EP1591026B1 - Scraping element and spraying device for filter tow - Google Patents

Abstract

An application element is adapted to apply an additive to the spread-out web of a filter tow (20). A scraper (33,34) is positioned transverse to the direction of movement of a filter tow. The scraper includes a sliding surface aligned parallel to the filter tow movement direction. An independent claim is also included for a method of applying an additive to a moving spread out web of filter tow in a tobacco processing industry.

Description

The invention relates to a device for supplying a, preferably liquid, additive to a moving, spread web of filter material of the tobacco-processing industry by means of an applicator member. Furthermore, the invention relates to the use of a scraper element.

In the production of filter rods for the tobacco processing industry filter tow, which consists mostly of cellulose acetate, withdrawn from a supply as an endless strip and treated. The filter tow consists of a web of loosely adhering threads that are pulled apart to form a wide and mostly flat web so that the threads are moved side by side and substantially parallel. The propagation of the web takes place in a spreader nozzle. After spreading the sheet is an additive, which is usually liquid and consists for example of triacetin droplets, fed in finely divided form. The Droplets dissolve the threads, so that the threads adhere permanently to each other after their summary to a round strand and wrapping with a filter paper strip in a filter rod machine, that are networked.

Instead of a liquid additive, an additive consisting of a finely divided powdery substance can also be used. Processing equipment of the type described above are in the patents US 5 060 664 and US 4 511 420 described.

In EP-A-1 314 363 a filter manufacturing machine is disclosed wherein an additive is applied to a tow strip by means of spray nozzles. Each spray nozzle is associated with a front cover and a rear cover, the rear cover having a plurality of openings. Between the rear and front cover of the tow strip is passed.

In addition, both the rear and the front cover are formed with a heater. Below the vertically arranged front and rear covers each wells are arranged to collect excess liquid.

From the publication DE-A-199 59 034 It is known to spray filter tow with a transverse to the direction of movement of the filter tow row of nozzles with plasticizer. Here, the individual nozzles are controlled by upstream, the density of the filter tow in the sections concerned sensors.

Of great importance for the quality of the preparation are the good separation of the individual threads or fibers and / or a uniform application of finely divided plasticizer particles in the form of droplets or fine particles.

Based on this prior art, it is an object of the present invention to ensure a uniform distribution of a plasticizer on the filter material, so that the quality of the filter production is increased.

This object is achieved in a device for supplying a, preferably liquid, additive to a moving, spread web of filter material of the tobacco-processing industry by means of a job organ in that at least one Scraper element arranged transversely to the direction of movement of the filter material is provided with a sliding surface aligned substantially parallel to the direction of movement of the filter material.

In the hitherto existing Abstreifblechen that are used in a spraying for example Triacetinauftrag on Filtertow, larger amounts of plasticizer can accumulate at undesirable locations of the Abstreifblechs. The advantageous effect of the stripping element according to the invention with the sliding surface or guide surface consists in the fact that due to the extended sliding surface for the filter material, a guide is formed on the stripping element and thus no dead zones on the stripping arise in which collect droplets of the plasticizer. The steady accumulation of droplets in the dead zones results in a greater amount of plasticizer, which is entrained by the moving filter material at a certain amount or size. Due to the higher concentration of plasticizer in the filter material or Acetattowstreifen by the entrained lump unwanted holes are produced in the acetate part of a finished filter. The targeted avoidance of dead zones, in which plasticizer droplets can accumulate, thus significantly reduces the formation of holes by larger plasticizer lumps in a filter.

In order to achieve a uniform application of plasticizer and a homogenization of the plasticizer in the filter material while avoiding dead zones on Abstreifblech or stripping, it is advantageous if the sliding surface of the stripping element in the manner of a flat bar, in particular over the entire width of the expanded filter material is formed.

In particular, the sliding surface is designed in the manner of a groove in order to additionally collect and remove plasticizer not picked up by the filter material.

According to a preferred embodiment of the invention, the stripping element in cross section is approximately L-shaped or T-shaped or U-shaped, wherein preferably a part of the formed shape is arranged as a sliding surface of the stripping substantially or approximately parallel to the direction of movement of the filter material.

Further, in particular, the stripping element is designed in the manner of a channel to laterally divert, for example, collected in the gutter triacetin as a plasticizer above the funded filter material and lead to a reservoir for the plasticizer.

Moreover, it is advantageous if the position of the stripping element in the device is adjustable.

Moreover, it is advantageous if the device is formed closed, so that a housing is provided for the device in which the order of the additive takes place on the spread filter material.

Furthermore, the object is achieved by the use of a stripping element in a device for supplying a, preferably liquid, additive to a moving, spread web of filter material of the tobacco-processing industry by means of an applicator member, wherein the stripping element is arranged transversely to the direction of movement of the filter material and a essentially parallel to the direction of movement of the filter material having aligned sliding surface.

Advantageous embodiments of the stripping according to the invention will become apparent from the foregoing, so that reference is expressly made to the above.

Fig. 1

eine vergrößerte Querschnittsansicht eines Abstreifbleches gemäß dem Stand der Technik;

Fig. 2a, Fig. 2b

jeweils einen Querschnitt eines erfindungsgemäßen Abstreifbleches in einer vergrößerten Ansicht und

Fig. 3

eine Ansicht einer Besprüheinrichtung mit Abstreifblechen in einem Querschnitt.

The invention will now be described by way of example without limiting the general inventive idea by means of exemplary embodiments with reference to the drawings, to which reference is expressly made, moreover, with regard to all details of the invention which are not explained in greater detail in the text. Show it:

Fig. 1

an enlarged cross-sectional view of a Abstreifbleches according to the prior art;

Fig. 2a, Fig. 2b

in each case a cross section of a stripper according to the invention in an enlarged view and

Fig. 3

a view of a sprayer with Abstreifblechen in a cross section.

In the following figures, identical or similar elements or corresponding parts are provided with the same reference numerals, so that a corresponding renewed idea is disregarded.

In Fig. 1 a section of a device for spraying filter tow is shown in cross-section, wherein the device has a Abstreifblech 15. The Abstreifblech 15 is hook-shaped or V-shaped or formed in the manner of a parabola. At the Bottom of Abstreifblechs 15, the spread filter tow 20 is transported according to the marked conveying direction F over. Here, in the lowest point of the stripping plate 15, the filter tow 20 and the stripping plate 20 touch each other.

By applying triacetin to the filter tow 20, for example by means of an application nozzle or an application brush, which is not shown here, droplets of triacetin are applied to the filter tow 20. Due to the volatility of the triacetin droplets, the atmosphere in the spraying device ( Fig. 3 ) enriched with triacetin droplets.

Due to the tangential contact of the filter tow 20 in the lowest point of the stripping plate 15 is formed in the conveying direction of the filter tow 20 in the region of the contact point, a dead zone 17, in which accumulate the triacetin droplets. This results in a lump 18 of triacetin, which is carried along or entrained only after reaching a predetermined size or amount of the filter tow 20 transported over.

In Fig. 2a is a cross-section of an inventive Abstreifblech 15 is shown, which has at the lowest point a horizontal sliding surface 25 which is arranged parallel to the extended surface of the filter tow 20. By the horizontal continuation of the sliding surface 25, the dead zone (reference numeral 17, Fig. 1 ) avoided.

The flat sliding surface 25 has the effect of a guide for the filter tow 20 over the entire width of the filter tow 20. Furthermore, the sliding surface 25 has the effect of a spoiler, ie, at production speeds, the filter tow 20 is easily sucked against the bottom of the sliding surface 25, so that applied triacetin continuously through the tow 20 of the sliding surface 25th is stripped off. The accumulation of larger amounts of triacetin droplets in a dead zone (reference 17, Fig. 1 ) is prevented.

Fig. 2b shows a cross section of a further Abstreifblechs 15 according to the invention, in which the sliding surface 25 at the end of the sliding surface 25 as a boundary has a vertical wall 26. Through the vertical wall 26, the sliding surface 25 is also formed as a kind of groove for receiving and carrying away from the filter material or filter tow 20 not recorded or excess plasticizer.

In Fig. 3 For example, a means 30 for applying a plasticizer, eg triacetin, to the deployed filter tow 20 is shown in a schematic cross-sectional view. The filter tow 20 is transported according to the conveying direction F from right to left. In the lower region of the device 30, an application nozzle 31 is arranged, which generates a spray cone 32 with plasticizer droplets of triacetin. By means of the application nozzle 31, a fine, mist-like atomization of a plasticizer, such as triacetin, achieved.

The filter tow 20 is guided through lower stripping plates 33, 34 through the device 30. The lower Abstreifbleche 33, 34 are arranged in the lower region of the device 30. Above the filter tow 20 three Abstreifbleche 15 are arranged, which are provided with an approximately parallel to the direction of movement of the filter tow 20 aligned sliding surface 25. In addition, in the inlet region of the filter tow 20 in the device 30, a further Abstreifblech 16 is disposed above the filter tow 20, which has no sliding surface, as this Abstreifblech far away from the place of application of the plasticizer on the filter tow 20 in the device 30 is.

The stripping plates 15 are U-shaped or V-shaped in the filter-near area, so that a trough-like or groove-like depression is formed. In this groove-like depression, the softener droplets flying around and draining from the housing wall are collected in the upper region of the device and discharged laterally above the filter tow 20.

LIST OF REFERENCE NUMBERS

15

stripper

16

stripper

17

dead zone

18

lump

20

filter tow

25

sliding surface

26

wall

30

Facility

31

applicator

32

spray cones

33

stripper

34

stripper

F

conveying direction

Claims (13)

1. Device (30) for supplying a, preferably liquid, additive to a moving, spread-out web (20) of filter material of the tobacco-processing industry by means of an application member (31), characterised in that at least one stripping element (15), arranged transversely to the movement direction of the filter material (20) and having a sliding surface (25) aligned substantially parallel to the movement direction of the filter material (20), is provided.
2. Device (30) according to Claim 1, characterised in that the sliding surface (25) of the stripping element (15) is designed in the manner of a flat strip, in particular over the entire width of the spread-out filter material (20).
3. Device (30) according to Claim 1 or 2, characterised in that the sliding surface (25) is designed in the manner of a channel.
4. Device (30) according to one of Claims 1 to 3, characterised in that the stripping element (15) is of approximately L-shaped or T-shaped or U-shaped design in cross-section.
5. Device (30) according to one or more of Claims 1 to 4, characterised in that the stripping element (15) is designed in the manner of a channel transversely to the movement direction of the filter material (20).
6. Device (30) according to one or more of Claims 1 to 5, characterised in that the position of the stripping element (15) is adjustable.
7. Device (30) according to one or more of Claims 1 to 6, characterised in that the device (30) is of closed design.
8. Use of a stripping element (15) in a device (30) for supplying a, preferably liquid, additive to a moving, spread-out web (20) of filter material of the tobacco-processing industry by means of an application member (31), the stripping element (15) being arranged transversely to the movement direction of the filter material (20) and having a sliding surface (25) aligned substantially parallel to the movement direction of the filter material (20).
9. Use according to Claim 8, characterised in that the sliding surface (25) of the stripping element (15) is designed in the manner of a flat strip, in particular over the entire width of the spread-out filter material (20).
10. Use according to Claim 8 or 9, characterised in that the sliding surface (25) is designed in the manner of a channel.
11. Use according to one of Claims 8 to 10, characterised in that the stripping element (15) is of approximately L-shaped or T-shaped or U-shaped design in cross-section.
12. Use according to one or more of Claims 8 to 11, characterised in that the stripping element (15) is designed in the manner of a channel transversely to the movement direction of the filter material (20).
13. Use according to one or more of Claims 8 to 12, characterised in that the position of the stripping element (15) is adjustable.

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