JPH0233516B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The object of the invention is a device for supplying ink to the plates of letterpress, offset, flexograph and other printing presses.

[Prior Art] The inking devices installed in almost all printing presses are similar and handle only one type of ink for each printing. The configuration and functions of these mechanisms are as follows.

The ink fountain serves as an ink storage and ink supply, and the amount of ink flow is controlled by deforming a flexible steel blade that engages a metal roller called an "ink ductor roller." The ink is
It enters between this blade and the ink fountain roller,
An ink film forms on the surface of the ink ductor roller, the thickness of which is determined by the pressure applied to the underside of the blade by an adjustment screw.

A device in which flexible rollers and metal rollers are arranged alternately transfers and adjusts the ink film so that it is suitable for inking. Depending on the manufacturer and the viscosity and quality of the applied ink, the number, diameter, and arrangement of flexible and metal rollers will vary.

With this type of inking principle, the ink fountain can only roughly adjust the thickness of the ink film in zones with a width of approximately 20 to 40 mm. Ink ductor rollers are generally adjustable in extrusion.

The ink film emerging from the outlet of the ink fountain is relatively thick and unsuitable for good inking, but its refinement is achieved by ink mixing rollers that stretch, roll, mix and homogenize the ink film. It is done. The ink mixing roller refines the ink film through this action, and because it moves in the axial direction and also rotates, it is called a "swinging roller".
It is called. The ink mixing roller adjusts the ink film zone by zone to avoid unevenness caused by the surface tension of the ink.

The ink film applied to the printing press plate must have perfect regularity and consistency of thickness in a given zone. The allowable error is about 2 to 3 μm above and below the target value.

The ink that forms the ink film has a certain degree of viscosity determined by its composition, by additives, if any, and by the mechanical properties of the ink applicator, depending on factors such as paper and printing type. Must be.

The quality of ink mixing largely determines the quality of printing.

[Problem to be solved by the invention]

Conventional inking devices can also largely meet the above requirements. However, conventional inking devices have the following drawbacks in addition to being bulky.

Since the thickness of the ink film cannot be precisely adjusted in each narrow zone, it is difficult to perform soft tint printing of lowercase letters in juxtaposition.

If the surface area to be printed is negligibly small compared to the total printing area of the printing press, the consumption of ink will be unreasonably high. This consumption prints in various colors,
This becomes noticeable when printing a small number of sheets in succession.

At the beginning of printing, the ink cannot be stabilized until after a considerable number of copies have been printed, leading to wasted paper.

Based on the basic principles of this type of inking, it is inappropriate to apply inks of various colors in one printing. This is because the swing roller quickly mixes the ink while moving and rotating in the axial direction, making it impossible to supply a thin ink film of each color from the ink fountain or to adjust the flow rate.

Several patents have been filed with the aim of eliminating these drawbacks. All of these patents use slightly different methods, but are based on the same printing principle, using circumferential grooves on the inking roller or the rollers before and after it, or by scraping the remaining ink after mixing by the inking roller. It is proposed to create discontinuous zones between inks of different colors by These methods are temporary measures, and the ink application locations are different from each other, making them unsuitable for continuous printing of extremely small numbers of sheets. The mere fact that a special swing roller, not to mention the ink fountain, has to be adjusted for each different print represents extra work for the printer and is often not compatible with time economy. This actually negates the advantages of this method.

If a printing company wants to print in multiple colors, it must handle each color one by one, and it must run as many prints on the printing press as there are colors. An exception to this is three-color printing or four-color printing, in which any color can theoretically be achieved by superimposing three primary colors. However, this printing is limited to certain types of printed matter and still requires three or four passes through the printing press.

Therefore, it is difficult to perform multicolor printing at low cost.

French Patent No. 1275206, No. 1341700 and No.
2194570 presents a solution for simplifying conventional inking devices by eliminating almost the entire row of inking rollers.

The basic idea of the above patent is that two rollers,
That is, by pressing a metal roller and a roller coated with a flexible material together and applying ink directly to the offset plate, a single rolled and metered ink film is produced. With this method, it is not possible to adjust the thickness of the ink film for each zone or to separate inks of different colors. This solution theoretically uses the same amount of ink for each point on the plate. This appears to be satisfactory in the case of offset printing, where one color or one type of ink is used for each print. This is because almost all offset printing presses in use are equipped with inking devices with adjustment screws for each zone, similar to those used in letterpress printing.

In the case of letterpress printing, especially in the case of flat presses where pressure adjustment is not easy depending on the smoothness of the plate surface and is extremely affected by ink deposition, it is possible to adjust the thickness of the ink film zone by zone. It is essential.

Ink has different density and viscosity depending on its type or color, so to achieve the specified ink application,
It is necessary to adjust to various thicknesses. In order to realize an offset or letterpress inking device that processes several colors simultaneously, where each ink film has to be inked individually, the above-mentioned considerations have to be taken into account, Adjustments must be made to allow the printer to use a thin "ribbon" of ink.

[Means for solving problems]

According to the object of the present invention, an inking device is provided which is used to form one or several ink films on a metal roller functioning as an inking plate, which is suitable for direct inking onto printing plates. The thickness of the ink film can be finely adjusted in each narrow zone.

The apparatus of the present invention eliminates the ink mixing roller bank and allows inks of different colors or properties to be contained in separate compartments within a highly accurate rotary ink fountain. The ink fountain roller is preferably made of metal;
Ink is applied to the ink application roller that applies ink to the printing plate.

According to the present invention, the ink forming roller is eliminated;
Ink can be applied directly to the printing plate using a special metal roller that acts as a heat sink and is coated with an elastomer whose flexibility does not interfere with the formation of an ink film. In this case, the separator is made of a self-lubricating flexible material such as Teflon, and the coated elastomer on the surface of the coated roller can be protected with varnish to prevent damage to the areas on which the ink separator acts.

Alternatively, a metal ink mixer may be used and an elastomer-coated roller may be added to transfer the ink film from the ink mixer to the plate surface. Note that the rotation of the roller must closely match the rotation of the printing plate support so that the ink lands on the same location each time the roller rotates.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings, but what will be described here is one type or number of applications that can be incorporated into a flat pressure printing press, which is one of the many application examples of the present invention. Relating to a seed inking device.

This type of inking device, which will be explained below, is manufactured with extremely high mechanical precision, and the operating parts that form and dispense the ink film are machined to a depth of about 2 to 3 μm plus or minus the target value. Tolerances required.

The selection of steel used and the accuracy of the grinding are also important in this example.

The underframe of the inking device according to the invention consists of two side plates 1 which are rigidly connected by keyed tie beams 3. The two movable side plates 2 supported by this underframe swing when the two cams 13 are moved by the support shaft of the operating lever 14.
The function of this operating lever is to
The purpose is to stop ink deposition by separating the ink dispenser roller 4 from the ink applicator roller 11. An ink release roller 4 connecting two movable side plates 2 receives the ink film. The ink fountain roller 4 has a shaft that rotates between two double race ball bearings 28 with automatic clearance adjustment (see FIG. 2). As shown in FIG. 2, the inside of the ink dispenser roller 4 acts as a radiator to dissipate the amount of heat generated by the rolling of the ink and also due to the friction of the separator 15 that partitions the ink in the case of multicolor printing. A plurality of blades 30 are provided. The circumferential surface portion 29 covering the above blade is several 1/10 mm
It is hard chrome plated throughout and is finely polished or polished to increase the adhesion and ductility of the ink film. This circumferential surface portion 29 is carefully ground before being polished. The example gear 12 shown in FIG. 1 moves in accordance with the movement of the printing plate, and the movement of this gear train drives the ink dispenser roller 4.
The ink applicator roller 11 is directly inked by the ink ductor roller 4, and the ink film is re-formed on the ink ductor roller 4 with each revolution.

The abutment 24A shown projecting upwardly on the rear side in the second embodiment of FIG. It is attached by two girdle receivers formed of. The support base is removable so that the ink fountain can be cleaned.

The adjustment screw holder 20 shown in FIGS.
is firmly fixed. The screw 18A shown in the second embodiment of FIG. 4 acts on a lever 19A that can displace and adjust the blade 25A. In the first embodiment shown in Figures 1-3, each blade is independently adjustable. Abutment 24 and adjustment screw holder 2
0 is machined from hardened and polished steel with high mechanical strength.

Each blade 25 shown in FIGS. 2 and 3 is
Made of heat-treated spring steel that has both hardness and elasticity. The 35 blades 25 shown in FIG. 3 forming this device are hardened and polished on all surfaces.

A member 31 shown in FIG. 3 made of heat-treated steel serves as a reference angle for attaching the blade 25. The member is ground so that it is rigidly fixed to the abutment 24 and serves as a mounting angle reference.

Attaching the blade 25 to its abutment 24 requires great care. To install, immerse the entire part in a solvent and then dry with compressed air.

The first blade 25 is placed against the mounting angle reference member 31 shown in FIG. 3 and fixed with a key, and the next blade is placed next to the first blade before being fixed. In this way, one after another, the last blade 2
5, this last blade retains the blade assembly over its entire length by means of a clamping member 32 to keep it in shape. An airtight joint 21 is provided to prevent the mechanical adjustment from becoming contaminated. The blades are adjacent to each other and can be displaced relative to each other without affecting their degree of adjustment. The blades are impermeable to ink and in the null position abut a stop 23, shown in FIG. 2, which adjusts each blade 25 to the same position. These individual blades together form a single blade assembly which is precisely shaped and precisely honed in the portion facing the mating ink fountain roller 4. .

The ink conveyed by the ink ductor roller 4 is rolled, homogenized, and
An ink film suitable for printing is formed, which is conventionally removed from the ink fountain 27 between the ink cartridge and the blade 25.

The thickness of the ink film can be adjusted in 1μm increments.
One rotation of the screw corresponds to approximately 10 μm.

The cam 9 and its operating lever 8 shown in FIG. 1 adjust the overall ink application by elastically deforming the two movable side plates 2 that support the ink dispenser roller 4.

The positioning screw 5 makes it possible to precisely determine the position of the ink fountain in relation to the ink fountain roller 4.

The blade assembly is set approximately 5 .mu.m from the ink ductor roller 4 and must not touch the ink ductor roller to avoid abnormal blade wear and harmful heating of the device.

As is clear from FIGS. 1 to 3, the separator holder 16 holds the separator holder 16, and the bearing screw 17
The separator 15 whose position relative to the ink dispenser roller 4 is adjusted by the separator 15 ensures division of various inks.

Pressure roller 10 made of rubber with shore hardness of approximately 70
equalizes the ink film when the ink contains impurities.

The separator is made of a rigid or semi-rigid material of the type such as high molecular weight polyurethane, polyethylene, etc., and is made of wicks to limit heating or abrasion during printing.
or lubricated by other known methods or made of microporous material. The material is impregnated with wax or with a lubricating liquid, e.g. an ink repellent such as silicone, before use. Water acting on a chromed surface is also a good ink repellent.

As an example, a method for manufacturing a separator that hardly increases temperature will be described below.

Approximately 500g per ^1m2 , 1mm thick felt paper,
Approximately 15% of protected polyurethane or epoxy resin
% solution to fix the fibers, and then impregnated with wax having a melting point of about 90°. After cooling, the separator is cut and finished. Next, the parts of the separator that come into contact with the blades and the ink fountain roller are impregnated with a hard putty that resists the pressure of the rolled ink and ensures complete sealing.

The above putty is made from wax and synthetic resin.

Depending on the type of paper and ink used, the ink may be gelled before printing.

Another aspect of the invention concerns the simplification of the manufacture of the inking device and is primarily well suited for the manufacture of semi-professional offset machines.

In this form, it is not necessary to adjust the ink flow rate for each narrow zone, and it is not necessary to adjust the ink flow rate for each narrow zone.
A single hard blade 25A is used in place of the blade 25A shown in the figure. This blade is precisely shaped and its general adjustment is carried out in the same way as for the collecting blade 25 (see FIG. 4).

When working with inks of various colors and properties at the same time in this format, it is essential to be able to vary the pigment density of the ink depending on the color density of the shade to be achieved, instead of adjusting the ink flow rate zone by zone. . In fact, for the same shade, the color density is variable and changes directly in relation to the pigment density of the ink.

As an example, here is a simple way to change the pigment density of an ink to your liking.

The ink used may have a high pigment concentration;
Depending on the color density to be achieved, it may be diluted with known transparent additives. The basic adjustment for inking is based on the darkest tone, and other tones are adjusted based on this. Of course, the reverse operation may be used to thicken the ink by adding the same type of pigment to the ink that needs to be thickened. By using a densitometer, such adjustments can be made accurately and easily.

There are various types of mechanisms for supplying water to offset printing presses.

Inking devices, which are mainly installed on semi-professional printing presses, add water directly to the ink. However, most professional printing presses have one or more rollers, called "moisturizing rollers", which provide the necessary water to the plates. Some of these rollers have rotating and oscillating movements.

In many cases, due to the nature of ink, it is extremely difficult to prevent even a small amount of water from migrating into the ink. Therefore, when it is desired to handle inks of various colors or properties at the same time, the oscillating motion of the "humidifying roller" is necessary to prevent the water already mixed with the ink of one color from coming into contact with the ink of another color. need to be stopped.

〔Effect of the invention〕

It is more compact, more accurate, and more practical than conventional inking devices, and can process multiple inks of different colors or types at the same time, each with a width of 1 mm or less. The incorporation into a machine provides extremely advantageous applications of the present invention.

In addition to the above-mentioned wide range of applications of the invention in conventional printing presses, the invention also finds wide application in the printing of labels, paper, wrapping paper, etc.

There is no need to apply ink to the entire plate, and ink can be applied to specific areas depending on the printed material, so when printing small amounts of various colors one after another,
Alternatively, if the printing surface is small compared to the total printing surface of the printing press, significant ink savings can be made.

[Brief explanation of drawings]

FIG. 1 shows a partial side view of an inking device according to the invention. FIG. 2 is a detailed side view of the ink fountain roller and separator holder shown in FIG. 1. 3 is a detailed bottom view of the separator holder shown in FIG. 2. FIG. Figure 4 is similar to Figures 2 and 3.
3 is a detailed side view of a second embodiment of the abutment for adjusting the blade shown in the figures; FIG. 1... Side plate, 4... Ink dispenser roller, 11...
...Ink applicator roller, 12...Gear train, 13...
Cam, 20...Adjustment screw holder, 24...Abutment, 25...Blade, 27...Ink fountain.

Claims (1)

[Claims] 1. A flat circumferential surface coated with a hardened elastomer 2.
9 and radiates heat from this circumferential surface.
a blade 25 that adjusts the thickness of the ink supplied in a thin ribbon shape from the ink fountain to the circumferential surface 29 of the ink fountain roller 4; and a circumferential surface of the ink fountain roller 4. Lever mechanism 1 that can adjust the tip position of the blade 25 with respect to 29
8, 19, a separator 15 that partitions the inside of the ink fountain into a plurality of narrow sections, and a screw 17 that adjusts the pressing pressure of each separator 15 against the circumferential surface 29 of the ink fountain roller 4.
and an ink applicator roller 11 that transfers a thin ribbon-shaped ink film from the ink dispenser roller 4 and transfers it to the print. 2 Flat circumferential surface 2 coated with hardened elastomer
9 and radiates heat from this circumferential surface.
a blade 25 that adjusts the thickness of the ink supplied in a thin ribbon shape from the ink fountain to the circumferential surface 29 of the ink fountain roller 4; and a circumferential surface of the ink fountain roller 4. Lever mechanism 1 that can adjust the tip position of the blade 25 with respect to 29
8, 19, a separator 15 that partitions the inside of the ink fountain into a plurality of narrow sections, one side of the separator 15 is in contact with the circumferential surface of the ink fountain roller 4, and another side of the separator is in contact with at least one narrow section. A holder 16 that holds the separator so that it is in contact with the ink fountain forming surface of the blade, and a screw 17 that adjusts the pressing pressure of each separator 15 against the circumferential surface 29 of the ink fountain roller 4.
and an ink applicator roller 11 that transfers a thin ribbon-shaped ink film from the ink dispenser roller 4 and transfers it to the plate surface.