1. An apparatus for detecting and controlling solvent balance in printing ink, comprising:

a transport system for transporting the printing material or the printed product forward;

the ink supply system is positioned below one side of the paper feeding end of the conveying system and is used for supplying ink and solvent required by ink printing;

the impression system is positioned above the ink supply system and is used for carrying out ink printing on a printing stock by using the ink and the solvent provided by the ink supply system to obtain a printed matter;

the product inspection system is positioned on one side of the imprinting system, which is far away from the paper feeding end of the conveying system, and is used for sampling the printed products conveyed by the conveying system to obtain sampling samples;

and the control system is connected with the quality inspection system and is used for comparing the sampling sample obtained by sampling the quality inspection system with the standard sample and adjusting the liquid supply proportion of the ink and the solvent of the ink supply system to a balance proportion required by the standard sample according to a comparison result.

2. The apparatus of claim 1, further comprising a sampling system for sampling a sample of a product to be printed to obtain a standard sample, the sampling environment of the quality control system being the same as the sampling environment of the sampling system.

3. The apparatus of claim 1, wherein the delivery system comprises:

a conveyor belt for conveying the substrate or printed matter;

the paper conveying driving roller is positioned below the paper feeding end of the conveying belt, the paper conveying driven roller is positioned above the conveying belt, and the positions of the paper conveying driven roller and the paper conveying driving roller are up-down corresponding;

the first paper output driven roller is positioned below the paper output end of the conveying belt, the second paper output driven roller is positioned above the conveying belt, and the positions of the second paper output driven roller and the first paper output driven roller are vertically corresponding;

the printed material is conveyed forwards through the relative rotation of the paper conveying driving roller and the paper conveying driven roller, and the printed material is output through the relative rotation of the first paper output driven roller and the second paper output driven roller.

4. The apparatus of claim 2, wherein the imprinting system comprises:

an impression cylinder located above the conveyor belt;

the printing plate cylinder is positioned below the conveyor belt and corresponds to the impression cylinder up and down;

a doctor blade in contact with the plate cylinder.

5. The apparatus of claim 1, wherein the ink supply system comprises:

an ink mechanism for providing ink and a solvent mechanism for providing solvent;

a mixing mechanism for mixing the ink supplied from the ink mechanism and the solvent supplied from the solvent mechanism to form a mixed ink;

and the liquid feeding mechanism is used for supplying the mixed ink to the stamping system so that the stamping system performs ink printing.

6. The apparatus of any one of claims 1-5, wherein the quality inspection system comprises:

a sealing hood disposed above the conveyor belt of the conveyor system;

and a quality inspection camera arranged in the sealing cover and positioned right above the sealing cover and used for sampling the printed products above the conveyor belt, and the quality inspection camera is connected with the control system to convey the sampling samples to the control system.

7. A method for detecting and controlling the solvent balance of printing inks using the apparatus according to any one of claims 1 to 6, comprising:

the printing stock is conveyed forwards to the impression system through the conveying system, and the printing stock is subjected to ink printing by using mixed ink formed by ink and solvent provided by the ink supply system to obtain a printed matter;

after obtaining the printed matter, conveying the printed matter to a product inspection system through a conveying system, and sampling the printed matter through the product inspection system to obtain a sampling sample;

after the sampling sample is obtained, comparing the sampling sample with the standard sample, and automatically adjusting the liquid supply ratio of the ink and the solvent of the ink supply system to a balance ratio which can enable the sampling sample to meet the requirement of the standard sample according to the comparison result;

and (4) carrying out ink printing on the new printing stock by using the mixed ink reaching the balance ratio to obtain a printed matter meeting the standard sample requirement.

8. The method of claim 7, further comprising the step of sampling a sample of the product to be printed by the sampling system to obtain a standard sample.

9. The method of claim 8, wherein the sampling environment of the quality control system is the same as the sampling environment of the sampling system.

10. The method of claim 7, wherein sampling the printed matter with the quality inspection system includes the step of illuminating the printed matter conveyed by the conveyor system with a surface light source.

Background

In soft package printing, gravure printing has unique advantages, thick and solid ink color, clear layers, rich colors, quick printing, high printing resistance and high quality. The dry form of solvent-based gravure inks is volatile drying and is suitable for printing on paper, film, aluminum foil and many other materials. Meanwhile, the gravure press is high in printing speed, the thickness of a printing ink layer is large, and the volatile drying effect of the printing ink can be controlled by adjusting the proportion of the solvent.

In general, a specific solvent is prepared to control the evaporation and drying rate of the mixed ink (for example, acetate and isopropyl alcohol are prepared in a certain ratio, and the prepared solvent is hereinafter referred to as a drying solvent), but if the ratio is not appropriate, the following problems occur:

TABLE 1

Therefore, in the conventional production, it is necessary to control the proportion of the dry solvent in the mixed ink (the solvent is added to the ink) within a certain range, that is, to maintain the solvent balance. To maintain solvent balance, the viscosity of the mixed ink needs to be adjusted (i.e., the ratio of solvents is controlled), and is typically measured using a viscosity cup.

When the ink cup is used, the viscosity cup is placed in the liquid mixed with the ink, the viscosity cup is vertically lifted (the liquid on the upper part is flush with the cup opening), the stopwatch is pressed at the same time, the stopwatch is stopped when the streamline is cut off at the bottom of the cup, and the intermediate value is taken as the standard after continuous measurement for multiple times. After the measurement is finished, if the viscosity is found to be too large, adding a solvent for dilution (empirically estimating the addition amount); if the viscosity is found to be too low, the ink is added (the amount of addition is empirically estimated).

In the actual measurement process, the measurement value has larger error due to direct observation by human eyes; in addition, in the adjusting process, the adjustment is completely performed according to the experience of the operator, and a large error also occurs. Therefore, in the prior art, the method for manually adjusting the solvent balance through experience is long in corresponding ink adjusting time, whether ink adjusting is accurate or not is judged completely through experience of operators, dosage is not accurate, manual debugging is needed for many times, and a lot of time and waste of printing materials are caused.

Disclosure of Invention

The present invention is directed to solve the above problems, and an object of the present invention is to provide a device and a method for detecting and controlling the solvent balance of printing ink, which can detect the printing quality of a printed matter in real time, and automatically adjust the ratio of the printing ink to the solvent according to the detected printing quality, so as to control the ratio of the drying solvent within a certain range, thereby realizing dynamic solvent balance and improving the printing quality and efficiency.

To achieve the above object, one aspect of the present invention provides an apparatus for detecting and controlling solvent balance of printing ink, comprising: a transport system for transporting the printing material or the printed product forward; the ink supply system is positioned below one side of the paper feeding end of the conveying system and is used for supplying ink and solvent required by ink printing; the impression system is positioned above the ink supply system and is used for carrying out ink printing on a printing stock by using the ink and the solvent provided by the ink supply system to obtain a printed matter; the product inspection system is positioned on one side of the imprinting system, which is far away from the paper feeding end of the conveying system, and is used for sampling the printed products conveyed by the conveying system to obtain sampling samples; and the control system is connected with the quality inspection system and is used for comparing the sampling sample obtained by sampling the quality inspection system with the standard sample and adjusting the liquid supply proportion of the ink and the solvent of the ink supply system to a balance proportion required by the standard sample according to a comparison result.

The product quality inspection system further comprises a sampling system for sampling samples of products to be printed to obtain standard samples, and the sampling environment of the product quality inspection system is the same as that of the sampling system.

Wherein the delivery system comprises: a conveyor belt for conveying the substrate or printed matter; the paper conveying driving roller is positioned below the paper feeding end of the conveying belt, the paper conveying driven roller is positioned above the conveying belt, and the positions of the paper conveying driven roller and the paper conveying driving roller are up-down corresponding; the first paper output driven roller is positioned below the paper output end of the conveying belt, the second paper output driven roller is positioned above the conveying belt, and the positions of the second paper output driven roller and the first paper output driven roller are vertically corresponding; the printed material is conveyed forwards through the relative rotation of the paper conveying driving roller and the paper conveying driven roller, and the printed material is output through the relative rotation of the first paper output driven roller and the second paper output driven roller.

Wherein the imprint system includes: an impression cylinder located above the conveyor belt; the printing plate cylinder is positioned below the conveyor belt and corresponds to the impression cylinder up and down; a doctor blade in contact with the plate cylinder.

Wherein, the ink supply system includes: an ink mechanism for providing ink and a solvent mechanism for providing solvent; a mixing mechanism for mixing the ink supplied from the ink mechanism and the solvent supplied from the solvent mechanism to form a mixed ink; and the liquid feeding mechanism is used for supplying the mixed ink to the stamping system so that the stamping system performs ink printing.

Wherein, the quality control system includes: a sealing hood disposed above the conveyor belt of the conveyor system; and a quality inspection camera arranged in the sealing cover and positioned right above the sealing cover and used for sampling the printed products above the conveyor belt, and the quality inspection camera is connected with the control system to convey the sampling samples to the control system.

Further, the quality control system further comprises: and a surface light source disposed below the conveyor belt of the conveying system for irradiating the printed matter conveyed by the conveyor belt.

Preferably, a homogeneous layer made of the same material as the conveying belt is laid on the surface light source.

On the other hand, the invention also provides a method for detecting and regulating the balance of printing ink solvents by adopting the equipment, which comprises the following steps:

the printing stock is conveyed forwards to the impression system through the conveying system, and the printing stock is subjected to ink printing by using mixed ink formed by ink and solvent provided by the ink supply system to obtain a printed matter;

after obtaining the printed matter, conveying the printed matter to a product inspection system through a conveying system, and sampling the printed matter through the product inspection system to obtain a sampling sample;

after the sampling sample is obtained, comparing the sampling sample with the standard sample, and automatically adjusting the liquid supply ratio of the ink and the solvent of the ink supply system to a balance ratio which can enable the sampling sample to meet the requirement of the standard sample according to the comparison result;

and (4) carrying out ink printing on the new printing stock by using the mixed ink reaching the balance ratio to obtain a printed matter meeting the standard sample requirement.

Further, the method comprises the step of sampling a sample of the product to be printed by the sampling system to obtain a standard sample.

Wherein, the sampling environment of the quality control system is the same as the sampling environment of the sampling system.

Wherein sampling the printed matter by the quality control system includes irradiating the printed matter conveyed by the conveying system with a surface light source.

Before the printed matter conveyed by the conveying system is irradiated by the surface light source, the method also comprises the step of paving a material which is the same as the material of a conveying belt of the conveying system for conveying the printed matter on the surface light source.

Compared with the prior art, the device and the method for detecting and regulating the balance of the printing ink solvent have the following advantages:

the equipment and the method for detecting and regulating the balance of the printing ink and the solvent can detect the printing quality of a printed matter in real time, automatically regulate the proportion of the printing ink and the solvent according to the detected printing quality, control the proportion of the drying solvent within a certain range, realize dynamic solvent balance and improve the printing quality and efficiency.

The present invention will be described in detail with reference to the accompanying drawings.

Drawings

FIG. 1 is a perspective view of a printing ink solvent balance detection and control apparatus of the present invention;

FIG. 2 is a front view of the printing ink solvent balance detection and control apparatus of the present invention;

FIG. 3 is a schematic diagram of the structure at the sampling system of the present invention;

FIG. 4 is a schematic diagram of a method of printing ink solvent balance detection and regulation according to the present invention;

fig. 5 is a schematic structural diagram of the control system of the present invention.

Detailed Description

As shown in fig. 1 and fig. 2, which are a perspective view and a front view of the apparatus for detecting and controlling the balance of printing ink solvent in the present embodiment, it can be seen that the apparatus for detecting and controlling the balance of printing ink solvent in the present embodiment includes: a transport system 100 for transporting the substrate or print onwards; an ink supply system 300 located below the paper feed end side of the conveying system 100 for supplying ink and solvent required for ink printing; an imprinting system 200 located above the ink supply system 300 for performing ink printing on a printing material by using the ink and the solvent supplied by the ink supply system 300 to obtain a printed product; the product inspection system 400 is positioned on one side of the imprinting system 200, which is far away from the paper feeding end of the conveying system 100, and is used for sampling the printed products conveyed by the conveying system 100 to obtain sampling samples; and the control system (not shown in the figure) is connected with the product inspection system 400 and is used for comparing the sampling sample obtained by sampling the product inspection system 400 with the standard sample and adjusting the liquid supply ratio of the ink and the solvent of the ink supply system 300 according to the comparison result to enable the sampling sample to reach the balance ratio required by the standard sample. In addition, the system also comprises a sampling system for sampling the sample of the product to be printed to obtain a standard sample, and the sampling environment of the quality control system is the same as that of the sampling system. Besides being connected with the quality inspection system, the control system is also connected with the conveying system 100, the ink supply system 300, the imprinting system 200 and the like so as to control the systems to execute corresponding actions.

It should be noted that the conveying system 100, the ink supply system 300, the stamping system 200, the quality inspection system 400, etc. of the apparatus of the present embodiment are all mounted on a corresponding frame (not shown) to be supported by the frame, and each system operation is driven by a corresponding power device (not shown), and the frame and the power device are structures that are easily obtained by those skilled in the art, and will not be described here.

In the embodiment, the conveying system 100 conveys the printed material or the printed matter 500, where the printed material may be paper, that is, the printed material may be paper to be printed without ink printing, and correspondingly, the printed matter is printed after ink printing. The configuration of the apparatus of the present embodiment will be described with reference to the case where the printing material is a sheet, as an example, only.

Specifically, the conveying system of the present embodiment may adopt the following structure, including: the conveyor belt 108 for conveying the paper to be printed (i.e., the printing material) and the printed sample (printed product 500) obtained by the ink printing of the imprinting system 200 is driven by a conveyor belt power device (not shown in the figure) to move; a paper conveying driving roller 102 positioned below the paper feeding end of the conveying belt 108 and a paper conveying driven roller 101 positioned above the conveying belt 108, wherein the positions of the paper conveying driven roller 101 and the paper conveying driving roller 102 are vertically corresponding and rotate relatively; a first exit driven roller 105 located below the exit end of the conveyor belt 108 and a second exit driven roller 104 located above the conveyor belt 108, wherein the positions of the second exit driven roller 104 and the first exit driven roller 105 correspond to each other up and down and rotate relatively. In addition, the paper-feeding device further comprises a pair of paper-feeding adjusting rollers 103 and 106 arranged below the conveyor belt 108 and respectively arranged below the conveyor belts on the left side and the right side of the conveyor belt 108 close to the quality inspection system.

When the device is designed, a conveyor belt driving roller 107 and a conveyor belt driven roller 109 are respectively arranged at two ends of a conveyor belt 108, the conveyor belt 108 is driven to move by the rotation of the conveyor belt driving roller, and the device for driving the conveyor belt driving roller to rotate can be a manual device or an electric device, for example, the conveyor belt driving roller is connected with a hand-operated handle, and can also be connected with a motor and designed into an electric mode.

The paper feeding driving roller 102 and the paper feeding driven roller 101 are driven to rotate relatively by a paper feeding power device (not shown in the figure), and the first paper output driven roller 105 and the second paper output driven roller 104 are driven to rotate relatively, so that the paper to be printed is pressed on the conveyor belt 108 by the relative rotation of the paper feeding driving roller 102 and the paper feeding driven roller 101, and the paper to be printed is conveyed forwards by the conveyor belt 108, so that the paper to be printed becomes printed paper (printed matter, which can also be called as a printed sample or a sample), and the printed paper is output by the relative rotation of the first paper output driven roller 105 and the second paper output driven roller 104 after being sampled by the quality inspection system.

When the conveying system conveys the paper to be printed forward (forward, i.e. toward the paper outlet end) from the paper inlet end to the position of the impression system 200, the impression system 200 performs ink printing on the paper to be printed by using the mixed ink provided by the ink supply system 300.

The imprint system 200 of the present embodiment may adopt a gravure printing system, which includes: an impression cylinder 201 located above the conveyor belt 108; a plate cylinder 203 located below the conveyor 108, corresponding up and down to the position of the impression cylinder 201; a doctor blade 202 in contact with a plate cylinder 203. The inking system 300 can transfer the mixed ink onto the plate cylinder 203, and the plate cylinder 203 and the impression cylinder 201 are driven to rotate relatively by an impression power device (not shown in the figure), so that the mixed ink provided by the inking system is printed on the paper to be printed and forms the required pattern, and the excessive mixed ink transferred onto the plate cylinder 203 can be scraped off by the scraper 202. In addition, other configurations of the imprint system 200 may be used, as known in the art.

As shown in fig. 2, the ink supply system for supplying the mixed ink to the imprint system 200 may have the following structure including: an ink mechanism for providing ink and a solvent mechanism for providing solvent; a mixing mechanism for mixing the ink supplied from the ink mechanism and the solvent supplied from the solvent mechanism to form a mixed ink; and the liquid feeding mechanism is used for supplying the mixed ink to the stamping system so that the stamping system performs ink printing.

Specifically, the ink mechanism for supplying ink comprises an ink barrel 301 for containing ink, an ink feeding pipe 303 arranged on the ink barrel 301, and an ink feeding pump 302 arranged on the ink feeding pipe 303, wherein the ink in the ink barrel 301 is pumped out through the ink feeding pump 302, and the ink feeding pump 302 is connected with a control system to adjust the rotating speed under the control of the control system so as to adjust the flow rate of the pumped-out ink.

And the solvent mechanism for supplying the solvent comprises a solvent barrel 307 for containing the solvent, an upper solvent pipe 309 arranged on the solvent barrel 307, and an upper solvent pump 308 arranged on the upper solvent pipe 309, wherein the solvent in the solvent barrel 307 is pumped out by the upper solvent pump 308, and the upper solvent pump 308 is connected with the control system to adjust the rotating speed under the control of the control system so as to adjust the flow rate of the pumped-out solvent.

The ink supplied by the ink mechanism and the solvent supplied by the solvent mechanism are mixed by a liquid mixing mechanism, which includes an ink tank 305 communicating with an ink supply pipe 303 of the ink mechanism and an upper solvent pipe 309 of the solvent mechanism at the same time, and a stirring roller 306 is disposed in the ink tank 305 for uniformly stirring the ink and the solvent entering the ink tank 305 to form a mixed ink. In the design, the stirring roller 306 may be a stirring roller with a helical blade, so that the solvent and the ink added to the ink tank 305 and the mixed ink in the ink tank 305 can be quickly and uniformly mixed.

Above the gutter 305 is arranged a inking mechanism which supplies mixed ink to the imprinting system for ink printing of the paper to be printed by the imprinting system. Should go up liquid mechanism includes: a portion of an ink form roller 310 disposed within the mixed ink in the ink tank 305, and an ink distribution roller 304 positioned above and cooperating with the ink form roller 310. The ink application roller 310 rotates constantly and picks up the mixed ink in the ink tank 305 while rotating, and transfers the picked-up mixed ink to the ink distribution roller 304 that is in contact with the ink application roller 310 by rotation, and the resulting mixed ink is transferred to the plate cylinder 203 that is in contact with the ink distribution roller 304 while the ink distribution roller 304 rotates (the ink distribution roller 304 may function to make the mixed ink adhere uniformly thereto). The plate cylinder 203 and the impression cylinder 201 rotate relatively, and when the paper to be printed passes between the two cylinders, the mixed ink on the plate cylinder 203 is obtained under the pressure of the two cylinders. By the above-described process, the transfer of the mixed ink from the gutter 305 toward the imprint system is completed, and the ink printing is completed on the sheet to be printed by the imprint system.

And after the printing of the ink is finished on the paper to be printed, the paper to be printed becomes the printed paper, the printed paper is continuously conveyed forwards through the conveying system to the product inspection system 400, and the sampling is carried out through the product inspection system 400.

As shown in fig. 1 and 2, the product inspection system 400 may have a configuration including: a seal hood 401 disposed above the conveyor belt 108 of the conveyor system; a quality inspection camera 402, which is arranged in the sealing cover 401 and directly above the sealing cover, is used for sampling the printed sample above the conveyor belt 108, is connected with the control system, and transmits the sampled sample obtained by photographing to the control system, and the quality inspection camera 402 adopts a camera in the prior art, which can work according to control instructions to acquire image data and transmit the image data to the control system.

The sealing cover 401 is a hollow conical body with a narrow top and a wide bottom, a top is sealed, and a bottom is opened, and a circle of transparent material is arranged at the edge of the lower opening. When the device is arranged, a small gap is formed between the bottom of the sealing cover 401 and the conveying belt 108, so that when printed paper on the conveying belt 108 passes through the lower part of the sealing cover 401, the paper and the lower end of the transparent material have a small gap, and a closed shooting detection environment is formed above the gap.

Since the ambient light intensity affects the detection environment during sampling, the quality inspection camera 402 is installed in the sealed cover 401. Four lateral walls of sealed cowling 401 of this embodiment are light-tight, and the printing opacity phenomenon also can not appear because of sealed in the position of top installation quality control camera, consequently, greatly reduces the influence of environmental micronic dust and ambient lighting to the effect of shooing. And the edge of the bottom of the sealing cover 401 is made of a fully transparent material, so that a clearer sample electronic pattern can be obtained by the product inspection camera.

In order to ensure uniform irradiation of the printed paper and reduce ghost image when the quality inspection camera samples, a surface light source 403 (shown in fig. 1-3) for irradiating the printed sample conveyed by the conveyor belt 108 is further disposed below the conveyor belt 108 of the conveying system, and a homogeneous layer 404 made of the same material as the conveyor belt 108 is laid on the surface light source 403. Because the printed paper to be sampled is fixed on the conveyor belt and only a small gap is reserved between the printed paper and the transparent material surface at the bottom of the sealing cover, the influence of floating objects such as dust in the air on sampling of the product inspection camera is greatly reduced.

In addition, the printed paper enters the area where the quality inspection camera is located through the conveyor belt, and the surface light source is installed below the conveyor belt, so the conveyor belt adopted in the present embodiment should be made of a material that is transparent to light as in the prior art.

In this embodiment, after the printed paper is photographed and sampled by the quality control camera, the photographing result is transmitted to the control system, the control system compares the sampling sample (which is an image of the printed paper) obtained by sampling by the quality control camera with the standard sample, and adjusts the liquid supply ratio of the ink and the solvent of the ink supply system 300 according to the comparison result until the liquid supply ratio reaches the balance ratio required by the standard sample.

The standard sample is obtained by shooting a sample of a printed product by a sampling system, and the sampling system is completely consistent with the environment of a product inspection system, namely, all materials such as a surface light source, a homogeneous layer material paved on a conveyor belt, a product inspection camera and the like in the product inspection system are completely consistent with the surface light source and the like in the sampling system, so that the sampling environment of the product inspection system is ensured to be completely consistent with the sampling environment in the sampling system, and the influence of the environment on a sampling result is eliminated.

Before sampling printed paper or printing ink on paper to be printed through a quality inspection system, a standard sample of a product sample to be printed is obtained. After the images of the standard samples are obtained, the images are stored in a sample database, different sample images are stored in the sample database, the different sample images correspond to different balance proportions of the ink solvents in the mixed ink, and in the application, the types and the numbers of the standard samples in the sample database can be updated at any time according to needs.

After the sampling sample is obtained, the image shapes and colors of the sampling sample and the standard sample are compared, that is, the color depth difference of the two samples in different positions in a unit range is compared, and the color depth difference of different color channels (such as three color channels of RGB) is compared and quantified, so that the problem of which color of ink occurs can be determined. And then determining the adding proportion of the ink and the solvent according to the color depth difference. Then, the ink feeding pump or the solvent feeding pump is controlled by the proportioning controller to work as required, the amount of ink and the solvent added by the two pumps can be controlled by controlling the running time of the two pumps, so that the balance proportion of the ink and the solvent in the mixed ink consistent with the standard sample is obtained, and then the actions of the ink feeding pump and the solvent feeding pump are controlled, so that the mixed ink with the balance proportion is always formed, and the new paper to be printed is subjected to ink printing by the mixed ink with the balance proportion.

The equipment can detect the printing quality of the printed matter in real time through the quality detection system, and automatically adjust the proportion of the ink and the solvent provided by the ink supply system according to the detected printing quality so as to control the proportion of the solvent in the mixed ink within a certain range, realize dynamic solvent balance and improve the printing quality and efficiency.

The invention also provides a method for detecting and regulating the balance of printing ink solvents by adopting the equipment in addition to the equipment, which comprises the following steps:

the method comprises the steps that paper to be printed is conveyed forwards to an impression system through a conveying system, and mixed ink formed by ink and solvent provided by an ink supply system is used for printing the ink on the paper to be printed to obtain a printing sample;

after obtaining the printing sample, conveying the printing sample to a product inspection system through a conveying system, and sampling the printing sample through the product inspection system to obtain a sampling sample;

after the sampling sample is obtained, comparing the sampling sample with the standard sample, and automatically adjusting the liquid supply ratio of the ink and the solvent of the ink supply system to a balance ratio which can enable the sampling sample to meet the requirement of the standard sample according to the comparison result;

and (4) carrying out ink printing on the new paper to be printed by utilizing the mixed ink reaching the balance ratio to obtain a printed matter meeting the standard sample requirement.

The method further comprises the step of sampling a sample of a product to be printed by a sampling system to obtain a standard sample, wherein the sampling environment of the sampling system is the same as that of a product inspection system, and the adopted structure can also be the same, or the product inspection system can also be used as the sampling system.

The sampling of the printing sample by the quality control system comprises a step of irradiating the printing sample conveyed by the conveying system by a surface light source, and a step of paving a material which is the same as the material of the conveying belt 108 of the conveying system for conveying the printing sample on the surface light source before irradiating the printing sample conveyed by the conveying system by the surface light source.

Specifically, as shown in fig. 4 and 5, the method of the present invention includes:

s01, sampling a sample of a product to be printed by the product inspection camera 1 of the sampling system to obtain a standard sample, and storing an image of the standard sample in a sample database of the computer;

s02, operating an adjusting system (namely a control system) to enable the conveying system to operate so as to convey the paper to be printed forwards through the conveying belt;

s03, when the paper to be printed is conveyed forwards to the impression system, the mixed ink with certain concentration preset in the ink tank of the impression system and the ink supply system is used for printing ink on the paper, so that the paper to be printed becomes the printed paper;

s04, the printed paper is conveyed forwards continuously by the conveyor belt and reaches a product inspection area below a sealing cover of the product inspection system, the surface light source works and irradiates from bottom to top and penetrates through the homogeneous piece and the conveyor belt to be shot into the sealing cover, and the product inspection camera 2 takes pictures of the printed paper on the conveyor belt for sampling and obtains a sampling sample. In the sampling process, the positions of the printed paper are adjusted through the matching of the paper conveying adjusting roller 106 and the paper conveying adjusting roller 103, so that the printed paper in a quality inspection area (namely an area shot by a quality inspection camera) is in the same horizontal plane, and the shooting effect is improved;

s05, after the sampling samples are obtained, the processing module in the control system compares the image shapes and colors of the sampling samples and the standard samples, and when the colors are compared, the color depth difference of the two samples in different positions in the unit range is compared, and the following comparison results are obtained:

if the defect of the unknown product exists, the machine gives an alarm to prompt a worker to adjust and overhaul, and the program is finished.

And secondly, if the product defects do not exist, obtaining an ideal solvent equilibrium state (namely the ink and the solvent in the mixed ink reach the equilibrium ratio), and obtaining an ideal printed matter, and ending the comparison program.

And thirdly, if the defects exist in the database, determining the cause of the defects through computer comparison. That is, it is determined which color of ink has a problem, and then the adding ratio of ink and solvent is determined according to the color depth difference, and accordingly, an adding raw material signal, an adding raw material type signal, and an adding raw material ratio signal are sent to the ink supply system: if the signal is a solvent adding signal, the solvent pump is started to work; if the signal is an add ink signal, the ink pump is operated. Namely, according to the determined adding proportion of the ink and the solvent, the ink feeding pump or the solvent feeding pump is controlled by the proportioning controller to work as required, and the amount of the ink and the amount of the solvent added by the two pumps are controlled by controlling the running time of the two pumps, so that the balance proportion of the ink and the solvent in the mixed ink which is consistent with the standard sample is obtained.

When the computer system judges the defects of the product (namely, the printed paper), the database of the computer system is pre-stored with the defective images of different printing effects caused by the defects of the solvent. During comparison, the processing module can compare with the defective map again according to the difference in sample comparison to confirm the cause (whether the cause is too little or too much solvent), and during the printing process, when a new defect map is obtained, the new defect map can be automatically updated into the database, so that the database has certain learning capacity.

After a certain proportion of solvent and/or ink is added, the concentration of the ink solvent in the mixed ink in the ink tank is changed to form the mixed ink with new concentration.

And S06, after the mixed ink with the new concentration is obtained, performing ink printing on the next paper to be printed by using the mixed ink with the new concentration to obtain a printed matter meeting the requirements of the standard sample.

It should be noted that, in order to achieve the same image effect as the sample of the product to be printed, the steps of S01 to S06 may be repeated for a plurality of times until the printed product has no product defects. And then, carrying out ink printing on a new printing stock by using the mixed ink which meets the required ink solvent balance ratio to obtain a printed matter.

In conclusion, the device and the method can detect the printing quality of the printed matter in real time, and automatically adjust the proportion of the printing ink and the solvent according to the detected printing quality so as to control the proportion of the dry solvent within a certain range, realize dynamic solvent balance and improve the printing quality and efficiency.

Although the present invention has been described in detail, the present invention is not limited thereto, and those skilled in the art can modify the principle of the present invention, and thus, various modifications made in accordance with the principle of the present invention should be understood to fall within the scope of the present invention.