SET OF DEVICES FOR IMPROVING THE OFFSET PRINTING SYSTEM

Abstract

 The present utility model relates to the set of devices for the offset printing system, which devices reduce the water surface tension which is thus more uniformly distributed on the offset plate allowing the surface thereof to be dampened with a smaller quantity of water. The present utility model achieves excellent offset printing quality with only 20% of the amount of dampening solution which is normally used, and 0% isopropylic acid, which is also regularly used in Alcolor printers.

Description

TECHNICAL FIELD

[0001] The present utility model relates to a set of devices for improving the offset printing system. More specifically, the utility model modifies the molecular structure of water by reducing the surface tension so that a smaller amount of water can wet a larger area of the printing plate of the offset system.

BACKGROUND ART

[0002] Offset printing is a planographic process whose essence consists of repulsion between water and grease (greasy paint).
The term off-set comes from "offset lithography" (literally, out-of-place lithography), making reference to indirect printing (in lithography, printing was direct with paper having direct contact with the matrix).

[0003] Nowadays in the offset printing system, a wetting solution or simply source solution composed of several chemicals is used. Among the chemicals that make up a wetting solution there are water, glycol, acids, bases, natural gum, detergent, fungicide, bactericide and others.

[0004] The wetting solution reduces the water surface tension, helps to wash the grease off the offset plate and eliminates fungi and bacteria but has serious drawbacks, such as favoring the emulsification of the paint that causes imbalance during the process with consequent increase of dot gain, loss of brightness, loss of drying, increased ink consumption and paper breakage in the rotary printers, shortening of blanket and roll life and the disposal of water from the wetting system with high level of chemicals.

[0005] There are printers that use isopropyl alcohol in the offset printing process, which help the wetting system by reducing tarnish and possible print defects. This product causes strong smell in the printing room, is aggressive in direct contact with the skin, besides being another chemical for disposal.

[0006] International Patent Application PCT/JP2007/074167 on behalf of NIPPON LITHOGRAPH, INC. and entitled "system for providing dampening water by lowering the surface tension of water to be used in offset printing, so-called lithographic printing system" describes a water treatment system for providing wetting solution for offset printing which comprises: a channel through which water can flow; a processor for magnetically treating the water passing through the channel; and a photocatalytic processor for photocatalytically treating the water passing through the channel. The abovementioned document reduces 100% of the wetting solution and isopropyl alcohol by 100%.

SUMMARY OF THE INVENTION

[0007] The present utility model will provide significant advantages over the devices used in the offset printing system, allowing an increase of its performance and presenting a more favorable cost-benefit ratio.

[0008] The present utility model refers to a set of devices for improving the offset printing system.

[0009] Specifically, the present utility model modifies the molecular structure of water by reducing the surface tension so that a smaller amount of water can wet a larger area of the printing plate of the offset system.

[0010] The world is increasingly focused on preservation and sustainability of nature and in this context the present utility model was developed for new printers to reduce 100% the use of the wetting solution, which is composed of several chemicals and isopropyl alcohol by 100% in Alcolor printers. In used printers if there are gaps in the rollers there will be a reduction of up to 80% the use of the wetting solution which is composed of several chemicals and isopropyl alcohol by 100% in Alcolor printers.

[0011] The present utility model reduces the water surface tension, which is distributed with better uniformity in the offset plate, thus allowing wetting an area with less water.

[0012] The lower the amount of water in the wetting system of an offset printer, the better the print quality will be. By reducing the system water automatically, the ink load should be reduced resulting in a lower emulsification index as a consequence.

BRIEF DESCRIPTION OF DRAWINGS

[0013] The structure and operation of the present utility model together with additional advantages thereof may be better understood by reference to the accompanying drawings and the following descriptions:

Figure 1 shows a flowchart with the devices present in one embodiment of the present utility model;

Figure 2 shows a front view of the devices present in one embodiment of the present utility model; and

Figure 3 shows the system devices for improving the offset printing system of one embodiment of the present utility model.

DETAILED DESCRIPTION OF THE INVENTION

[0014] While the present utility model may be susceptible to different embodiments, the preferred embodiment is set forth in the following detailed description with the understanding that it should be considered exemplary of the principles of the invention and is not intended to limit the scope of the present utility model to what has been illustrated and described herein.

[0015] The offset printing system is comprised of a mutual rejection between water and paint. The offset plate is composed by graphics and counter-graphics areas. In the graphics area there is a pre-sensitive layer with lipophilic characteristic that rejects the water and has affinity with the ink for being oily. In the counter-graphics area is the aluminum substrate with cavities that accumulate tiny droplets of water with hydrophilic characteristics that reject the paint.

[0016] The present utility model reduces the water surface tension, which is distributed with better uniformity in the offset plate, thus allowing to wet an area with less water.

[0017] The lower the amount of water in the wetting system of an offset printer, the better the print quality will be. By reducing the system water automatically, the ink load should be reduced resulting in a lower emulsification index as a consequence.

[0018] The present utility model allows the desired water-ink balance to be gained, such as:

• balance of printing throughout the process;
• lower point gain;
• higher brightness;
• better ink drying;
• ink consumption savings;
• paper consumption savings;
• Less paper shredding on rotating printers.

[0019] The present utility model is composed of the following devices:

(1) - Cartridge filter - to minimize the amount of molecular residues and particulates present in the water from the public network, thus avoiding accumulation of impurities in the bottom of the lung tank.

(2) - Lung tank - storing public water treated by this utility model and feeding the metering tank with electric float. The return of the tubs falls into the metering tank without having contact with the lung tank.

(3) Refrigerator - coupled to the lung tank that stores the water treated by the present utility model while maintaining the temperature between 12 - 16°C. The water treated by the present utility model already promotes very low emulsification level of the paint and keep with the temperature between 12 - 16°C, reducing even more the possibility of emulsifying. When printers work at high speed, the print cylinders reach high temperatures, which are undesirable for the process, so cooled water helps the performance of the offset printing process.

(4) - Special cartridge filter of a micro for backwashing - to minimize the amount of molecular residues and particles that may be present in the water from the public network, thus avoiding clogging in the paths that the water will go through in the present utility model. This optimizes the process without interrupting the offset printing process for filter washing.

(5) - Return pump.

(6) - Rotor for measuring liters/minute treated by the present utility model;

(7) Magnetic device - to obtain a good offset printing, it is known that reduction of surface tension and increase of water conductivity are important factors. The development of this utility model has always been based on practical PRELLO offset printing tests with wetting system. PRELLO is equipment that faithfully reproduces the printing proofs that will serve as the standard to guide the printer in the execution of the work.

[0020] Several studies have shown that water flowing with turbulent flow through certain magnetic field arrays has reduced surface tension and increased conductivity. We prepared several magnetic field arrays that were submitted to PRELLO's practical test and finally we arrived at a model that allowed to make an excellent offset printing with only 20% wetting solution that is used regularly and 0% isopropyl alcohol also regularly used in Alcolor printers.

[0021] Several studies have shown that water flowing with turbulent flow through certain magnetic field arrays has reduced surface tension and increased conductivity.

[0022] Therefore, several magnetic field arrays were prepared that were submitted to PRELLO's practical test and finally a model was obtained that allowed an excellent offset printing with only 20% wetting solution that is used regularly and 0% isopropyl alcohol also regularly used in Alcolor printers.

(8) - Filter with UV lamp - consists of a UV-C lamp and a special impregnated fabric with titanium dioxide. UV light irradiated on the surface of the impregnated fabric with titanium dioxide with energy equal to or greater than band gap energy, moves one of its electrons from one field of the molecule to another field and, thus, the valence bands are formed. When the UV irradiation is interrupted, the photocatalyst returns to the initial state. In the water absorbed in the impregnated fabric with titanium dioxide these gaps of valence bands generate highly oxidizing hydroxyl radicals that decompose organic compounds. Its oxidizing power is greater than that of ozone and fluorine.

(9) - (O₂) eliminator

(10) - during the water treatment process and especially in the passage through the filter with UV lamp, occurs the formation of O₂ which is eliminated at this stage.

[0023] Therefore, as can be seen in the operation of the present utility model, the water from the public network passes through the cartridge filter (1) for the return pump (5), through the magnetic device (7), through the special filter with UV lamp (8), through the O₂ eliminator (9), through the refrigerator (3) and finally to the lung tank (2).

[0024] Figure 1 shows a flowchart with the devices present in one embodiment of the present utility model, wherein (1) represents the cartridge filter, (2) lung tank, (3) refrigerator, (4) special cartridge filter for backwashing (5) pump, (6) rotameter, (7) magnetic device, (8) UV filter with photocell, (9) O₂ eliminator and (10) represents the return tank of the printer. This tank only receives water from the lung tank, but no water from it goes to the lung tank thus avoiding contamination of the whole system.

[0025] The components of the electrical part are: circuit breaker; water solenoid, photocell, buzzer, timer, hour meter, electric float, buttonhole and reactor.

[0026] Figure 2 shows a front view of the printing system devices, wherein (1) and (2) represent a metal tube, (3) represents a metal ring, (4) represents a sealing ring, (5) represents a quick coupling, (6) represents a flange, (7) represents an adjusting ring, (8) represents a metal tube, (9) represents a magnet and (10) represents a metal threaded bush

[0027] Figure 3 shows the system devices for improving the offset printing system of one embodiment of the present utility model, wherein (1) represents a special fabric impregnated with titanium dioxide, (2) represents a synthetic tube, (3) represents a glass tube, (4) represents a UV lamp, (5) represents a synthetic flange, (6) represents a photocell, (7) represents a quick coupler, (8) represents a fixing bar and (9) represents a metal nut.

[0028] In view of the foregoing, it is apparent to one skilled in the art that the present utility model has the following advantages over the prior art:

It is ecologically correct, reducing 80% of the chemical wetting solution and isopropyl alcohol by 100%;

Reduced ink consumption by working with less water on the printing plate due to the reduced water surface tension. When we reduce the wetting water compulsorily we have to lower the ink load.

[0029] Reduced paper consumption by faster cleaning of printer machine startup.

[0030] Excellent ink transfer, balance throughout the printing process, better drying and brightness, lower point gain among other benefits due to the low emulsification of the ink.

[0031] Increases the life of blanket and printer rolls that are harmed by the wetting solution and isopropyl alcohol; and

[0032] Lower aggressiveness to health of employees working at the printer.

[0033] Thus, although only some embodiments and exemplifications of the present utility model have been presented, it is known that various omissions, substitutions and changes in the set of devices for improving the offset printing system can be accomplished by a skilled person without departing from spirit and scope of this utility model.

[0034] It is expressly provided that all combinations of elements performing the same function in substantially the same way, to achieve the same results, are within the scope of the present utility model. Substitutions of elements from one embodiment described to another are also contemplated in this utility model.

Claims

1. A set of devices for the offset printing system characterized in that it comprises:

(1) cartridge filter;

(2) lung tank;

(3) refrigerator;

(4) cartridge filter of a micro with backwash;

(5) return pump;

(6) rotameter;

(7) magnetic device;

(8) filter with UV lamp;

(9) O₂ eliminator; and

Components of the electrical part.

2. A set of devices for the offset printing system according to claim 1, characterized in that the refrigerator is coupled to the lung tank which stores the treated water at a temperature between 12-16°C.

3. A set of devices for the offset printing system according to claim 1, characterized in that it uses only 20% of wetting solution and is free of isopropyl alcohol.

4. A set of devices for the offset printing system according to claim 1, characterized in that the filter with UV lamp (8) consists of a UV-C lamp and a special fabric impregnated with titanium dioxide and photocell.

5. A set of devices for the offset printing system according to claim 1, characterized in that the components of the electrical part comprise a circuit breaker; a water solenoid, a photocell, a buzzer, a timer, an hour meter, an electric float, buttonhole and a reactor.

6. A set of devices for the offset printing system according to claim 1, characterized in that the lung tank stores the treated water and feeds the dosing tank with an electric float.

7. A set of devices for the offset printing system according to claim 1, characterized in that the water from the public network passes through the cartridge filter (1) for a return pump (5), passes through the magnetic device (7), then by the special filter with UV lamp (8), then by the O₂ eliminator (9), the refrigerator (3) and finally to the lung tank (2).

Drawing