GB2145918A - Producing filler material, particularly for cigarette filters - Google Patents

Abstract

Filler material, particularly for cigarette filters, is produced by feeding a first stream (72) of substantially continuous filaments of filler material onto a pin roller (80) which is driven at a speed such that the filaments are broken by the pins into irregular lengths and are projected from the roller in random orientations. The broken filaments are collected on a carrier stream (74), also comprising filamentary material, for delivery to a rod-making unit (92). More than one stream could be supplied to the pin roller so that the broken filaments can comprise a mixture of filaments of different filler materials. The carrier steam may comprise filler material which is different from that in the first stream and may comprise a fibrillated web. <IMAGE>

Description

SPECIFICATION Producing filler material, particularly for cigarette filters This invention relates to an apparatus and method for producing filler material, particularlyforcigarette filters, Cigarette filters have commonly been made from filtertowwhich consists of a cluster of crimped monofilaments, usually of cellulose acetate. The tow isdrawnfrom a bale, is stretched by differential-speed rollers separate the filaments and spread them out evenly, and is finally compressed to form a stream having thecross-section of the completed filters. A plasticisersuch astriacetin is usually sprayed onto the filamentswhiletheyarespread out.The compressed streamoffilaments may be enclosed in a continuous wrapper or maybe set by means of steam or some other source of heattoform a continuous rod which is then cutat regular intervals.

One aspect of the present invention provides apparatus for producing filler material, comprising means for conveying a substantially continuous first stream of long filaments, means for engaging said stream and for breaking the filaments into relatively shorterfilaments of irregular lengths, said engaging means including a conveyor having a surface adapted to engage said filaments and meansfordriving the conveyor such thatthe filaments of the stream are engaged bythesurfaceandbroken into irregular lengths by tension applied to the filaments, means for conveying a carrierstream of filaments, and means for combining the broken filaments from said first stream withthecarrierstreamtoform a combined stream, said combining means including means for depositing said broken filaments on said carrier stream in substantially random orientations.The combined stream may befedto a rod-forming device in which the stream is laterally compressed and formed into a continuous rod. The conveyor surface preferably has sharp projectionsforengaging filaments, and a wall may be provided defining with said conveyor a channel through which filaments on said conveyor pass, said proiections extending across said channel substantiallyto said wall. The projections may be forwardly-inclined relative to the direction of move ment of theconveyorsurface. The conveyor could bea pin roller.

The combining means may include means for showeringthe brokenfllaments, and may include means for reducing the width ofthe stream on said band. The combining means could comprise pneuma tic means,which could supplya stream directlytoa rod-shaping device.

Wherethe apparatus is used forfilter production the conveying means forthe first or carrier stream could be adapted to feed conventional filtertow and include meansfor blooming the tow or it could include means forfibrillating a web of other filter material. At least two different streams may be fed to form the first stream and so be engaged by the conveyorto produce a mixture of broken filaments. There could bea plurality of said conveyors, and a common carrier stream so thatthe combined stream includes broken filaments from at least two different conveyors. The carrier stream itself may comprise two or more combined streams. The first and carrier streams may, therefore, each comprise several different filter materials (from different forming streams).In any eventthe first and carrier streams may comprise the same or differentfilter materials.

Fluid additive, such as plasticiser, where required, could be applied to either or both streams, e.g. in the case of the first stream before the filaments are broken, or bythe conveyorwhich breaksthefila- ments, or in the case of the carrier stream, before or after it received the broken filaments.

The first and carrier streams may be derived from a common stream, so that said stream is divided into a stream which becomes said first stream and passes to said conveyor and a stream which becomes said carrier stream.

Another aspect of the invention provided apparatus for producing filter rod, comprising means for producing a filler stream of relatively shortfilaments from a first stream of filter material, said producing means comprising means for feeding relatively long filaments of filter material and means for engaging the filaments and breaking them into shorterfilaments of irregular lengths, means for conveying a carrier stream of relatively long filaments of filter material, means for depositing the filler stream on the carrier stream so that the short filaments of the filler stream are arranged in substantially random orientations on the carrier stream, and means for forming continuous filter rod from the combined filler and carrier streams.

Alternatively the carrier stream consists of a fibrillated web offilter material.

Afurther aspect ofthe invention provides a method of producing filler material, comprising conveying a substantially continuous first stream of long filaments, engaging the filaments while conveying them in a substantially longitudinal direction and breaking them into relatively shorter filaments of irregular lengths, conveying a carrier stream of filler material, and depositing the short filaments from said first stream on said carrier stream in substantially random orientations to form a combined stream.

The invention will be further described, by way of example only, with reference to the accompanying diagrammatic drawings, in which; Figure lisa side view of part of a machine for producing filter rod; Figure 2 is an enlarged section of a portion of a pin roller in a plane normal to the axis ofthe roller; Figure 3 is an elevation on an enlarged scale of part of the surface of the roller of Figure 2, Figure 4 is a plan view of a modification of the machine of Figure 1; Figure 5 is a side view of another modification of the machine of Figure 1; Figure 6 is a side view of another machine for producing filter rod; Figure 7 is a side view of a further machine for producing filter rod; Figure 8 is an enlarged sectional view of a modification ofthe machine of Figure 6 or Figure 7; and Figure 9 is a side view of a still further machine for producing filter rod.

Figure 1 shows crimped filter tow 10 being fed downwards between rollers 11 and 12 and then between rollers 13 and 14which rotateata higher speed than the rollers 11 and 12 so as to stretch the tow. lfthetow 10 is uncrimped the rollers 11, 12 are unnecessary. On leaving the rollers 13 and 14, the tow is caught by pins 15 on the periphery of a roller 16 rotating at a high speed, e.g. approximately 5000 R.P.M. or generally within the range 1000 to 8000 R.P.M.

The pins 15 ofthe rollerl6engagethe monofila mentsofthefiltertowand breakthem into portions of various lengths which are initially conveyed further by the roller 16 before being delivered into a downwardly extending duct 17. The periphery ofthe roller may, as shown, be formed with approximately radial passages 18through which air is blown outwards from a manifold 19 to assist in removing the filaments from the roller; alternatively, air at atmospheric pressure may be admitted into the manifold 19 and may be displaced through the passages 18 by a centrifugal pumping action. Inthe upperregion ofthe roller 16, there may be suctionto help in pulling thefibres onto the roller.

On leaving the roller 16,the broken filaments are randomly orientated. They are subsequently deposited on a carrier stream moving on the line 20, as described with reference to Figures 5-9.

We have found by experiment that a pin roller is a particularly effective and reliable means of breaking up continuous monofilaments of filter tow so asto produce a stream of randomly orientated filaments.

Our experiment was carried out with a typical crimped filtertow of cellulose acetate. Although the crimping is assumed to assistthe pins in gripping the filaments so as to break them, we envisage that it will be possible to use filaments which are crimped less than is desirable in the case of conventional filter manufacture, and possibly not at all. Reduced crimping, orthe elimination of crimping, would reduce the costs ofthe initial filtertow material.

Thetowfeed, including the rollers 11 to 14, may take various known forms. One example is described in United States Defensive Publication T 941011, which is referred to in its entirety. The tow feed may in general include means for "blooming" the tow pneumatically in any known manner. Also there may be means for applying plasticiser, e.g. in any known manner; alternatively, plasticiser may be blown out through the passages 18 orotherwise applied afterthe tow has reached the roller 16 and at least partially been broken. A basictowfeed arrangement which may be used is shown diagrammatically in U.S. Patent No 3658626; in this connection it should be noted that other details described in that U.S. patent and in the related U.S.Patent No.3377220 (apart from the tow chopping arrangement) may be employed in carrying outthe present invention; for example, a non wrapped filter rod may be produced in the manner described mainly in U.S. Patent No 3377220.

The rollers 11 to 14shown in Figure 1 (or one roller of each pair) may be axiallyfluted or may be rubber-coated so as to grip the tow or may be conventional so-called threaded rollers having circumferential grooves.

It should be noted that a curved wall 45 forming an extension of one wall ofthe duct 17 passes around the roller 16 and together with a curved wall 25 around the roller 13, forms a scraper 26 which helps to ensurethat the broken filaments oftowcontinue on the roller 16, ratherthan passing round the roller 13. The wall 25 is mounted as close as possibletothe rolleri3forthat purpose, allowing only running clearance.

The tips of the pins 15 on the roller 16 are as close as possible to the surfaces ofthe roller 13 and 14, again allowing just running clearance.

Figure 2 is an enlarged section of part ofthe perpheral portion ofthe drum 16, showing one ofthe pins 15 and one ofthe radial passages 18. In particular, it shows that each ofthe pins 15 forwardly inclined.

Not only is the axis ofthe pin inclined to a radius ofthe roller, but the front face of the tapered outer end ofthe pin is preferably inclined to a radius at that point by an angle or (alpha) which is preferably approximately 10 to 15 degrees but may generally be within the range 5 to 40 degrees. The passage 18 is shown radial, but it may instead be inclined atthe same angle asthe axis ofthe pins.

The roller itself may be of aluminium. Within a peripheral portion 16Aofthe roller 16there is preferably a moulded sleeve 1 6B of plastics material in which the inner ends of the pins are encased as shown in Figure 2.

Figure 3 shows one preferred arrangement ofthe pins and air passages in the periphery ofthe roller 16.

The pins lie in rows 27 which are inclined by a small angle to their direction of movement (shown by the arrow 28). Furthermore, the pins within adjacent rows are staggered with respect to one another. This, coupled with the high speed of rotation of the roller, helpstoensurethatnofilamentcan movefromany significant distance around the roller 16without being engaged by one of the pins. On each side ofthe roller there is a flange 1 6C (only one of which is shown) which projects radially so that its surface is flush with the tips ofthe pins. The width of the roller 16 (between theflanges) may be approximately 200-250 mm to accommodate the normal width ofthespread stream of filtertow.Alternatively the tow stream fed to the roller 16 could be narrower so thatthe roller need not be as wide as this; the roller and stream could be as narrow as 25-100mm.

As an idea of scale (but by way of example only) the roller 16 shown in Figure 1 has a diameter of 120 mm.

The pins 15 project3 mmfromthe the peripheral surface ofthe roller and are spaced apart in the tows 27 (Figure 3) at intervals of 7 mm.

The average length ofthe broken filaments leaving the roller 16 will generally depend upon the speed of the roller 16 in relation to that ofthe tow 10, on the density of pins on the roller, on the strength of the monofilaments, and on the friction between the filaments onthe one hand andthe pins and roller surface on the other hand. In a testwhich we performed, using tow of average denier, e.g. total denier 40-50,000 and 3-4 denier perfilament,the broken filaments were between about 6 mm and about 60 mm long.

Figure 4shows a conveyor band 40 onto which fibres are delivered over an area 41, and side bands 42 and 43 which converge while moving in the same direction as the band 40 so as to gather in the fibres. A narrow stream 44 of randomly orientated fibres is thus produced and is fed to a rod-forming device (not shown). In place ofthe converging bands 42 and 43, there may be converging fixed side walls.

The band 40 may be porous and suction may be transmitted th rough it from below so asto grip the fibres on the band where appropriate. For example, in Figure 4, the suction chamber may be tapered so that its sides correspond to the converging bands 42 and 43.

In the absence of converging bands 42 and 43, there may be converging air pressure manifolds, above the band 40 or below it, from which air jets are directed inwardsto displace the fibres towards the centre of the conveyor 40 as they move on the conveyor.

Alternatively, other means may be provided for gathering in a relatively wide stream of fibres to produce a narrowstream such as can be compressed readilytothe cross-section of a finished cigarette filter e.g. as described in U.S. Patent No.3548837.

Another possibility is that the broken fibres delivered bythe roller 16may be showered and formed into a narrowstream in the manner of a cigarette makig machine, ag.the Molins Mark 6, 8 or 9 machine, the Hauni Garant machine or the SASIB:SIG MA machine. Other possible ways of collecting the stream offibres are as disclosed in British Patent Specification No. 2048968. If the fibres are sufficiently short, it mightbe possible to trim the stream (as practised in modern cigarette making machines) before delivering the stream to a rod-forming device.

[nstead of gripping the broken fibres by the action of suetion appliedthrough it, the conveyor40 maybe electrostatically charged to grip the fibres where necessary.

Another possibility is that the fibres leaving the roller 16 may enter through the side of a horizontally extending pipe through which air is blown to propel the fibres, e.g. directly into the rod-forming device.

The air may be blown obliquely into the pipe so as to produce a vortex tending to roll the stream of fibres.

This arrangement is indicated in Figure 5, which shows a modified arrangement in which the rollers 11-14 of Figure 1 are replaced by a single roller 50 placed in a similar position to the roller 13 and cooperating with an opposed guide 52 which is connected to a rear wall 54 surrounding the pin roller 16. Part of the guide 52 converges towards the roller 50 and serves to guide the tow stream 56 onto the roller.

Downstream of this part, adjacent its connection 58 to the wall 54, the guide 52 follows the periphery of the roller 50 and defines a lead-in channel 60forthe pin roller 16. As compared with the Figure 1 arrangement the tow is more restricted at the position of initial contactwith the pin roller 16; this may havethe advantage that shorterfibres can be produced. As with the Figure 1 arrangement the clearance allowed forthe pins 15 (by the walls 45, 54 and roller 50) is minimal. A substantially horizontal pipe 132 extends belowthe chute 134 and includes oblique air inlets 136. The stream thus produced is delivered to a rod-making unit 138 on a carrier stream 140 of suitable filter material.

Figure 6 shows a bale 62 of crimped filtertowfrom which a continuous stream 63 is drawn by pretension rollers 64 and stretching rollers 66. A banding jet 68 is provided upstream ofthe rollers 64 to spread the tow.

Downstream of the rollers 66 a further banding jet or jets 70 are arranged to split the tow into two streams 72,74.This may be achieved by directing the jet or jets 70 so thatthe stream 63 is laterally split. The main stream 72, which preferably comprises at least 70% of the tow in the stream 63 is directed upwards over a roller76 and into a funnel-shaped transport jet 78 into which air is blown to conveythe tow onto the periphery of a pin roller8O.Thetransportjet78 may be similarto that disclosed in British Patent Specification No 1588506 or in U.S. Patent Specification No 3106945. The pin roller 80 acts on the tow stream 72 and projects a stream of broken fibres into a chute 82 in a mannersimilartothe pin roller 16 of Figure 1.

The stream 74 comprising a part ofthe stream 63 after splitting by the banding jets 70 is conveyed forward (by downstream rollers 84) in substantial alignment with the stream 63 and passes directly beneath the chute 82. Additional banding jets 86, acting on the stream 74 may be provided for controlling its width prior to passage beneath the chute 82. The arrangement is such that the shower of broken fibres descending from the chute 82falls on the banded tow stream 74which subsequently acts as a carrierforthose fibres. A conveyor band 88 could be provided to supportthe stream 74.

Afterthe fibres from the pin roller 80 have been showered onto the carrier stream 74 both the fibres and the stream are passed through a plasticising chamber 90. Subsequently the plasticised stream and fibres are passed to a filter rod making unit 92 which formsfilter rods 94. In the filter rod making unit 92 continuous filter rod is formed, which may be wrapped or unwrapped, as before. The rod shaping means in the unit 92 may be such that the carrier stream 74 is wrapped around thefibres rather in the mannerthatthe paper wrapper is wrapped around a filler stream in a conventional rod forming unit. The rod 94 may therefore comprise a central core of broken filaments from the stream 72 encased in an annular sheath including the stream 74.

Figure 7 shows another machine for producing filter rod, including a pin roller 96 and chute 98 which are similarto the pin roller 80 and chute 82 ofthe machine of Figure 6. A transport jet 100, which may be similar to the jet 78 of Figure 6, is also provided. Atowstream 102 for delivery to the transport jet 100 is conveyed by rollers 104 from atow bale (not shown). The rollers 104could correspond to the roller 66 of Figure 6. The stream 102 passes through a plasticising chamber 106 before reachingthetransportjet 100.

The brokenfibres issuing from the chute 98 fall onto a carrier stream 108 comprising fibrillated sheetfilter material. Acontinuous web of the sheetfilter material is withdrawn from a reel 110 by rollers 112 and 1 t4, between which the tension in the web is controlled. A fibrillating roller 116, preferably rotating at relatively high speed, makes a series of discontinuous slits in the web to form numerous substantially parallel fibres.

The roller 116 may be a pin roller substantially similarto the pin roller 16. Otherways offibrillating a web of material are disclosed in British Patent SpecificationsNos. 1073741, 1244982,1298561, 1421324,1421325,and 1440111,andin U.S. Patent Specifications Nos. 3474611 and 3675541.

After fibrillation the stream 108 passes through a plasticising chamber 118 and beneath the chute 98 from which it receives the showered fibres from the stream 102. Subsequently the stream 108 and conveyed fibres are formed into a continuous rods in a rod making unit 1 20,which may be similarto the unit 92, and cutto produce filter rods 122.

The filter material ofthe reel 110 may be substantiallysimilarto that ofthe stream 102 or may be different.

Thus both streams 102 and 108 may be cellulose acetate, the stream 102 normally being in fibrous tow form and the stream 108 being initially in sheetform.

However, one or both streams 102,108 could be of alternative plastics filtering material, e.g. polypropylene, in which case plasticising is normally unnecessary. Where plasticising is necessarythis could be carried out downstream ofthe position where the broken fibres are fed onto the stream 108, i.e. in a similar position tothe chamber90 of Figure 6.

Similarly, in the Figure 6 machine, the chamber90 could be replaced with separate devices acting on the respective streams 72,74 or even with a device acting upstream of the splitting banding jets 70. Even where plasticising would normally be necessary on materials ofthe kind used for both the carrier and the broken fibres such plasticising may not be necessaryfor either the carrier or the filter since sufficient plasticiser to create a stable rod or otherwise modify the filter material could be supplied either two said carrier or said filler. Possibly some migration of plasticiser may take place within the stream before final curing.

The plasticising chambers 90, 106, 118 could be substantially similarto conventional plasticising chambers, in which plasticiser is usually sprayed, e.g.

as used on theAMCEL 103 tow unit, but could be of otherforms. For example the plasticiser may be foamed for application to the tow or otherfibres substantially as a stream offoam. This could be particularly usefulfor preserving or creating coherence in a stream of broken fibres.

In the Figure7 arrangement an additional treatment station may be provided to produce crimp in the fibrillated web. This station may be located at or adjacentthe chamber 118 and may include means for treating opposite sides of the web in different ways, e.g. with different fluid additives or amounts thereof, so thatthe filaments produced by fibrillation become crimped. Plasticising, if necessary, could than take place downstream of this additional treatment station, and could be performed after showering from the chute 98 has taken place.

The carrier stream 108 could comprise a conventional tow stream. The reel 110 would be replaced buy a tow baleandthetow bloomed in conventional manner. The filter material in thetowstream 102 may be different from that in the stream 108.

Figure 8 shows in cross-sectional view a banding jet 124 comprising an annular passage 126 along which a tow stream 128 may be conveyed whilst subjected to the action of banding air streams, introduced for examplethrough ports 130.Thearrangement is such thatthe stream 128 is spread around the passage 126 so that it assumes a U-shape. The banding jet 124 could comprise a progressive change in shape from a conventional flat configuration tothat shown in the drawing, so that the stream 128 is initially spread out in substantiallyflat plane.Having obtained a Ushaped tow stream 128 this can advantageously be used as a carrier stream for broken tow fibres showered onto it, (or otherwise delivered onto it). For example, a banding jet 124 could be located downstream ofthe jet 86 in Figure 6 to act on the stream 74.

Similarly a guide similarto the banding jet 124 could beprovidedtopreshapeappropriatelythestream 108 in Figure 7.

In order to improve the filtering characteristics of the completed filters, an additional filtering material may be added to the stream of randomly orientated fibres used to produce the filter rod. For example, particles of carbon or other filtering material may be sprinkled on to the stream offibres, by a unit 142 as indicated in Figure 1 for example.

Another possibility is that broken fibres of a different material may be included with the cellulose acetate fibres. For example, the different material may comprise fibres of plastics material or of carbon, carbon based or carbon carrying material, the carbon in each case being preferably activated. Such material may be fed as continuous fibres and may be brokenup randomly by being fed to the roller 1 6 together with the cellulose acetatefibres, or by being fed a separate roller corresponding to the roller 16. In either case, the fibres of additional material are preferably broken up randomly and are fed in random orientations into ortogetherwith the cellulose acetate fibres.

An arrangement including two pin rollers 144,146, each similarto the roller 16, is shown in Figure 9. Afirst stream 148 offibrous filtering material is fed to the roller 1 44togetherwith a second stream 150 of a different fibrous filtering material, so that a mixture of broken fibres from the two streams is deposited on a band 152 belowthe rollertoform a carrier stream 151.

The band 152 passes beneath the other pin roller 146 to which a third stream 154 of a different fibrous filtering material is supplied, so that at its downstream end the band 152 carries a stream 156 of broken fibres oftheth ree different filtering materials,fordeliveryto a rod-making unit 158. The band 152 may be supplied with suction or other means to ensure positive conveyance ofthe stream.

In the machine shown in Figure 9 driving means 160, 162 for the respective pin rollers 144,146 is indicated diagrammatically. This may take any convenient form and may, for example, comprise separately controlled motors or chain and sprocket connections to a main motorforthe rodforming unit 158. It will be understood that driveforthe rollers 16 (Figures 1,5), 80 (Figure 6), and96 (Figure 7) may be derived in a similar way.

As a means of controlling the filter manufacturing operation, the resultant filter rod orthe stream of fibres used to form it may be continuously monitored asto its weight, for example by means of a nucleonic scanning device. In response to a signal from the nucleonic orotherweight monitoring device, the rate at which the continuous cellulose acetate fibres is fed towards the pin roller 16,forexample, may be automatically controlled so as to maintain the weight per unit length of the completed filter rod substantially constant. Alternatively, or additionally, where trimming ofthe stream of broken fibres is provided,the signal may be similarly used to control the trimming device.Particularly where impregnation offluid additive has alreadytaken place, however, this may result in rapid fouling ofconvenitional trimming devices; an acceptable alternative would be to use a high speed air stream or other trimming device which does not directly contact the stream.

The material from which the broken fibres are produced need not be cellulose acetate tow. Thus, any ofthearrangementsshownin Figures 1,4-7, or9 could be supplied with alternative material capable of being fed as a substantially coherent stream but separable into fibres or particles. For example, any of the streams 10,63,102,148,150,154 could be fibrillated webs of cellulose acetate or other suitable material. Anothersuch alternative material is foamed sheet material, e.g. foamed cellulose acetate or, more generally, foamed or filler material having filtering properties, e.g. polypropylene. Thus polypropylene or other plastics material in suitable form (e.g. fibrous, possibly produced by fibrillating basic sheet material which mightbefoamedorfilled) orcarbonfibres might be used instead of (or in addition to) cellulose acetatetowfor production of broken fibres or particles.Asuitable material is a filled polypropylene marketed by the Shell Chemical Company underthe trade mark CARIFIL. The action of a pin roller such as the roller 16 on such a material is to produce randomly orientated particles ofvarying length in a similar mannerto that produced with conventional tow. The stream 102 could be supplied from a reel similartothe reel 110 and could comprise a flattened foam web of suitable material.

Claims (25)

1. Apparatusfor producing filler material, comprising means for conveying a substantially con tinuousfirststreamoflongfilaments, meansfor engaging said stream and for breaking the filaments into relatively shorterfilaments of irregular lengths, said engaging means including a conveyor having a surface adapted to engage said filaments and means for driving the conveyor such that the filaments ofthe stream are engaged by the surface and broken into irregular lengths bytension applied to the filaments, meansforconveying a carrier stream of filaments, and meansfor combining the brokenfilamentsfrom said first stream with the carrier stream to form a combined stream, said combining means including means for depositing said broken filaments on said carrier stream in substantially random orientations.

2 Apparatus according to claim 1, including means for feeding the combined stream to a rodforming device in which the stream is compressed and formed into a continuous rod.

3. Apparatus according to claim 1 or claim 2, wherein at least one of the means for conveying the first stream and the means for conveying the carrier stream includes meansforopening afiltertow.

4. Apparatus according to any preceding claim, wherein at least one ofthe means for conveying the first stream and the means for conveying the carrier stream includes means forfibrillating a continuous web of filter material.

5. Apparatus according to any preceding claim, including means for conveying a common stream of filamentary material and for splitting said stream to form said first stream and said carrier stream.

6. Apparatus according to claim 5,whereinthe splitting means includes means for pneumatically separating said common stream.

7. Apparatus according to any preceding claim, wherein said meansfor conveying the carrier stream includes means for conveying asubstantiallycon- tinuousstream, means for engaging thefilaments of the stream and for breaking them into irregular lengths, and means for conveying the carrier stream as broken filaments.

8. Apparatus according to any preceding claim, wherein at least one of said means for conveying the first stream and said means for conveying the carrier stream includes means for receiving and conveying two streams of different filler material.

9. Apparatus according to any preceding claim, wherein the depositing means includes means for projecting broken filaments from the conveyor sub stantially in random orientations.

10. Apparatus according to claim 9, wherein the broken filaments are showered onto the carrier stream.

11. Apparatus according to claim 10, including pneumatic means for directing filaments onto the carrier stream.

12. Apparatus according to any preceding claim, including means for applying a solid orfluid additive to at least one of said streams.

13. Apparatusaccordingto any preceding claim, wherein said conveyor has sharp projections for engaging the filaments.

14. Apparatus according to any preceding claim, wherein apertures are provided in said conveyor surface, including means for blowing airthrough the apertures to propel filaments away from the surface.

15. Apparatus according to claim 14, including means for applying a treating fluid to the filaments through said apertures.

16. Apparatus according to any preceding claim, including means for shaping the carrier stream so as to confine at least pa rtially the broken filaments.

17. Apparatus according to claim 16, wherein the shaping means comprises pneumatic guide means.

18. Apparatus according to claim 17, wherein the pneumatic guide means is arranged so that the carrier stream is progressively wrapped around the broken filaments.

19. Apparatus according to any preceding claim, wherein said conveyor is arranged such that filaments of said first stream engaged by said surface are moved substantially in a longitudinal direction of said surface.

20. Apparatus according to any preceding claim, wherein said conveying means forsaid first stream includes meansforcontrolling the speed ofthefirst stream upstream of said conveyor.

21. Apparatus for producing filter rod, comprising meansfor producing a filler stream of relatively short filaments from a first stream offilter material, said producing means comprising meansforfeeding relatively long filaments offilter material and means forengaging thefilaments and breaking them into shorterfilaments of irregular lengths, means for conveying a carrier stream of relatively long filaments of filter material, means for depositing the filler stream on the carrier stream so thatthe short filaments of the filler stream are arranged in substantially random orientations on the carrierstream, and meansfor forming continuous filter rod from the combined filler and carrier streams.

22. Apparatus according to claim 21, including means for diverting part of the first stream to form the carrier stream.

23. A method of producing filler material, comprising conveying a substantially continuous first stream of long filaments, engaging the filaments while conveying them in a substantially longitudinal direction and breaking them into relatively shorterfilamentsof irregularlengths, conveying acarrierstream of filler material, and depositing the shortfilaments from saidfirststream on said carrier stream in substantially random orientations to form a combined stream.

24. Apparatus according to claim 1 andsubstan- tially as herein described with particular reference to the accompanying drawings.

25. A method according to claim 23 and substantiallyas herein described with particular reference to the accompanying drawings.