An isobaric tipping paper glue flexible coating device

Abstract

The application discloses a kind of isobaric water-tight paper glue water flexible coating device, belong to cigarette processing technical field.The device includes glue seat, glue inlet unit, rotating distribution body, and drive unit of driving rotating distribution body rotation.Glue seat is hollow cylinder structure, rotating distribution body is coaxial cylinder rotating body, rotatably arranged in glue seat, accommodating cavity is formed in rotating distribution body, rotating distribution body is provided with multiple distribution through slots, one end of distribution through slot is communicated with accommodating cavity, the other end is oppositely arranged with glue outlet on glue seat.The cross-sectional area A of accommodating cavity and the sum ΣQ 孔道 Meet isobaric distribution condition, the glue pressure difference of each glue outlet is less than three percent.Solve the problem of multiple glue supply pressure inconsistency in prior art by using pure mechanical structure to realize isobaric distribution, without electronic pressure regulator, improve coating uniformity.

Description

Technical Field

[0001] This invention belongs to the field of cigarette processing technology, and specifically relates to an isobaric flexible coating device for cork paper glue. Background Technology

[0002] During cigarette production, when the filter tip and the cigarette are joined, a layer of tipping paper (commonly known as cork paper) needs to be wrapped around the outer circumference of both the filter tip and the cigarette to fix the filter tip onto the cigarette, forming a complete filter cigarette. Therefore, glue needs to be evenly coated on the inner surface of the tipping paper to ensure that the tipping paper firmly wraps around the circumference of the filter tip and the cigarette, thus reliably fixing the filter tip, cigarette, and tipping paper together.

[0003] Currently, there are two main methods for coating tipping paper: one is full glue coating, which involves coating the entire inner surface of the tipping paper with glue to increase adhesion; the other is partial glue coating, which requires the opening of tiny vent holes in specific parts of the filter tip to allow air circulation during cigarette combustion and reduce the generation of harmful substances during combustion. Therefore, a glue-free area must be left in the corresponding part of the tipping paper on the outer layer of the filter tip to avoid glue clogging the vent holes on the filter tip.

[0004] In the prior art, Chinese patent CN1192726C discloses an apparatus and method for applying adhesive to the wrapping material of rod-shaped items in the tobacco processing industry. It employs a cylindrical glue roller with several glue nozzles connected to the surface of the roller wall via glue tubes. Inside the roller is a rotating roller with multiple shallow glue grooves corresponding to the glue nozzles on its surface. These shallow glue grooves are connected to multiple glue input units via internal glue pipes. The incoming glue passes through the pipes, the shallow glue grooves, and the glue tubes, ultimately reaching the glue nozzles to achieve glue application. Because the rotating roller surface has isolation blocks, when the isolation blocks block the entrance to the glue tubes, the glue nozzles corresponding to those tubes will not output glue, thus achieving glue application.

[0005] Chinese patent CN106890755A discloses a coating device for strip materials, which is an improvement on CN1192726C. Specifically, it features multiple radially extending through holes distributed on an inner drum (rotating roller). These through holes guide the glue from the center to the outside of the inner drum. The outer ends of the through holes on the inner drum have drum grooves that connect to glue tubes attached to a cylindrical glue roller, thus achieving glue application. When the outer ends of the through holes on the inner drum do not have grooves, no glue is applied, thereby achieving the application of fish glue.

[0006] Chinese patent CN219442121U uses an independent electronic pressure regulator and pressure sensor for each channel to control the glue supply pressure.

[0007] However, the aforementioned existing technical solutions all have the following drawbacks: Because the cylindrical glue roller contains multiple glue supply pipes, and each solution utilizes these pipes to introduce glue into different shallow grooves on the surface of the rotating roller, the limited installation space and fluid pressure loss cause a difference in glue pressure between the near-end outlet (closer to the glue inlet) and the far-end outlet (farther from the inlet). According to Poiseuille's law, ΔP = 8ηLQ / πr 4 Differences in tube length can result in the glue output at the far end being only 40% to 60% of that at the near end; this leads to uneven glue coating thickness on the tipping paper at both ends, affecting the quality of cigarette rolling and product consumption. At the same time, glue overflow caused by differences in glue flow also affects the machine's production efficiency and maintenance.

[0008] To address the pressure balance issue in multi-channel glue supply, conventional technologies employ glue distribution islands, pressure distribution, and adjustment devices, hoping to compensate for the differences by fine-tuning the pressure. However, on the one hand, the pressure difference is extremely small, making it difficult for conventional devices to achieve such high-precision measurement and adjustment; on the other hand, glue pressure distribution devices are expensive, and the technology is often controlled by foreign manufacturers, resulting in high costs and unstable supply. Summary of the Invention

[0009] The technical problem to be solved by the present invention is: in the existing cork paper glue coating device, the glue pressure at the far end and near end of the glue outlet is inconsistent due to the difference in length of multiple glue supply pipes, which leads to uneven glue coating thickness, and the existing solutions using electronic voltage regulating devices are high in cost, slow in response and insufficient in accuracy. The present invention provides an equal pressure cork paper glue coating device that ensures that the glue supply pressure of all glue coating channels is completely equal from the physical structure.

[0010] Terminology definition: The “flexible coating” of the present invention refers to the ability to switch between various coating patterns such as full glue coating, single glue-free area coating, and double glue-free area coating by means of the combination of a through-groove glue tank and isolation blocks on the surface of the rotating dispensing body, without changing the hardware, by adjusting the number, height and distribution of the isolation blocks, without the need to change the device or stop the machine for adjustment.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: an isobaric flexible coating device for cork paper adhesive, comprising: The glue holder is driven by the driver 2 to switch between working angle 1 and working angle 2. The glue holder is a hollow cylindrical structure. The glue holder is provided with at least two glue channels of equal diameter and length along the axial direction. The glue channels are symmetrically arranged on both sides of the transverse center point of the water-tip paper. One end of the glue channel is connected to the inner wall of the cylindrical structure, and the other end is connected to the glue outlet provided on the surface of the glue holder. The glue feeding unit is fixed to the glue base and the glue feeding shaft via a connecting flange. The glue feeding shaft of the glue feeding unit is rotatably installed in the glue feeding sleeve, which is fixed by the frame connector. When the glue base and the glue feeding shaft are at the working angle 1, the glue inlet of the glue feeding sleeve is connected to the glue channel of the glue feeding shaft, and the glue enters the receiving cavity and is supplied to the water-pressed paper through the channel and the glue outlet. When the glue seat and the glue inlet shaft are at working angle 2, the glue inlet of the glue inlet sleeve and the glue channel of the glue inlet shaft are not connected. At this time, the water-tight paper stops running and the glue supply stops. The rotating dispensing body is a coaxial cylindrical rotating body, coaxially fitted inside the glue holder. When the glue holder and the glue inlet shaft are at working angle 1, the rotating dispensing body is driven to rotate by the driver, tracking and synchronizing with the movement of the tipping paper. The cylindrical hollow area of ​​the rotating dispensing body constitutes the glue receiving cavity. The glue from the glue inlet unit enters the receiving cavity through the glue inlet for mixing and pressure balancing. When the glue holder and the glue inlet shaft are at working angle 2, the glue supply to the receiving cavity is cut off.

[0012] The cylindrical wall of the rotating dispensing body has glue grooves on its circumferential surface that correspond to the glue channel positions of the glue seat. The glue grooves are through groove structures set along the circumferential direction, and the axial width of each glue groove is greater than or equal to the diameter of the glue channel on the side wall of the glue seat. The flow cross-sectional area of ​​the receiving cavity is at least 1.25 times the sum of the flow cross-sectional areas of all glue channels.

[0013] More preferably, the cylindrical outer wall of the rotating dispensing body and the cylindrical inner wall of the glue base are rotatably fitted with a gap, the gap size being 0.01 mm to 1.5 mm.

[0014] Further preferably, the inner diameter D of the receiving cavity and the diameter d of a single glue channel satisfy D≥d×√(k×N), where k is the maximum design flow coefficient and k≥1.25, and N is the number of glue channels.

[0015] Further preferably, the inner diameter D of the receiving cavity and the diameter d of the single glue channel satisfy D≥2d, and the glue supply flow rate of the receiving cavity satisfies Q_main≥1.5×Σ(Q_channel).

[0016] Further preferred, the glue supply flow rate of the receiving cavity Q_main ≥ 2 × Σ(Q_channel); or Q_main ≥ 4 × Σ(Q_channel).

[0017] More preferably, the receiving cavity is a variable diameter conical structure, with its distal diameter D2 being larger than its proximal diameter D1, and D2 ≥ D1 + 1 mm.

[0018] In a further preferred embodiment, the wall of the glue holder is provided with at least one transverse pipe along the axial direction, which connects to symmetrical glue channels on both sides of the transverse center point of the tipping paper. This arrangement ensures that the glue pressure between the symmetrically arranged glue channels remains balanced, thereby ensuring a uniform glue flow rate.

[0019] More preferably, the adhesive channel of the rotating dispensing body has at least one isolation block spaced at intervals on its radial surface. When the isolation block rotates with the rotating dispensing body to block the adhesive channel inlet of the adhesive seat, the dispensing nozzle corresponding to the adhesive channel stops dispensing adhesive; when the isolation block leaves the adhesive channel inlet, the dispensing nozzle resumes dispensing adhesive.

[0020] Further preferably, the isolation blocks are of at least two types: The first isolation block has a height flush with the surface of the rotating body and a circumferential arc length of less than 3mm. Its circumferential arc length corresponds to blocking the entrances of all glue channels. This design ensures that no glue is applied at the cutting line position of each sheet of tipping paper, reducing the frequency of cutting tool maintenance. The second isolation block has a height flush with the surface of the rotating body and a circumferential arc length greater than or equal to 8mm and less than (cigarette circumference - 2mm). Its circumferential arc length corresponds to blocking only the entrances of the glue channels in the middle position. This design ensures that no glue is applied at the perforation positions of each sheet of tipping paper, reducing blockage of the holes, maintaining good ventilation, and thus achieving flexible glue distribution.

[0021] In a further preferred embodiment, the glue channel of the rotating dispensing body has n isolation blocks evenly spaced on its radial circumferential surface. The sections of the glue channel with isolation blocks and the sections without isolation blocks cooperate to form a glued + unglue area on a unit length of tipping paper. The rotating dispensing body tracks and synchronizes with the movement of the tipping paper, thereby enabling the rotating dispensing body to apply glue in real time at a linear velocity of 1 / n of the tipping paper's linear velocity, thereby reducing the relative velocity between the rotating dispensing body and the side wall of the glue seat and reducing wear.

[0022] A method for applying cork paper adhesive, using any of the isobaric flexible cork paper adhesive application devices described above, includes the following steps: Step S1: The glue enters the receiving cavity of the rotating dispensing body through the glue inlet and the glue dispensing unit; In step S2, the adhesive is mixed in the receiving cavity to form a uniform pressure field; Step S3: The rotating dispensing body rotates under the drive of the driver, tracking and synchronizing with the length of the tipping paper. The rotating dispensing body rotates at a speed of 1 / n of the linear velocity of the tipping paper, where n is the number of isolation blocks evenly distributed on the surface of the rotating dispensing body. Under the action of equal pressure, the glue in the receiving cavity enters each glue channel on the glue seat through the glue tank, and then is applied to the surface of the tipping paper through the glue nozzle. Step S4: When the rotating dispensing body rotates until the isolation block on its surface blocks the glue channel inlet, the glue nozzle corresponding to the glue channel stops dispensing glue, forming a glue-free area; otherwise, the glue nozzle resumes dispensing glue, forming a glued area.

[0023] More preferably, in step S3, the rotating dispensing body rotates at a speed of 1 / n of the linear speed of the cork paper, where n is the number of evenly distributed isolation blocks on the surface of the rotating dispensing body, in order to reduce the relative speed between the rotating dispensing body and the inner wall of the glue seat.

[0024] In a further preferred embodiment, in step S4, the isolation block includes at least a first isolation block and a second isolation block. The first isolation block blocks all glue channel inlets, forming a full-width glue-free area in the transverse direction. The second isolation block only blocks the middle glue channel inlet, forming a glue-free area corresponding to the vent hole position of the filter nozzle.

[0025] Compared with the prior art, the present invention has the following beneficial effects: First, by setting up a large-volume receiving cavity as a pressure balancing chamber and making quantitative designs based on Poiseuille's law (the cross-sectional area of ​​the receiving cavity is at least 1.25 times the total cross-sectional area of ​​all channels), the flow velocity of the glue in the receiving cavity is much lower than that in a single channel. This ensures that the glue supply pressure of all glue application channels is completely equal from a physical structure perspective, and the difference in glue pressure at each outlet is less than 3%, while the difference in traditional multi-channel glue supply schemes is as high as 40% to 60%.

[0026] Secondly, by designing the receiving cavity as a conical structure (the distal diameter D2 is greater than the proximal diameter D1 and D2≥D1+1mm), the pressure loss along the flow path of the adhesive is compensated, further improving the uniformity of the adhesive pressure of multiple channels. This is particularly suitable for scenarios with a large number of channels or a large axial distribution range.

[0027] Third, it eliminates the need for electronic pressure regulators and pressure sensors, relying entirely on mechanical structures to achieve equal pressure dispensing, fundamentally eliminating the risk of electronic component failure, significantly improving the reliability and lifespan of the device, and greatly reducing manufacturing costs.

[0028] Fourth, by periodically setting isolation blocks on the surface of the glue tank of the rotating dispensing body, the periodic blocking of the glue channel inlet by the isolation blocks as the dispensing body rotates enables free switching between two working modes: full glue application and mixed glue application. The glue pattern formed in the mixed glue mode, with alternating glue-covered and glue-free areas, can precisely correspond to the position of the filter nozzle vent, preventing glue from clogging the vent.

[0029] Fifth, by setting transverse pipes with symmetrical connecting channels inside the glue base wall, the pressure difference on both sides caused by slight changes in manufacturing tolerances or working conditions is further compensated, ensuring the uniformity of the transverse glue coating thickness of the tipping paper.

[0030] Sixth, the through-groove glue tank design ensures that the axial length of the glue tank covers the entire distribution area of ​​the channels, and the glue supply conditions at the entrance of each channel are consistent. Combined with the pressure equalization effect of the receiving cavity, the pressure drop difference caused by the difference in length of multiple glue supply pipes is fundamentally eliminated. Attached Figure Description

[0031] Figure 1a A schematic diagram of the glue holder at working angle 1; this figure is an isometric view of the entire device, showing the working state in glue application mode. The main components marked in the figure include: driver 2, driver, drive shaft, glue nozzle, glue holder, connecting flange, material to be coated, glue inlet, and glue dispensing unit.

[0032] Figure 1b A schematic diagram of the glue holder at working angle 2; this diagram is an isometric view of the entire device. When the tipping paper stops running, the driver 2 rotates the glue holder, causing the glue nozzle to move away from the tipping paper, and simultaneously the glue and the driver stop running. The main components marked in the diagram include: driver 2, driver, drive shaft, glue nozzle, glue holder, connecting flange, material to be coated, glue inlet, and glue inlet unit.

[0033] Figure 2a A schematic diagram showing the rotating dispensing body with isolation blocks 1 on its surface; this figure is an exploded view of the device, showing the internal mating structure between the rotating dispensing body and the glue holder. The labeled components include: driver, drive shaft, isolation block 1, glue tank, rotating dispensing body, receiving cavity, glue holder, channel, glue outlet, connecting flange, glue inlet channel, glue inlet, glue inlet shaft, and glue hole.

[0034] Figure 2b The diagram shows the glue distribution of the full-coverage adhesive coating, with spacer block 1 as the dividing point. This diagram is an unfolded view of the glue coating effect on the cork paper, showing the glue pattern under the action of spacer block 1. The labels include: the material being coated, the non-adhesive area 1, and the glued area.

[0035] Figure 3a A schematic diagram showing a rotary distributor with isolation blocks 1 and 2 on its surface; this figure is an exploded view of the device, showing the rotary distributor structure with dual isolation blocks. Labels include: driver, isolation block 2, isolation block 1, glue tank, glue seat, channel A, channel B, channel C, channel D, glue nozzle, connecting flange, glue inlet channel, glue inlet, glue inlet shaft, and glue hole.

[0036] Figure 3b The diagram shows the glue distribution of the full-adhesive coating, consisting of spacer block 1 and spacer block 2. This diagram is an unfolded view of the glue coating effect on cork paper, showing the pattern of the flower glue under the action of the two spacer blocks. The labels include: coated material, non-adhesive area 1, glued area, and non-adhesive area 2.

[0037] Figure 3cA schematic diagram showing the glue entering the receiving cavity through the glue inlet and glue inlet pipe when the glue seat and glue inlet shaft are at working angle 1.

[0038] Figure 3d A schematic diagram showing multiple evenly distributed isolation blocks on the surface of the rotating dispensing body, corresponding to the glue pattern on the cork paper, and reducing the rotation speed of the rotating dispensing body.

[0039] Figure 4a A schematic diagram of a cavity arrangement; this figure is a radial sectional view of the device, showing the structural design of a cylindrical cavity of equal diameter. Labels include: glue seat, channel, nozzle, connecting flange, glue tank, spacer block, cavity, and glue inlet direction.

[0040] Figure 4b and Figure 4c This diagram illustrates an alternative cavity design; it is a radial sectional view of the device, showing the structural design of the variable-diameter conical cavity. Labels include: glue seat, channel, nozzle, connecting flange, cavity, D1 (proximal diameter), and D2 (distal diameter). Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0042] Example 1: Refer to Figure 1a , Figure 1b , Figure 2a and Figure 3a This embodiment provides an isobaric flexible coating device for cork paper glue, including a glue holder, a glue infeed unit, a rotary dispensing body, and a driver.

[0043] The glue holder is a hollow cylindrical fixed structure that maintains its relative position to the tipping paper and remains stationary relative to the glue inlet unit during application. The glue holder has at least two channels of the same diameter and length arranged symmetrically on both sides of the transverse center point of the tipping paper. One end of each channel connects to the inner cylindrical wall of the glue holder, and the other end connects to a glue nozzle located on the outer surface of the glue holder. Multiple sets of glue nozzles are arranged axially along the surface of the glue holder.

[0044] The glue dispensing unit is fixedly connected to the glue holder via a connecting flange. The glue dispensing unit is connected to at least one glue inlet, which is connected to an external glue supply system. The glue dispensing unit contains a glue dispensing shaft with glue holes that communicate with the glue inlets to introduce glue into the device.

[0045] The rotating dispensing body is a coaxial cylindrical rotating body, coaxially fitted inside the glue holder, and driven to rotate by a driver via a drive shaft. The rotational speed of the rotating dispensing body is synchronized with the conveying speed of the coated material, the tipping paper. The cylindrical outer wall of the rotating dispensing body and the inner diameter of the glue holder are in a rotatable gap fit, with a gap range of 0.01mm-1.5mm, meaning the inner diameter of the glue holder is equal to the outer diameter of the rotating dispensing body plus a gap of 0.01mm to 1.5mm.

[0046] The cylindrical hollow region of the rotary dispensing body forms the adhesive receiving cavity. Adhesive from the dispensing unit enters the receiving cavity through the inlet and adhesive holes, where it is mixed and pressure balanced. Adhesive grooves corresponding to the positions of the channels are formed on the circumferential surface of the rotary dispensing body's cylindrical wall. These grooves are through-grooves along the circumference, and their length covers the axial area of ​​all the channels on the adhesive base.

[0047] The driver is connected to the rotating dispenser via a drive shaft and is used to drive the rotating dispenser to rotate relative to the glue holder. The speed of the driver is adjusted to match the feed speed of the tipping paper.

[0048] During operation, the glue from the glue inlet passes through the glue feeding unit and enters the receiving chamber. The receiving chamber acts as a large-volume pressure-balancing chamber, allowing the glue to mix thoroughly and form a uniform pressure field. The glue then flows from the receiving chamber through the glue tank into the channel, and finally through the glue outlet to be applied to the surface of the cork paper.

[0049] Example 2: Based on Example 1, this example further illustrates two working modes: full glue application and fish maw application.

[0050] Reference Figure 1a In the full-adhesion coating mode, the glue tank surface of the rotating dispensing body is not equipped with a shielding structure, and all glue nozzles continuously dispense glue, forming a continuous and complete glue coating area on the tipping paper surface, i.e., the full-adhesion area. This is suitable for ordinary filter tip assembly processes without ventilation holes.

[0051] Reference Figure 1b In the fish maw application mode, the isolation block structure on the surface of the rotating dispensing body periodically blocks the entrance of the channel, causing the dispensing nozzle to dispense glue intermittently, forming a fish maw pattern with alternating glued and unglued areas. The unglued areas correspond to the positions on the tipping paper where ventilation holes need to be reserved, preventing glue from clogging the filter nozzle's ventilation holes.

[0052] The fish maw application mode is achieved by using an isolation block structure on a rotating dispensing body. The specific structural configuration and pattern formation method are described in Examples 3 and 4.

[0053] Example 3: Reference Figure 2a and Figure 2bThis embodiment further illustrates the structure and adhesive pattern of the single isolation block configuration based on Embodiment 1.

[0054] Isolation blocks 1 are spaced apart on the surface of the glue tank of the rotating dispensing body. The isolation block 1 is a raised structure, and its outer arc surface is consistent with the outer circumference of the rotating dispensing body, that is, the outer side surface of the isolation block 1 and the outer circumference of the rotating dispensing body maintain the same radius. When the isolation block 1 rotates with the rotating dispensing body to the position corresponding to the inlet of the channel, its arc surface cooperates with the inner wall of the glue seat to block the inlet of the channel and prevent glue from entering the channel; when the isolation block 1 does not block the inlet of the channel, the glue flows out through the channel and the glue nozzle under the pressure of the receiving cavity and is applied to the surface of the cork paper.

[0055] Reference Figure 2b When using the separator block 1, a horizontally continuous rectangular glue area is formed on the surface of the tipping paper. The glue area is a continuous and complete glued area to ensure the bonding strength of the cigarette. Only in the length direction (conveyor direction) of the tipping paper are there intervals of no glue area 1. The no glue area 1 is a blank area covering the entire width of the tipping paper in the horizontal direction, corresponding to the splicing boundary position of a single cigarette.

[0056] This configuration is suitable for standard filter tip assembly processes that do not require vent holes.

[0057] Example 4: Reference Figure 3a and Figure 3b This embodiment further illustrates the structure and adhesive pattern of the dual-isolation block configuration based on Embodiment 1.

[0058] Isolation blocks 1 and 2 are simultaneously installed on the surface of the glue tank of the rotating dispensing body, with different heights. The channels on the glue base are divided into four groups: channel A, channel B, channel C, and channel D, arranged symmetrically along the axial direction. The height of isolation block 1 is designed to block all channels, i.e., its maximum height, allowing access to the entrances of all four groups of channels A, B, C, and D; the height of isolation block 2 is designed to block only the middle channels, i.e., the entrances of channels B and C, without blocking channels A and D.

[0059] By configuring the different heights of isolation block 1 and isolation block 2, two-stage glue dispensing control is achieved, forming more complex fish maw patterns.

[0060] Reference Figure 3b When a double-isolation block configuration is used, the following pattern features are formed on the surface of the tipping paper: the glue-free area 1 is a blank area covering the entire width of the tipping paper in the horizontal direction, corresponding to the cigarette splicing boundary position; the glue-free area 2 is a horizontal long blank area in the middle of the tipping paper, corresponding to the filter vent position; the glue area is distributed on the glued areas on the upper and lower sides of the glue-free area 2 to ensure the splicing bonding strength.

[0061] This configuration is suitable for the assembly process of ventilation filter nozzles with vent holes. By forming a glue-free area 2 at the position of the corresponding filter nozzle vent hole, glue is prevented from clogging the filter nozzle vent hole. At the same time, the glue areas on the upper and lower sides ensure the bonding strength of the assembly.

[0062] Example 5: Refer to Figure 4a This embodiment, based on embodiment 1, further illustrates the equal-diameter cylindrical scheme of the receiving cavity and the quantitative design relationship.

[0063] The receiving cavity adopts a cylindrical cavity design with a uniform diameter of D, and its axial length covers the entire distribution area of ​​the channels. The diameter of a single channel is d. Quantitative design is performed based on the isobaric distribution conditions of Poiseuille's law. The cross-sectional area of ​​the cavity is A = πD² / 4, and the total cross-sectional area of ​​the N channels is Σa = N × πd² / 4. The isobaric distribution condition requires that the cross-sectional area of ​​the cavity be at least k times the total cross-sectional area of ​​the channels, i.e., A ≥ k × Σa. Substituting, we get: πD² / 4 ≥ k × N × πd² / 4, Simplifying, we get: D ≥ d × √(k × N), Where k is the maximum design flow coefficient, k≥1.25; N is the number of ducts.

[0064] Specifically: when N=2, D≥d×√(1.25×2)=1.58d; when N=4, D≥d×√(1.25×4)=2.24d; when N=6, D≥d×√(1.25×6)=2.74d. And so on.

[0065] This quantitative relationship ensures that the cross-sectional area of ​​the cavity is at least equal to the total cross-sectional area of ​​all channels, so that the flow velocity of the glue in the cavity is much lower than that in a single channel, thereby obtaining a uniform glue pressure field in the cavity.

[0066] Calculation of flow safety margin: Design maximum flow rate Q of the receiving cavity 主 The actual total flow rate ΣQ of each channel 孔道 The Q condition is satisfied between them. 主 ≥k×ΣQ 孔道 , where k≥1.25.

[0067] The actual flow velocity V within the cavity 主 =ΣQ 孔道 / A, Flow velocity V in a single channel 孔 =Q 孔道 / a. Substituting D≥√(kN)·d, we can obtain V. 主 ≤(1 / k)×V 孔 That is, the flow rate of glue in the cavity does not exceed 1 / k of the flow rate in the channel, further ensuring uniform pressure distribution.

[0068] The glue supply flow rate of the receiving cavity meets Q 主 ≥1.5×ΣQ 孔道 More preferably, Q 主 ≥2×ΣQ 孔道 The most preferred option is Q. 主 ≥4×ΣQ 孔道 , where ΣQ 孔道 This is the total flow rate when all glue channels are dispensing glue simultaneously.

[0069] When the inner diameter D of the receiving cavity satisfies D≥2d and the glue supply flow rate satisfies Q 主 ≥1.5ΣQ 孔道 At the same time, the receiving cavity always has sufficient pressure equalization capacity, so that the pressure difference between the dispensing outlets is less than 3%.

[0070] Example 6: Refer to Figure 4b This embodiment further illustrates another variable-diameter conical scheme for the receiving cavity, based on Embodiment 1.

[0071] The receiving cavity adopts a conical design, with its proximal diameter D1 and distal diameter D2 satisfying D2>D1, meaning the distal diameter of the receiving cavity is larger than the proximal diameter. Specifically, the diameter difference is designed to be D2≥D1+1mm.

[0072] The purpose of the conical design is to compensate for the pressure loss during the axial flow of the adhesive. Adhesive flows in from the proximal end of the receiving cavity (the end closest to the inlet) and flows axially towards the distal end. Due to the pressure loss along the flow path of the viscous fluid, the pressure at the distal end is lower than that at the proximal end. By designing the receiving cavity as a conical structure with a larger diameter at the distal end than at the proximal end, the larger flow cross-sectional area at the distal end reduces the adhesive flow velocity, thereby compensating for the pressure loss along the flow path and ensuring a balance of adhesive supply pressure between the distal and proximal channels.

[0073] This variable diameter conical design can further improve the uniformity of adhesive dispensing pressure in multiple channels, making it particularly suitable for applications with a large number of channels or a wide axial distribution range.

[0074] Example 7: Based on any of the above embodiments, at least one transverse pipe can be provided axially inside the wall of the glue holder to maintain the connection between the symmetrical channels on both sides of the tipping paper, so as to further balance the glue pressure.

[0075] The transverse channels connect symmetrical channels on both sides of the transverse center point of the tipping paper, allowing the glue to flow freely between the two channels. This compensates for pressure differences on both sides caused by minor variations in manufacturing tolerances or working conditions, further ensuring the uniformity of the glue coating thickness.

[0076] Example 8: This example provides a method for applying cork paper adhesive using the above-described device, comprising the following steps: Step S1: The glue enters the receiving cavity of the rotating dispensing body through the glue inlet and the glue dispensing unit; Step S2: The adhesive is mixed in the receiving cavity and a uniform pressure field is formed; Step S3: The rotating dispensing body rotates at a speed that is synchronized with the conveying speed of the tipping paper under the drive of the driver. The glue in the receiving cavity enters the glue tank and the channels on the glue seat under the action of equal pressure, and then is applied to the surface of the tipping paper through the glue nozzle. Step S4: When the rotating dispensing body rotates until the isolation block on its surface blocks the channel entrance, the dispensing nozzle corresponding to the channel stops dispensing glue, forming a glue-free area; when the isolation block leaves the channel entrance, the dispensing nozzle resumes dispensing glue, forming a glued area.

[0077] Different glue patterns (full glue or patterned glue) can be formed by configuring the number, height, and distribution of the isolation blocks.

[0078] Technical effect verification The technical effects of the present invention will be further illustrated below by comparing experimental data.

[0079] Pressure uniformity comparison The pressure difference of the glue outlets is less than 3% when using the equal pressure receiving cavity design of the present invention, while the pressure difference between the far and near glue outlets of the traditional multi-channel glue supply scheme is as high as 40%-60%.

[0080] Quantitative Design Parameter Table of Accommodation Cavity 2 1.25 1.58 1.25 4 1.25 2.24 1.25 6 1.25 2.74 1.25 4 1.5 2.45 1.5 4 2.0 2.83 2.0 4 4.0 4.00 4.0 According to Poiseuille's law, under the condition that the cross-sectional area of ​​the cavity satisfies A≥k×Σa, the flow velocity of the glue in the cavity is V. 主 ≤(1 / k)×V 孔 Ensure that the glue pressure at the entrance of each channel is basically consistent.

[0081] In summary, this invention, by setting a large-volume receiving cavity as a pressure balancing chamber and using Poiseuille's law for quantitative design, ensures uniform glue supply pressure in all glue application channels from a physical structure perspective. It eliminates the need for electronic pressure regulating devices and multiple pressure adjustment devices, fundamentally eliminating pressure drop differences caused by differences in pipe length, and realizing equal-pressure glue transfer.

Claims

1. A flexible coating device for cork paper adhesive based on equal pressure, characterized in that, include: The glue holder, driven by the driver 2, switches between working angle 1 and working angle 2. The glue holder is a hollow cylindrical structure with at least two glue channels of equal diameter and length arranged axially. The glue channels are symmetrically arranged on both sides of the transverse center point of the tipping paper. One end of each glue channel is connected to the inner wall of the cylindrical structure, and the other end is connected to the glue outlet provided on the surface of the glue holder. The glue holder is connected to a coaxial glue inlet shaft through a connecting flange. The glue feeding unit includes a glue inlet, a glue feeding sleeve, and a glue feeding shaft. The glue feeding shaft is rotatably disposed in the glue feeding sleeve. The glue feeding sleeve is fixed by a frame connector. When the glue seat and the glue feeding shaft are at a working angle 1, the glue inlet of the glue feeding sleeve is connected to the glue channel of the glue feeding shaft. The glue enters the receiving cavity and is supplied to the tipping paper through the channel and the glue outlet. When the glue seat and the glue inlet shaft are at working angle 2, the glue inlet of the glue inlet sleeve and the glue channel of the glue inlet shaft are not connected. At this time, the water-tight paper stops running and the glue supply stops. A rotating dispensing body, which is a coaxial hollow cylindrical rotating body, is coaxially fitted inside the hollow cylinder of the glue base. When the glue base and the glue inlet shaft are at working angle 1, the rotating dispensing body is driven to rotate by the driver, tracking and synchronizing with the movement of the tipping paper. The cylindrical hollow area of ​​the rotating dispensing body constitutes a glue receiving cavity. The glue from the glue inlet unit enters the receiving cavity through the glue inlet for mixing and pressure balancing. When the glue base and the glue inlet shaft are at working angle 2, the glue supply to the receiving cavity is cut off. The cylindrical wall of the rotating dispensing body has glue grooves on its circumferential surface that correspond to the glue channel positions of the glue seat. The glue grooves are through groove structures arranged along the circumferential direction, and the axial width of each glue groove is greater than or equal to the diameter of the glue channel on the side wall of the glue seat. The flow cross-sectional area of ​​the receiving cavity is at least 1.25 times the sum of the flow cross-sectional areas of all glue channels.

2. The isobaric flexible coating device for cork paper adhesive according to claim 1, characterized in that, The cylindrical outer wall of the rotating dispensing body and the cylindrical inner wall of the glue base are rotatably fitted with a gap, the gap being 0.01mm to 1.5mm in size.

3. The isobaric flexible coating device for cork paper adhesive according to claim 1 or 2, characterized in that, The inner diameter D of the receiving cavity and the diameter d of a single glue channel satisfy D≥d×√(k×N), where k is the maximum design flow coefficient and k≥1.25, and N is the number of glue channels.

4. The isobaric flexible coating device for cork paper adhesive according to claim 3, characterized in that, The inner diameter D of the receiving cavity and the diameter d of the single glue channel satisfy D ≥ 2d, and the glue supply flow rate of the receiving cavity satisfies Q. 主 ≥1.5×Σ(Q 孔道 ).

5. The isobaric flexible coating device for cork paper adhesive according to claim 4, characterized in that, The adhesive supply flow rate Q of the receiving cavity 主 ≥2×Σ(Q 孔道 ) or Q 主 ≥4×Σ(Q 孔道 ).

6. The isobaric flexible coating device for cork paper adhesive according to claim 1, characterized in that, The cavity is a tapered structure with a variable diameter, where the distal diameter D2 is larger than the proximal diameter D1, and D2 ≥ D1 + 1 mm.

7. The isobaric flexible coating device for cork paper adhesive according to claim 1, characterized in that, At least one transverse pipe is axially arranged inside the wall of the glue holder, connecting symmetrical glue channels on both sides of the transverse center point of the tipping paper. This arrangement ensures that the glue pressure between the symmetrically arranged glue channels remains balanced, thereby guaranteeing a uniform glue flow rate.

8. The isobaric flexible coating device for cork paper adhesive according to claim 1, characterized in that, The adhesive channel of the rotating dispensing body has at least one isolation block spaced at intervals on its radial surface. When the isolation block rotates with the rotating dispensing body to block the adhesive channel inlet of the adhesive seat, the dispensing nozzle corresponding to the adhesive channel stops dispensing adhesive. When the isolation block leaves the adhesive channel inlet, the dispensing nozzle resumes dispensing adhesive.

9. The isobaric flexible coating device for cork paper adhesive according to claim 8, characterized in that, The isolation blocks are at least of two types: the first isolation block is flush with the surface of the rotating body, and its circumferential arc length corresponds to blocking the entrance of all glue channels. The circumferential arc length of the first isolation block is less than 3mm. This setting ensures that no glue is applied at the cutting line position of each piece of tipping paper, thereby reducing the number of times the cutting tool needs maintenance; the second isolation block is flush with the surface of the rotating body, and its circumferential arc length corresponds to blocking only the entrance of the glue channel in the middle position. The circumferential arc length of the second isolation block is greater than or equal to 8mm and less than (the circumference of the cigarette - 2mm). This setting ensures that no glue is applied at the punched hole position of each piece of tipping paper, thereby reducing the blockage of the holes, maintaining good ventilation of the holes, and thus achieving flexible glue distribution.

10. The isobaric flexible coating device for cork paper adhesive according to claim 8 or 9, characterized in that, The glue channel of the rotating dispensing body has n isolation block areas evenly spaced on its radial circumferential surface. The sections of the glue channel with isolation blocks and those without isolation blocks cooperate to form a glued + unglue area on a unit length of tipping paper. The rotating dispensing body tracks and synchronizes with the movement of the tipping paper, thereby enabling the rotating dispensing body to apply glue in real time at a linear velocity of 1 / n of the tipping paper's linear velocity, thus reducing the relative velocity between the rotating dispensing body and the side wall of the glue seat and reducing wear.

11. A method for applying cork glue, using the isobaric cork glue flexible coating device as described in any one of claims 1 to 10, characterized in that, Includes the following steps: Step S1: The glue enters the receiving cavity of the rotating dispensing body through the glue inlet and the glue dispensing unit; Step S2, the adhesive is mixed in the receiving cavity and a uniform pressure field is formed; In step S3, the rotating dispensing body rotates under the drive of the driver, tracking and synchronizing with the length of the tipping paper. Under the action of equal pressure, the glue in the receiving cavity enters each glue channel on the glue seat through the glue tank, and then is applied to the surface of the tipping paper through the glue nozzle. Step S4: When the rotating dispensing body rotates until the isolation block on its surface blocks the glue channel inlet, the glue outlet corresponding to the glue channel stops dispensing glue, forming a glue-free area. Conversely, the nozzle resumes dispensing glue, creating a glued area.

12. The method according to claim 11, characterized in that, In step S3, the rotating dispensing body rotates at a speed of 1 / n of the linear velocity of the cork paper, where n is the number of evenly distributed isolation blocks on the surface of the rotating dispensing body, in order to reduce the relative speed between the rotating dispensing body and the inner wall of the glue seat.

13. The method according to claim 11, characterized in that, In step S4, the isolation block includes at least a first isolation block and a second isolation block. The first isolation block blocks all glue channel entrances, forming a full-width glue-free area in the transverse direction. The second isolation block only blocks the entrance to the middle glue channel, forming a glue-free area corresponding to the vent position of the filter tip.

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