IL37646A

IL37646A - Method and apparatus for the manufacture of a cigarette filter

Info

Publication number: IL37646A
Application number: IL37646A
Authority: IL
Original assignee: Burrus & Cie
Priority date: 1970-10-12
Filing date: 1971-09-02
Publication date: 1974-09-10
Also published as: ES395923A1; FI51425C; IE35700L; FI51425B; DK132367B; FR2109848A5; SE374646B; KR780000509B1; NL7112095A; US3762281A; DE2065727A1; IE35700B1; NL164191B; ES420216A1; YU254971A; LU64040A1; DE2057451B2; SU572176A3; JPS5412558B1; AR201182A1

Description

s for of The present invention relates to a of turing a cigarette in which sections of fibrous and of filter materials are arranged in and to a device for putting that method into In one method of making multiple individual filter sections are spaced to a cover which is wrapped partly round and then a filtering medium is discharged from a hopper into the spaces between the filter By regulation of the depth of the filter material in the it is sought to regulate the pressure of that material in the base of the hopper and hence the degree to which the said spaces are The drawback of this method is that the degree of filling can scarcely be controlled by the depth of filter material in the hopper and is unsatis actory oven at low speeds of production In another known method for the production of multiple the individual filter chambers are charged with the filtration material with the aid of a wheel containing recesses round its periphery or by means of a chain carrying This mechanism is very complicated and again does not enable the degree of filling to be matched to the nature of the filtering medium In yet another known the individual spaced filter sections are wrapped up to an with an initial cover the width of which is less than the circum of the filter sections to be this strip containing perforations for the passage of The assembly is fed a filler to air drawn through the initial cover from filter spaces to be with the Upon completion the whole requires further in a cover This is very complicated it is not possible for the units being to be supported on a conveyor below the filler results in further the use of two cover strips increases production costs leads to formation of false air passages in the finished The purpose of the inventio to provide a method and a device from the above with which it is a simple matter to fill the filter spaces the filling being regulated accordin to the nature of the filtering medium The method here proposed comprises the of securing a succession of filter elements or uniformly spaced and in axial to a continuously fed strip there being provided between adjacen filter wads a succession of with feed for fillings of filter materials continuously advancing the resulting cover strip into and through a fixed zone of reduced pressure wherein air is evacuated from each successive space in state having at least one filling aperture where each space in succession is opened to said filling discharging through each said feed aperture into each said open space in succession a predetermined quantity of filter material from said filling then bringing together the edges the cover strip in overlapping relationship so as to form a tube completely enclosing the filter wads and fillings of running filter material in said spaces cementing together the overlapping edges of the strip to complete the It is preferable to use a cover strip coated with a thermoplastic on the side coming into contact with the and filter join these to the cover strip by the use of a heater soften the thermoplastic coating at least at particular The invention also relates to device for facutring cigarette filters in whic sections fibrous and sections of are arranged in which a feed mechanism for continuously advancing a cover stri in one means for feeding a succession of uniformal spaced and axially aligned wads on to the continuously cover strip means fixing the individual filter wads to the strip the spaced apart filter wads is guided and continuously ed a forming member adjacent said means of guidance and conveyance by which the cover moves is wrapped around the spaced apart filter wads the sides of the travelling with the cover a guide member shaping the cover strip into a tube completely the wads and spaces between them filled with so that edges of the cover strip longitudinal centre line and for the closing edge of the closing member to run helically about the longitudinal centre line of the cylindrical part of the storage so that as the closing is turned in the direction for it is initially that end of the discharge slot that lies towards the suction aperture which is this being followed by those parts of the discharge slot which are farther from the suction aperture as the closing member continues to The invention is described by way of in conjunction the accompanying in 1 is a diagrammatic side elevation of device for producing a cigarette filter Figure 2 is a section through the filler along the line in Figure 3 is a section along the line in Figure Figure is an enlarged section along the line in Figure Figure is a section along the in Figure to show the fixing mechanismj 6 is a section along the line i Figure show the top welding arrangements Figure 7 is a section along the line in Figure to show the Figure S is a section along the line in Figure to show the bottom welding and Figure is a longitudinal section of the adjusting mechanism serving to bring the operating cycle of filter element feed into line with that of the cutting In equipment shown in way of example in Figure the arrangements for continuously feeding a succession of uniformly spaced and aligned filter 1 and on a continuously fed cover include a known in the cigarette industry as a which is described in detail in Patent Specification This machine has two for holding lengths of filter such cellulose as cellulose for and two rotary drums which serve to receive The machine is worked by the driving chain Round their the 6 contain running parallel to their axes of to receive the lengths of filter the drums also having radial cutouts in which cutters rotate for dividing the lengths of filter material into the smaller filter 1 and The lengths of filter material having been divided into the smaller filter wads 1 and these are released by 6 on to a spacing and conveying by which the wads 1 and 2 are alternately fed forwards in axial in the direction of the arrow and spaced uniformly the uniformly spaced and axially aligned filter wads 1 and 2 are fed continuously to a cover likewise continuously on which they are being guided at the as shown in Figure by the guide members 10 and 11 and held in in relati to one by a pressure situated above and running round in the cover strip That face of the cover stri which lies towards the filter wads 1 and 2 is coated with an adhesive such for a which softens under the action of so that it possible for the individual filter wads 1 and directly they have been discharged on to cover strip to be secured to it with the aid of a thereby preventing relative that is to say preventing any alteration in their As can be seen from Figure the cover strip rests on a while the heater can be pressed from through a slot in the support against the cover strip thus indirectly against the filtor wads 1 and 2 that require to be anchored in The temperature of the heater should preferably be The heater 13 is so arranged that it can moved clear of the cover strip 3 this is to avoid burning The individual filter 1 and 2 having been secured to tho cover strip the latter is fed on to an endless conveyor these parts being fed jointly on to a guide track that functions as a on which the cover strip as it moves is wrapped round tho filter wads 1 and 2 attached to so as to form at least shape a letter This assembly is then carried by the conveyor belt 15 to a filler shown in greater detail in Figures 3 and which serves for the introduction of filter such as for into tho space formed the individual filter wads 1 and To ensure proper filling of the spaces 17 with the filter the discharge side of the storage container 18 of the filler 16 is connected to a suction situated considered in relation to the direction motion of the cover strip before the charge aperture 20 of the filler head 16 by a slidin which rests on the filter wads 1 and 2 and encloses them to the extent of at least The width of the sliding member 1 is approximately equal to the diameter of the filter 1 and which are to be wrapped 2 it to the cover strip 3 the side faces and running parallel to each other and to the tion of motion of the conveyor belt 15 serving to provide sealing contact with the inner faces of the of the cover strip this spaces bounded by the end faces of the filter wads 1 and the cover strip 3 the sliding surface of the sliding member 19 are formed at The distance between the suction aperture 22 and the charge aperture 20 is greater than the length of the spaces 17 formed between the wads 1 and so as wads these between the suction aperture 22 and the charge aperture 20 are to all intents and purposes enclosed so as to be completely apart from the filter wads 1 and the result being that the suction arrangement 21 is able to evacuate these spaces through the wads 1 and Because of the partial vacuum prevailing in the spaces the of the shaped cover strip are held and virtually sealed against the side faces and 19b of sliding membe length of the suction aperture 22 in the sliding face of the sliding measured in the direction of travel of the cover strip 3 is greater than the length of the wads to be so that the suction is able to act also on the end faces of the wads between which the spaces 17 to be evacuated are This is ularly important the filter wads in use have their lowest flow resistance in the axial directione the entire filter wad adjacent to the space 17 to be ated is thus brought under partial so that nothing can detract the ef ectiveness thereo The thu3 evacuated arrive forthwith under the discharge aperture 20 of the storage container which constitutes the charging the running filter material in the container is sucked aneously into the spaces 17 extending from the sliding In order to promote complete filling of the spaces and the flow of the filter material in the container 18 down through the discharge slit the filler head l6 is equipped with a the effect of which is to cause the filler head 16 mounted resiliently on flat springs in Figure 3 to vibrate at 100 cycles per second in a vertical β The filler 16 is suspended by the springs a 26 which runs parallel to the track 25 provided for the conveyor bolt 15 and clamped to the said guide by means of e The screws 28 serve for horizontal alignment of the sliding member 19 in relation to filter wads 1 and 2 below while the screws 29 rigidly connected to guide enable the amplitude of vibration of the filler head imparted by the vibrator to be Since the width of the eliding member 19 is equal to the diameter of the filter the discharge slot 20 can be made relatively this being very important for unhindered of the filter At the end of the discharge slot 20 is a trimming which bounds the of the filter wads 1 and 2 as they pass through and trims off the excess of filter This trimming edge bein exposed to heavy wear when the equipment is is provided on an interchangeable which can be inserted into the sliding member The underside of the trimmer is provided with verse which remove any grains of running filter material that still remain on the filter pick them up and release them into the succeeding spaces when certain filter materials are used for an undesirable amount of dust whifch is deposited on the upper face of the filter and darkens the trimmer also be equipped with a suction through which the dust coating can be removed by the creation of a very slight partial To enable the size of the discharge slot 20 to be adapted to the particle size of the filter the bottom of the storage container is made Within this bottom portion is a closing in eliding contact with the interior face of the cylindrical member and designed to turn about the longitudinal centre line For rotating the closing member there is a while a thrust by a spring towards the plate 35 can home into recesses in various positions on plate The closing member 33 thus shaped like a section of the curved surface of a cylinder and is made as thin as so as to keep to minimum the force that needs to be exerted on the handle to move the closing member when the container 18 The closing edge of the closing member 33 is also made oblique or sharpened in relation to the inner face of the cylindrical member so as to facilitate movement of the closing member 33 it runs helically round the longitudinal axis 37 of the cylindrical member so that as the closing member 33 turned in the direction for it is initially the end of the discharge slot 20 that lies towards the suction aperture 22 which is this being followed by those parts of the discharge slot 20 which are farther from the suction aperture 22 as the closing member continues to There is also advantage in thus being able to close the discharge slot 20 when the running of the installation is interrupted or when the clamping 27 released and the filler head l6 is removed to expose the cover strip that lies below and carries the filter wads 1 and To prevent the storage container which is fed from the reserve container 38 from being is entered by two lengths of 39 each with its top end joined to a feed for the filter with its bottom end situated at the filling level of the container In the example the pipe 39 nearer to the suction aperture 22 contains a facing towards the suction to increase the outflow of filter the consumption of which is greatest at that To cut off the supply of filter material from the reserve container storage container 18 is also provided with a which can be slid across the lower ends of the feed pipes In the terminal portion sliding member the upper part of the track 25 so shaped that the cover strip converted into a complete a suction device being provided at the removal of any running filter material remaining between the edges of the cover For joining together the now overlapping edges of the cover there now follows a sealing as shown in Figure a heatable which can bo applied to the tube that is to be To prevent any of the filter in filter tips fitted to from finding its way between the outside of the filter wads and the inside of tho cover strip and into the the cover strip should stuck to the filter wads round their entire To that the heatable element provided with a guidance in radius of curvature being the same as the outside radius of the tube that is to be To achieve precision in tho diameter of the the guidance channel 48 in the heatable element 7 is immediately followed by another such channels cooling which can be lowered on to the tube so as to cause the to When the tube has been stuck it is passed to a cutting in which it is divided up in such a way that the length of each filter assembly is six times the length of a filter for a As the cutting head must be precisely synchronised with the movement of the filter wads within the finished a timing 52 is also to synchronise tho machine feeding the filter wads 1 and 2 on to the cover strip the drive of tho cutting head 1 by which the tube filled with filter material is divided into given The drives of the feed mechanism and that of the cutting head 51 are linked together by a Between the first part 3 the second part of the connecting shaft is an adjusting which rotates with the for altering the relative angular position of the two parts of the The adjusting member has two 55 in axial which can slide axially in relation to each the part bearing which engage in helical in the other To shift part of the adjusting member in the axial direction in relation to tho other part driven by an electric is which in rotating displaces the intermediate member 60 and hence also the part Beyond the cutting head is another adhesive joining 61 1 and in which the heater 62 bears against the The guide channel 63 in this heater is in section and cements the as yet uncemented part of the cover strip 3 formed into a tube to the filter wads 1 and so that these adhere to the cover strip round their entire periphery and no running filter material can escape from the spaces between the faces of the wads and the strip Endless spiral run round and exert pressure on the upper side of the lengths of Experiments have shown that with such when a partial vacuum of at least 5 mercury column is the amounts of a filter material such as used hitherto that can be filled into the spaces 17 between the filter wads 1 and 2 are twice as great as when no vacuum is with an output of about filter units a minut This clearly demonstrates the ef ectiveness of the suction arrangement Even with such a high the spaces in the filters are tightly and the complete freeing of the sides of the wads from the filter material and from filter material dust by the trimmer 31 and the suction device produces clean cut surfaces when the filter units are divided by the cutting head insufficientOCRQuality

Claims

1. CLAIMS V. A method of manufacturing a cigarette filter in which sections of fibrous and sections of free-running filter materials are arranged in sucession, which comprises the steps of rc ■ securing a succession of filter elements or wads, uniform ljr spaced and in axial alignment, to a continuously fed filter-tip cover strip there being provided between adjacent filter wads a sucoesion of spaces, with feed apertures, for fillings of free-running filter materials; continuously advancing the resulting cover strip into and through a fixed zone of reduced pressure v/herein air is evacuated from each suc^ssive space in closed-off state; A continuously moving the filter strip, with spaces in closed-off state, to and in contact with a filler head having at least one filling aperture where each said space in succession is opened to said filling aperture; discharging through each said feed aperture into each . said open space in succession a pre-determined quantity of free- · running filter material from said filling head; then bringing together the edges of the cover strip in overlapping relationship so as to form a tube complotely enclosing the filter wads and intervening fillings of free-running filter material in said spaces; and ' firmly cementing together the overlapping edges of the strip to complete the so-formed tube. .

2. , A method ao defined in claim 1, characterised by the fact that the cover atrip has the side which comes into con- tuot v/ith the filter wads coated with a thermoplastic^, and that the filter wads ure joined to the cover strip by the applica- 37646/2 tion of heat, at least at particular points,'"to soften the thermoplastic coating. ·.

3. A method as defined in claim 1, in which the cover strip, after the formation of a tube completely enclosing the filter wads and the free-running filter material, is joined to the wads round their entire periphery by application of heat . for softening the thermoplastic coating.

4. A method as defined in claim 1, in which the filling aperture of the filler head can be regulated.

5. A method as defined in claim 1, in .whic -a partial vacuum of at least 3 cm. , and preferably at least 5 cm, , of mercu-ry column i3 created in the evacuation zone in contact with the filter wads,

6. A method as defined in claim 1, in which the filler head which has the filling aperture is caused to vibrate in the, direction of filling.

7. A method a3 defined in claim 1 , in which the filler head is caused to vibrate at a frequency of 100 cycles per second in the direction of filling,,

8. A device for manufacturing cigaretto filters in which ' seotions of fibrous and sections of free-running filter mate-rials are arranged in succession, which comprises; a feed mechanism for continuously advanoing a bover strip in one direction; means for continuously feeding a succession of uniformal spaced and axially aligned filter wads on to the continuously advanced cover strip; 37646/2 strip; means of guidance and conveyance by which tho cover strip bearing tho spaced apart filter wads is guided and continuously fed forward; a forming member adjacent said means of guidance and conveyance by which the cover strip, as it moves forward, is wrapped round the spaced apart filter wads attaohed to it so as to form at least approximately a letter U; a stationary suction arrangement fitted above the means . of guidance and conveyance, such that it makes contact, between the arms of the U-shaped cover strip, with the upper sides of the filter wads travelling forward with the cover strip and the facing inner surfaces of the U-shaped cover strip; whereby air is evacuated through said filter wads and through said intervening spaces; means substantially sealing the spaces so ovacuatod; a filling head for charging free-running filter material into tho evacuated spaces between the wads, this filling head being situated above the mean's of guidance and conveyance and connected to the suction arrangement by a common sliding surface which makes a sealing contact on tho upper sides of the filter wudw trnvo'.U.inK forward w th t o oovor strip; a guide member shaping tho cover atrip into a tube completely enclosing the filter wads and the spaces between them filled with free-running filter material, so that the edges of the cover strip overlap; means for joining together the overlapping edges' of tho cover strip; and means whereby the tube filled with sections made up of filter wads and fillings of free-running filter material is divided up into given lengths.

9. A device as defined in claim 8, in which the means 37646/2 of fixing the' individual filter wads to the cover strip consists of a heater, which is movable towards and away from tha side of the cover strip.which faces away from the filter wads, and in which a shift mechanisra is provided for bringing the heater close enough to the cover strip, as thio moves forward, for the adhesi- · ve on the cover strip, which softens under heat, to be softened at least at given points, the said mechanism moving the heater far enough away from the cover strip when this is at res to prevent it from being damaged by the radiant heat from the heater. .

10. A device as, defined in claim 8, in which the means of guidance and conveyance consists of an endless conveyor belt.

11. A device as defined in claim 10, in which the forming member by which the cover strip, as it moves forward, is wrapped round the filter wads attached to it so as to form at least approximately a letter U, consists of a sliding plate and a pressure device bearing' on the filter ads, which, gra- . dually shape the conveyor belt, along with the cover strip moving with it, to the desired shape.

12. Λ, device as defined in claim 8, provided with means of synchronisation, for synchronising the drive of the feed mechanism, by v/hich the filter wads are fed. on to the cover strip, v/ith tho drive for the means by which the tube filled with filter material is divided into 'given lengths, the drives for the feed mechanism and for the said dividing means being linked together ' by a two-part shaft, an adjusting member being provided between the first and second parts respectively of tho connecting shaft and rotating with the second part, for altering the angular position of tho two parts of tho connecting shaft, within given limits, in relation to each other. 37646/2

13. A devico as defined in claim 12, in whic adjusting member has two parts in axial alignment, which can t slide axlally in relation to each other, one of them bearing guides, which engage in helical grooves in the other part; and in which means of adjustment are provided for altering the 'axial position of at least one part of the adjusting member in relation to the other part thereof.

14. A device as defined in claim 8, in which the suction arrangement and the filler head are connected by a common elongated sliding member having a suction aperture and extendin in the direction of travel of the filter wads and providing a ·'_, sliding face which forms a sealing contact on the upper sides of the wads travelling forward with the cover strip, the width ' of the sliding member is approximately equal to the diameter of the wads to be wrapped in the cover strip, and the side faces of the sliding member are parallel to each other and to the direction of travel of the cover strip and are such as to make a. sealing contaot with the facing surfaces of the arms of the U-ohupod oovor strip.

15. A device as defined in claim 14, in whioh the distance between the suction aperture in the sliding face and the charge aperture is greater than the length of the spaces formed between the filter wads.

16. A device as defined in claim 15, in whioh the length of the euction aperture in the sliding face, measured in the direction of travel of the cover strip, is greater than the maximum length of the filter wads to be covered,

17. A device as defined in claim 8, in which the fil^i ler head is .equipped with a storage^ container, the discharge 37646/2 slot in which constitutes the charge aperture, and a means of closure working in conjunction with the discharge slot is provided for the purpose of regulating the opening of the latter.

18. A device as defined in claim 17, in which the bottom portion of the storage container is cylindrical, the means of olosure being a scoop-shaped closing member, in contaot with the; interior face of the said cylindrical portion, about the longitudinal centre lino of which it can be turned; and in which . the closing edge of the closing member runs helically round the longitudinal axis of the cylindrical portion of the storage container, so that as the closing member is turned in the direction for opening, it is initially the end of the discharge slot lying towards the suction aperture which is freed, this being followed by those parts of the discharge slot which are farther from the suotion aperture as the closing member continues to turn.

19. A device as defined in claim 17, in which the storage container is entered by at least one length of pipe, one end of which can be connected to a feed inlet for ,tho free-running filter material, while the other end is situated at the filling level of the storage container.

20. A device as defined in claim 8, in which tho guide arrangement for converting the cover strip into a cdmpl.ete tube ... is provided with a suction device for the removal of any free-running filter material remaining between the edges of the oover strip.

21. A device as defined in claim 8, in which the moano by which the overlapping edges of the cover strip are joined together incorporate a heatablc element, which can be lowered o '37646/2 element contains a guidance channel, approximatel semi-circular in section, the radius of curvature of which is equal to the outside radius of the tube to be produced; and in which the guidance channel in the heatable element is immediately followed by another such channel, in cooling unit provided for causin 'the heat-softened adhesive to set.

22. A device, as defined in claim 21 , in which the ' heatable element is followed, in the direction of travel of the means of guidance and conveyance, by a second heatable' element- having a guidance channel which joins the as yet non-adhering part of the oover strip formed into a tube to the filter wads.

23. A method as defined in claim 1 , wherein the cover strip provided with spaced filter elements is maintained under reduoed pressure until the same has paesed beyond said filler head.

24. A method as defined in claim 1, according to which there is used a cover strip which is coated v/ith a thermoplastic synthetic material' at the side coming in contact with the filter elements, and the individual filter elements, before reaching the suction part, are fixedly connected with the coverin , strip by softening, at least in Gpots, the thermoplastic synthetio coating by means of heat; that thereupon the spaces, located between the individual filter elements, are evacuated and then filled with the free-flowing filter material, and that finally, after formation of a closed tube, completely surroundin the filter elements and the fillings of free-flowing filter material^ the covering atrip is glued to the filter elements throughout their entire circumference by softening the thermoplastic .·'·-;