CN1216691A - Method and device for coating material on filter material - Google Patents

Abstract

The invention relates to a method and a device for applying substances to the fibers of a filter material for smokable articles, wherein fibrous or sheet-like filter materials are dusted with micronized solid substances.

Description

Method and device for coating material on filter material

The present invention relates to a method and apparatus for coating the fibers of filter material for smoking articles.

German patents DE 39 04 239 C1 and DE 38 20 089C2 have disclosed fiber coating materials for cigarette filters, which are (more specifically) physiologically and organoleptically safe polycarboxylic acids or acid salts thereof, such as esterified citric, tartaric, succinic and malic acids.

For this purpose, a fine particle suspension of polycarboxylic acid or its acid salt suspended in an organic liquid medium which is crystallized at room temperature and processing temperature with a particle size of less than 50 μm is applied to the fiber (DE 39 04 239 C1) .

Another solution is to dissolve the anhydrides of dicarboxylic acids or polycarboxylic acids in organic solvents, apply them to the fibers and, if necessary, hydrolyze them (DE 38 20 089 C2).

The disadvantage of the above-mentioned application of suspensions or solvents (such as triacetate) is that when the concentration of the suspension is high, it becomes viscous and cannot be pumped, which is why ordinary methods cannot be applied to filter belts. The reasons for the above materials.

It is an object of the present invention to provide a method and a device for coating fibrous materials of filter materials for smoking articles which do not have the above-mentioned disadvantages. More specifically, the present invention aims to provide a method and an apparatus in which even high concentrations of materials can be applied by a simple method and apparatus.

In order to achieve the above object of the present invention, the present invention provides a method of applying material to the fibers of the filter material of smoking articles, characterized in that the fibrous or sheet-like filter material is sprinkled with micronized solid material .

In order to realize the above-mentioned object of the present invention, the present invention also provides a kind of device to the fiber coating material of the filter material of smoking article, and it contains:

a) micronized solid material meter;

b) nozzles for pneumatically conveying metered solid material into the powder chamber, and

c) Fibrous or sheet-like filter material passing through the above-mentioned powder chamber.

The advantages obtained by the present invention are based on the fact that by means of an atomization procedure, the micronized solid material is applied to the fibrous or sheet-shaped filter material in a nearly unlimited amount, so that the coating operation can be carried out in a very short time. This is done at high concentrations, which are not possible with the prior art application of suspensions, and due to such high concentrations, hitherto impossible effects can be achieved.

Tests have shown that the concentration of micronized solid materials can reach 10 times higher than that achieved so far.

Thus, it is possible to increase the selective retention capacity of the filter and/or modify the flavor of the cigarette without increasing the draw resistance, which is sometimes unavoidable when using a denser filter material in order to achieve a specific flavor difference. Great resistance.

The above-mentioned advantageous operation of applying the material to the filter belt ensures the activity of the filter fiber bundle, since no combustion, oxidation or damage occurs during smoking.

Although theoretically there is no limit to the amount applied, in practice there is a limit to the filter's resistance to draw. The resistance must not be too great.

According to a preferred embodiment, the particle size is a maximum of 50 μm, more specifically a maximum of 10 μm of solid material or a homogeneous mixture of solid materials, because such extremely small particles can ensure a good distribution and thus make the filter texture after treatment uniform.

It has been found that it is advantageous to supply the solid material in a metered manner, metering or metering the solid material according to the production rate of the filter, as a result of which it is ensured, for example, that the same amount of material is always applied per unit fiber length.

The above distribution or metering is preferably carried out by a hopper delivering the micronized solid material intermittently in combination with a precision distributor operated by gravity and a twin screw conveyor feeding the micronized solid material into a pneumatically operated conveying section. By inputting feedback information on the filter production rate it can be ensured, for example, that the same amount of micronized solid material is always applied per unit fiber length.

The micronized solids are conveyed pneumatically through a solids nozzle so that they are transported by the vacuum created in the tube, resulting in the near complete elimination of agglomeration.

The pneumatically conveyed solids/air stream is passed through a mixing zone for optimum distribution of the solids in the air stream and to break up any agglomerates.

The actual spreading takes place in a powder chamber which is provided with openings in the direction of movement of the sheet-like or fibrous filter material so that the passage of the filter material is not hindered.

Triacetate is applied to the fiber material at the entrance or exit of the powder chamber, preferably at the entrance of the powder chamber to further improve the adhesion of the micronized solid material on the filter material .

The gap for the filter material to enter the powder chamber is adjustable to ensure non-contact delivery of the filter material and to prevent metered solid material from leaking out of the powder chamber.

In order to better coat the solid material in the powder chamber, the charge state of the filter material can be adjusted by means of an ionization rod consisting of a rod electrode and a counter electrode, which are installed at the entrance of the powder chamber The distance from the powder chamber is 50-150mm, and it is perpendicular to the conveying direction of the filter material. The ionization rod described above charges the surface of the filter material to enhance the adhesion of the micronized solid particles.

If it is desired to apply particularly large quantities of micronized particles to the filter material, it can be spread on both sides of the filter material. For this purpose, two nozzles are installed in the powder chamber, feeding micronized solid particles from below and above.

The filter material dusted with micronized solid particles exits the powder chamber rolled into a filter rod which is processed into a filter product in the usual way.

The outlet of the powder chamber is preferably connected with an aspirator that can suck air and micronized solid material through the powder chamber (if necessary, it can be connected with the powder chamber through a dust collector).

The vacuum degree at the outlet of the powder chamber is adjustable, which allows the excess air to be discharged from the pneumatic conveying area of the solid material. The vacuum degree of the powder chamber can be adjusted through the valve on one side of the powder chamber.

During the production process and metering stage, the vacuum degree of the above-mentioned exhaust fan is preferably kept constant to ensure that there is always a constant product coated on the filter belt and to prevent dust from leaking out of the powder chamber.

Below in conjunction with accompanying drawing, illustrate the present invention in more detail according to the embodiment of the device to the fiber coating material of filter belt, in the accompanying drawing,

Figure 1 is a schematic diagram of the device of the present invention; and

Figure 2 is an enlarged schematic view of the powder chamber with additional nozzles.

A felt-like filter tow is introduced by conventional means via tension rollers 33 (shown simply) and guide rails 35 into a spreader 36 which can coat the filter tow 32 with triacetate.

At the outlet of the above-mentioned applicator 36 along the moving direction of the filter fiber bundle 32, the filter fiber bundle 32 enters two ionization rods 39 (i.e. an electrode rod and a charge generator 41 with an ignition limiter to supply a negative potential Before the gap between the counter electrodes), the tension roller 37 is passed around again.

The filter fiber bundle 32 enters the inlet slit 43 (see Figure 2) of the powder chamber 34 from the gap between the two ionization rods 39, and the inlet slit 43 is open along the moving direction of the filter fiber bundle 32, so the filter fiber bundle will not be hindered. Beam 32 passes.

The size of the gap 43 for the filter fiber bundle 32 to enter the powder chamber 34 can be adjusted along the direction perpendicular to the moving direction of the filter fiber bundle 32, and adjusted to both ensure the non-contact transmission of the filter fiber bundle 32 and prevent the powder chamber 34 from The fluid solid substance leaked out.

In the powder chamber 34, the tensioned filter fiber bundle 32 is sprinkled with micronized solid material by means of two nozzles 52 respectively positioned above and below the filter fiber bundle 32 shown in FIG. or mixed solid materials.

On the side opposite to the inlet slit 43 of the powder chamber 34, an outlet slit 54 is provided, on which a standard nozzle 44 for producing filter tips is installed, and the filter fiber bundle 32 is merged into a filling in the nozzle 44. Air-absorbing rods filled with powder.

Then the filter rod sprinkled with solid particles made by the above method is wrapped with filter paper, and cut into filter rods of required length, so that they can be sent into the cigarette manufacturing machine in the next production step, in the cigarette manufacturing machine , the above-mentioned filter rod is cut into a rod segment of a suitable length, and connected with a cigarette rod to make a finished cigarette with a filter tip.

The preparation of micronized solid materials and mixed solid materials including physiologically safe and sensory-good materials is described below. More specifically, polycarboxylic acids or acid salts of polycarboxylic acids such as citric acid, tartaric acid, succinic acid, malic acid, ascorbic acid and acidic esters, mono-di-saccharides (such as glucose, cane sugar) and flavorings (vanillin, menthol, etc.).

Finely ground micronized pure solid material or uniformly mixed micronized solid material has a particle size of up to 50 μm, and is intermittently fed into an accurate meter 14 from a supply hopper 12 adapted to the processing capacity, and in the meter 14 The height of the particle layer is detected by the MAX/MIN (maximum/minimum) sensor. When the amount of material is reduced to the minimum amount, the sensor is activated immediately, so that the hopper 12 is fed with solid material again. Once the amount of material added reaches the maximum amount, the material is automatically fed stop.

A gravity operated precision meter 14 feeds the solids and mixed solids via a twin screw conveyor 16 driven by an electric motor 15 to a pneumatically operated conveyor 17 . The precision meter 14 is electrically connected with the filter tip making machine, that is to say, the amount of each filter rod measured is input in the electronic controller 19 of the precision meter 14 as a fixed value, therefore, the productivity of the filter tip is The speed command value of the precision meter 14 and its control target value. The machine speed is detected by an encoder 20 on the cutter 22 of the filter making machine which cuts the annular filter rod into individual filters.

The solid material measured by the precision meter 14 falls in free fall through the tube 23 downwards into the solids nozzle 26 . At this time, due to the action of the grease-free compressed air 30 blown out by the nozzle ring of the solid nozzle 26, the solid material is pneumatically blown into the inside of the pipe 17 connected to the nozzle 26, and is conveyed due to the vacuum formed inside the pipe 17. solid material.

In order to distribute the solid material in the air stream well and to break up any agglomerates, the solid material/air stream flows through a mixing zone 18 formed by a tube leading vertically downward into the powder chamber 34 .

On the top of the powder chamber 34, there is a horizontal wide slot nozzle 52, the width of the nozzle 52 perpendicular to the production line direction, that is, the moving direction of the filter fiber bundle 32, is at least as large as the entrance or exit of the three-acetate essence applicator 36. Corresponds to the width of the filter fiber bundle at the place. The distance between the nozzle 52 and the filter fiber bundle 32 can be freely adjusted by adjusting the wide slit nozzle 52 vertically upward or downward (as shown by arrow 56).

In general, although the use of a single nozzle 52 is sufficient in principle, it is also possible to use a modified embodiment shown in FIG. The solid material/air flow from the pneumatic conveying section is dispersed at the inlet of the two nozzles, and the degree of dispersion of the material flow can be adjusted freely.

Below the filter tow 32, the powder chamber 34 tapers into a suction duct 58, the vacuum of which can be adjusted to extract excess air from the pneumatically conveyed solid material.

The vacuum degree in the powder chamber 34 can be adjusted by a valve 38 installed on one side of the powder chamber. The aspirated dust-laden carrier air is fed into a portable dust collector 40 for cleaning. The dust collector 40 or the vacuum of the powder chamber 34 is generated by a downstream blower 50 . During the production process and the metering stage of the material, the vacuum degree of the exhaust fan 50 is kept constant to ensure that the product is evenly and constantly coated on the filter belt, and to prevent dust from leaking out of the powder chamber 34.

The charge condition is controlled by the ionization rod 39 to obtain the mesh filter fiber bundle of the best coating state of the solid material. The powder chamber is sprinkled with micronized solid material, which adheres to the filter fiber bundle 32 coated with triacetin on the fiber. The opened filter tow 32 is subsequently rolled into an annular filter rod and processed in a conventional manner into a cigarette filter, which is attached to a cigarette rod in the next production step by wrapping paper.

Instead of the filter fiber bundle made of the above-mentioned air-permeable mesh filter material, the above-mentioned device 10 may spray micronized solid particles on, for example, filter paper to form a filter fiber bundle.

As another example, the triacetate applicator 36 can be arranged at the outlet of the powder chamber 34 as viewed along the conveying direction of the filter fiber bundle 32 (certainly before the filter material is combined into a filter rod).

Claims (22)

1. Method for applying material to fibers of a filter material for smoking articles, characterized in that the fibrous or sheet-like filter material (32) is dusted with micronized solid material. 2. The method according to claim 1, characterized in that micronized pure or homogeneously mixed solid material is used, the particle size of which is at most 50 μm, more particularly at most 10 μm. 3. A method according to claim 1 or 2, characterized in that said solid material is metered. 4. A method according to claim 3, characterized in that said metering is carried out according to the production rate of the filter tip. 5. A method according to any one of claims 1 to 4, characterized in that the metered micronized solid material is introduced into the powder chamber (34) by a pneumatic conveyor (17, 18, 26), and the above-mentioned fibrous or The sheet-shaped filter material (32) is sent through the above-mentioned powder chamber (34) at an angle of 45° to the conveying direction of the above-mentioned solid material. 6. A method according to any one of claims 1 to 5, characterized in that the filter belt (32) coated with triacetate is introduced into the above-mentioned powder chamber (34), and then merged into a filter rod. 7. The method according to claim 5 or 6, characterized in that, in the above-mentioned powder chamber (34), the above-mentioned micronized solid material is spread to it from above and below the above-mentioned fibrous or sheet-like filter material (32). 8. A method according to any one of claims 5 to 7, characterized in that said fibrous or sheet-like filter material is charged by ionization at the inlet of said powder chamber (34) as seen in its conveying direction. 9. A device for coating material on fibers of filter material for smoking articles, comprising: a) micronized solid material meter (12,14,16); b) nozzles (26) for pneumatically conveying the metered solid material into the powder chamber (34) and c) Fibrous or sheet-like filter material (32) passing through the above-mentioned powder chamber (34). 10. The device according to claim 9, characterized in that, the conveying route of said fibrous or sheet-like filter material (32) passing through said powder chamber (34) is substantially perpendicular to the pneumatic conveying direction of said micronized solid material. 11. Apparatus according to claim 9 or 10, characterized in that said meter comprises a feed hopper (12) intermittently delivering micronized solid material and a precision meter (14, 16). 12. 11. Apparatus according to claim 11, characterized in that said gravity operated precision meter (14, 16) comprises a twin screw conveyor (16) for conveying said micronized solid material to a pneumatically operated conveying section. 13. According to the device of claim 11 or 12, it is characterized in that the above-mentioned precision meter (14,16) is electrically connected with the filter tip making machine, so the production rate of the filter tip can be used as the actual value of the above-mentioned precision meter (14,16). Speed value, and as its control target value. 14. Device according to any one of claims 9-13, characterized in that said powder chamber (34) is provided with an opening in the direction of movement of said fibrous or sheet-like filter material (32). 15. According to the device according to any one of claims 9 to 14, it is characterized in that the three-acetate essence applicator (36) is arranged on the above-mentioned powder chamber (34) along the above-mentioned conveying direction of the above-mentioned fibrous or sheet-shaped filter material (32). ) before or after . 16. According to the device according to any one of claims 9～15, it is characterized in that the gap (43) for introducing the above-mentioned fibrous or sheet-like filter material (32) in the above-mentioned powder chamber (34) is adjustable, therefore, It can ensure the non-contact transmission of the above-mentioned filter material (32) and prevent the leakage of the above-mentioned fluidized solid material. 17. Device according to any one of claims 9-16, characterized in that a nozzle for rolling said fibrous or sheet-like filter material (32) into a filter rod is mounted at the outlet of said powder chamber (34). 18. A device according to any one of claims 9 to 17, characterized in that a plurality of ionizing rods (39) are arranged at the entrance of said powder chamber (34) along the conveying direction of said filter material (32). 19. 18. Apparatus according to any one of claims 9-18, characterized in that said powder chamber (34) comprises a valve (38) for regulating the vacuum in said powder chamber (34). 20. 19. Apparatus according to any one of claims 9-19, characterized in that a dust collector (40) is connected to said powder chamber (34). twenty one. Device according to any one of claims 9-20, characterized in that a blower (50) for forming said vacuum in said powder chamber (34) is connected to said powder chamber (34). twenty two. The device according to claim 21, characterized in that said blower (50) sucks air and micronized solid material through said powder chamber (34) and said dust collector (40).

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