Drying method of coating machine

Abstract

According to the drying method of the coating machine, a coating is not completely dried in a high-temperature environment, the coating is kept wet when being output from a box body, and then the coating is completely dried under the action of cold air without being heated through the action of the cold air and the coating; and wrinkles, dark marks and surface cracking of the coating in a high-temperature environment are avoided.

Description

Technical Field

[0001] The invention relates to the technical field of coating processing, in particular to a drying method of a coating machine. Background Art

[0002] Coating machines are mainly used for surface coating production of films, papers, etc. This machine coats a layer of glue, coating or ink with specific functions on the rolled substrate, dries it and then rewinds it. Existing coating machines dry the films and papers after coating them, which reduces the water content of the paper, making it fragile and easy to break, and causing curling, wavy lines or wrinkles, which seriously affects the product quality.

[0003] A patent document in China with application number 202210028366.4 and publication date 2022.4.5 discloses a five-roll coater and a coating method thereof, including an unwinding unit, a pulling-in unit, a corona unit, a coating correction unit, a five-roll coating unit, a drying bellows unit, a first cooling and traction unit, a rolling rehumidification unit, a steam rehumidification unit, a second cooling and traction unit, a winding correction unit and a winding unit; after the substrate is coated and dried by the five-roll coating unit, the surface of the coated product is humidified twice by the rolling rehumidification unit and the steam rehumidification unit to keep the surface humidity of the coated product balanced with the atmospheric humidity.

[0004] In this coating method, the substrate is thoroughly dried by a drying bellows and then humidified. A hot air furnace is provided in the drying bellows for providing hot air. Thus, when the substrate is thoroughly dried directly by hot air, cracks and cracks may occur in the substrate. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a drying method for a coating machine, in which the coating is not completely dried in a high temperature environment, the coating is kept moist when it is output from the box, and then the coating is acted on by cold air without heating the coating, so that the coating is completely dried under the action of cold air; wrinkles, dark marks, and surface cracks are avoided in the high temperature environment.

[0006] In order to solve the above technical problems, the technical solution used in the present invention is:

[0007] A drying method for a coating machine according to the present invention comprises the following steps:

[0008] S1. Preset a drying degree K of the substrate coating in the coating machine, and the drying degree K is less than 100%.

[0009] S2. Input the substrate into the coating machine for preliminary drying.

[0010] S3. Use cold air to thoroughly dry the substrate output by the coating machine.

[0011] Preferably, S1 also includes dividing the coater into a first drying area, a second drying area and a third drying area, and presetting the total exhaust volume K required for evaporating the slurry, the drying load A of the first drying area, the drying load B of the second drying area and the drying load C of the third drying area; the drying load A of the first drying area and the drying load C of the third drying area are both smaller than the drying load B of the second drying area.

[0012] Preferably, the first drying area is provided with more than one first drying box; S1 also includes a method for calculating the drying load of the first drying box, specifically:

[0013] Z1. Determine the airflow pressure of each first drying box in the first drying area according to the slurry viscosity force of the substrate entering the current first drying box; the airflow pressure of the first drying box is less than the slurry viscosity force.

[0014] Z2. Determine the airflow velocity of each first drying box by the airflow pressure of each first drying box.

[0015] Z3. Determine the exhaust volume of each first drying box by the air flow velocity of each first drying box.

[0016] Z4. Determine the drying load of each first drying box by the proportion of the exhaust volume of each first drying box in the total exhaust volume required for evaporating the slurry.

[0017] Preferably, the third drying area is provided with more than one third drying box; S1 also includes a method for calculating the drying load of the third drying box, specifically:

[0018] X1. Determine the airflow pressure of each first drying box in the third drying area according to the current slurry viscosity force of the substrate entering each third drying box; the airflow pressure of the third drying box is equal to the current slurry viscosity force.

[0019] X2. Determine the air flow velocity of each third drying box by the air flow pressure of each third drying box.

[0020] X3. Determine the exhaust volume of each third drying box by the air flow velocity of each third drying box.

[0021] X4. Determine the drying load of each third drying box by the proportion of the exhaust volume of each third drying box in the total exhaust volume required for evaporating the slurry.

[0022] Preferably, after X4, the following steps are also included:

[0023] X5. Calculate the air drying energy of each third drying box according to the drying load of the third drying box and the current flow rate of the slurry.

[0024] X6. While keeping the air-drying energy of each box unchanged, increase the exhaust volume of the third drying box and reduce the thermal power of the third drying box.

[0025] Preferably, the second drying area is provided with more than one second drying box; S1 also includes a method for calculating the drying load of the second drying box, specifically: by Y=B / N, the average drying load Y of each second drying box in the second drying area is calculated, and N is the number of second drying boxes in the second drying area.

[0026] Preferably, S1 further includes calculating the heat power of the second drying box and the exhaust volume of the second drying box.

[0027] Compared with the prior art, the beneficial effects of the drying method of the coating machine described in the present invention are mainly reflected in: the coating of the substrate is not thoroughly dried in the coating machine, so that the coating is not completely dried in a high temperature environment. The coating can still remain moist after being output from the coating machine, and then the coating is continued to be thoroughly dried by cold air. The cold air acts on the coating without heating the coating, which can not only prevent the coating from wrinkling, dark marks, and surface cracks in a high temperature environment, but also make the coating completely dry.

[0028] Since the slurry-coated substrate is not dry when entering the coating machine, the slurry has strong fluidity on the substrate. When the airflow dries the slurry, the slurry will move relative to the substrate. The present invention reduces the airflow pressure of the first drying box so that the airflow pressure of the first drying box is less than the force of the slurry viscosity. The airflow in the first drying area will not drive the slurry to move relative to the substrate, which can avoid the slurry being blown away by excessive airflow pressure and improve the adhesion effect of the slurry coating on the substrate.

[0029] At the same time, in the first drying area, the air flow pressure is determined according to the current slurry viscosity force, so that the exhaust volume of more than one first drying box increases successively, so that the drying load gradually increases. In this way, when part of the slurry is dried to form a coating, the drying load can be increased to improve the drying effect of the slurry.

[0030] In the third drying area, while keeping the air drying energy unchanged, the exhaust volume of the third drying box is increased and the thermal power of the third drying box is reduced; this can further prevent the coating from being completely dried at high temperature and further reduce the risk of coating cracking.

[0031] The present invention performs preliminary drying of the coating in a high temperature environment, and after the substrate is output from the coating machine, the coating is thoroughly dried by cold air, thereby preventing wrinkles, dark marks and surface cracks from occurring on the coating in a high temperature environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and other purposes, features and advantages of the present invention will become more clear by more specific description of the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals indicate the same parts in all the accompanying drawings, and the accompanying drawings are not deliberately scaled to the actual size, and the focus is on illustrating the main purpose of the present invention.

[0033] Figure 1 A schematic diagram of a coating machine for implementing the present invention.

[0034] Figure 2 It is a flow chart of the present invention.

[0035] Description of the drawings: box body 1, second drying device 2, substrate 3. DETAILED DESCRIPTION

[0036] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and implement it. However, the embodiments cited are not intended to limit the present invention. In the present embodiment, it should be understood that the orientations or positional relationships indicated by terms such as "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, 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 therefore cannot be understood as a limitation of the present invention.

[0037] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element and integrated therewith, or there may be an intermediate element at the same time. The terms "installed", "one end", "the other end" and similar expressions used in the present invention are for illustrative purposes only.

[0038] like Figure 1-2As shown; a coating machine described in this embodiment includes more than one interconnected box 1 and a second drying device 2, in each box is respectively provided with a first drying device (not shown in the figure) and a conveying device (not shown in the figure), the conveying device is a conveying roller; the first drying device and the second drying device 2 are both air nozzles; the conveying roller and the air nozzle are both prior art and are not described here. The first drying device is connected to a heat source (not shown in the figure), the second drying device 2 is connected to a cold source (not shown in the figure) and is arranged near the output end of the conveying device, the conveying device is used to convey a substrate 3 coated with slurry, in this embodiment, the conveying device drives the substrate 3 to move at a speed of 70m / min. The first drying device is used to incompletely dry the slurry coating, and the second drying device is used to thoroughly dry the slurry coating. In this embodiment, the interconnected boxes are divided into a first drying area A, a second drying area B and a third drying area C, respectively.

[0039] A drying method for a coating machine described in this embodiment comprises the following steps:

[0040] S1. The drying completion degree K of the substrate coating in the coating machine is preset, and the drying completion degree K is less than 100%. In this embodiment, the drying completion degree K of the substrate coating in the coating machine is 90%. The coating machine is divided into a first drying area, a second drying area, and a third drying area, and the total thermal power J required for evaporating the slurry, the total exhaust volume K required for evaporating the slurry, the drying load A of the first drying area, the drying load B of the second drying area, the drying load C of the third drying area, and the force data corresponding to different viscosities of the slurry are preset.

[0041] The drying load A of the first drying area and the drying load C of the third drying area are both smaller than the drying load B of the second drying area. The first drying area is provided with one or more first drying boxes; the second drying area is provided with one or more second drying boxes; the third drying area is provided with one or more third drying boxes; in one embodiment, three first drying boxes are provided; eight second drying boxes are provided; and three third drying boxes are provided.

[0042] S2. Input the substrate into the coating machine for preliminary drying.

[0043] S3. Use cold air to thoroughly dry the substrate output by the coating machine.

[0044] The calculation method of the drying load of the first drying box is as follows:

[0045] Z1. Determine the airflow pressure of each first drying box in the first drying area according to the slurry viscosity force of the substrate entering the current first drying box; the airflow pressure of the first drying box is less than the slurry viscosity force. In this embodiment, the viscosity of the current slurry is detected by a viscosity detection probe, and then the current slurry viscosity force is determined by the current slurry viscosity data.

[0046] Z2. Determine the airflow velocity of each first drying box by the airflow pressure of each first drying box. Determining the airflow velocity by airflow pressure is a prior art and will not be described here.

[0047] Z3. Determine the exhaust volume of each first drying box by the airflow velocity of each first drying box. In this embodiment, the total air volume of each first drying box is preset first, and then the airflow velocity of the current first drying box is used to determine the air intake volume of the current first drying box, and the exhaust volume of the first drying box is obtained by subtracting the air intake volume of the corresponding first drying box from the total air volume of the first drying box.

[0048] Z4. Determine the drying load of each first drying box by the proportion of the exhaust volume of each first drying box in the total exhaust volume K required for evaporating the slurry.

[0049] Z5. Determine the thermal power of the first drying box by the proportion of the drying load of the first drying box in the total thermal power J required for evaporating the slurry.

[0050] The calculation method of the drying load of the third drying box is as follows:

[0051] X1. Determine the airflow pressure of each first drying box in the third drying area according to the current slurry viscosity force of the substrate entering each third drying box; the airflow pressure of the third drying box is equal to the current slurry viscosity force.

[0052] X2. Determine the airflow velocity of each third drying box by the airflow pressure of each third drying box. Determining the airflow velocity by airflow pressure is a prior art and will not be described here.

[0053] X3. Determine the exhaust volume of each third drying box by the airflow velocity of each third drying box. In this embodiment, the total air volume of each third drying box is preset first, and then the airflow velocity of the current third drying box is used to determine the air intake volume of the current third drying box, and the exhaust volume of the third drying box is obtained by subtracting the air intake volume of the corresponding third drying box from the total air volume of the third drying box.

[0054] X4. Determine the drying load of each third drying box by the proportion of the exhaust volume of each third drying box in the total exhaust volume K required for evaporating the slurry.

[0055] X5. Calculate the air drying energy of each third drying box according to the drying load of the third drying box and the current flow rate of the slurry. Specifically, air drying energy = drying load of the third drying box * current flow rate of the slurry.

[0056] X6. While keeping the air drying energy of each box unchanged, increase the exhaust volume of the third drying box and reduce the thermal power of the third drying box. Specifically, air drying energy = thermal power of the third drying box + exhaust volume of the third drying box.

[0057] X7. Determine the thermal power of the third drying box by the proportion of the drying load of the third drying box in the total thermal power J required for evaporating the slurry.

[0058] S1 also includes a method for calculating the drying load of the second drying box, specifically: by Y=B / N, the average drying load Y of each second drying box in the second drying area is calculated, and N is the number of second drying boxes in the second drying area. Then the thermal power of the second drying box and the exhaust volume of the second drying box are calculated. Then the thermal power of the second drying box is determined by the proportion of the drying load of the second drying box in the total thermal power J required for evaporating the slurry.

[0059] Specifically, the total exhaust volume of the second drying area is obtained by subtracting the total exhaust volume K required for evaporating the slurry from the total exhaust volume of the first drying area and the total exhaust volume of the third drying area; then the exhaust volume corresponding to each second drying box is determined by the number of second drying boxes; then the thermal power of each second drying box is determined by the thermal power of the second drying box = average drying load of the second drying box / exhaust volume of the second drying box.

[0060] In the coating machine of the present invention, the coating of the substrate is not dried thoroughly, so that the coating is not completely dried in a high temperature environment, and the coating can still remain moist after being output from the coating machine, and then the coating is continued to be thoroughly dried by cold air. The cold air acts on the coating without heating the coating, which can prevent the coating from wrinkling, dark marks, and surface cracks in a high temperature environment and can also make the coating completely dry.

[0061] Since the slurry-coated substrate is not dry when entering the coating machine, the slurry has strong fluidity on the substrate. When the airflow dries the slurry, the slurry will move relative to the substrate. The present invention reduces the airflow pressure of the first drying box so that the airflow pressure of the first drying box is less than the force of the slurry viscosity. The airflow in the first drying area will not drive the slurry to move relative to the substrate, which can avoid the slurry being blown away by excessive airflow pressure and improve the adhesion effect of the slurry coating on the substrate.

[0062] At the same time, in the first drying area, the air flow pressure is determined according to the current slurry viscosity force, so that the exhaust volume of more than one first drying box increases successively, so that the drying load gradually increases. In this way, when part of the slurry is dried to form a coating, the drying load can be increased to improve the drying effect of the slurry.

[0063] In the third drying area, while keeping the air drying energy unchanged, the exhaust volume of the third drying box is increased and the thermal power of the third drying box is reduced; this can further prevent the coating from being completely dried at high temperature and further reduce the risk of coating cracking.

[0064] The following is described by way of examples;

[0065] Refer to Table 1, which is a table of drying load and exhaust volume data corresponding to the second drying box, the second drying box, and the third drying box.

[0066]

[0067] Table 1

[0068] In S1, the total exhaust volume K required for evaporation of slurry is preset to 48876Nm 3 / h; the drying load A of the first drying area is preset to be 16%; the drying load B of the second drying area is preset to be 72%; the drying load C of the third drying area is preset to be 12%. At the same time, the force data corresponding to different viscosity of slurry are preset.

[0069] In S1, the average drying load Y of the second drying boxes N0.4-N0.11 in the second drying area is 9%; the exhaust volume of each second drying box is 4399Nm 3 / h.

[0070] In Z3, it is determined that the exhaust volume of the first drying box N0.1 in the first section is 1466Nm 3 / h, the exhaust volume of the first drying box N0.2 in the second section is 2444Nm 3 / h, the exhaust volume of the first drying box N0.3 in the last section is 3910Nm 3 / h; the drying load of the first drying box in the first section is 3%; the drying load of the first drying box in the second section is 5%; the drying load of the first drying box in the last section is 8%.

[0071] In X3, the exhaust volume of the third drying box N0.12 in the first section is determined to be 3910Nm 3 / h, the exhaust volume of the third drying box N0.13 in the second section is 1466Nm 3 / h, the exhaust volume of the first drying box N0.14 in the last section is 489Nm 3 / h; the drying load of the third drying box in the first section is 8%; the drying load of the third drying box in the second section is 3%; the drying load of the third drying box in the last section is 1%.

[0072] In this specification, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0073] In the description of this specification, the description with reference to the terms "preferred embodiment", "further embodiment", "other embodiments" or "specific example" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0074] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A drying method for a coating machine, characterized in that: The following steps are involved: S1, presetting the drying completion degree K of the substrate coating in the coating machine, the drying completion degree K is less than 100%; S2, inputting the substrate into the coating machine for preliminary drying; S3. Use cold air to thoroughly dry the substrate output by the coating machine.

2. The drying method of the coating machine according to claim 1, characterized in that: S1 also includes dividing the coating machine into a first drying area, a second drying area and a third drying area, and presetting the total exhaust volume K required for evaporating the slurry, the drying load A of the first drying area, the drying load B of the second drying area and the drying load C of the third drying area; the drying load A of the first drying area and the drying load C of the third drying area are both smaller than the drying load B of the second drying area.

3. The drying method of the coating machine according to claim 1, characterized in that: The first drying area is provided with more than one first drying box; S1 also includes a method for calculating the drying load of the first drying box, specifically: Z1, determining the airflow pressure of each first drying box in the first drying area according to the slurry viscosity force of the substrate entering the current first drying box; the airflow pressure of the first drying box is less than the slurry viscosity force; Z2, determining the air flow velocity of each first drying box by the air flow pressure of each first drying box; Z3, determining the exhaust volume of each first drying box through the air flow velocity of each first drying box; Z4. Determine the drying load of each first drying box by the proportion of the exhaust volume of each first drying box in the total exhaust volume K required for evaporating the slurry.

4. The drying method of the coating machine according to claim 1, characterized in that: The third drying area is provided with one or more third drying boxes; S1 also includes a method for calculating the drying load of the third drying box, specifically: X1. Determine the airflow pressure of each first drying box in the third drying area according to the current slurry viscosity force of the substrate entering each third drying box; the airflow pressure of the third drying box is equal to the current slurry viscosity force; X2. Determine the airflow velocity of each third drying box by the airflow pressure of each third drying box; X3, determining the exhaust volume of each third drying box by the air flow velocity of each third drying box; X4. Determine the drying load of each third drying box by the proportion of the exhaust volume of each third drying box in the total exhaust volume K required for evaporating the slurry.

5. The drying method of the coating machine according to claim 4, characterized in that: X4 also includes the following steps: X5. Calculate the air drying energy of each third drying box according to the drying load of the third drying box and the current flow rate of the slurry; X6. While keeping the air-drying energy of each box unchanged, increase the exhaust volume of the third drying box and reduce the thermal power of the third drying box.

6. The drying method of the coating machine according to claim 1, characterized in that: The second drying area is provided with more than one second drying box; S1 also includes a method for calculating the drying load of the second drying box, specifically: by Y=B / N, the average drying load Y of each second drying box in the second drying area is calculated, and N is the number of second drying boxes in the second drying area.

7. The drying method of the coating machine according to claim 1, characterized in that: S1 also includes calculating the thermal power of the second drying box and the exhaust volume of the second drying box.

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