the following:…: no ink accumulation or leakage occurred; △: small amount of ink accumulation occurred, but did not result in leakage; x: ink leakage There has occurred.

[0031]

According to the present invention, the length A in the width direction of the ink supply roller and the length in the width direction of the ink passage area of the peripheral wall of the plate cylinder are provided.
B, the width C of the outer roller satisfies the relationship of A <B <C to achieve the arrangement shown in FIG. 2, and the ink shielding layer is formed along the side edge of the ink-permeable area, When the ink is placed outside the inner peripheral surface of the plate cylinder, the inner surface of the ink passage area near the end of the ink supply roller is kept uneven, so that excess ink is accumulated at the end of the ink supply roller. However, the ink is repeatedly supplied and collected only between the uneven portion of the inner surface of the plate cylinder peripheral wall and the ink supply roller, and is effectively prevented from leaking from the side edge of the plate cylinder. Therefore, it is not necessary to adjust the size of the gap between the ink supply roller and the inner surface of the peripheral wall of the plate cylinder by a conventional method, and it is possible to effectively prevent the ink from leaking from the plate cylinder and obtain a uniform image. Can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a specific example of a stencil printing apparatus of the present invention.

FIG. 2 is a schematic cross-sectional view showing the arrangement of an ink supply roller, an ink passage area of a plate cylinder, and an outer roller of the stencil printing apparatus of the present invention.

FIG. 3 is a schematic view showing an ink shielding layer of Example 1.

FIG. 4 is a schematic view showing an ink shielding layer of Example 2.

FIG. 5 is a schematic view showing an ink shielding layer of Example 3.

FIG. 6 is a schematic view showing an ink shielding layer of Example 4.

FIG. 7 is a schematic view showing an ink shielding layer of Example 5.

FIG. 8 is a schematic view showing an ink shielding layer of Example 6.

FIG. 9 is a schematic view showing a plate cylinder of Comparative Example 1.

FIG. 10 is a schematic diagram showing a plate cylinder of Comparative Example 2.

FIG. 11 is a schematic view showing a configuration of a conventional plate cylinder.

FIG. 12 is a schematic view showing a configuration of a conventional plate cylinder.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 plate cylinder 1a ink-permeable area 1b ink-impermeable area 2 stencil sheet mounting seat 3 clamp piece 4 ink supply roller 5 doctor roller 6 outer roller 7 ink 8 ink shielding layer 11 screen 12 intermediate layer (120 mesh screen) 13 Outer layer (305 mesh screen) S stencil paper P printing paper

Claims (5)

[Claims] 1. A cylindrical plate cylinder having a peripheral wall having an ink impervious area provided along each side edge and an ink impervious area defined therebetween, and a cylindrical plate cylinder adjacent to an inner surface of the peripheral wall. An ink supply roller disposed in the plate cylinder, and an outer roller disposed outside the plate cylinder so as to face the ink supply roller. And rotating the plate cylinder about its central axis, and printing on the printing paper by sandwiching the printing paper conveyed in synchronization with the rotation between the plate cylinder and the outer roller. In the stencil printing machine described above, when the width direction length of the ink supply roller is A, the width direction length of the ink-permeable area of the plate cylinder peripheral wall is B, and the width direction length of the outer roller is C. A <B <C, and the entire ink supply roller The outer roller is arranged so as to face the ink-impermeable area, the outer roller is arranged such that each end faces each ink-impermeable area, and the peripheral wall has a width from a side edge of the ink-impermeable area. A stencil printing machine comprising an ink shielding layer disposed so as to extend beyond a position facing an adjacent end of the ink supply roller in the direction of the ink supply roller, outside the inner surface of the peripheral wall. 2. The stencil printing machine according to claim 1, wherein the ink shielding layer is formed by attaching a film to an outer surface of the peripheral wall. 3. The stencil plate according to claim 1, wherein the ink shielding layer is formed by closing an ink-permeable region of the peripheral wall from an outer surface thereof with a material having a thickness smaller than the thickness of the peripheral wall. Printing device. 4. The screen according to claim 1, wherein the peripheral wall further includes a screen layer wound around an outer surface thereof, and the ink shielding layer is formed by attaching a film to an outer surface of the screen layer. Item 2. A stencil printing apparatus according to item 1. 5. The peripheral wall further includes a screen layer wound on an outer surface thereof, and the ink shielding layer is formed by closing the screen layer with a suitable material. 2. The stencil printing machine according to 1.