CN220496779U

CN220496779U - Coating die head

Info

Publication number: CN220496779U
Application number: CN202321544444.2U
Authority: CN
Inventors: 靳世东; 彭礼明; 林仪珊; 曾西平; 喻东旭
Original assignee: Shenzhen Huake Tek Co Ltd
Current assignee: Shenzhen Huake Tek Co Ltd
Priority date: 2023-06-16
Filing date: 2023-06-16
Publication date: 2024-02-20
Anticipated expiration: 2033-06-16

Abstract

The utility model relates to the technical field of coating equipment, in particular to a coating die head which comprises an upper die head and a lower die head which are oppositely arranged, wherein a coating slit is formed between the upper die head and the lower die head through a gasket, one end, close to an outlet of the coating slit, of the lower die head is connected with a buffer plate, and the buffer plate is inclined downwards relative to a plane where the upper surface of the lower die head is located. The coating die head comprises an upper die head, a lower die head, a gasket and a buffer plate, wherein the tail end of the lower die head is connected with the buffer plate for buffer transition, so that after coating liquid flows out from a coating slit outlet, the pressure can be released before the coating liquid contacts with a substrate, and the coating liquid can be further spread and leveled on the buffer plate by utilizing gravity, so that the coating uniformity of the coating liquid on a film material is improved.

Description

Coating die head

Technical Field

The utility model relates to the technical field of coating equipment, in particular to a coating die head.

Background

The nano silver wire conductive film is widely applied to large-size touch capacitive screens, and the mass production of the nano silver wire conductive film adopts a wet coating mode, and the nano silver wire water-based conductive ink or the organic phase conductive ink is coated on a PET (polyethylene terephthalate) substrate in a slit coating mode and is subjected to thermal sintering to obtain the conductive film. Because the slit coating adopts large-width coating, film defects easily appear in the coating process due to instability of conductive ink fluid to cause failure, common coating direct defects include longitudinal dry-wet alternate stripes (MD stripes), transverse dry-wet alternate stripes (TD stripes), local area uneven-Mura, compound defects between the former three and the like, indirect defects include shrinkage cavities, silver wire aggregation, surface impurities and the like, and the defects directly cause the yield of the conductive film to be reduced, so that the waste is extremely caused.

When in slot coating, the coating liquid is coated on the surface of the substrate through a coating die head, the structure of the coating die head can influence the flow uniformity of the coating liquid in the coating die head, and further the coating quality of the film material is influenced. Existing coating dies typically include an upper die, a lower die, and a gasket sandwiched between the upper and lower dies, with the gasket forming a coating slot between the upper and lower dies, and the die coating liquid flows out through the outlet of the coating slot (i.e., the coating lip). On one hand, the coating liquid in the slit is easy to form turbulence due to the action of shearing force and pressure, so that the uniformity of the coating liquid is reduced; on the other hand, the positions of the coating die head and the back roller are relatively fixed, the coating angle is not easy to adjust, and further, the dynamic contact line of the coating liquid and the substrate cannot be controlled, so that coating defects are easy to generate. The Chinese patent No. 208527143U discloses a slit die head structure for a coating machine, wherein a buffer groove is arranged on a lower die lip, the pressure of slurry entering the buffer groove from a feeding channel is relieved by the buffer groove, the fluidity of the slurry in a discharge groove is improved, the device can play a certain role in buffering, but the uniformity of the slurry at an outlet is reduced due to pressure change when the slurry flows out from the slit outlet, and the slurry is not easy to uniformly spread on a substrate, so that the coating defect of a film material is caused.

Disclosure of Invention

The utility model provides a coating die head which can effectively reduce the coating defect of a film material and improve the production yield.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

the utility model provides a coating die head, includes the relative last die head and the lower die head that sets up, go up the die head with be formed with the coating slit through the gasket between the lower die head, the lower die head is close to the one end of coating slit export is connected with the buffer board, the buffer board is relative lower die head upper surface place plane downward sloping.

Further, a first buffer groove is formed in the buffer plate, close to the outlet of the coating slit, and the arrangement direction of the first buffer groove is perpendicular to the flowing direction of the coating liquid.

Further, a second buffer groove is formed in the upper surface of the lower die head, close to the outlet of the coating slit, and the arrangement direction of the second buffer groove is perpendicular to the flowing direction of the coating liquid.

Further, the first buffer groove and the second buffer groove are arc grooves.

Further, the depth of the first buffer groove is smaller than the depth of the second buffer groove.

Further, the width of the first buffer groove is 1.5-2.5mm, and the depth is 0.5-1mm; the width of the second buffer groove is 1.5-2.5mm, and the depth is 1-2mm. Preferably, the width of the first buffer groove is 2mm, and the depth is 1mm; the width of the second buffer groove is 2mm, and the depth is 1.5mm.

Further, the buffer plate is inclined downward at an angle of 5-30 °. Preferably, the buffer plate is inclined downward at an angle of 10-20 °.

Further, a strong magnetic film is attached to the bottom of the buffer plate and the inclined surface of the lower die head near the outlet of the coating slit, a magnetic roller is attached to the strong magnetic film, and the magnetic roller is used as a fulcrum to support the buffer plate.

Further, the magnetic roller can roll along the inclined plane of the lower die head and drive the buffer plate to rotate along the fixed position of the buffer plate and the lower die head.

Further, the buffer plate is made of polytetrafluoroethylene, and the thickness of the buffer plate is 2-3mm.

Compared with the prior art, the utility model has the beneficial effects that:

(1) The coating die head comprises an upper die head, a lower die head, a gasket and a buffer plate, wherein the tail end of the lower die head is connected with the buffer plate for buffer transition, so that after coating liquid flows out from a coating slit outlet, the pressure can be released before the coating liquid contacts with a substrate, and gravity acts on the buffer plate for further spreading and leveling, so that the coating uniformity of the coating liquid on a film material is improved.

(2) According to the coating die head, the second buffer groove is arranged on the lower die head, so that the coating liquid in the coating slit can be buffered once, the discharge pressure of the coating liquid flowing out of the slit outlet onto the buffer plate is reduced, turbulent flow of the coating liquid from the upstream is restrained, uniform spreading of ink is facilitated, meanwhile, the second buffer groove can be utilized for carrying out primary interception on the coating liquid, and the uniformity of the coating liquid is further improved.

(3) According to the coating die head, the strong magnetic film and the magnetic roller are arranged, so that the inclination angle of the buffer plate can be adjusted in real time according to actual production requirements in the coating process, the state that coating liquid flows out of the slit onto the surface of the buffer plate is adjusted, the collision state of the coating liquid with a substrate after flowing out of the buffer plate is further controlled, the real-time regulation and control of the dynamic contact line of the coating liquid and the substrate is realized, the uniform coating of the coating liquid on the surface of the substrate is ensured, and the coating defect of a film material is reduced.

(4) The coating die head of the utility model is used for coating slurry, has few coating defects of film materials and high yield, and can be adapted to the existing coating system to realize mass production.

Drawings

For a clearer description of embodiments of the utility model or of solutions in the prior art, the drawings which are used in the description of the embodiments or of the prior art will be briefly described, it being obvious that the drawings in the description below are only some embodiments of the utility model, and that other drawings can be obtained from them without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a coating die of the present utility model;

FIG. 2 is a schematic view of another embodiment of a coating die of the present utility model;

FIG. 3 is a two-dimensional plan view of a nano-silver wire conductive film coated by using a coating die of the present utility model under a laser microscope;

fig. 4 is a two-dimensional plan view under a laser microscope of a conductive film of nano silver wire coated using a conventional coating die.

Wherein: 1-upper die head, 2-lower die head, 3-gasket, 4-coating slit, 5-buffer plate, 6-first buffer tank, 7-second buffer tank, 8-strong magnetic film, 9-magnetic roller, 10-back roller and 11-substrate.

Detailed Description

The technical solutions of the present utility model will be clearly and completely described below in conjunction with specific embodiments, and it is apparent that the described embodiments are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to fall within the scope of the utility model.

As shown in fig. 1, a coating die head of the present utility model comprises an upper die head 1 and a lower die head 2 which are oppositely arranged, wherein a coating slit 4 is formed between the upper die head 1 and the lower die head 2 through a gasket 3, one end of the lower die head 2, which is close to the outlet of the coating slit 4, is connected with a buffer plate 5, and the buffer plate 5 is inclined downwards relative to the plane of the upper surface of the lower die head 2. According to the coating die head disclosed by the utility model, the tail end of the lower die head 2 is connected with the buffer plate 5 for buffer transition, so that after the coating liquid flows out from the outlet of the coating slit 4, the pressure can be released before the coating liquid contacts the base material 11 on the back roller 10, and the coating liquid can be further spread and leveled on the buffer plate 5 by utilizing the action of gravity, so that the coating uniformity of the coating liquid on a film material is improved.

Specifically, a first buffer groove 6 is arranged on the buffer plate 5 near the outlet of the coating slit 4, and the arrangement direction of the first buffer groove 6 is perpendicular to the flowing direction of the coating liquid. Through set up first buffer tank 6 on buffer board 5, in the coating liquid flows out from coating slit 4 export back entering buffer tank, through the mode of overflow outflow, on the one hand can release fluid pressure, improves the homogeneity of coating liquid, on the other hand, can utilize first buffer tank 6 to intercept granule and the bubble of gathering in the coating liquid to guarantee the coating quality. The buffer tank is inclined downwards at a certain angle, so that the thickness of a wet film can be locally increased, and meanwhile, the coating liquid in a low surface tension area is reduced to flow to the edge for accumulation under the action of gravity, so that the phenomenon of overlarge edge is avoided.

Specifically, a second buffer groove 7 is arranged on the upper surface of the lower die head 2 near the outlet of the coating slit 4, and the arrangement direction of the second buffer groove 7 is perpendicular to the flowing direction of the coating liquid. By providing the second buffer tank 7 on the lower die head 2, the coating liquid can be buffered once in the coating slit 4, the discharge pressure when the coating liquid flows out from the outlet of the coating slit 4 onto the buffer plate 5 is reduced, turbulent flow of the coating liquid from upstream is suppressed, uniform spreading of the coating liquid is facilitated, meanwhile, the coating liquid can be stopped preliminarily by the second buffer tank 7, and the uniformity of the coating liquid is further improved.

Specifically, as shown in fig. 1 and fig. 2, the first buffer slot 6 and the second buffer slot 7 are arc-shaped slots, and it should be noted that both ends of the first buffer slot 6 and both ends of the second buffer slot 7 are closed. The depth of the first buffer tank 6 is smaller than the depth of the second buffer tank 7. More specifically, the width of the first buffer tank 6 is 1.5-2.5mm, and the depth is 0.5-1mm; the width of the second buffer tank 7 is 1.5-2.5mm, and the depth is 1-2mm. Preferably, the width of the first buffer tank 6 is 2mm, and the depth is 1mm; the width of the second buffer tank 7 is 2mm, and the depth is 1.5mm. By arranging the buffer groove as an arc groove, coating liquid is prevented from accumulating in the buffer groove, and meanwhile, stable inflow and outflow of the coating liquid are facilitated; through setting up the degree of depth of first dashpot 6 and being less than the degree of depth of second dashpot 7, the second dashpot 7 carries out preliminary buffering and cuts off, blocks big agglomerate grain and big bubble in the coating liquid, and first dashpot 6 carries out secondary buffering and cuts off, blocks little agglomerate grain and the little bubble of non-interception, further improves the homogeneity of coating liquid through dual cushioning effect to improve coating quality.

Specifically, as shown in fig. 2, the buffer plate 5 is inclined downward at an angle of 5-30 °. Preferably, the buffer plate 5 is inclined downward at an angle of 10-20 °. The buffer plate 5 is in non-rigid connection with the lower die head 2, for example, the buffer plate 5 can be fixed in a cementing manner, so that the inclination angle of the buffer plate 5 can be changed within a certain range, the inclination angle of the buffer plate 5 can influence the flow speed of the coating liquid on the buffer plate 5, and when the inclination angle is smaller, the flow speed is small, and the required time is long; when the inclination angle is large, the gravity effect is obvious, the flow speed is high, the film thickness of the coating liquid is small, the fluctuation phenomenon is easy to occur, and the coating defect is caused.

Specifically, the bottom of the buffer plate 5 and the inclined surface of the lower die head 2 are close to the outlet of the coating slit 4, a strong magnetic film 8 is attached, a magnetic roller 9 is attached to the strong magnetic film 8, and the magnetic roller 9 is used as a fulcrum to support the buffer plate 5. The magnetic roller 9 can roll along the inclined plane of the lower die head 2 and drive the buffer plate 5 to rotate along the fixed position of the buffer plate and the lower die head 2. The magnetic roller 9 is contacted with the strong magnetic film 8 through a tangential point, and is fixed on the strong magnetic film 8 by strong magnetic attraction without sliding off; the fixed magnetic roller 9 plays a supporting role on the buffer plate 5, so that the position of the buffer plate 5 is fixed, and the inclination angle of the buffer plate 5 is kept stable. The magnetic roller 9 can roll on the strong magnetic film 8 on the inclined surface of the lower die head 2, so that the position and the height of the magnetic roller relative to the outlet of the coating slit 4 are changed, and the buffer plate 5 is driven to rotate when the magnetic roller 9 rolls due to the strong adsorption effect of the magnetic roller 9 and the strong magnetic film 8 at the bottom of the buffer plate 5, so that the inclination angle of the buffer plate 5 is adjusted, and at the moment, the tangential point position of the magnetic roller 9 and the strong magnetic film 8 at the bottom of the buffer plate 5 is changed, so that the real-time adjustment of the inclination angle of the buffer plate 5 is realized. Through setting up strong magnetism film 8 and magnetism roller bearing 9 for in the coating process, can adjust buffer board 5 inclination in real time according to actual production needs, thereby adjust the coating liquid and flow out to the state on the buffer board 5 surface from coating slit 4 export, and further control coating liquid flow out the back through buffer board 5 with substrate 11 collision state, realize the real-time regulation and control to the dynamic contact line of coating liquid and substrate 11, guarantee the even coating of coating liquid at substrate 11 surface, reduce the membrane material coating defect.

Specifically, the buffer plate 5 is made of polytetrafluoroethylene, and the thickness is 2-3mm. The buffer plate 5 is a light plate, has a smooth surface, has a length corresponding to the size of the coating die head, and has a width selected according to actual production requirements.

The method for preparing the nano silver wire conductive film by coating the coating die head comprises the following specific steps: starting a coating line power supply, and preheating for 30min; setting a temperature rise program in an oven, wherein the temperatures of six drying units at the rear end are respectively set as follows: drying at 75-120-100-60 deg.c; uniformly dispersing the prepared nano silver wire conductive ink coating liquid, and placing the coating liquid in a material cylinder; starting a coating device, setting relevant parameters, and setting the wet film thickness to be 30-33 mu m and the coating sheet resistance to be 25-30Ω; the angle of the buffer plate is adjusted to 20 degrees, and the speed of the coater is set to 8m/min; pumping the nano silver wire conductive ink into a coating head, and pushing the coating head; spreading ink onto the base film through spreading of the gasket, groove buffer, lip coating, and buffer plate; and conveying the base film through a back roller, and entering a drying system to be solidified and sintered at low temperature to obtain the nano silver wire conductive film. The surface effect of the prepared conductive film is shown in the following table:

as shown in fig. 3, the nano silver wire conductive film coated by the coating die head of the utility model has good surface quality under a laser microscope. Fig. 4 is a two-dimensional plan view of a conventional conductive film of nano silver wire coated by a coating die head without a buffer plate under a laser microscope, when the buffer plate 5 is not provided, the coating liquid has a certain viscosity and is easy to accumulate at the coating head, so that intermittent transverse stripes appear on the coated film material.

The coating die head disclosed by the utility model is used for coating slurry, has few coating defects of film materials, good coating effect and high yield, can be matched with the existing coating system, and realizes mass production.

The utility model has been further described with reference to specific embodiments, but it should be understood that the detailed description is not to be construed as limiting the spirit and scope of the utility model, but rather as providing those skilled in the art with the benefit of this disclosure with the benefit of their various modifications to the described embodiments.

Claims

1. The utility model provides a coating die head, its characterized in that includes the upper die head and the lower die head of relative setting, upper die head with be formed with the coating slit through the gasket between the lower die head, the lower die head is close to the one end of coating slit export is connected with the buffer board, the buffer board is relative lower die head upper surface place plane downward sloping.

2. A coating die as in claim 1, wherein a first buffer slot is provided in the buffer plate adjacent to the coating slot outlet, the first buffer slot being disposed in a direction perpendicular to the direction of flow of the coating liquid.

3. A coating die as in claim 2, wherein a second buffer slot is provided on the upper surface of the lower die near the coating slot outlet, the second buffer slot being disposed in a direction perpendicular to the direction of flow of the coating liquid.

4. A coating die as in claim 3, wherein said first buffer slot and said second buffer slot are arcuate slots.

5. A coating die as in claim 3, wherein the depth of said first buffer slot is less than the depth of said second buffer slot.

6. A coating die as in claim 5, wherein the first buffer slot has a width of 1.5-2.5mm and a depth of 0.5-1mm; the width of the second buffer groove is 1.5-2.5mm, and the depth is 1-2mm.

7. A coating die as in claim 1, wherein said buffer plate is inclined downwardly at an angle of 5-30 °.

8. The coating die of claim 7, wherein a strong magnetic film is attached to the bottom of the buffer plate and the inclined surface of the lower die near the outlet of the coating slot, and a magnetic roller is attached to the strong magnetic film, and the magnetic roller supports the buffer plate as a fulcrum.

9. The coating die of claim 8, wherein the magnetic roller is adapted to roll along the inclined surface of the lower die and to rotate the buffer plate along its fixed position with the lower die.

10. A coating die as in claim 1, wherein the buffer plate is polytetrafluoroethylene and has a thickness of 2-3mm.