CN109677119B

CN109677119B - Packaging box printing process capable of preventing excessive emulsification of printing ink and generation of residues

Info

Publication number: CN109677119B
Application number: CN201910164933.7A
Authority: CN
Inventors: 朱建江
Original assignee: Suzhou Hengchen Printing Technology Co ltd
Current assignee: Suzhou Hengchen Printing Technology Co ltd
Priority date: 2019-03-05
Filing date: 2019-03-05
Publication date: 2021-01-15
Anticipated expiration: 2039-03-05
Also published as: CN109677119A

Abstract

A packaging box printing process for preventing ink from being excessively emulsified and residues is characterized in that after a plate cylinder of a printing machine is separated from paper, the surface of the plate cylinder is blown by a first air supply device; blowing the surface of the ink by using a second air supply device at the interface which is just contacted with the ink when the plate cylinder of the printing machine is coated with the ink; blowing the surface of the ink at the position where a plate cylinder of the printing machine is separated from the ink after ink is hung on the plate cylinder by using a third air supply device; putting a plurality of rotors which can be fully paved at the inner bottom of an ink pool into the ink pool of the printing machine, and driving the rotors to rotate at the outer bottom of the ink pool by a magnetic stirrer; the invention can effectively reduce the mixing of dampening solution and other substances during the printing of the ink in the printing stage, prevent excessive emulsification and the generation of large-particle substances in the ink which influence the printing effect, ensure the printing quality, greatly improve the printing efficiency and ensure that the residual ink after printing can be normally used for a long time.

Description

Packaging box printing process capable of preventing excessive emulsification of printing ink and generation of residues

Technical Field

The invention belongs to the field of advanced manufacturing and automation of printing technology, and particularly relates to a packaging box printing process for preventing excessive emulsification of ink and generation of residues.

Background

Emulsification of ink, residue, etc. have a significant effect on print quality.

In the printing industry, slight emulsification is inevitable and necessary for smooth offset printing, but excessive emulsification has a great influence on the printing quality, and the emulsification degree of the ink must be minimized on the premise that the surface of the printing plate is not dirty. The excessive emulsification causes the reduction of color reproduction quality and the reduction of ink transparency, and for color printing, the subtractive color mixing of three primary colors dots is influenced, so that the colors cannot be correctly reduced, and the like.

In addition, even if the production optimization is very reasonable, the problem of residual ink is difficult to avoid, and the residual ink is thrown away, cannot be used well or not used, so that the overstocked capital and the waste are caused. In production, the residual ink can be reused by means of adding the residual ink into new ink, printing the residual ink on low-end products and the like, but sometimes the problems of unstable product quality, increased defective rate and the like are caused, and the problems are not paid for, and most manufacturers have to discard the residual ink in order to ensure the printing quality, reduce the defective rate and avoid increasing the process complexity; moreover, some profitable large printing factories use only a little of ink raw materials (non-residual ink) after the printing factories are opened, and the ink raw materials are discarded completely after a certain service life, so that the environment is greatly polluted, and the resource is seriously wasted. In residual inks, large amounts of ink skin and particulate residue, as well as portions of fountain solution, are typically present and often accompanied by severe ink emulsification.

The problem of ink emulsification arises in production and can be roughly attributed to several reasons:

(1) paper; most of offset paper and coated paper commonly used in the production process of the printing machine has some surface active substances and connecting material fillers, particularly in the printing of a packaging box, the surface active substances are transferred to an ink roller and a water tank through a printing plate by soaking of dampening solution, peeling of a rubber blanket and rolling for countless times in the printing process, and the emulsification speed of the ink is increased invisibly. The influence of offset paper is larger, and particularly the paper with poor sizing and poor hole sealing is easy to fall off. The paper powder is transferred to the ink roller through the printing plate and mixed with the ink in the ink duct, so that the viscosity of the ink is reduced, the water absorption of the ink is increased, and the emulsification of the ink is accelerated.

(2) Viscosity of the ink; the ink has high viscosity and water resistance, and the emulsification value is small; if the ink has a low viscosity and a high fluidity and the intermolecular polymerization force is reduced, the ink is easily emulsified.

(3) Dampening solution; the fountain solution comprises common fountain solution, nonionic surfactant fountain solution, alcohol fountain solution and the like. The alcohol fountain solution is volatilized quickly, so that the emulsifying degree of the printing ink is greatly reduced. While the pH value of the common fountain solution is necessarily detected by common test paper in the using process of the common fountain solution, and is controlled to be 3.

(4) Temperature and humidity; the temperature and humidity in the plant, as well as the speed of the machine, all have a considerable effect on the ink emulsification. If the higher the temperature of the workshop, the stronger the fluidity of the ink, the lower the viscosity, the lower the water resistance, and if the machine speed is high, the interaction increases and the temperature of the surface of the ink roller increases. Therefore, in order to ensure the printing quality, the workshop must control the temperature around 20 ℃.

At present, a common method for preventing the ink from being excessively emulsified is to add an anti-emulsifier (also called a water repellent agent and a water-ink balancing agent) to the ink. The added anti-emulsifying agent is only partially adsorbed on the surface of the pigment, most of the auxiliary agents are in a free state in the ink, so that the using amount of the anti-emulsifying agent is increased, the free anti-emulsifying agent can also generate side effects of influencing the surface tension and printability of the ink, and the like, and the method can only reduce the emulsification value of the ink to about 60 percent generally, but for high-speed printing, the emulsification value of the ink is required to be controlled to be below 40 percent or even lower.

In addition, some inks, such as UV frosted ink, have residues during printing, which is a problem of headache for many printing manufacturers, because the large amount of residues not only greatly increase the cost of the printing manufacturers, but also seriously affect the production efficiency. In the preparation of UV matte inks, the raw materials used must be carefully considered, but even then, in actual production, the polymerization of particulate residues within the ink can still occur due to particles on the printed material, variations in ambient temperature, the bonding of particles between different components, and the like.

If can effectively reduce the interfusion of thing such as fountain solution when printing ink printing in the printing stage, prevent excessive emulsification and the large granule material that influences the printing effect in the printing ink from generating, then not only can guarantee printing quality, improve printing efficiency greatly, can also make the remaining printing ink after the printing normally use in a long time.

Disclosure of Invention

The invention aims to provide a packaging box printing process capable of effectively preventing ink from being excessively emulsified.

Another object of the present invention is to provide a process for printing a packing box which can reduce the residue in the ink and allow the residual ink to be used normally for a long period of time.

In order to solve the technical problem, the invention discloses a packaging box printing process for preventing excessive emulsification of ink and generation of residues, wherein after a plate cylinder of a printing machine is separated from paper, the surface of the plate cylinder is blown by a first air supply device; blowing the surface of the ink by using a second air supply device at the interface which is just contacted with the ink when the plate cylinder of the printing machine is coated with the ink; blowing the surface of the ink at the position where a plate cylinder of the printing machine is separated from the ink after ink is hung on the plate cylinder by using a third air supply device;

the first air supply device, the second air supply device and the third air supply device comprise air supply pipes and air return pipes which are arranged in parallel, the air supply pipes blow out dry cold air, and the air return pipes are arranged on two sides or the periphery of the air supply pipes;

and a plurality of rotors which can be fully paved on the inner bottom of the ink pool are put into the ink pool of the printing machine, and the magnetic stirrer is used for driving the rotors to rotate at the outer bottom of the ink pool.

Preferably, the rotor is one of a shuttle shape, a dumbbell shape, or a mixture thereof.

Preferably, the ink jet head further comprises spherical particles which are put into the ink reservoir simultaneously with the rotor, and the spherical particles are made of ceramic or glass.

Preferably, the rotor is wrapped with a ceramic layer.

Preferably, the maximum length of the rotor and the spherical ceramic particles is not more than 1 cm.

Preferably, the maximum rotational speed of the rotor does not exceed 20 r/min.

Preferably, an axial flow fan is further installed in the dampening system of each ink zone of the printing press.

Preferably, the air supply temperature of the first air supply device is 10-20 ℃, and the air supply temperature of the second air supply device and the third air supply device is 20-30 ℃.

Preferably, the maximum air blowing speeds of the second air blowing device and the third air blowing device should not cause ink splashing.

The printing process for the packaging box for preventing the excessive emulsification of the printing ink and the generation of the residues at least has the following advantages:

1. the first air supply device can blow off paper impurities stained on the surface of the plate cylinder during printing and can also play a role in cooling the plate cylinder.

2. Through a large amount of practical observations, the border that just contacts with printing ink when the printing plate cylinder of printing machine hangs the china ink to and the printing plate cylinder of printing machine hang the china ink back and printing ink and break away from the department is the most, the place of getting into printing ink easily of fountain solution, and the fountain solution that gets into printing ink can temporarily stay on the printing ink surface, through drying the wet solution that temporarily stays on the printing ink surface that weathers as much as possible of mode in these two places, can reduce the emulsification of printing ink to a great extent to effectively guarantee the printing, especially the effect of high-speed printing.

3. The rotor and the spherical particles are collided in a large amount, so that the residues generated in the printing ink during printing are effectively disturbed and crushed to a certain extent.

4. The rotation of the small rotors enables the ink to be uniform in the small local spaces, and even can replace the original ink stirrer in the ink pool, so that the side effect of accelerating the emulsification of the ink brought by the original ink stirrer is avoided.

5. By preventing excessive emulsification of the ink and formation of residues, the printing quality is powerfully ensured, the production efficiency is improved, the normal service time limit of the residual ink after printing is longer than that of the common residual ink, the residual ink can be added into new ink for use or even directly used, unnecessary waste of a large amount of ink is avoided, the cost is saved, and the printing ink is environment-friendly and energy-saving.

Drawings

FIG. 1 is a schematic diagram of the position relationship of the first, second and third blowing devices.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.

It will be understood that terms such as "having," "including," and "comprising," when used herein, do not preclude the presence or addition of one or more other elements or groups thereof.

Example 1

As shown in fig. 1, the direction indicated by the arrow is the direction of rotation of the plate cylinder 1; a kind of packing box printing technology preventing the ink from excessively emulsifying and producing the residue, after the plate cylinder 1 of the printing press is disengaged from the paper, blow the surface of the plate cylinder with the first air supply unit 2; blowing the surface of the ink by using a second air supply device 3 at the boundary which is just contacted with the ink when the plate cylinder 1 of the printing machine hangs the ink; blowing the surface of the ink at the position where the plate cylinder 1 of the printing machine is separated from the ink after ink is hung on the plate cylinder by using a third air supply device 4;

the first air supply device 2, the second air supply device 3 and the third air supply device 4 comprise an air supply pipe a and an air return pipe b which are arranged in parallel, the air supply pipe a blows dry cold air, and the air return pipe b is arranged on two sides or the periphery of the air supply pipe a; the drying cold air of the second air supply device and the drying cold air of the third air supply device can bring excessive volatilization of the ink solvent sometimes, and a small amount of solvent can be supplemented if necessary to prevent the ink viscosity from being too high; the return air pipe can timely extract gas near the printing ink, and air in a workshop is prevented from being excessively polluted.

And, in the ink tank 5 of the printing machine, a plurality of rotors (not shown in the figure) which can be paved on the inner bottom of the ink tank are put, and the magnetic stirrer is used for driving the rotors to rotate at the outer bottom of the ink tank.

The rotors are spindle and dumbbell 1:1 hybrid. Fusiform and dumbbell shape, which can increase the collision probability and disturb or crush the residue.

The ink tank also comprises spherical particles which are put into the ink tank together with the rotor, and the spherical particles are made of glass. The spherical particles can increase the collision probability and can effectively prevent the rotor from blocking to stop rotating.

The rotor is wrapped by a ceramic layer. The ceramic layer prevents the rotor from chemically affecting the ink.

The length of the rotor and the spherical ceramic particles is 0.5-1 cm. Too large a rotor can cause difficulties in its autotransmission in viscous inks, and also can cause substances that can cause emulsification to be rapidly dispersed into the surrounding space, thereby exacerbating the emulsification.

The rotating speed of the rotor is 15 r/min. Too high a rotational speed may rather aggravate the emulsification.

And an axial flow fan is also arranged in the dampening system of each ink zone of the printing machine. The axial flow fan is a conventional choice of technicians in the field, is an advanced device configured in a printing machine, can quickly volatilize redundant fountain solution on devices such as a printing plate cylinder and the like in the area, and reduces the probability of excessive emulsification of ink.

The air supply temperature of the first air supply device is 10-20 ℃, and the air supply temperature of the second air supply device and the third air supply device is 20-30 ℃. The air supply temperature of the second air supply device and the third air supply device is slightly higher, so that the dampening liquid on the surface of the printing ink can be dried as much as possible.

The maximum air supply speeds of the second air supply device and the third air supply device can not cause ink splashing.

Example 2

Similar to embodiment 1, the difference is that the second air blowing means is eliminated.

Example 3

Similar to embodiment 1, the difference is that the third air blowing device is eliminated.

Example 4

Similar to embodiment 1, the difference is that the second and third air blowing devices are eliminated.

Example 5

The temperature of a production workshop is controlled to be about 20 ℃, weakly acidic fountain solution is adopted to be matched with offset rotary ink (Taiyuan), the emulsification rate of the ink during continuous high-speed printing for 1h and 2h is tested, and the results are as follows:

item	Emulsion ratio at 1h (%)	Emulsion ratio at 2h (%)
			Example 1	32	36
Example 2	35	40
			Example 3	36	39
Example 4	38	41

According to the test results, the dampening solution temporarily left on the surface of the printing ink can be dried by air drying as much as possible at the boundary part which is just contacted with the printing ink when the printing plate cylinder of the printing machine is hung with the printing ink and the part which is separated from the printing ink after the printing plate cylinder of the printing machine is hung with the printing ink, so that the emulsion rate of the printing ink can be reduced to a greater extent, and the printing effect can be effectively ensured.

Example 6

The temperature of a production workshop is controlled to be about 20 ℃, weakly acidic fountain solution is used in combination with offset rotary ink (Taiyuan), after continuous high-speed printing is carried out for 2 hours, in the method of example 1 and the method of removing the rotor and the spherical particles in example 1, the impurity content of an upper layer sample of the ink is respectively tested to be more than 10 microns, and the method of example 1 is found to be reduced by more than 40 percent compared with the method of removing the rotor and the spherical particles. Therefore, the method is beneficial to maintaining the quality of the ink and has certain effect on prolonging the normal service life of the residual ink. While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the embodiments shown and described without departing from the generic concept as defined by the claims and their equivalents.

Claims

1. A packaging box printing process for preventing ink from being excessively emulsified and generating residues is characterized in that after a plate cylinder of a printing machine is separated from paper, the surface of the plate cylinder is blown by a first air supply device; blowing the surface of the ink by using a second air supply device at the interface which is just contacted with the ink when the plate cylinder of the printing machine is coated with the ink; blowing the surface of the ink at the position where a plate cylinder of the printing machine is separated from the ink after ink is hung on the plate cylinder by using a third air supply device;

2. The process for printing a packing box to prevent the over emulsification of ink and the generation of residue according to claim 1, wherein the rotor is one of a shuttle shape, a dumbbell shape or a mixture thereof.

3. The printing process for a packing box for preventing the excessive emulsification of ink and the generation of residue as claimed in claim 2, further comprising spherical particles which are put into the ink reservoir simultaneously with the rotor, wherein the spherical particles are made of ceramic or glass.

4. The process of claim 3, wherein the rotor is wrapped with a ceramic layer.

5. The process for printing a packing box to prevent the excessive emulsification of ink and the generation of residue according to claim 4, wherein the maximum length of the rotor and the spherical ceramic particles is not more than 1 cm.

6. The process for printing a packing box to prevent the excessive emulsification of ink and the generation of residue according to claim 5, wherein the maximum rotation speed of the rotor does not exceed 20 r/min.

7. The process for printing a packing box to prevent the excessive emulsification of ink and the generation of residue according to claim 1, wherein an axial flow fan is further installed in the dampening system of each ink zone of the printing machine.

8. The printing process for a packing box for preventing the excessive emulsification of the ink and the generation of the residue as claimed in claim 7, wherein the air supply temperature of the first air supply device is 10 ℃ to 20 ℃, and the air supply temperature of the second air supply device and the third air supply device is 20 ℃ to 30 ℃.

9. The process of claim 8, wherein the maximum blowing speed of the second and third blowing devices does not cause ink splashing.