JPS63242546A - Ink-turbidity preventive device in ink supply system of offset press - Google Patents

Abstract

PURPOSE:To prevent an ink from invading into an ink supply system for another ink via a pressplate therefor, by a method wherein a rotatable body is brought into contact with a transfer roller or an ink cylinder at the position just after it came into contact with the adjacent surface downstream of an ink supply order, and a doctor knife is abutted on the periphery of the rotating body at a position downstream in the rotating direction. CONSTITUTION:An ink-turbidity preventive device is so disposed that a rotating body 1 is in contact with either a transfer roller 7 or an ink cylinder 8. A doctor knife 5 is so disposed as to contact the periphery of the rotating body 1 at a position downstream of the contact point of the transfer roller 7 or the ink cylinder 8 in the rotating direction of the rotating body 1. A black ink transferred to the transfer roller 7 or the ink cylinder 8 provided with the ink-turbidity preventive device in an ink supply system SI of a supplementary printing device SP is transferred to and accepted by the rotating body 1 rotating in contact with the roller 7 or the ink cylinder 8, furthermore being scraped off from the surface of the rotating body by a doctor knife 5 due to the rotation of the rotating body 1 to be recovered into an ink-recovery pan 6.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention is directed to the problem of ink turbidity in the ink supply system of an offset printing press that prints on the same side of a printing medium with different types of ink supplied by a plurality of ink supply systems. Regarding prevention devices.

[Prior art] The ink supply system of an offset printing press in the conventional technology, which prints on the same side of a printing material using different types of ink supplied by a plurality of ink supply systems, uses an upstream ink fountain or an ink fountain. It consists of a rail, an inking roller downstream, and a number of rollers and cylinders in between (for example, the 1971 Japan Newspaper Association).
(Refer to pages 208 to 210 of ``Newspaper Printing/Printing Edition Revised Edition'' published on September 310).

[Problems to be Solved by the Invention] Offset printing machine 1 that prints on the same side of a printing medium using different types of ink supplied by a plurality of ink supply systems
For example, in a rotary offset printing press with a supplementary printing device, printing plates using different types of ink share the same blanket surface, so each ink enters the ink supply system via the printing plate surface of the ink in the pond. invade.

Intrusion of such different types of ink into the ink supply system leads to ink kneading and, in particular, to turbidity.

Inks with weak color fit and brightness are required. When it comes to ink, the hue and brightness change, resulting in a decrease in print quality5! -It's coming.

[Means for Solving the Problems] This invention provides a method for preventing ink turbidity in an ink supply system of an offset printing press that prints with different types of ink supplied by a plurality of ink supply systems to the same surface of a printing medium. As for F2, there are fewer rollers and cylinders in one ink supply system.

Or, a rotatable rotating body is brought into contact with the position of the immediate crest that has been in contact with the adjacent surface on the downstream side of the ink supply order on one of the circumferential surfaces of the rotating body, and a position on the r-stream side in the rotational direction from the above-mentioned position with respect to the circumferential surface of the rotating body. A doctor knife is brought into contact with the ink, and a collector for scraping ink by the doctor knife is provided.

[Sakukawa] In the printing press, printing is performed using different types of ink supplied by multiple ink supply systems to the same side of the printing material. The pre-printed ink transferred from the printing surface to the blanket surface of the post-printing plate, enters the ink supply system through the printing plate surface of the post-printing plate, or is transferred from the printing plate surface of one ink to the shared planner surface. The ink transferred onto one side may enter the other ink supply system through the other ink printing plate surface.

When the ink that has entered is transferred to a roller or cylinder that is provided with an ink turbidity prevention device in the ink supply system, it is transferred and received by a rotating body that rotates in contact with the roller or cylinder.

Furthermore, as the rotary body rotates, the ink is scraped off from the circumferential surface of the rotary body using a doctor knife, collected in an ink collector, and then discharged to the outside.

[Example] Offsera 1 with reprinting device as an example of an offset printing press that prints on the same side of a printing material with different types of ink supplied by a plurality of ink supply systems - Ink supply system of a rotary printing press An embodiment in which the ink turbidity prevention device according to the present invention is applied will be described according to the 1:4 aspect.

As schematically shown in FIGS. 2(a) and 3(a), the offset rotary printing press with a reprinting device is equipped with the Shoshishiso V! 1
The ink turbidity prevention device according to the present invention is composed of a reprinting device SP and a reprinting device SP. It is provided in the ink supply system SI of ISr.

To explain the ink turbidity prevention device in detail, in FIG. 1, there is shown a rotary body 1 having an appropriate width in the axial direction and whose peripheral surface is made of a material with good ink receptivity.

For example, it is rotatably supported by a support shaft 4 at the tip of a bracket 3 attached to a stay 2 installed between frames (not shown) of a printing unit.

A doctor knife 5 is attached to the bracket 3, the tip of which comes into contact with the entire circumferential width of the rotating body 1, and an ink collector 6 is also attached directly below the doctor knife 5. The contact pressure and/or the contact angle of the doctor knife 5 can be adjusted by known means, and the ink collector 6 has a vent pipe (not shown) extending outside the printing unit. ) may be connected, and may be suctioned with a pump if necessary.

The installation position of the bracket 3 can be changed arbitrarily in the longitudinal direction of the stay 2. For example, as shown in Fig. The stay 2 can be fitted freely and fixed with a wedge at any position, or with a bolt screwed into the screw hole row of the stay 2 or the screw hole at the base of the bracket.
In the case of a round land, the bracket base may be formed into a clamping part that can be freely tightened, and the clamping part may be fitted onto the stay 2.

In the ink supply system Sl of the capture printing device S11.

・The ink turbidity prevention device is designed so that the rotating body 1 comes into contact with the roller rough as shown in FIG. 2(d), or
1m), it is installed so as to be in contact with the ink cylinder 8. Or, in some cases, it may be installed in both for more complete v1 functionality. ,Moreover,
This is because it prevents the ink from being sent back from the common blanket cylinder 9 and becoming cloudy.

In terms of effectiveness, it is preferable to install the ink turbidity prevention device as downstream as possible in the ink supply order of the ink supply system.

Then, the contact point of the doctor no-if 5 on the circumferential surface of one revolution 1 (:!) is the transition roller 7 or the ink cylinder 8.
The F flow value is 1d in the rotational direction of the rotating body l from the point of contact with the rotating body l.

If the object to be contacted is rubber such as a crossing roller, the surface of the rotating body l may remain copper or a copper alloy, for example, or
Or those plated or coated with these are preferable, and when the object to be in contact with is metal like the C Rexylinder 8, 1. Preferably.

In the example shown in ``-'', contamination of reprint ink with black ink is less of a problem from 1 color 1111-, so considering only the contamination of reprint ink with reprint ink, the ink turbidity prevention bag is It is installed only on the hn printing side.

Depending on the type of ink, install it on both sides.

The operation and function of the ink turbidity prevention device of C ink a (yarn feeding S) described in 2 will be described.

In the ink supply system S1 of the supplementary printing system Jll Sp.

The reprint ink stored in the ink fountain 11 is IN.

Crossing roller 7. It is supplied to the printing plate surface of the ha printing plate 15110 via the ink cylinder 8, etc., and the shared plate! −
It is transferred to the blanket surface of the trunk 9. 0 of the reprinting ink in the capture printing device and the printing ink supply system Sl (the red feeding path is the second
It is shown by a solid line in Figure (b) and Figure 3 (1)).

Also in the ink printing machine Tap, m and (ngi) are transferred to the plunket surface of the shared plankellers I to F519 with the same m.

The common blanket cylinder 9 is the 2nd Ufi (a) and the 31st Ufi (a).
′! 1(a), the printing paper U is printed by rotating counterclockwise. After that, the ink remaining on the black printing image area of the Plancher 1-side comes into contact with the non-image area on the printing plate surface of the hn printing plate cylinder IO, and the reprinting plate jn4
The non-image areas of the printing plate surface -1- of No. 10 are gradually sensitized by the residual ink.

In particular, in the printing area and its vicinity of the printing plate surface of the reprinting plate cylinder 10, the reprinting ink is wet enough to cause water loss and cannot be washed with water.
The non-printing area near the printing area on the printing plate surface J- of 0 is more 6 fat 1 Hi than other non-printing areas Ii! stomach.

Eventually, the residual black ink from Prankera 1 and Surface 2 was transferred to the oil-sensitized area, and the ink was

The ink supply system 81 l of the reprinting unit Bsp will be invaded.

However, in the ink supply system Sl of SP in hn printing equipment. Crossing roller equipped with an ink turbidity prevention device 7. Alternatively, the ink transferred to the ink cylinder 8 is transferred to the transfer roller 7. Alternatively, the dislocation is received by the rotating body l that rotates in contact with the ink cylinder 8.

Further, as the rotating body 1 rotates, the doctor knife 5 is dropped 1f1 from the surface of the rotating body and is collected in the ink collector (i).In a device equipped with a discharge pipe, the printing unit is removed by the discharge pipe.
・It is discharged outside.

The intrusion and removal route of the residual black ink reprinting device/rink supply thread SI\ is shown by broken lines in 2F4(b) and 3(b).

In this way, the residual amount of ink does not enter the reprinting device/ink 0 (from the ink turbidity prevention device in yarn feeding Sl), and the residual black ink does not mix and become turbid with the reprinting ink.

As described in detail above, intrusion of residual black ink often occurs from the image section and/or the non-image section on the side of the image section on the printing plate surface of post-printing.

Therefore, the position of the bracket device of the stay L is adjusted so that the contact area of one rotating body 1 corresponds to the area where residual and rotary intrusions occur frequently, or the number of brackets, that is, the number of rotary bodies installed is increased or decreased as appropriate.

The applicable printing system in the example in 1- is an offset rotary printing press with a supplementary printing device that shares the blanket cylinder.
The present invention can also be applied to a multicolor offset rotary printing press that does not share a plunket cylinder, and in that case, an ink turbidity prevention device is added to one ink supply system for post-printing. Provide t.

[Effect of the invention] The ink turbidity prevention device according to the invention is installed in the ink supply system.
! 2, dissimilar ink that has passed through the printing plate surface is removed by being scraped off from the circumferential surface of the roller or cylinder in the ink supply system via a rotating body, thereby reducing the mixing and turbidity of dissimilar ink. is prevented.

79 makes it possible to maintain the hue of the ink even when printing with a weak ink or an ink that requires brightness for a long time, allowing for high quality, wide variety of ink printing. can be obtained efficiently.

Moreover, the ink turbidity prevention device according to the present invention has already been developed (j
It is possible to install the ink 0 (yarn feeder) of an off-pit printing machine in Ura 111.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an ink turbidity prevention device according to the present invention in an ink supply system of a reprinting device of a rotary offset printing press. FIG. 2 is according to this invention. (Schematic diagram of an offset rotary printing press showing an example of application of the ink turbidity prevention device to the ink supply system of the reprinting device. Offsera 1- showing an application example of
7I, which is a schematic diagram of a rotary printing press: Black printing! A mouth
SP: Supplementary printing device SL: Supplementary printing device, ink supply system U: Rotating body for printing paper 2 Nisty 3 Nibracket 4: Support shaft 5: Doctor na, f 6: Ink recovery 7: Crossing reroll 8: Ink cylinder 9 : Plunket cylinder lO: Reprint cylinder 11: Ink fountain

Claims (3)

[Claims] (1) In an ink supply system of an offset printing press that prints on the same side of a printing material using different types of ink supplied by a plurality of ink supply systems, a roller and/or a cylinder in at least one ink supply system. A freely rotatable rotating body that contacts the peripheral surface of the rotary body at a position immediately after the contact history with the adjacent surface on the downstream side of the ink supply order, and a doctor knife that contacts the peripheral surface of the rotating body at a position downstream of the said position in the rotational direction. and an ink turbidity prevention device for the ink supply system, which consists of a scraping ink collector using a doctor knife. (2) An ink turbidity prevention device for an ink supply system according to claim 1, wherein the rotating body is divided in the axial direction. (3) An ink turbidity prevention device for an ink supply system according to claim 1 or 2, wherein the rotating body is adjustable in position in the axial direction.