A slot coating die head

Abstract

The present invention relates to the technical field of coating dies. The purpose is to provide a slit coating die, which can provide an additional mixing effect during the internal feeding process, so that the glue discharge process is more uniform and efficient, and at the same time can reduce the impact of the internal feeding pressure reduction. The technical solution is: a slit coating die, including a coating die body, characterized in that: the coating die body includes an upper die, a lower die hinged with the upper die to form a slit coating cavity, and a double helical column arranged in the lower die.

Description

Technical Field

[0001] The invention relates to the technical field of coating die heads, in particular to a slit coating die head. Background Art

[0002] Coating technology is widely used in coating and composite packaging of substrates such as paper and film. The key part of coating and composite equipment is the coating head, and the coating and scraping method used by the coating head will directly affect the quality and effect of coating.

[0003] CN217069432U discloses a slit coating die for low-viscosity slurry, which forms a slit channel between two die bodies by using a gasket to allow the slurry to flow; after passing through the slit channel, the slurry flows out from between two protruding structures to ensure that it does not diffuse due to capillary action and affect the uniformity of the coating formed by the slit coating.

[0004] The above-mentioned coating technology requires that the glue liquid be stirred and mixed first, and then transported to the coating die head through a feeding device for coating processing. However, the conventional coating die head cannot continuously stir and mix the glue liquid internally during the process of transporting the glue liquid, resulting in the mixing state of the glue liquid being the same as the state when it is transported to the inside; on the other hand, the final glue discharge state of the slit coating die head is directly affected by the pressure of the glue liquid inside the coating die head; when the supply pressure of the glue liquid is insufficient, it is easy to cause the final coating state to be uneven, and some areas will not be coated, thereby affecting the coating quality. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a slit coating die head, which can provide additional mixing effect during the internal feeding process, making the glue discharge process more uniform and efficient, while reducing the impact of the reduction in internal feeding pressure.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A slit coating die head, comprising a coating die head body, characterized in that: the coating die head body comprises an upper die head, a lower die head hinged with the upper die head to form a slit coating cavity, and a double helical column arranged in the lower die head;

[0008] The lower die head is horizontally provided with a cavity for positioning the double helical column, the double helical column comprises a double helical shaft with both ends fixed on the side wall of the lower die head and a plurality of helical blades arranged on the double helical shaft, and the space between the plurality of helical blades forms a mixing channel for mixing the glue liquid;

[0009] The cavity is connected to the glue inlet of the rear side wall of the lower die head through a plurality of glue inlet channels;

[0010] A toroidal space formed by two partitions is installed in the middle of the double helical column, and the toroidal space is connected to the glue coating port through a flow guide pipe, a filter component, and a glue outlet component in sequence.

[0011] The surfaces of the two partitions are both provided with a plurality of guide holes for the circulation of the glue liquid; and a plurality of mixing partitions are also installed between the two partitions, which are radially and symmetrically arranged from the double helical axis.

[0012] The filter assembly includes a support plate and a filter screen positioned on the inner wall of the slit coating chamber; a plurality of holes are opened on the surface of the support plate, and the plurality of holes are respectively connected to the diversion pipe through connecting pipes, and each of the filter screens is laid on the corresponding hole.

[0013] The glue outlet assembly includes a front sealing strip and a rear sealing strip arranged in parallel with each other, a material collection port located between the front sealing strip and the rear sealing strip, a pressurization channel located at the material collection port, and a plurality of diversion grooves located at the glue outlet, each of the diversion grooves being separated by a rubber strip.

[0014] The left and right ends of the front sealing strip and the rear sealing strip are connected to the side plates on both sides, and the side plates on both sides are the side walls on both sides of the lower die head; the multiple diversion grooves are parallel to each other and arranged along the length direction of the sealing strip.

[0015] The cross section of the front sealing strip is a U-shape with different heights on the left and right sides, and the pressure boost channel is formed between the bottom end of the front sealing strip and the rear sealing strip.

[0016] Two vertically arranged first screws are installed on the rear side of the lower die head, and the top ends of the two first screws jointly fix a horizontally arranged pin shaft, which is then hinged with the shaft sleeve at the rear end edge of the upper die head, so that the upper die head can be positioned at the top end of the lower die head in an openable and closable manner to form a slit coating cavity.

[0017] Two second screw rods are respectively installed on the left and right sides of the lower die head, and the bottom ends of the second screw rods are swingably hinged on the lower die head through rotating shafts; clamping grooves suitable for the second screw rods are installed at corresponding positions on both sides of the upper die head, and the second screw rod can be swung to embed its top into the clamping groove, so that the upper die head and the lower die head can be fastened to each other by rotating the nut provided on the second screw rod to press the clamping groove.

[0018] A number of adjusting studs are vertically installed on the top of the left and right sides of the upper die head, and the bottom end of each adjusting stud passes through the screw hole of the upper die head and is pressed on the lower die head, thereby forming a glue coating port with adjustable gap between the upper and lower die heads; there are also a number of tension springs that apply force to the upper die head and the lower die head 1 respectively to assist in the gap adjustment.

[0019] Each first screw rod and each second screw rod is respectively equipped with a nut for tightening the screw rod.

[0020] The beneficial effects of the present invention are:

[0021] 1. The mixing channel formed by the positive and negative spiral blades in the double helix column can achieve the mixing of two kinds of glue liquids; the partition and the mixing shaft are arranged in the middle of the double helix column, which can be stirred and mixed again at high speed and high pressure during the discharge process of various glue liquids, further improving the mixing degree of different glue liquids and improving the subsequent coating quality.

[0022] 2. The slot coating die head is provided with a filter assembly inside the slot coating cavity, and the filter assembly is directly connected to the mixing flow channel at the double spiral column, so that when the mixed glue liquid is extruded into the slot coating cavity, it can be dispersed toward the side first and then enter the slot coating cavity, thereby improving the diffusion efficiency of the glue liquid.

[0023] 3. The slit coating die head is equipped with a glue outlet assembly on the inner side of the glue coating port. The glue liquid entering the slit coating cavity is collected through the front sealing strip and the rear sealing strip, and a subsequent pressurization treatment is performed, and then the glue liquid is dispersed by using multiple diversion grooves; even if the glue liquid pressure decreases, multiple glue outlet slits can still be provided through the diversion groove, thereby reducing the probability of the occurrence of glue coating dead corners. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention (locked state).

[0025] Figure 2 This is one of the schematic diagrams of the open state structure of an embodiment of the present invention.

[0026] Figure 3 This is the second schematic diagram of the open state structure of an embodiment of the present invention.

[0027] Figure 4 Schematic diagram of the structure of the double helix column part in an embodiment of the present invention.

[0028] Figure 5 It is a schematic diagram of the cross-sectional structure of the lower die head in an embodiment of the present invention.

[0029] Figure 6 for Figure 2 Schematic diagram of the enlarged structure of part A in the middle.

[0030] Figure 7 Schematic diagram of the connection relationship between the filter assembly and the cavity in an embodiment of the present invention.

[0031] Figure 8 It is a schematic diagram of the enlarged structure of the end of the double helical shaft in an embodiment of the present invention.

[0032] Fig. 9 Schematic diagram of the structure of the filter assembly in an embodiment of the present invention.

[0033] In the figure: 1. lower die head; 1.1. positioning block; 2. upper die head; 3. first screw; 4. second screw; 5. rotating shaft; 6. tension spring; 7. glue coating port; 8. adjusting stud; 9. docking buckle; 10. clamping groove; 11. slit coating chamber; 12. filtering component; 12.1. connecting pipe; 13. glue outlet component; 14. double spiral column; 15. partition; 16. guide hole; 17. mixing screen; 18. side plate; 19. front sealing strip; 20. rear sealing strip; 21. collecting port; 22. boosting channel; 23. diversion slot; 24. diversion pipe; 25. support plate; 26. filter screen; 27. glue inlet; 27.1. glue inlet channel; 28. cavity; 29. ​​mixing flow channel; 30. positioning pin. DETAILED DESCRIPTION

[0034] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0035] The slit coating die shown in the accompanying drawings comprises a coating die body, which comprises an upper die 2, a lower die 1, a double spiral column 14 and a slit coating cavity 11 located between the upper die 2 and the lower die 1; the lower die 1 is equipped with two vertically arranged first screws 3 (each first screw is inserted into the through holes of two positioning blocks) through a plurality of positioning blocks 1.1 on its rear side, and the top ends of the two first screws are jointly fixed with a horizontally arranged pin 1.2, which is hinged to the sleeve at the rear end edge of the upper die 2, so that the upper die can be positioned at the top end of the lower die in an openable and closable manner to form a slit coating cavity; a nut (preferably a butterfly nut) is provided at the rear of each first screw, and one end of the nut is against the positioning block; the first screw can be driven to move along its axial direction by rotating the nut. Two second screws 4 are respectively installed on the left and right sides of the lower die head 1, and the bottom ends of the second screws 4 are swingably hinged on the lower die head through the rotating shaft 5; clamping grooves 10 suitable for the second screws are installed at the corresponding positions on both sides of the upper die head 2. When the upper die head is covered on the top of the lower die head, the second screw 4 can embed its top into the clamping groove 10 by swinging, so that the nut (preferably a butterfly nut) provided on the top of the second screw can press the clamping groove by rotating, thereby fastening the upper die head and the lower die head to each other (then, the nut on the first screw can be rotated to further clamp the upper die head and the lower die head to each other). The upper and lower die heads are fastened to each other to form the slit coating cavity 11; a horizontally arranged double helical column 14 (including a double helical shaft and a plurality of helical blades arranged on the double helical shaft (the helical blades on the left part of the double helical shaft have opposite spiral directions to the helical blades on the right part of the double helical shaft) is installed in the lower die head 1; a cavity 28 for positioning the double helical column is horizontally arranged in the lower die head 1, and the diameter of the cavity is suitable for the helical blades on the double helical shaft; a plurality of glue inlets 27 (comprising a plurality of helical blades) communicating with the outside are opened on the rear side wall of the lower die head; Figure 3It can be seen that: two glue inlets are provided on each side of the rear side wall, and glue inlet channels 27.1 connected to the glue inlet 27 are provided above the two ends of the cavity. The two ends of the double helical shaft are respectively inserted into the fixing holes on the left and right side walls of the lower die head for fixing, and the space between the multiple spiral blades on the double helical shaft forms a mixing flow channel 29 for mixing glue. The side of the double helical column 14 is provided with a guide pipe 24 arranged parallel to the double helical column, and the outer side of the guide pipe (close to the side of the slit coating cavity) is installed with a filter assembly 12, and the end of the slit coating cavity is provided with a glue outlet assembly 13. When the slit coating die is working, the two kinds of glue liquid are transported to the lower die head through the glue inlet 27 by the external feeding equipment (existing technology), and then mixed through the mixing flow channel of the double spiral column; then they are transported to the guide pipe 24, and then enter the filter component through a number of connecting pipes 12.1 (seven connecting pipes are shown in the figure) connected to the guide pipe, and then the glue liquid is evenly dispersed into the slit coating cavity through the filter component; as the glue liquid capacity increases, the glue liquid in the slit coating cavity 11 generates pressure, and finally squeezed outward through the glue coating port 7, and the entire coating process is completed after contacting with the external coating material.

[0036] In this embodiment, a plurality of tension springs 6 are respectively installed on the left and right sides of the lower die head 1, and a docking buckle 9 is installed on the corresponding sides of the upper die head 2 and the lower die head 1. The two ends of each tension spring are connected by docking the buckles 9 on the upper die head 2 and the lower die head 1, and a pressure is applied to make the upper die head 2 and the lower die head 1 close to each other. A plurality of positioning pins 30 are arranged on the upper die head 2, and the upper die head 2 is engaged with the lower die head 1 through the positioning pins; a plurality of adjustment studs 8 are respectively installed on the left and right sides of the top of the upper die head 2, and the bottom end of each adjustment stud 8 passes through the screw hole of the upper die head and abuts against the lower die head 1; by rotating the adjustment stud 8, the distance between the upper die head 2 and the lower die head 1 can be controlled (with the assistance of the tension spring 6), so as to adjust the size of the glue coating port 7 formed between the upper and lower die heads (the glue coating port is formed by the gap between the glue outlet assembly on the lower die head 1 and the upper die head 2), that is, the glue coating thickness of the slit coating cavity 11 is regulated.

[0037] like Figure 5As shown, the double helix column 14 is installed in the cavity at the middle position of the inner side of the lower die head 1, and two partitions 15 perpendicular to the double helix column are installed in the middle position of the double helix column, and a plurality of guide holes 16 are opened on the surfaces of the two partitions; a certain distance (5-20cm) is maintained between the two partitions 15 to form a toroidal space in the cavity, and a plurality of mixing screens 17 (three mixing screens are shown in the figure) are also installed between the two partitions, which are radially and symmetrically arranged from the double helix axis, and the toroidal space is communicated with the guide pipe 24 through a connecting pipe (the connecting pipe is omitted in the figure), and both sides of each partition 15 are connected through the guide holes 16; the mixing flow channel between the positive and negative spiral blades of the double helix column 14 can achieve the mixing of two kinds of glue liquids, and the partitions 15 and mixing screens 17 provided can perform high-speed and high-pressure stirring and mixing again during the discharge process of multiple glue liquids, which can further improve the mixing degree of different glue liquids and improve the subsequent coating quality. During specific operation, the external glue liquid is transported inward from the glue inlet on the outer surface of the lower die head 1, and finally injected into the cavity and flows along the mixing channel toward the annular space; in this process, the glue liquid moves in the mixing channel in the double spiral column 14 and frequently changes the flow direction, and repeatedly oscillates during the flow process to improve the mixing effect. The glue liquid is squeezed into the annular space from the guide hole 16 in the middle of the partition 15, and then passes through the mixing screen 17 and enters the subsequent guide pipe 24; in this process, the glue liquid concentrated in this area is stirred again through multiple mixing screens, further improving the mixing effect.

[0038] In this embodiment, a filter assembly 12 is provided inside the slit coating chamber 11 (see Figure 7 ), the filtering assembly includes a support plate 25 and a filter screen 26; a notch is provided on the inner wall of the slit coating chamber 11, and the support plate is integrally embedded in the notch for installation and positioning; a plurality of holes ( Figure 2The surface of the support plate 25 is flush with the inner wall of the slit coating chamber 11; the filter assembly is directly connected to the mixing channel at the double helical column 14, so that when the mixed glue liquid is squeezed into the slit coating chamber 11, it can first disperse toward the side of the slit coating chamber and then enter the middle area of ​​the slit coating chamber 11, thereby improving the diffusion efficiency of the glue liquid. During specific operation, the injected glue is extruded and mixed in the mixing channel of the double spiral column 14, and then pushed into the inside of the guide pipe 24, and then passes through the holes on the surface of the support plate 25; in this process, the impurities inside the glue passing through can be effectively filtered through multiple filter screens 26, and the glue can be quickly diffused toward the side through the guide pipe 24 to avoid excessive concentration of the glue; and the filter screen 26 can be cleaned after removing the support plate 25, and the cleaning process is simpler and more convenient.

[0039] In this embodiment (see Figure 2 , Figure 6 ), a glue discharging assembly 13 is installed inside the glue coating port 7; the glue discharging assembly 13 includes a front sealing strip 19 and a rear sealing strip 20, and the two sides of the slit coating cavity 11 are respectively the side plates 18 as the side walls of the lower die head, and the left and right ends of the front sealing strip 19 and the rear sealing strip 20 are both connected to the side plate 18; the space between the front sealing strip 19 and the rear sealing strip 20 forms a material collection port 21, and the cross section of the front sealing strip is different in height on the left and right sides ( Figure 6 It can be seen that it is a U-shaped (low on the left and high on the right), and a narrow boost channel 22 is formed between the bottom end of the boost channel 22 and the rear sealing strip. The left side of the boost channel 22 is provided with a plurality of channels arranged along the length direction of the sealing strip (i.e., perpendicular to the Figure 5The paper layout of the diverter groove 23 is arranged on the paper surface, and each of the diverter grooves 23 is separated by a rubber strip; the front sealing strip 19 and the rear sealing strip 20 collect the glue entering the slit coating chamber 11, and perform subsequent pressurization treatment through the pressurization channel; multiple diverter grooves 23 then disperse the glue; even if the glue pressure decreases, multiple glue outlet slits can still be provided through the diverter groove 23, thereby reducing the probability of glue coating dead corners. During operation, the glue flows from the collection port 21 at the top of the slit coating chamber 11 to the glue coating port, and after passing through the pressurization channel 22, it can flow out from the diverter groove 23. The glue is divided by multiple rubber strips on the inside of the diverter groove 23, so when it is finally coated on the external material, multiple layers of glue can be applied at a time; moreover, when the pressure inside the slit coating chamber 11 is insufficient, the glue can still enter any diverter groove 23 randomly through the booster channel 22; and when coating through multiple layers of diverter grooves, even if the glue does not enter some diverter grooves due to insufficient pressure, it can still be supplemented through the remaining diverter grooves, thereby reducing the situation where some areas are completely not exposed to the glue.

[0040] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0041] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A slot coating die, comprising a coating die body, characterized in that: The coating die body comprises an upper die (2), a lower die (1) hingedly connected to the upper die to form a slit coating cavity (11), and a double helical column (14) arranged in the lower die; A cavity (28) for positioning the double helical column is horizontally arranged in the lower die head, and the double helical column comprises a double helical shaft with two ends fixed on the side wall of the lower die head and a plurality of helical blades arranged on the double helical shaft, and the space between the plurality of helical blades forms a mixing channel (29) for mixing the glue liquid; The cavity is connected to the glue inlet (27) of the rear side wall of the lower die head through a plurality of glue inlet channels (27.1); A torus-shaped space formed by two partitions (15) is installed in the middle of the double helical column, and the torus-shaped space is connected to the glue coating port (7) through the flow guide pipe (24), the filter assembly (12), and the glue outlet assembly (13) in sequence; The surfaces of the two partitions are provided with a plurality of guide holes (16) for the circulation of the glue liquid; a plurality of mixing screens (17) are also installed between the two partitions and are radially and symmetrically arranged from the double helical axis. The filter assembly comprises a support plate (25) and a filter screen (26) positioned on the inner wall of the slit coating chamber; a plurality of holes are provided on the surface of the support plate, the plurality of holes are respectively connected to the diversion pipe through a connecting pipe (12.1), and each filter screen is laid on a corresponding hole; The glue outlet assembly comprises a front sealing strip (19) and a rear sealing strip (20) arranged in parallel with each other, a material collection port (21) located between the front sealing strip and the rear sealing strip, a pressurizing channel (22) located at the material collection port, and a plurality of diverter grooves (23) located at the glue outlet, each of the diverter grooves being separated by a rubber strip.

2. The slot coating die according to claim 1, characterized in that: The left and right ends of the front sealing strip and the rear sealing strip are connected to the side walls on both sides of the lower die head; the multiple diversion grooves are parallel to each other and arranged along the length direction of the sealing strip.

3. The slot coating die according to claim 1, characterized in that: The cross section of the front sealing strip is a U-shape with different heights on the left and right sides, and the pressure boost channel is formed between the bottom end of the front sealing strip and the rear sealing strip.

4. The slot coating die according to claim 1, characterized in that: Two vertically arranged first screws (3) are installed on the rear side of the lower die head, and the top ends of the two first screws jointly fix a horizontally arranged pin shaft (1.2), which is then hinged with the shaft sleeve at the rear end edge of the upper die head, so that the upper die head can be positioned at the top end of the lower die head in an openable and closable manner to form a slit coating cavity.

5. The slot coating die according to claim 1, characterized in that: Two second screw rods (4) are respectively installed on the left and right sides of the lower die head, and the bottom ends of the second screw rods are swingably hinged on the lower die head through rotating shafts (5); clamping grooves (10) suitable for the second screw rods are installed at corresponding positions on both sides of the upper die head, and the second screw rod can be inserted into the clamping groove by swinging, so that the upper die head and the lower die head can be fastened to each other by rotating the nut provided on the second screw rod to press the clamping groove.

6. The slot coating die according to claim 1, characterized in that: A plurality of adjusting studs (8) are vertically mounted on the top of the left and right sides of the upper die head, and the bottom end of each adjusting stud passes through the screw hole of the upper die head and is pressed on the lower die head, thereby forming a glue coating port (7) with adjustable gap between the upper and lower die heads; and a plurality of tension springs (6) are provided to respectively apply force to the upper die head and the lower die head to assist in gap adjustment.

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