Online adjusting system and method for water content of paper for web printing

Abstract

The invention discloses a paper moisture content online adjusting system for web printing, which comprises humidity monitors arranged on a paper conveying part of a rotary press and at the tail end of a drying device of the rotary press; the spraying system is arranged on a paper conveying part of the rotary press; the intelligent control system is arranged on the side face of a paper conveying part of the rotary press; wherein the intelligent control system is electrically connected to a rotary press operation control system, and the humidity monitor and the spraying system are electrically connected to the intelligent control system. By means of the humidity sensor and the spraying system, real-time water content monitoring and regulation are conducted on roll paper for book and periodical rotary printing in the production process, the water content of the paper is adjusted on line on a single rotary press, the production investment of an enterprise is reduced, the water content of the roll paper is rapidly adjusted through the online adjusting system, and the production efficiency is improved. And meanwhile, the energy consumption is low, medium and small printing enterprises are suitable for use, and production efficiency is stabilized on the premise of effectively improving production quality.

Description

Technical Field

[0001] The present invention relates to the technical field of printing paper moisture adjustment, and specifically relates to an on-line adjustment system and method for the moisture content of web paper used in printing. Background Art

[0002] Books, as a traditional information carrier, play an increasingly important role in our lives. The paper used in book production is mainly composed of cellulose, which is a very hydrophilic substance with strong water absorption and dehydration properties. During the storage, transportation, and printing processes of paper, changes in temperature and humidity cause changes in the water content of the paper, resulting in expansion and contraction. The main reasons for the change in paper size caused by changes in paper moisture are as follows: When the paper moisture changes, the single fibers that make up the paper can absorb water and expand or lose water and contract, causing changes in the shape of the entire fiber, thereby causing changes in the size of the paper.

[0003] The shape changes of the fibers inside the paper due to the gain and loss of moisture will ultimately lead to changes in the size of the paper, which has an adverse impact on printing. When the water content of the paper is too high, the binding force between the fibers, fillers, and sizing agents in the paper is likely to decrease, thereby affecting the surface strength of the paper and resulting in problems such as powder shedding and fluffing during the book printing process. The occurrence of powder shedding and fluffing reduces the hardness and stiffness of the paper edge, and it is easy to have problems with unstable positioning during paper feeding, resulting in misregistration. If the water content of the paper is too low, the paper has poor elasticity, and the dot imprints are likely to expand during printing, resulting in a large dot gain rate. At the same time, changes in the water content of the paper will also cause quality problems such as uneven cut edges of the book core after book trimming, affecting the aesthetics of the book, causing product quality problems, bringing production losses to the enterprise, and increasing the operating cost.

[0004] The production workshop humidity control schemes of existing large printing enterprises mainly use air conditioners for cooling and dehumidification, supplemented by heating devices for temperature control to prevent the temperature drop caused by air conditioner dehumidification, but the energy consumption is relatively high; or use air conditioners for temperature control and independent dehumidifiers for humidity control, which not only has high energy consumption but also has poor humidity control uniformity; or use an intelligent temperature and humidity control system to adjust the operating status of air conditioners and humidity equipment according to the real-time monitored environmental conditions, but the cost is relatively high. For small and medium-sized enterprises, if they want to implement the above schemes, it will bring a significant increase in the operating cost of the printing enterprise, making the enterprise lose its market competitiveness. Summary of the Invention

[0005] One object of the present invention is to provide an on-line moisture content adjustment system for web printing paper, which can monitor and control the real-time moisture content of the web paper in the production of book rotary printing through a humidity sensor and a spraying system, adjust the moisture of the paper on-line on a single rotary printing press, reduce the production input of enterprises, and provide an on-line moisture content adjustment method for web printing paper to solve the problems raised in the above-mentioned background technology.

[0006] To solve the above technical problems, the technical solutions provided by the present invention are as follows: One object of the present invention is to provide an on-line moisture content adjustment system for web printing paper, including: A humidity monitor, which is arranged on the paper feeding part of the rotary printing press and at the end of the drying device of the rotary printing press, is used for monitoring the moisture content data of different positions of the web paper in real time and outputting the moisture content monitoring data; A spraying system, which is arranged on the paper feeding part of the rotary printing press, is used for spraying water to the web paper passing through the spraying system to adjust the moisture content of different positions of the web paper to reach the standard range required for printing; And an intelligent control system, which is arranged on the side of the paper feeding part of the rotary printing press, is used for receiving the monitoring data of the humidity monitor and intelligently controlling the start and spray size adjustment of the spraying system according to the moisture content monitoring data output by the humidity monitor; Wherein, the intelligent control system is electrically connected to the operation control system of the rotary printing press, and the humidity monitor and the spraying system are respectively electrically connected to the intelligent control system.

[0007] Further, the humidity monitor includes a first humidity monitor, a second humidity monitor and a third humidity monitor with the same structure and function. Specifically, the first humidity monitor is arranged on the front side of the paper feeding part of the rotary printing, the second humidity monitor is arranged on the rear side of the paper feeding part of the rotary printing, and the third humidity monitor is arranged on the paper output side at the end of the drying device of the rotary printing press.

[0008] Further, the intelligent control system transmits a control signal to the operation control system of the printing press to adjust the drying temperature of the drying device of the rotary printing press according to the moisture content monitoring data output by the third humidity monitor.

[0009] Further, the first humidity monitor, the second humidity monitor and the third humidity monitor all include a plurality of humidity sensors. The plurality of humidity sensors are arranged in a one-dimensional array perpendicular to the paper feeding direction, and the array position of each humidity sensor can be freely adjusted according to the width of the web paper.

[0010] Further, the spraying system is specifically arranged between the first humidity monitor and the second humidity monitor.

[0011] Further, the spray system includes a plurality of nozzles arranged in a one-dimensional array perpendicular to the paper feeding direction. The number of nozzles is not less than the number of humidity sensors, and the activation and spray amount of each nozzle are independently controlled by the intelligent control system.

[0012] Another object of the present invention is to provide an online moisture content adjustment method for web printing paper, including: S01 Paper feeding: After fixing the web paper on the paper feeding rack, the web paper is conveyed through the paper feeding mechanism; S02 First moisture content measurement: The first humidity monitor detects the moisture content data of the web paper and forms an output signal to be transmitted to the intelligent control system; S03 Adjustment determination: The intelligent control system analyzes the first moisture content data transmitted in S02 and determines whether to activate the spray system; S04 Second moisture content measurement and feedback determination: The second humidity monitor performs a second detection on the moisture content of the web paper after step S03, and transmits the second detection data to the intelligent control system to determine whether to adjust the spray amount of the spray system; S05 Printing: The web paper after step S04 is printed through the printing press color unit; S06 Drying: The printed paper after step S05 is dried through the drying device of the printing press; S07 Third moisture content measurement and feedback determination: The third humidity monitor performs a third detection on the moisture content of the printed paper after step S06, and transmits the third detection data to the intelligent control system to determine whether to give a control signal to the running control system of the rotary printing press to adjust the drying temperature of the drying device; S08 Folding: The printed paper after step S07 is folded through the folding mechanism to form the inner page book block of the book.

[0013] Further, in the adjustment determination process of step S03, the specific determination rule is: if the first moisture content data meets the production standard range, the nozzles of the spray system are closed; if the first moisture content data is lower than the production standard range, the nozzles of the spray system are opened.

[0014] Further, in the feedback determination process of step S04, the specific determination rule is: if the second detection data is still lower than the production standard range, the spray amount of the spray system is increased; if the second detection data meets the production standard range, the spray amount of the spray system is maintained; if the second detection data is higher than the production standard range, the spray amount of the spray system is decreased.

[0015] Further, in the feedback determination process of step S07, the specific determination rule is as follows: If the third detection data is lower than the production standard range, the intelligent control system transmits a control signal to the running control system of the rotary printing press to reduce the drying temperature of the drying device while maintaining the printing speed; if the third detection data meets the production standard range, the intelligent control system transmits a control signal to the running control system of the rotary printing press to maintain the drying temperature of the drying device while maintaining the printing speed; if the third detection data is higher than the production standard range, the intelligent control system transmits a control signal to the running control system of the rotary printing press to increase the drying temperature of the drying device while maintaining the printing speed.

[0016] The beneficial effects of the present invention are as follows: Through the humidity sensor, the present invention monitors the real-time water content of the web paper in the rotary printing of books and periodicals during production, and controls the spray system through the intelligent control system to adjust the water content of the paper online on a single rotary printing press, so that the web paper reaches the printing production standard range before printing. Then, the humidity sensor is used to monitor the water content of the printed paper after drying again, and the drying temperature is adjusted in a timely manner to stabilize the water content of the printed paper after drying, ensuring that the inner page booklets after folding will not cause production quality problems due to changes in the water content of the paper during subsequent post-press processing. The online adjustment system of the present invention can quickly adjust the water content of the web paper, and at the same time has low energy consumption and is suitable for small and medium-sized printing enterprises to use, effectively improving production quality and stabilizing production efficiency on the premise. Description of the Drawings

[0017] Figure 1 is a block diagram of the online adjustment system of the present invention; Figure 2 is a flow chart of the online adjustment system of the present invention.

[0018] In the figure: 100. Online adjustment system, 1. Temperature monitor, 11. First humidity monitor, 12. Second humidity monitor, 13. Third humidity monitor, 2. Spray system, 3. Intelligent control system, 4. Printing press running control system, 5. Drying device. Detailed Embodiments

[0019] To make the technical problems solved by the present invention, the technical solutions adopted and the achieved technical effects clearer, the technical solutions of the present invention will be further described below with reference to the drawings and through specific embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of convenience of description, only parts related to the present invention are shown in the drawings rather than all of them.

[0020] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0021] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0022] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0023] The technical solution of the present invention will be further described below with reference to the drawings and through specific embodiments.

[0024] As Figure 1 - Figure 2 shown, an object of the present invention is to provide an on-line moisture content adjustment system 100 for web printing paper, including: A humidity monitor 1, which is arranged on the paper feeding part of the rotary printing machine and at the end of the drying device 5 of the rotary printing machine, and is used for real-time monitoring of the moisture content data of different positions of the web paper and outputting the moisture content monitoring data; A spray system 2, which is arranged on the paper feeding part of the rotary printing machine, and is used for spraying water to the web paper passing through the spray system 2 to adjust the moisture content of different positions of the web paper to reach the standard range required for printing; And an intelligent control system 3, which is arranged on the side of the paper feeding part of the rotary printing machine, and is used for receiving the monitoring data of the humidity monitor 1 and intelligently controlling the start and spray size adjustment of the spray system 2 according to the moisture content monitoring data output by the humidity monitor 1; Among them, the intelligent control system 3 is electrically connected to the rotary printing press operation control system 4, and the humidity monitor 1 and the spraying system 2 are respectively electrically connected to the intelligent control system 3.

[0025] The humidity monitor 1 includes a first humidity monitor 11, a second humidity monitor 12, and a third humidity monitor 13 with the same structure and function. Specifically, the first humidity monitor 11 is arranged on the front side of the paper feeding part of the rotary printing press, the second humidity monitor 12 is arranged on the rear side of the paper feeding part of the rotary printing press, and the third humidity monitor 13 is arranged on the paper outlet side at the end of the drying device 4 of the rotary printing press. When producing and printing books and periodicals, the basic process of the rotary printing link is that the web paper enters the printing color group after running smoothly in the paper feeding part, enters the drying system after printing, and then undergoes folding and semi-finished product stacking. In order to achieve the high efficiency and stability of the printing link, when the web paper runs in the paper feeding part, it first automatically joins the paper on the paper feeder, then enters the tension control unit. After the tension is stable, it enters the printing color group. During the implementation process, the first humidity monitor 11 is specifically installed between the tension control unit and the paper feeder on the front side of the paper feeding part, which can detect the moisture content of the web paper in advance and provide a certain reaction time for the operation of the spraying system 2. And the second humidity monitor 12 is installed between the tension control unit and the first color group of the printing color group on the rear side of the paper feeding part, mainly to provide a certain penetration time for the water mist sprayed on the surface of the web paper, so as to effectively control the moisture content of the web paper.

[0026] The first humidity monitor 11, the second humidity monitor 12, and the third humidity monitor 13 all include a plurality of humidity sensors. The plurality of humidity sensors are arranged in a one-dimensional array perpendicular to the paper feeding direction, and the array position of each humidity sensor can be freely adjusted according to the width of the web paper. The humidity sensors used in this embodiment are specifically infrared humidity sensors, and the number of infrared humidity sensors required is 3. The specific array distribution positions are 1 at each of the left and right edges of the web paper and 1 at the center line position of the web paper. The array distribution positions of the 3 humidity sensors in this embodiment refer to the paper sample selection positions for measuring the moisture change in the middle and at the edges of the paper sheet and the moisture change in the transverse direction of the web in GB / T 462-2003 "Determination of Moisture in Paper and Board".

[0027] The infrared humidity sensor emits infrared light from its light source. The parallel light is reflected onto the material to be measured through a lens, a filter disc, and a mirror. Part of the infrared light is absorbed, and the other part is scattered and then focused onto a photoelectric conversion element by a concave mirror. The light-receiving element converts the light signal into an electrical signal. The magnitude of this signal is related to the water content of the material to be measured. The output signal is amplified and converted into a unified standard signal for display, recording, control, or transmission to a computer system for relevant processing. Its principle is based on molecular structure. For example, the nitrogen-hydrogen bond in water will absorb near-infrared light of a specific wavelength. At a specific wavelength, the reflected near-infrared energy is inversely proportional to the number of molecules that absorb near-infrared light, thereby achieving non-destructive and non-contact real-time online measurement of the moisture content on the surface of the web paper. The infrared humidity sensor is selected with a moisture measurement range of 0 - 100%, a measurement resolution of 0.01% - 0.2%, a measurement diameter of 40 - 60 mm, a measurement distance of 150 - 400 mm, and a measurement speed of 0 - 200 ms to adapt to the printing speed of about 260 m / min for web offset printing.

[0028] The spray system 2 is specifically arranged between the first humidity monitor 11 and the second humidity monitor 12, specifically in the middle of the tension control unit of the paper feeding section. While adjusting the running tension of the web paper, the spray water replenishment operation of the spray system 2 is completed.

[0029] The spray system 2 includes a plurality of nozzles arranged in a linear array perpendicular to the paper feeding direction. The number of nozzles is not less than the number of humidity sensors, and the startup and spray size of each nozzle are independently controlled by the intelligent control system 3. The atomizing nozzle can provide regulation of liquid pressure and gas pressure to regulate the flow rate and atomizing angle. The selected flow rate range is from 2.8 liters per hour to 10 liters per hour. The liquid pressure and gas pressure of the nozzle can be adjusted multiple times within a very short time. The adjustment controller can achieve an automatic "on / off" operation with 100 - 180 cycles per minute, and the air pressure for the cylinder operation is greater than 2.4 bar.

[0030] The intelligent control system 3 transmits a control signal to the printing press operation control system 4 according to the moisture content monitoring data output by the third humidity monitor 13 to adjust the drying temperature of the drying device 5 of the web offset press.

[0031] Another object of the present invention is to provide an online adjustment method for the moisture content of paper used in web printing, including: S01 Paper feeding: After fixing the web paper on the paper feeding rack, the web paper is conveyed through the paper feeding mechanism; S02 First moisture content measurement: The first humidity monitor 11 detects the moisture content data of the web paper and forms an output signal to be transmitted to the intelligent control system 3; S03 Adjustment Judgment: The intelligent control system 3 analyzes the first measured moisture content data transmitted in S02 and determines whether to activate the spray system 2; the specific judgment rule is: if the first measured moisture content data meets the production standard range, the nozzles of the spray system 3 are closed, and if the first measured moisture content data is lower than the production standard range, the nozzles of the spray system 3 are opened; S04 Second Measurement of Moisture Content and Feedback Judgment: The second humidity monitor 12 conducts a second detection on the moisture content of the web paper after the S03 step, and transmits the second detection data to the intelligent control system 3 to determine whether to adjust the spray volume of the spray system 2; the specific judgment rule is: if the second detection data is still lower than the production standard range, the spray volume of the spray system 2 is increased, if the second detection data meets the production standard range, the spray volume of the spray system 2 is maintained, and if the second detection data is higher than the production standard range, the spray volume of the spray system 2 is decreased; S05 Printing: The web paper after the S04 step is printed through the printing press color unit; S06 Drying: The printed paper after the S05 step is dried through the printing press drying device 5; S07 Third Measurement of Moisture Content and Feedback Judgment: The third humidity monitor 13 conducts a third detection on the moisture content of the printed paper after the S06 step, and transmits the third detection data to the intelligent control system 3 to determine whether to give a control signal to the rotary printing press operation control system 4 to adjust the drying temperature of the drying device 5; the specific judgment rule is: if the third detection data is lower than the production standard range, the intelligent control system 3 transmits a control signal to the rotary printing press operation control system 4 to lower the drying temperature of the drying device 5 while maintaining the printing speed, if the third detection data meets the production standard range, the intelligent control system 3 transmits a control signal to the rotary printing press operation control system 4 to maintain the drying temperature of the drying device 5 while maintaining the printing speed, and if the third detection data is higher than the production standard range, the intelligent control system 3 transmits a control signal to the rotary printing press operation control system 4 to raise the drying temperature of the drying device 5 while maintaining the printing speed; S08 Folding: The printed paper after the S07 step is folded through the folding mechanism to form the inner page booklets of the book.

[0032] The above embodiments only illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, there are various changes and modifications to the present invention, and these changes and modifications all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An on-line moisture content adjustment system for web-fed printing paper, characterized in that, Comprising: A humidity monitor, which is arranged on the paper feeding part of the rotary printing machine and at the end of the drying device of the rotary printing machine, and is used for real-time monitoring of the moisture content data of different positions of the web paper, and outputting the moisture content monitoring data; A spray system, which is arranged on the paper feeding part of the rotary printing machine, and is used for spraying and replenishing water to the web paper passing through the spray system, and adjusting the moisture content of different positions of the web paper to reach the standard range required for printing; And an intelligent control system, which is arranged on the side of the paper feeding part of the rotary printing machine, and is used for receiving the monitoring data of the humidity monitor, and intelligently controlling the start and spray size adjustment of the spray system according to the moisture content monitoring data output by the humidity monitor; Wherein, the intelligent control system is electrically connected to the operation control system of the rotary printing machine, and the humidity monitor and the spray system are respectively electrically connected to the intelligent control system.

2. The on-line moisture content adjustment system for web-fed printing paper according to claim 1, characterized in that: The humidity monitor includes a first humidity monitor, a second humidity monitor and a third humidity monitor with the same structure and function. Specifically, the first humidity monitor is arranged on the front side of the paper feeding part of the rotary printing machine, the second humidity monitor is arranged on the rear side of the paper feeding part of the rotary printing machine, and the third humidity monitor is arranged on the paper outlet side at the end of the drying device of the rotary printing machine.

3. The online moisture content adjustment system for web-fed printing paper according to claim 1, characterized in that: The intelligent control system transmits a control signal to the operation control system of the printing machine according to the moisture content monitoring data output by the third humidity monitor to adjust the drying temperature of the drying device of the rotary printing machine.

4. The on-line moisture content adjusting system for web-fed printing paper according to claim 2, characterized in that: The first humidity monitor, the second humidity monitor and the third humidity monitor all include a plurality of humidity sensors. The plurality of humidity sensors are arranged in a linear array perpendicular to the paper feeding direction, and the array position of each humidity sensor can be freely adjusted according to the width of the web paper.

5. The online moisture content adjustment system for web-fed printing paper according to claim 1, characterized in that: The spray system is specifically arranged between the first humidity monitor and the second humidity monitor.

6. The online moisture content adjustment system for web-fed printing paper according to claim 1, characterized in that: The spray system includes a plurality of nozzles arranged in a linear array perpendicular to the paper feeding direction. The number of the nozzles is not less than the number of the humidity sensors, and the start and spray size of each nozzle are independently controlled by the intelligent control system.

7. An online moisture content adjustment method for web printing paper, characterized in that, Specifically, it includes the following steps: S01 Paper feeding: After fixing the web paper on the paper feeding rack, the web paper is conveyed through the paper feeding mechanism; S02 First moisture content measurement: The first humidity monitor detects the moisture content data of the web paper and forms an output signal to be transmitted to the intelligent control system; [[ID=,13]]S03 Adjustment determination: The intelligent control system analyzes the first moisture content data transmitted in S02 and determines whether to turn on the spray system; S04 Second moisture content measurement and feedback determination: The second humidity monitor performs a second detection on the moisture content of the web paper after step S03, and transmits the second detection data to the intelligent control system to determine whether to adjust the spray volume of the spray system; S05 Printing: The web paper after step S04 is printed through the printing units of the printing machine; S06 Drying: The printed paper after step S05 is dried through the drying device of the printing machine; S07 Third moisture content measurement and feedback determination: The third humidity monitor performs a third detection on the moisture content of the printed paper after the S06 step, and transmits the third detection data to the intelligent control system to determine whether to give a control signal to the rotary printing press operation control system to adjust the drying temperature of the drying device; S08 Folding: The printed paper after the S07 step is folded through a folding mechanism to form the inner page book block of the book.

8. The on-line moisture content adjusting method for web-fed printing paper according to claim 7, characterized in that: In the adjustment determination process of the S03 step, the specific determination rule is: if the first measured moisture content data meets the production standard range, the nozzle of the spray system is closed; if the first measured moisture content data is lower than the production standard range, the nozzle of the spray system is opened.

9. The method for on-line adjusting the moisture content of the paper for web printing according to claim 7, wherein: In the feedback determination process of the S04 step, the specific determination rule is: if the second detection data is still lower than the production standard range, the spray volume of the spray system is increased; if the second detection data meets the production standard range, the spray volume of the spray system is maintained; if the second detection data is higher than the production standard range, the spray volume of the spray system is decreased.

10. The online moisture content adjustment method for web-fed printing paper according to claim 7, characterized in that: In the feedback determination process of the S07 step, the specific determination rule is: if the third detection data is lower than the production standard range, the intelligent control system transmits a control signal to the rotary printing press operation control system to lower the drying temperature of the drying device while maintaining the printing speed; if the third detection data meets the production standard range, the intelligent control system transmits a control signal to the rotary printing press operation control system to maintain the drying temperature of the drying device while maintaining the printing speed; if the third detection data is higher than the production standard range, the intelligent control system transmits a control signal to the rotary printing press operation control system to increase the drying temperature of the drying device while maintaining the printing speed.

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