Slit metering film-forming applicator

Abstract

The utility model discloses a slit metering film-forming applicator which comprises an upper applying roller and a lower applying roller which can be close to each other or separated from each other, the upper applying roller and the lower applying roller are close to each other to form an applying roller pressing area, and a paper web penetrates through the applying roller pressing area and is conveyed when the upper applying roller and the lower applying roller rotate. Die heads are arranged above the upper coating roller and the lower coating roller, each die head comprises a plane die lip and a curved-surface die lip, the curved-surface die lip is sequentially provided with a feeding hole and a material uniformizing cavity from top to bottom, a slit is formed in the attaching position of the plane die lip and the curved-surface die lip, and a glue coating is added from the feeding hole and flows along the material uniformizing cavity and the slit; the glue coating is metered through the slit and then flows out downwards to form a material film, and the material film freely falls down and then is attached to the surfaces of the upper coating roller and the lower coating roller. According to the utility model, the film is directly formed by using the die head and the slit therein, so that the film is high in precision, strong in stability and high in visualization degree; compared with a traditional structure, the production cost is lower, and the service life of the mechanism is longer.

Description

Technical Field

[0001] The utility model relates to the mechanical technical field of papermaking machines and coating machines, and more particularly to a slit metering film-forming applicator. Background Art

[0002] Traditional metering rod film transfer applicators are essential components of papermaking and coating machines. They apply glue or coating to both sides of a paper web online. Their main components are: two rubber-coated applicator rollers, two scraper beams positioned outside the rollers, a pair of frames for mounting one applicator roller, and a pair of pivoting arms for mounting the other. The pivoting arms can rotate a certain angle to move one applicator roller toward or away from the other (commonly known as "closing" and "splitting"). When the rollers are joined, a nip is formed to coat the paper passing through it. After the rollers are separated, a gap is created between the two rollers, facilitating paper threading operations and routine maintenance. The two scraper beams are mounted on two pairs of swinging arms, which can rotate a certain angle toward and away from the adjacent applicator rollers (commonly known as "closing" and "splitting"). One pair of swinging arms is mounted on the frame, while the other pair is mounted on the pivoting arms and rotates with them. Its working principle is: the glue coating is applied to the surface of the coating roller through the feeding chamber of the scraper beam, and the excess glue coating is recycled after returning. The metering rod installed on the scraper beam measures the glue coating on the surface of the coating roller and scrapes off the excess glue coating, and then forms the required uniform material film on the surface of the coating roller. The material film is then transferred to the running paper web through the pressure area after the two glue rollers are combined.

[0003] The metering rod in the prior art measures the amount of coating by measuring the size of the grooves on its surface during use. In order to accurately control the amount of coating applied, it is necessary to have metering rods of various specifications for replacement. The metering rods may become scrapped due to wear and tear of the grooves, which makes them lose their function. The metering rods are expensive and are consumable parts. Frequent replacement and scrapping lead to high operating costs. Due to the presence of grooves, they are easily clogged by glue, paper fibers, or other impurities. Once the clogged rod becomes "sticky", it must be replaced immediately for timely treatment. However, the machine does not need to be shut down during the replacement of the metering rod (otherwise, the loss is greater). During the replacement of the metering rod, coating cannot be applied, resulting in substandard products, which causes losses and waste. The metering rod in the prior art provides pressure through a pressurized airbag during use, generating a linear pressure between the metering rod and the coating roller. This linear pressure causes the coating roller to be worn by the metering rod, requiring regular regrinding of the rubber roller surface of the coating roller. The existing scraper beam is positioned outside the roller, requiring more space in the direction of paper web travel. While the film transfer applicator can be installed on a new machine with a redesigned layout, retrofitting older equipment, especially immersion-type sizing machines, can significantly limit space, ultimately leading to insufficient operating space. In existing film transfer applicators, while a portion of the adhesive is applied to the paper surface, a significant amount of backflow occurs. The ratio of applied adhesive to backflow has reached 1:9 or even higher. This results in significant capacity and power consumption for the corresponding loading system, leading to excessively high operating costs. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a slit metering film-forming applicator, which improves the film-forming accuracy of the applicator, increases the stability of operation, reduces the loss of equipment and raw materials, and reduces operating costs.

[0005] The utility model provides the following technical solutions: a slit metering film-forming applicator, comprising an upper coating roller and a lower coating roller that can be brought close to or separated from each other, the upper coating roller and the lower coating roller being brought close to form a coating roller pressure zone, the paper web passes through the coating roller pressure zone and is conveyed when the upper coating roller and the lower coating roller rotate, a die head is provided above the upper coating roller and the lower coating roller, the die head comprises a flat die lip and a curved die lip, the curved die lip is provided with a feed hole and a material mixing cavity from top to bottom, a slit is provided at the joining point of the flat die lip and the curved die lip, the glue coating is added from the feed hole and flows along the material mixing cavity and the slit, the glue coating is metered by the slit and flows downward to form a material film, and the material film is applied to the surfaces of the upper coating roller and the lower coating roller after falling freely.

[0006] As an improvement, the material mixing chamber includes a primary material mixing chamber and a secondary material mixing chamber. The primary material mixing chamber is larger than the secondary material mixing chamber. After the flat die lip and the curved die lip are fitted together, a primary material mixing chamber, a slit, a secondary material mixing chamber, and a slit are formed in sequence from top to bottom. The glue coating flows along the feed hole, the primary material mixing chamber, the slit, the secondary material mixing chamber, and the slit, and is measured by the slit below and then flows downward to form a material film.

[0007] As an improvement, two or more feed holes are provided. When more than two feed holes are provided, the distance between two adjacent feed holes remains consistent.

[0008] As an improvement, the distance between the flat die lip and the curved die lip is adjustable, thereby changing the gap of the slit to adjust the thickness of the material film.

[0009] As an improvement, the die head can be movably mounted on the die head frame, and the die head can be movably adjusted to the working position, the material preparation position or the roller changing position. The working position is above and directly facing the upper coating roller or the lower coating roller, the material preparation position is located above the side of the upper coating roller or the lower coating roller, and the roller changing position is away from the upper coating roller or the lower coating roller.

[0010] As an improvement, a receiving hopper is provided at the material preparation position to receive and recycle excess glue and coating below the die head.

[0011] As an improvement, a vacuum degassing hood is also included, which is connected to a vacuum pump. The vacuum degassing hood is arranged in the front running position close to the upper coating roller and the lower coating roller after the material film is applied to the upper coating roller and the lower coating roller, and is used to suck away the air at that position to ensure stable transportation of the material film.

[0012] As an improvement, it also includes an applicator frame, on which an oil cylinder and an applicator arm are provided. The oil cylinder is connected to the applicator arm and drives the applicator arm to swing during operation. One of the upper applicator roller and the lower applicator roller is rotatably set on the applicator frame, and the other is rotatably set on the applicator arm, and the upper applicator roller and the lower applicator roller are moved closer or separated by the operation of the oil cylinder.

[0013] As an improvement, an air diverter is also included, which is connected to a fan externally. The air diverter is arranged on the output side of the upper coating roller and the lower coating roller. The air diverter blows out air to form an air cushion and then transports the paper web.

[0014] As an improvement, a guide roller is further included. The guide roller is arranged on the input side of the upper coating roller and the lower coating roller and is used for winding and supporting the paper web.

[0015] Beneficial effects of the utility model:

[0016] 1. Use the die head and the slit in it to directly form the film, which has high precision, strong stability and high visualization.

[0017] 2. There is no consumption of wearing parts such as metering rods, so the production cost is lower.

[0018] 3. After the metering rod is eliminated, the wear of the roller surface is reduced, the interval between regrinding of the applicator roller is extended, the service life of the rubber layer of the applicator roller is extended, and the subsequent rubber coating cost is reduced.

[0019] 4. The scraper beam device is eliminated, which saves more space in the paper web running direction.

[0020] 5. The die head is used for direct film formation, with almost no backflow of adhesive coating, and the capacity and power consumption of the loading station are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of the applicator of the present invention, in which the upper roller is fixed and the lower roller moves, and the paper web runs downward.

[0022] Figure 2 This is a structural schematic diagram of the applicator of the present invention, in which the upper roller moves and the lower roller is fixed, and the paper web runs downward.

[0023] Figure 3 This is a schematic structural diagram of the applicator of the present invention, in which the upper roller is fixed and the lower roller moves, and the paper web runs upward.

[0024] Figure 4 This is a structural schematic diagram of the applicator of the present invention, in which the upper roller moves and the lower roller is fixed, and the paper web runs upward.

[0025] Figure 5 This is a schematic diagram of the cross-sectional structure of the die head of the present utility model.

[0026] In the figure: 1. Paper web (arrow represents the direction of paper web running), 2. Working position (where the die head is located), 3. Material preparation position (where the die head is located), 4. Roller changing position (where the die head is located), 5. Vacuum degassing hood, 6. Material receiving hopper, 7. Guide roller, 8. Die head frame, 9. Upper coating roller, 10. Lower coating roller, 11. Coating roller pressure area, 12. Coating device frame, 13. Coating device rotating arm, 14. Oil cylinder, 15. Air diverter, 16. Flat die lip, 17. Curved die lip, 18. Feed port, 19. Primary material distribution chamber, 20. Secondary material distribution chamber, 21. Slit, 22. Material film. DETAILED DESCRIPTION

[0027] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0028] See attached Figure 1-4The figure only schematically shows the positional relationship of each component and is only used to explain the working principle of the applicator. Not all components in actual application are drawn, and it is not proportional to the actual product. Figure 1-Figure 4 The arrow in the middle shows the direction of paper web running. According to the process requirements of paper coating, paper can be divided into single-sided sizing or coating and double-sided sizing or coating. Figure 1-Figure 4 The corresponding die head can be fed with rubber material for gluing, or can be coated with coating material, or can stop working without feeding material to achieve the effect of single-sided coating.

[0029] like Figure 1 、 2 , 3, 4, and 5 show a specific embodiment of the slit metering film-forming applicator of the present invention. This embodiment includes an upper coating roller 9 and a lower coating roller 10 that can be brought together or separated from each other. When the upper coating roller 9 and the lower coating roller 10 are brought together, a coating roller pressure zone 11 is formed. The paper web passes through the coating roller pressure zone 11 and is conveyed when the upper coating roller 9 and the lower coating roller 10 rotate. A die head is provided above the upper coating roller 9 and the lower coating roller 10. The die head includes a flat die lip 16 and a curved die lip 17. The curved die lip 17 is provided with a feed hole 18 and a material mixing cavity from top to bottom. A slit 21 is provided at the joint of the flat die lip 16 and the curved die lip 17. The adhesive coating is added through the feed hole 18 and flows along the material mixing cavity and the slit 21. The adhesive coating is metered by the slit 21 and flows downward to form a material film 22. The material film 22 falls freely and adheres to the surface of the upper coating roller 9 and the lower coating roller 10.

[0030] When the present invention is in use, the upper and lower coating rollers 9, 10 rotate at the operating speed, and the upper and lower coating rollers 9, 10 can be brought together and separated (commonly known as "rolling together" and "separating"). When the rollers are "closed," a coating roller nip 11 is formed to coat the paper web 1 passing through the nip. After "separating," a certain gap is formed between the two rollers to facilitate paper feeding operations and routine maintenance. The coating roller nip 11 is a contact area of ​​a certain length formed by the upper and lower coating rollers 9, 10 being squeezed together after the "rolling together" process. When the upper and lower coating rollers 9, 10 are separated after the "separating" process, the coating roller nip 11 immediately disappears. The die head is composed of two parts: a flat die lip 16 and a curved die lip 17. The curved die lip 17 is tightly fitted with the flat die lip 16 to form a slit 21. After being metered through the slit 21, the material film 22 flows out. The liquid adhesive coating is transported from the feeding device to the feed hole 18, enters the die head through the feed hole 18, and flows out through the slit 21 after being sorted by the material-leveling chamber. The outflowing liquid is accurately measured by the slit 21 to form a material film 22 with uniform thickness. After the material film 22 falls freely, it adheres to the rubber surface of the upper coating roller 9 and the lower coating roller 10, and is transferred to the front and back of the paper web 1 through the coating roller pressure area 11, thereby completing the coating work.

[0031] As an improved specific embodiment, the material mixing chamber includes a primary material mixing chamber 19 and a secondary material mixing chamber 20. The primary material mixing chamber 19 is larger than the secondary material mixing chamber 20. After the flat die lip 16 and the curved die lip 17 are fitted together, a primary material mixing chamber 19, a slit 21, a secondary material mixing chamber 20, and a slit 21 are formed in sequence from top to bottom. The glue coating flows along the feed hole 18, the primary material mixing chamber 19, the slit 21, the secondary material mixing chamber 20, and the slit 21, and is measured by the slit 21 below and then flows downward to form a material film 22.

[0032] like Figure 5 As shown, the further refined structure sets the material mixing chamber as a larger first-level material mixing chamber 19 and a smaller second-level material mixing chamber 20. The glue coating flows from the feed hole 18 through the first-level material mixing chamber 19, the first slit 21, and the second-level material mixing chamber 20 in sequence, which can better organize and stabilize the glue coating, and then make the thickness uniform when it reaches the second slit 21 and flows downward, forming a high-quality material film 22 to ensure the application quality.

[0033] As an improved specific implementation manner, two or more feed holes 18 are provided. When more than two feed holes 18 are provided, the distance between two adjacent feed holes 18 remains consistent.

[0034] The implementation method is not shown in the figure. During the specific implementation, according to the different widths of the paper web 1, multiple feed holes 18 can be used to transport the glue coating, and the distance between two adjacent feed holes 18 is kept consistent to ensure that the glue coating flows out evenly and stably, and the corresponding width of the material slurry cavity and the slit 21 are used to flow out the material film 22 of the corresponding width for application, which is suitable for the application of paper webs 1 of different widths.

[0035] As an improved embodiment, the distance between the flat die lip 16 and the curved die lip 17 is adjustable, thereby changing the gap of the slit 21 to adjust the thickness of the film 22 .

[0036] In an embodiment not shown in the figures, when a die head with a fixed slit 21 is used, the amount of adhesive applied is adjusted by varying the pressure and flow rate of the adhesive entering the die head, supplemented by variable frequency control of the motor of the pump connected to the die head. In this specific implementation, the thickness of the film 22 is adjusted by making the spacing between the flat die lip 16 and the curved die lip 17 adjustable, thereby varying the gap size of the slit 21.

[0037] As an improved specific embodiment, the die head can be movably mounted on the die head frame 8, and the die head is movably adjusted to the working position 2 or the material preparation position 3 or the roller changing position 4. The working position 2 is directly above the upper coating roller 9 or the lower coating roller 10, the material preparation position 3 is located above the upper coating roller 9 or the lower coating roller 10, and the roller changing position 4 is away from the upper coating roller 9 or the lower coating roller 10.

[0038] like Figure 1 、 2 As shown in Figures 3 and 4, the die head frame 8 is used to install the die head. The die head is set to be movable according to the needs of the production process, and the working position 2, the material preparation position 3, and the roller changing position 4 are set accordingly. The die head frame 8 can be provided with a corresponding track and supplemented by a power mechanism such as a motor or a cylinder and a chain or a gear transmission group for power transmission, thereby realizing horizontal or vertical movement of the die head. When the die head is in the working position 2, normal coating work is carried out; when the die head is in the material preparation position 3, material changing work is carried out; when the die head is in the roller changing position 4, it is away from the two roller bodies to facilitate the replacement of the two roller bodies. This is more convenient and practical to use.

[0039] As an improved specific implementation method, the material preparation position 3 is provided with a receiving hopper 6 to receive and recover the excess glue coating below the die head.

[0040] like Figure 1 、 2 As shown in Figures 3 and 4, at the preparation position 3, it is still necessary to continue feeding to prevent the slit 21 of the die head from being blocked, so a receiving hopper 6 is further provided to receive and recycle the glue coating to avoid waste of raw materials.

[0041] As an improved specific embodiment, it also includes a vacuum degassing hood 5, which is externally connected to a vacuum pump. The vacuum degassing hood 5 is arranged in the front running position after the material film 22 is applied to the upper coating roller 9 and the lower coating roller 10, close to the upper coating roller 9 and the lower coating roller 10, and is used to suck away the air at the location to ensure stable transportation of the material film 22.

[0042] like Figure 1 、 2 As shown in Figures 3 and 4, a slight gap exists between the vacuum degassing hood 5 and the surfaces of the upper and lower coating rollers 9 and 10, preventing contact with the roller surfaces and thus preventing any interference with the rotation of the two rollers. The vacuum degassing hood 5 is connected to a vacuum pump, which, when in use, extracts some of the air from the hood. The vacuum pump's motor is frequency-controlled, gradually increasing the amount of air extracted as vehicle speed increases. Once the air is extracted from the vacuum degassing hood 5, a certain degree of vacuum is achieved, ensuring that the film is not disturbed by wind and maintaining stable operation.

[0043] As an improved specific embodiment, it also includes an applicator frame 12, on which a cylinder 14 and an applicator arm 13 are provided. The cylinder 14 is connected to the applicator arm 13 and drives the applicator arm 13 to swing during operation. One of the upper applicator roller 9 and the lower applicator roller 10 is rotatably set on the applicator frame 12, and the other is rotatably set on the applicator arm 13, and the upper applicator roller 9 and the lower applicator roller 10 are then moved closer or separated by the operation of the cylinder 14.

[0044] like Figure 1 、 2 As shown in Figures 3 and 4, the applicator frame 12 is used to install one of the upper applicator roller 9 or the lower applicator roller 10, and the applicator arm 1 is used to install the other lower applicator roller 10 or the upper applicator roller 9. The applicator arm 13 is powered by the oil cylinder 14 to rotate clockwise or counterclockwise, and rotates a certain angle to make the upper applicator roller 9 and the lower applicator roller 10 move closer and separate (commonly known as "roller closing" and "roller separation"). After "roll closing", a coating roller pressure zone 11 can be formed to apply coating to the paper web 1 passing through the pressure zone. After "roll separation", a certain gap is formed between the two rollers to facilitate paper feeding operations and daily maintenance. As shown in the figure, according to the different operating modes of the paper web 1, the layout of the upper applicator roller 9 and the lower applicator roller 10 can be flexibly adjusted, and the applicability is more extensive.

[0045] As an improved specific embodiment, it also includes an air diverter 15, which is connected to the fan externally. The air diverter 15 is arranged on the output side of the upper coating roller 9 and the lower coating roller 10. The air diverter 15 blows out air to form an air cushion and then transports the paper web.

[0046] like Figure 1 、 2 As shown in Figures 3 and 4, an air diverter 15 is mounted on the die head frame 8 and connected to a fan. During operation, the fan draws air into the air diverter 15 and blows it into the air diverter 15. The blown air is then blown out through the slits or holes on the arcuate surface of the air diverter 15, forming an air cushion that supports the paper web 1 emerging from the coating roller nip 11. It should be noted that the surface of the paper web after coating from the coating roller nip 11 is covered with a moist film 22. Using an air cushion to support the film 22 prevents damage. The motor of the fan in the air diverter 15 is frequency-controlled, allowing the air volume and pressure to be adjusted according to the production process requirements, ultimately controlling the tension of the paper web 1.

[0047] As an improved specific embodiment, it further includes a guide roller 7, which is arranged on the input side of the upper coating roller 9 and the lower coating roller 10 and is used for winding and supporting the paper web.

[0048] like Figure 1 、 2 As shown in Figures 3 and 4, the guide roller 7 is installed at the die head frame 8. The guide roller 7 is also called the "introduction roller" and can rotate at the working speed to support the paper web so that it can smoothly enter the coating roller nip area 11 between the upper coating roller 9 and the lower coating roller 10.

[0049] The above are only preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, certain improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A slit metering film-forming applicator, characterized in that: The invention comprises an upper coating roller (9) and a lower coating roller (10) which can be brought closer to or separated from each other, wherein the upper coating roller (9) and the lower coating roller (10) are brought closer to form a coating roller nip (11), and the paper web passes through the coating roller nip (11) and is transported when the upper coating roller (9) and the lower coating roller (10) rotate. A die head is provided above each of the upper coating roller (9) and the lower coating roller (10), and the die head comprises a flat die lip (16) and a curved die lip (17). The curved die lip (17) is provided with a feed hole (18) and a material mixing cavity from top to bottom, and a slit (21) is provided at the joint of the flat die lip (16) and the curved die lip (17). The adhesive coating is added through the feed hole (18) and flows along the material mixing cavity and the slit (21). The adhesive coating is metered by the slit (21) and flows downward to form a material film (22). The material film (22) falls freely and is applied to the surfaces of the upper coating roller (9) and the lower coating roller (10).

2. A slit metering film-forming applicator according to claim 1, characterized in that: The material mixing chamber includes a primary material mixing chamber (19) and a secondary material mixing chamber (20), wherein the primary material mixing chamber (19) is larger than the secondary material mixing chamber (20), and the flat die lip (16) and the curved die lip (17) are bonded to form a primary material mixing chamber (19), a slit (21), a secondary material mixing chamber (20), and a slit (21) arranged in sequence from top to bottom. The adhesive coating flows along the feed hole (18), the primary material mixing chamber (19), the slit (21), the secondary material mixing chamber (20), and the slit (21), and is metered by the lower slit (21) before flowing downward to form a material film (22).

3. A slit metering film-forming applicator according to claim 1 or 2, characterized in that: The number of the feed holes (18) is two or more. When more than two feed holes (18) are provided, the spacing between two adjacent feed holes (18) remains consistent.

4. A slit metering film-forming applicator according to claim 1 or 2, characterized in that: The distance between the flat die lip (16) and the curved die lip (17) is adjustable, thereby changing the gap of the slit (21) to adjust the thickness of the material film (22).

5. A slit metering film-forming applicator according to claim 1 or 2, characterized in that: The die head is movably mounted on a die head frame (8), and the die head is movably adjusted to a working position (2), a material preparation position (3), or a roller changing position (4). The working position (2) is directly above the upper coating roller (9) or the lower coating roller (10), the material preparation position (3) is located above the upper coating roller (9) or the lower coating roller (10), and the roller changing position (4) is away from the upper coating roller (9) or the lower coating roller (10).

6. The slit metering film-forming applicator according to claim 5, characterized in that: The material preparation position (3) is provided with a receiving hopper (6) for receiving and recovering excess glue coating below the die head.

7. A slit metering film-forming applicator according to claim 1 or 2, characterized in that: The invention also includes a vacuum degassing hood (5), which is externally connected to a vacuum pump. The vacuum degassing hood (5) is arranged at a front running position after the material film (22) is applied to the upper coating roller (9) and the lower coating roller (10), close to the upper coating roller (9) and the lower coating roller (10), and is used to suck away the air at the position so that the material film (22) can be transported stably.

8. A slit metering film-forming applicator according to claim 1 or 2, characterized in that: The invention also includes an applicator frame (12), on which an oil cylinder (14) and an applicator rotating arm (13) are arranged. The oil cylinder (14) is connected to the applicator rotating arm (13) and drives the applicator rotating arm (13) to swing during operation. One of the upper applicator roller (9) and the lower applicator roller (10) is rotatably arranged on the applicator frame (12), and the other is rotatably arranged on the applicator rotating arm (13). The upper applicator roller (9) and the lower applicator roller (10) are moved closer to or apart by the operation of the oil cylinder (14).

9. A slit metering film-forming applicator according to claim 1 or 2, characterized in that: The invention also includes an air diverter (15), which is externally connected to a fan and is arranged on the output side of the upper coating roller (9) and the lower coating roller (10). The air diverter (15) blows out air to form an air cushion to receive and transport the paper web.

10. The slit metering film-forming applicator according to claim 9, characterized in that: The invention also comprises a guide roller (7), which is arranged on the input side of the upper coating roller (9) and the lower coating roller (10) and is used for winding and supporting the paper web.

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