DE4209606A1 - Method and device for treating at least one web of threads filter material for cigarette filters - Google Patents

Abstract

A tow is drawn from a bale and its normally interlaced fibers are separated from each other by applying to the fibers a positive or a negative electric charge so that the neighboring fibers repel each other, the separated fibers are contacted by particles of finely atomized plasticizer which carry electric charges of opposite polarity so that they are attracted to the separated fibers, such charging of the fibers and the application of plasticizer can take place prior or subsequent to at least partial conversion of the tow into a rod-like filler. Several tows can be treated simultaneously to thus enhance the output of the machine and/or to improve the quality of the products.

Description

The invention relates to a method for treating minde at least one web of filter material (tow) for cigarette filters.

The invention also relates to a device for handling at least one strip of filament-containing fil Term material (tow) for cigarette filters.

Under threads are single threads or single fibers or with interconnected threads or fibers understood, insofar as they can be separated.

When producing filter rods, this is done by a bale filter tow peeled off in an endless strip that individual threads or fibers (e.g. from cellulose acetate) stands, processed before it forms a filter strand gathered with a wrapping strip, the seam area is provided with adhesive, wrapped and in individual filter rods single or multiple usage length is cut. In practice, the preparation usually takes place in such a way that the filter material strip after pulling it off the bale next loosened and widened by air nozzles then very widely spread in a stretching zone and in this condition with droplets of plasticizer (e.g. triacetin) is sprayed on the surface of the fa which makes fibers or adhesives, to which they stick. The The strip prepared in this way then becomes the strand gathered, encased and easier in single filter rods or cut multiple lengths of use.

It is of great importance for the quality of the preparation a good separation of the individual threads or fibers  and / or an even application of finely divided soft maker particles in the form of droplets or fine particles.

The object underlying the invention is another in the case of moving filter material in the form of a strip Type of separation of the threads or fibers during the Promotion to create.

Another task is another type of Application of finely divided particles (e.g. droplets) of plasticizer on a filter material strip during to provide for its funding.

Another job is to evenly build up preparation of two or more strips of filter material hen, which are also made of different materials can exist.

The solution according to the invention is that the Filter material web during its promotion with electri is charged by their influence, the Threads (fibers) are separated.

An advantageous development of the invention, the self inventive step is that the with electric charges of a certain polarity struck filter material web sprayed during its conveyance is with finely divided plasticizer particles, which with elec charges of opposite polarity are struck.

Another advantageous development of the invention, the independent inventive rank also exists in that several, preferably two, sheets of filter mat rial are promoted on the loads of Charge sources for separating the threads or fibers opened  are brought up, and that the sizes of the charges each a constant value can be regulated, the constant Values can be different depending on the type of Filter material in the individual webs.

Further embodiments of the invention are the subordinate process claims.

The aforementioned invention is characterized by a Arrangement for applying electrical charges to the fil term material strips during its promotion to the association the threads or fibers.

An advantageous development of the device according to the Invention that has an independent inventive rank is characterized by a device for loading the one with charges of a certain polarity Filter material strip during its promotion with parti of plasticizer liquid, the charges of the opposite polarity.

Another advantageous development of the invention, the is also independent inventive rank characterized by several, preferably two filter mats radial strips onto which loads from charge sources are applied are bar, and through control arrangements to keep the electrical charges (field strengths) in the areas of individual strips of filter material, the charging of the Filter material strips with different charge strengths can be advantageous if the strips from differ Chen filter materials exist.

Further embodiments of the invention are the subordinate to see ten device claims.

The advantages associated with the invention are that due to the repulsive forces of the filter material  applied charges a good separation of the threads or Fibers is achievable.

According to a preferred development of the invention with the same constant inventive rank can on the filter mat rial applied charges can be used with Ladun plasticizer parts with opposite polarity kel, e.g. B. apply droplets of plasticizer uniformly, so that a filter strand homogeneously provided with plasticizer can be formed.

Finally, according to another preferred further education of the invention with independent inventive rank two or more strips of filter material that even come out from under different filter materials can exist, processed be without a ge for each filter material strip Entire treatment arrangement with stretching device and same must be provided.  

The invention is based on an embodiment tenden drawing explained in more detail.

Show it:

Fig. 1 shows a separation device within a processing system for run in a flat sheet filter tow, the charges by Rei environment of the tow coated with insulator who rolls the what softener droplets ent with charges opposite in polarity are applied,

Fig. 2 is a charge source including a high-voltage source,

Fig. 3 is an operating with electric charges club zelungsvorrichtung within a conditioning facility for filter tow, which is arranged downstream of the Towstreifens to a strand of an apparatus for applying plasticizer in the field of gathering,

Fig. 4 shows details of the apparatus for applying plasticizer to Fig. 3 in an enlarged scale,

Fig. 5 shows a variant of the device according to Fig. 4,

Fig. 6 is a side view of an installation for applying charges to two adjacent run Towstrei fen for the purpose of separation of threads or fibers,

Fig. 7 is a plan view of a plant according to Fig. 6,

Fig. 8 is a variant of a plant according to Fig. 6.

In Fig. 1 is shown as an example of a device according to the invention, a machine for producing a filter strand for the production of filters for cigarettes or the like smokable articles in a schematic side view. The filter material has separable threads or fibers made of cellulose acetate or a similar material made of plastic or natural materials, which are electrical non-conductors. The device consists of two main building groups, a processing device 1 for filtertow fed in an endless filter material strip and a Bear processing device 2 for the production of coated filter rods.

The preparation device 1 has a pair of rollers 3 for the continuous pulling of a single thread or single fibers aufwei send endless filter material strip 4 (web) from a bale 6 . After removal from the bale 6 , the filter tow strip passes on its way to the pair of rollers 3 , on which it is guided over a deflection roller 5 , two air nozzles 7 and 8 , which serve to spread and loosen the tissue of the film termi stripes. The pair of rollers 3 are followed by two further pairs of rollers 9 and 11 , between which there is a carrier device 12 for applying liquid plasticizer, for. B. triacetin, on the spread between the pairs of rollers 9 and 11 out guided filter material strips 4 and a device 15 for applying electrical charges befin det. Of the individual rollers of the roller pairs 9 and 11 , one roller is advantageously provided with grooves on its circumference, while the counter roller has a smooth surface made of elastic material. All pairs of rollers 3 , 9 and 11 are from a main drive motor 13 via belt drive 13 a. . . c drivable. Instead of a main drive motor 13 , one or more separate drives for the rollers can also be provided in pairs. The speed of the pair of rollers 3 is less than that of the pair of rollers 9 , so that the pairs of rollers 3 and 9 form a stretching device. The speed of the pair of rollers can be changed via a gear 14 , the translation of which can be changed by a controllable adjusting motor 16 . The speed ratio between the roller pairs 3 and 9 specifies the degree of stretching of the filter material strip 4 . In the exemplary embodiment shown, the brake rollers 3 are driven. But they can also be designed as non-driven drag rollers, which serve as brake rollers due to friction. The filter material strips 4 which are spread out and stretched in the stretching device between the rollers 3 , 9 and 11 are fed to the application device 15 for electric charges, which have two driven rollers 42 , 43 consisting of electrical non-conductors (insulators) which have grinders (tips) 44 , 46 are connected to earth 47 , 48 . As a result of the existing friction between the moving filter material strip 4 and the rollers 42 , 43 , electrical charges are generated, of which the charges of one polarity, negative charges in the case of cellulose acetate, remain on the filter material strip 4 and are carried away with it. As a result of Coulomb's repulsive forces, the negative charges on the filter material separate the individual threads or fibers from one another in a desired manner.

The charges of opposite polarity, ie positive charges at Celluloseace, are separated from the negative charges by being removed on the surfaces of the rollers 42 , 43 and reaching the earth 47 , 48 via the grinders 44 , 46 .

The charges applied to the filter material strips 4 can be used in addition to separating the filaments or fibers of the filtows in a very advantageous independent inventively manner to finely divided liquid plasticizers, e.g. B. triacetin to apply to the filter material. Such plasticizer, which can be replaced by a solvent in other filter material, softens the surface of the threads or fibers so that they stick together on their surfaces. The very uniform application of the plasticizer is important for the quality of the filters produced. For this purpose, a dosing device 51 , z. B. a metering pump that promotes liquid plasticizer from an on-board container 52 to an electrode 53 , which is connected to that pole of a charge source 54 , for. B. a high voltage source is connected, the charges that are opposite with respect to the polarity rialstreifen 4 located on the Filtermate charges, in the example, positive charges. The so (positive) charged droplets of plasticizer (such. As triacetin) are attracted to the (negative) charges on the fiber and result in a very homogeneous spray pattern on the filter material strip 4. Details of such an electrostatic spray device for filter material are shown in US Defensive Publication 665476 of Official Gazette 860/3 of March 18, 1969.

The filter material strip 4 thus treated, sprayed with plasticizer, is passed from its expanded shape into a gathered, strand-like shape 10 after passing through a pair of rollers 11 . From the processing device 1 ge reaches the strip of material in an inlet funnel 11 of the processing device 2 , in which it is summarized and on a stripped from a reel 18 and by means of a gluing device 19 provided with hot melt adhesive sheathing strips 21 is placed. The wrapping strip 21 and the combined filter material strip 4 arrive on a format tape 22 , the two components through a for mat 23 , which wraps the wrapping strip 21 around the Filterma material strand and thereby forms an endless filter strand 24 . This seam runs past a cooling strip 26 , in which the adhesive seam is solidified. Subsequently, filter rods 28 are continuously cut off from the filter strand 24 by means of a knife apparatus 27 , which are transferred from an accelerator 29 into a depositing drum 31 , in which they are conveyed in the transverse axial conveying direction. From the cuttings drum 31 , the filter rods reach a cantilever belt 32 , from which they are processed for further processing or are stored temporarily.

Tricity instead of a charge formation on the fibers or filaments of the filter material strip 4 by generating Reibungselek and subsequent separation of the charges can accelerator as Fig. 2 by a corona discharge from a connected to a pole of a high voltage source 56 peak-shaped electrode 57 charges the appropriate polarity (positive or negative) applied to a filter material strip. The charges are shown as negative charges in the example. One of the tip 57 opposite Gegenelek electrode 58 is connected to earth 59 , as well as the other pole of the high voltage source 56th

The charge source according to the invention, e.g. B. a high voltage source or a charge source described in subordinate figures, can also be arranged in other areas of the processing device 1 , indicated by arrows A. . . C are designated.

A measuring device for the field strength can measure the size of the Detect loads of filter material strips and the charge delivery of the charge source in terms of compliance control a desired field strength.  

Fig. 3 shows a variant of the editing apparatus 1, wherein the charges on the filter material in the region D between the roller pairs 11 and the inlet funnel 17 are applied from a charge source 61. An order device 62 for applying oppositely charged plasticizer droplets is located in an area in which the filter material strip 4 is combined in a strand, which is denoted by 10 .

Fig. 4 shows, on an enlarged scale, details of the spraying of the filter material strip 4 with loaded plasticizer droplets. A metering pump 63 conveys liquid plasticizers via lines 64 , 66 and 67 to nozzles 68 , 69 , 71 in an annular electrode 72 which is connected to the positive pole of a charge source 73 . The plasticizer droplets flowing out through the nozzles are charged positively and attracted by the negative charges on the strand 10 . As a result of the symmetrical arrangement of the nozzles, finely distributed mists 74 , 76 and 77 can be generated and the filter material can thus be sprayed very homogeneously. Of course, the arrangement of more or fewer supply nozzles is possible, which are advantageously arranged symmetrically to the filter material strand 10 .

FIG. 5 shows a variant of FIG. 4, in which the strand 10 is tubular. Inside the tube 10 be there is a perforated tube 78 , from which liquid plasticizer emerges with a positive charge and arrives in the form of a mist 79 from the inside onto the tube walls of the filter material. A very good, homogeneous result is achieved by applying plasticizers from the inside and outside. Of course, other nozzles, not shown, can be arranged in the intermediate spaces between the nozzles 68 , 69 , 71 , so that the plasticizer mist practically mist the outer surface of the strand 100 .

FIGS. 6 and 7 show an independently inventive appli cation of the invention to a Filtertowaufbereitung through which the yarns or fibers of two strips 4 a, 4 b can be processed TERIAL of Filterma. The strips 4 a, 4 b can be narrow according to the invention compared to the current practice in Rich direction perpendicular to the conveying direction (which of course also applies to the variants of FIGS. 1 to 5), because arrangements 81 a, 81 b for applying electrical charges the separation of the fibers or threads, for. B. in cellulose acetate strips (filter tow). This advantageous type of separation is otherwise only achieved by a very wide spread of the filter material strip, which causes problems for space reasons when two or more strips of material are to be processed together and then formed into filter strands. The Anordnun gene 81 a, 81 b can be designed as discharge rods (corona discharges), such as those sold by Haug GmbH & Co. KG, Echterdingen, DE, under the type designation ALSA 030-500. The lower geer end of the roller pair 9 can serve as the counter electrode. It is also possible to provide a special counter electrode.

The discharge rods 81 a, 81 b are supplied with electrical energy by charging devices 82 a, 82 b, for example of the type AG-3/7612 from the Haug company.

The electrical field strengths associated with the electrical charges on the strips 4 a, 4 b can be detected by measuring devices 83 a, 83 b, for example of the type Stato 11/7209 from Haug.

The output signals of the measuring devices 83 a, 83 b can be fed to comparators 84 a, 84 b, to which set values from set point generators 86 a, 86 b can also be supplied.

By means of the control loops for the field strengths, the singularizing forces for the threads or fibers of the filter material strips 4 a, 4 b can be kept at constant values, which, with the appropriate setting of the setpoint generator, can also be different. Such an operation is particularly advantageous if the Fil termaterialstreifen 4 a, 4 b to be processed differ from each other, z. B. consist of different material. In this case, it can be avoided that a controlled on drivable roller pair 9 and 3 must be provided for each strip, because de ren function, at least in part, of the different separating forces of the different electrical charges applied by the arrangements 81 a and 81 b be taken over.

Fig. 8 shows a variant in which a common for both Anord openings 81 a, 81 b counter electrode 87 is arranged in the middle between the two filter material strips 4 a, 4 b.

The arrangements 81 a, 81 b can be provided at different points in the processing plant 1 . They can also be arranged after spraying devices for finely divided droplets of plasticizer with opposite electrical charge, as shown in FIGS . 1, 3, 4 and 5 Darge.

In the examples shown, cellulose acetate strips negatively charged. But it is by using appropriate Charge sources also possible to apply positive charges. In this case, the plasticizer droplets are negative load.

Claims (21)

1. A method for treating at least one web of filaments having filter material (tow) for cigarette filters, characterized in that the filter material web is subjected to electrical charges during its conveyance, by the influence of which the filaments are separated. 2. The method according to claim 1, characterized in that the electrical charges from a charge source a spray discharge applied to the filter material web whose repulsive forces separate the threads nen. 3. The method according to claim 1 and / or 2, characterized records that he spray discharge between metal tips follows. 4. Method according to one or more of the preceding Claims, characterized in that the size of the a charge source and delivered to the filter material charge taken over by the railways to a constant value is valid. 5. The method according to claim 1, characterized in that electric charges, the repulsive forces of which are the threads of separate each other by friction between the moving fil term material web and at least one insulator and after following separation of the charges on the filter material to be brought. 6. Procedure in particular according to one or more of the above forthcoming claims, characterized in that the with  electric charges of a certain polarity te filter material web is sprayed during its promotion with finely divided plasticizer particles, which with electri charges of the opposite polarity are. 7. The method according to claim 6, characterized in that the filter material web is combined into one strand and that the plasticizer from the outside, preferably from several distributed sources. 8. The method according to claim 6 and / or 7, characterized records that the filter material web is tubular and that the plasticizer from the inside onto the filter material is applied. 9. The method according to one or more of claims 6 to 8, characterized in that the stream or streams of rivers solvent before applying the electrical La doses. 10. Method in particular according to one or more of the above forthcoming claims, characterized in that several preferably two webs of filter material who promoted the, on the charges of charge sources for separating the Threads are applied and that the sizes of the charges each be regulated to a constant value. 11. The method according to claim 10, characterized in that the field strengths generated by the charges in the range of individual webs of filter material and the ener Power supply to the charge source for the purpose of keeping constant  field strengths (charges) in the areas of the individual Filter material webs is controlled. 12. The method according to claim 10 and / or 11, characterized records that the field strengths (charges) on differ values are regulated when the filter materials in the individual filter material webs are different. 13. Device for treating at least one strip of filaments having filter material (tow) for cigarette filters, characterized by an arrangement ( 15 ) for bringing electrical charges onto the filter material strips ( 4 ; 4 a, 4 b) during its conveyance for the purpose of separating the threads . 14. The apparatus according to claim 13, characterized by a charge source ( 56 ), preferably a high voltage source, with spray electrodes ( 57 , 58 ) for applying charges to the filter material strip ( Fig. 2). 15. The apparatus of claim 13 and / or 14, characterized by at least one control loop ( 81 a ... 86 a, 81 b ... 86 b) for keeping the size of the strips on the filter material constant ( 4 ; 4 a, 4 b) emitted electrical charges (elec trical field strengths) ( Fig. 6 to 8). 16. The apparatus according to claim 15, characterized by an arrangement ( 42 .... 48 ) for generating charges on the Fil termaterialstreifen ( 4 ) by friction between the Filterma material strips and an insulator ( 42 , 43 ) and subsequent separation of the charges, wherein the charges of undesired polarity are continuously removed ( Fig. 1). 17. The device, in particular according to one or more of the preceding claims 13 to 16, characterized by a device ( 12 ) for loading the filter material strip with charges of a certain polarity ( 4 ) during its conveyance with particles of softening liquid, the charges of the opposite Have polarity ( Fig. 3 to 5). 18. The apparatus according to claim 17, characterized by a device ( 62 ) for loading the filter material strip ( 4 ) combined into a strand ( 100 ) from the outside and / or inside. 19. The apparatus according to claim 18, characterized by a metering device ( 63 ) for the metered supply of Weichma cher fluid to the device ( 62 ). 20. The device in particular according to one or more of the preceding claims 13 to 19, characterized by a plurality, preferably two filter material strips ( 4 a, 4 b) onto which charges from charge sources ( 81 a, 81 b) can be applied, and by control arrangements ( 82 a ... 86 a, 82 b ... 86 b) to keep the electrical charges (electric field strengths) constant in the areas of the individual filter material. 21. The apparatus as claimed in claim 20, characterized by control arrangements for keeping the electrical charges (electric field strengths) constant at different values in the areas of the individual filter material strips ( 4 a, 4 b), the different values preferably being predefined as a function of different filter materials ( 86 a, 86 b).