A forming gun for producing a hollow filter rod

Abstract

The application discloses a forming gun for producing hollow filter rods, which comprises a steam section and a cooling section. The steam section comprises an upper steam pressing plate and a lower steam pressing plate. The cooling section comprises an upper cooling pressing plate and a lower cooling pressing plate. The upper steam pressing plate is provided with a shaping structure, which is located at the upper part of a forming channel and is used for flattening the cloth tape mark on the filter rod. The upper cooling pressing plate is provided with an air inlet hole, and the lower cooling pressing plate is provided with an air outlet hole. The air inlet hole is connected with a cooling air supply pipeline, and the air outlet hole is connected with a negative pressure air suction pipeline. The cooling section is changed from the original opposite blowing mode to the upper blowing and lower suction mode. The upper cooling air is uniformly applied on the filter rod, and the lower cooling air is used for discharging heat and moisture through negative pressure, so that the cooling section is ensured to be free of condensate water, and the hardness of the filter rod is ensured. The shaping structure is arranged in the steam section. During the tows band setting process, the cloth tape mark on the upper part of the filter rod is opened and flattened, so that the cloth tape mark defect caused by the cloth tape extrusion on the surface of the original hollow filter rod can be effectively overcome, and the production quality is improved.

Description

Technical Field

[0001] This invention relates to the field of hollow filter rod molding technology, and specifically to a molded smoke gun for producing hollow filter rods. Background Technology

[0002] The forming principle of paperless hollow filter rods is that the filament bundle sprayed with triacetyl ester (plasticizer) enters the smoke gun, is quickly shaped after passing through high-temperature steam, and is rapidly cooled and dried by cooling air, which improves the hardness and forming quality of the filament bundle.

[0003] The steam gun in filter rod forming equipment is a crucial step in the filter rod wrapping and forming process, and its structural design directly affects the product quality. Currently used steam guns, such as the steam forming equipment disclosed in Chinese patent CN210017845U, involve plasticizer-sprayed fiber bundles being gradually wrapped by a fabric belt upon entering the steam gun. The filter rods, driven by the fabric belt, enter from one end of the steam section and are conveyed to the cooling section, then exit from the cooling section. During this conveying process, the steam section of the gun uses high-temperature steam to shape the fiber bundles, which are then cooled in the cooling section to form the filter rods.

[0004] Currently, the steam section uses steam to simultaneously spray the filter rods from both the upper and lower pressure plates of the smoke gun channel. The cooling section uses the same method, spraying cold air from both the upper and lower sides simultaneously. This opposing blowing method leads to poor heat and moisture removal from the filter rods during production, resulting in insufficient hardness of the fiber bundle. Furthermore, due to insufficient steam sealing, the steam homogenization of the fiber bundle within the smoke gun is inadequate, leading to quality defects such as roughening of the center hole as production speed increases. In the cooling section, the moisture and heat generated by the steam cannot be quickly dried and cooled, resulting in poor hardness of the hollow filter rods and flattening of the bottom filter rods at the bottom of the filter rod tray.

[0005] Furthermore, the fabric belt used in the hollow filter rod forming machine is made of nylon. Ideally, the fabric belt completely wraps around the filaments as they travel within the belt, preventing the formation of fabric belt marks. However, since the fabric belt is made of yarn and has a tendency to shrink, after the equipment has been running for a period of time, the fabric belt will loosen, creating a "slit" in the wrapping. The filaments cannot be completely wrapped within the fabric belt, resulting in fabric belt marks appearing in these "slits." The manifestation of this is as follows... Figure 1 As shown, a "protrusion" will form on the surface of the filter rod. The "protrusion" will affect the roundness of the composite filter rod, which in turn will affect the splicing of the tipping paper in the cigarette rolling process, making it easy to produce wrinkled cigarettes and leaky cigarettes.

[0006] Therefore, there is a need for a molded smoke gun that can effectively improve the quality of hollow filter rods. Summary of the Invention

[0007] To address the aforementioned problems, this invention provides a molded cigarette holder for producing hollow filter rods. By redesigning the steam flow pattern and sealing structure, it ensures that saturated steam is evenly applied to the tobacco bundle. The cooling section has been changed from a direct-flow method to an upward-blowing, downward-suction structure, allowing the upper cooling air to be evenly applied to the filter rod, while the lower cooling air is expelled by a negative pressure fan to remove heat and moisture, ensuring no condensation in the cooling section and guaranteeing the rigidity of the cigarette rod. Furthermore, a shaping structure is incorporated into the steam section to effectively eliminate fabric imprints on the surface of the hollow filter rod, ensuring its roundness.

[0008] Specifically, the present invention is implemented as follows:

[0009] A forming smoke gun for producing hollow filter rods includes a steam section near the inlet end of the smoke gun and a cooling section near the outlet end of the smoke gun; the steam section includes an upper steam pressure plate and a lower steam pressure plate, with a forming channel formed between the upper and lower steam pressure plates for passing through a fiber bundle; the steam section is used to steam-shape the fiber bundle entering the forming channel; the cooling section includes an upper cooling pressure plate and a lower cooling pressure plate, with a cooling channel formed between the upper and lower cooling pressure plates; the cooling section is used to cool the steam-shaped fiber bundle into filter rods.

[0010] The upper cooling plate is provided with an air inlet, and the lower cooling plate is provided with an air outlet. The air inlet is connected to the cooling gas supply pipe, and the air outlet is connected to the negative pressure suction pipe. The dry cooling medium enters the cooling channel through the air inlet and is then sucked out through the air outlet.

[0011] Furthermore, the upper steam pressure plate is provided with a shaping structure, which is located in the front half of the upper steam pressure plate near the smoke gun inlet in the forming channel, and is used to flatten the cloth tape print on the filter rod.

[0012] Furthermore, the shaping structure includes:

[0013] The shaping chamber is located inside the forming channel of the upper steam pressure plate. Its width is greater than that of the forming channel. It is used to make the cloth belt wrapping the filter rod slightly open after entering the shaping chamber.

[0014] The shaping block, located inside the shaping cavity, is used to flatten the fabric tape print on the filter rod after the fabric tape is opened.

[0015] Furthermore, the lower steam pressure plate is provided with several evenly distributed steam dispersion structures, which are connected to the steam supply pipeline;

[0016] The upper steam pressure plate is provided with a steam guiding structure, which is connected to the steam dispersing structure. The steam dispersing structure diverts the steam from the steam supply pipeline. Part of the steam is sprayed into the forming channel from below, and the other part of the steam rises and enters the steam guiding structure.

[0017] The steam guiding structure is used to guide the upward steam downwards and spray steam from the top of the forming channel into the forming channel.

[0018] Furthermore, the steam dispersion structure includes: a steam hole and a lower steam injection hole, the steam hole being connected to the lower steam injection hole, the lower steam injection hole being located at the bottom of the forming channel and used to inject steam into the filament bundle;

[0019] Furthermore, the steam guiding structure includes a steam through hole and an upper steam injection hole, the steam through hole and the upper steam injection hole are connected, the steam through hole and the steam hole are connected, the upper steam injection hole is located at the upper part of the forming channel, and after the steam enters the steam through hole from the steam hole, the steam is injected into the filament bundle from the upper steam injection hole.

[0020] Furthermore, the steam hole has a recessed platform structure, and a sealing ring is provided inside the recessed platform.

[0021] Furthermore, the lower steam pressure plate is provided with a sealing strip, which is located on the side of the steam hole away from the forming channel.

[0022] Furthermore, the lower steam pressure plate is provided with a steam return hole, which is connected to a condensate return pipe for collecting condensate.

[0023] Furthermore, the steam supply pipeline is equipped with multiple adjusting knobs, each of which corresponds to a steam dispersion structure for adjusting the steam quantity.

[0024] Compared with the prior art, the working principle and beneficial effects of the present invention are as follows:

[0025] (1) The molded smoke gun provided by the present invention adopts the method of steam diversion and guiding back-blowing in the steam section, and is further supplemented by effective sealing to ensure that saturated steam is evenly applied to the wire bundle, which solves the problem of insufficient steam homogenization in the original smoke gun steam section and provides a basis for speeding up the equipment.

[0026] (2) The cooling section has been changed from the original blowing method to the top blowing and bottom suction method. The upper cooling air is evenly applied to the filter rod, and the lower cooling air is discharged through negative pressure to ensure that there is no condensation in the cooling section, thereby ensuring the hardness of the tobacco strip.

[0027] (3) A shaping structure is set in the steam section. During the shaping process of the fiber bundle, the cloth tape is opened and the cloth tape imprint on the upper part of the filter rod is flattened, which can effectively overcome the cloth tape imprint defects caused by the extrusion of the cloth tape on the surface of the original hollow filter rod and improve the production quality. Attached Figure Description

[0028] Figure 1 A schematic diagram of the structure of a filter rod with a printed cloth strip;

[0029] Figure 2A front view of a filter rod with a printed fabric strip;

[0030] Figure 3 This is a schematic diagram of the structure of the molding smoke gun for producing hollow filter rods in Example 1;

[0031] Figure 4 This is a schematic diagram of the upper steam pressure plate in Example 1;

[0032] Figure 5 This is a schematic diagram of the lower steam pressure plate in Example 1;

[0033] Figure 6 This is a schematic diagram of the steam flow direction in the steam section of Example 1;

[0034] Figure 7 This is a schematic diagram of the cold airflow direction in the cooling section of Example 1;

[0035] Figure 8 for Figure 4 A magnified view of a section at point A in the middle;

[0036] Figure 9 This is a schematic diagram of the shaping structure in Example 1;

[0037] Figure 10 This is a cross-sectional view of the shaping structure in its working state in Example 1;

[0038] Figure 11 for Figure 10 A sectional view of section AA in the middle;

[0039] Figure 12 for Figure 10 A sectional view of section BB in the middle;

[0040] Figure 13 for Figure 10 A sectional view of the CC section;

[0041] Figure 14 This is a comparison diagram of the hardness of the existing cigarette gun molded filter rod and the cigarette gun molded filter rod of the present invention in Example 2;

[0042] Figure 15 This is a comparison chart of the circumferential CPK values ​​of the existing cigarette filter rod and the cigarette filter rod of the present invention in Example 2.

[0043] Figure label:

[0044] 1-Filter rod; 11-Cloth tape imprint; 21-Lower steam pressure plate; 211-Inlet pressure plate; 212-Steam hole; 213-Steam return hole; 214-Sealing strip mounting groove; 215-Lower forming groove; 22-Upper steam pressure plate; 221-Steam through hole; 222-Upper forming groove; 23-Steam section connecting block; 31-Lower cooling pressure plate; 311-Lower cooling groove; 32-Upper cooling pressure plate; 321-Upper cooling groove; 33-Cooling section connecting block; 41-Steam supply pipeline; 42-Condensate return pipeline; 43-Adjusting knob; 44-Cooling gas supply pipeline; 45-Negative pressure suction pipeline; 51-Shaping block; 52-Shaping cavity. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0046] Example 1

[0047] like Figure 3 As shown, this embodiment provides a forming smoke gun for producing hollow filter rods, including a steam section and a cooling section. The steam section includes an upper steam pressure plate 22 and a lower steam pressure plate 21, and the cooling section includes an upper cooling pressure plate 32 and a lower cooling pressure plate 31. The upper steam pressure plate 22 and the upper cooling pressure plate 32 can be opened and closed vertically via a steam section connecting block 23. During normal production, the upper steam pressure plate 22 and the upper cooling pressure plate 32 are in a tightly closed state under the action of the smoke gun locking device 24. A forming channel is formed between the upper steam pressure plate 22 and the lower steam pressure plate 21 for the passage of the fiber bundle. The fiber bundle, sprayed with plasticizer, enters the steam section through the forming channel inlet and undergoes steam shaping. A forming channel is formed between the upper cooling pressure plate 32 and the lower cooling pressure plate 31 for the passage of the steam-shaped filter rod, used for cooling and drying the steam-shaped filter rod.

[0048] Specifically, such as Figure 5As shown, the lower steam pressure plate 21 includes: steam holes 212, sealing strip mounting grooves 214, steam return holes 213, and a lower forming groove 215 in the middle. The lower steam pressure plate 21 has an inlet pressure plate 211, and eight steam holes 212, each corresponding to a steam supply pipeline 41. The bottom of the lower forming groove 215 has a lower steam injection hole. The steam holes 212 and the lower steam injection hole are connected inside the lower steam pressure plate 21. Steam from the steam supply pipeline 41 enters the lower steam pressure plate 21 from the bottom and is partially ejected from the steam holes 212, while part of it is directly sprayed onto the filter rod from the lower steam injection hole. Each steam supply pipeline 41 is equipped with an adjusting knob 43 to adjust the amount and pressure of steam entering the forming channel. High-temperature resistant rubber strips are laid inside the sealing strip mounting groove 214 to reduce steam leakage inside the steam section. The steam return hole 213 is connected to the condensate return pipe 42, and the steam flows out from the condensate return pipe 42 after condensation.

[0049] The upper steam pressure plate 22 is provided with steam passage holes 221 and an upper forming groove 222. The upper forming groove 222 and the lower forming groove 215 together form a forming channel. The bottom of the upper forming groove 222 is provided with an upper steam injection hole. There are seven steam passage holes 221. Counting from the entrance of the forming channel, the third steam hole 212 is located at a position with a shaping structure. The remaining seven steam holes 212 are connected to the steam passage holes 221 one by one. The steam passage holes 221 and the upper steam injection holes are connected inside the upper steam pressure plate 22. After steam enters the upper steam pressure plate 22 from the steam holes 212 and the steam passage holes 221, it is sprayed onto the yarn bundle from the upper steam injection holes. The steam holes 212 and the steam passage holes 221 adopt a recessed platform design, and a sealing ring is provided inside the recessed platform. The steam section adopts a sealing ring + sealing strip design, which on the one hand ensures that the steam hole 212 and the steam through hole 221 can fit tightly, ensuring that the saturated steam is applied evenly to the fiber bundle, and on the other hand prevents steam leakage, ensuring the uniformity of the top and bottom blowing steam and the stability of the steam pressure inside the steam section, thereby avoiding burr defects in the center hole of the filter rod and improving the forming quality of the filter rod.

[0050] like Figure 8 As shown, the shaping structure includes a shaping cavity 52 and a shaping block 51. The shaping block 51 is located inside the shaping cavity 52 and is shaped like an iron, used to remove the fabric tape marks 11 on the filter rod 1. Specifically, as... Figure 9-13 As shown, the filter rod 1 that has just entered the forming channel is not fully formed. Since the width of the forming cavity 52 is greater than the width of the forming channel, when the filter rod 1 wrapped by the cloth tape 12 reaches the position of the forming cavity 52, the cloth tape 12 is temporarily freed from the restriction of the forming channel and can be slightly loosened. The filter rod 1 wrapped by the cloth tape 12 is exposed at the position of the cloth tape imprint 11 on the surface. The forming block 51 just comes into contact with the filter rod 1 after the cloth tape 12 is opened, and irons the cloth tape imprint 11 on the filter rod 1, which can effectively eliminate the cloth tape imprint on the surface of the filter rod strip wrapped by the cloth tape in the forming cavity 203.

[0051] The upper cooling plate 32 has an upper cooling groove 321, and the lower cooling plate 31 has a lower cooling groove 311. The upper cooling groove 321 and the lower cooling groove 311 together form the forming channel (cooling channel) of the cooling section. The upper cooling groove 321 has an air inlet, which is connected to the cooling gas supply pipe 44. The cooling gas supply pipe 44 is connected to an external refrigerated dryer unit, and the refrigerated dry gas enters the interior of the cooling section through the cooling gas supply pipe 44. The lower cooling groove 311 has an air outlet, which is connected to a negative pressure suction pipe 45. The negative pressure suction pipe 45 is connected to an external negative pressure air pump. Under the action of the external negative pressure air pump, the negative pressure suction pipe 45 discharges the heat and condensate generated in the steam section. Through the upward blowing and downward suction design of the refrigerated dryer section, the heat and condensate generated by the steam action can be effectively absorbed quickly, and the hardness of the filter rod can be guaranteed.

[0052] Example 2

[0053] The workshop process personnel recorded the test results of 15 groups, each with 30 hollow filter rods. The results are the average hardness of each group. The sampling was random, and the samples were newly produced filter rods that had not been cured. The following averages are all results from the filter rod comprehensive test bench.

[0054] (1) Hardness statistics

[0055] The hardness data of the filter rods formed by existing cigarette guns are shown in Table 1, and the hardness data of the filter rods formed by the present invention are shown in Table 2.

[0056] Table 1. Statistical table of hardness data before modification

[0057] Serial Number hardness(%) Serial Number hardness(%) Serial Number hardness(%) 1 78.2 6 78.2 11 78.2 2 77.9 7 78.5 12 78.7 3 78.1 8 77.9 13 79.1 4 78.0 9 77.6 14 77.8 5 78.8 10 78.3 15 77.5

[0058] Table 2. Statistical table of hardness data after modification

[0059] Serial Number hardness(%) Serial Number hardness(%) Serial Number hardness(%) 1 82.3 6 81.6 11 82.4 2 81.9 7 81.9 12 82.4 3 81.6 8 81.7 13 82.3 4 82.4 9 82.6 14 82.6 5 82.0 10 82.2 15 82.3

[0060] See Table 1-2 and Figure 14 The filter rod formed by the present invention has an average hardness of 82.15%, which is 3.96% higher than the average hardness of 78.19% of the filter rod formed by the existing smoke gun.

[0061] (2) Statistical analysis of circumferential CPK (Quality Process Control Capability) values

[0062] Table 3. Statistical table of circumferential CPK data before modification

[0063] Serial Number Circumferential CPK Serial Number Circumferential CPK Serial Number Circumferential CPK 1 0.821 6 0.938 11 0.965 2 0.782 7 0.798 12 0.882 3 0.919 8 0.779 13 0.794 4 0.734 9 0.776 14 0.855 5 0.694 10 0.783 15 0.763

[0064] Table 4. Statistical table of circumferential CPK data after modification

[0065] Serial Number Circumferential CPK Serial Number Circumferential CPK Serial Number Circumferential CPK 1 1.066 6 1.260 11 1.268 2 1.078 7 1.379 12 1.253 3 1.157 8 1.023 13 1.269 4 1.595 9 0.970 14 1.414 5 1.298 10 1.109 15 1.168

[0066] See Table 3-4 and Figure 15 In this invention, the average circumferential CPK value reaches 1.22, which is 0.401 higher than the existing average circumferential CPK value of 0.819 (the larger the CPK, the better the quality).

[0067] (3) Roundness data statistics

[0068] Table 5. Statistical table of average roundness before modification.

[0069]

[0070]

[0071] Table 6. Statistical Table of Mean Roundness After Modification

[0072] Serial Number Mean roundness Serial Number Mean roundness Serial Number Mean roundness 1 0.287 6 0.262 11 0.214 2 0.260 7 0.259 12 0.308 3 0.263 8 0.219 13 0.301 4 0.250 9 0.306 14 0.282 5 0.292 10 0.326 15 0.234

[0073] It is easy to see from the statistical analysis of the average roundness before and after the modification that the roundness of the hollow filter rod after the modification is significantly improved compared to before the modification (the smaller the roundness value, the better).

[0074] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A forming gun for producing a hollow filter rod, comprising a steam section near an inlet end of the forming gun and a cooling section near an outlet end of the forming gun; the steam section comprises an upper steam pressure plate and a lower steam pressure plate, a forming channel for passing a tow band is formed between the upper steam pressure plate and the lower steam pressure plate, and the steam section is used for steam setting the tow band entering the forming channel; the cooling section comprises an upper cooling pressure plate and a lower cooling pressure plate, a cooling channel is formed between the upper cooling pressure plate and the lower cooling pressure plate, and the cooling section is used for cooling the steam set tow band into a filter rod; characterized in that, an air inlet hole is arranged on the upper cooling pressure plate, an air outlet hole is arranged on the lower cooling pressure plate, the air inlet hole is connected with a cooling air supply pipeline, and the air outlet hole is connected with a negative pressure air suction pipeline, and dry cooling medium enters the cooling channel through the air inlet hole and is sucked out from the air outlet hole; a shaping structure is arranged on the upper steam pressure plate, the shaping structure is located in a front half of the forming channel of the upper steam pressure plate near the inlet end of the forming gun, and is used for flattening a cloth band mark on the filter rod; the shaping structure comprises: a shaping cavity located in the forming channel of the upper steam pressure plate, the cavity has a width greater than that of the forming channel, and is used for slightly opening the cloth band wrapped around the filter rod after entering the shaping cavity; a shaping block arranged in the shaping cavity, and used for flattening the cloth band mark on the filter rod after the cloth band is opened.

2. A plug wrap forming gun for producing a hollow filter plug according to claim 1, characterized in that a plurality of steam dispersion structures are arranged on the lower steam pressure plate and uniformly distributed, and the steam dispersion structures are connected with a steam supply pipeline; a steam guide structure is arranged on the upper steam pressure plate, the steam guide structure is connected with the steam dispersion structures, steam from the steam supply pipeline is branched by the steam dispersion structures, a part of the steam is sprayed into the forming channel from a lower direction of the forming channel, and another part of the steam goes upward into the steam guide structure; the steam guide structure is used for guiding the upward steam downward and spraying the steam into the forming channel from an upper direction of the forming channel.

3. A plug wrap forming gun for producing a hollow filter plug according to claim 2, characterized in that the steam dispersion structure comprises a steam hole and a lower steam outlet hole, the steam hole is communicated with the lower steam outlet hole, and the lower steam outlet hole is located at a bottom of the forming channel and used for spraying steam to the tow band.

4. A plug wrap forming gun for producing a hollow filter plug according to claim 2, characterized in that the steam guide structure comprises a steam through hole and an upper steam outlet hole, the steam through hole and the upper steam outlet hole are communicated, the steam through hole is connected with the steam hole, and the upper steam outlet hole is located at an upper part of the forming channel, steam entering the steam through hole from the steam hole is sprayed to the tow band from the upper steam outlet hole.

5. A plug wrap forming gun for producing a hollow filter rod as defined in claim 3, wherein the steam hole is a sunken platform structure, and a sealing ring is arranged in the sunken platform.

6. A plug wrap forming gun for producing a hollow filter plug according to claim 5, characterized in that a sealing strip is arranged on the lower steam pressure plate and located on a side of the steam hole away from the forming channel.

7. A plug wrap forming gun for producing a hollow filter plug according to claim 2, wherein a steam backflow hole is arranged on the lower steam pressure plate and connected with a condensate backflow pipeline, and is used for collecting condensate.

8. A plug wrap forming apparatus for producing a hollow filter rod according to any one of claims 2 to 7, wherein, a plurality of adjusting knobs are arranged on the steam supply pipeline, each adjusting knob corresponds to a steam dispersion structure, and is used for adjusting the amount of steam.

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