Apparatus and method for forming filter rods

Abstract

An apparatus for forming filter rods for aerosol-generating articles is provided, including a first source and a second source, the first source being configured to supply filter material in a form of a first tow, and the second source being configured to supply filter material in a form of a second tow; a single driven delivery roller configured to advance the first tow and the second tow; and an extrusion tool configured to process the first tow and the second tow, the delivery roller being arranged such that the first and the second tows are advanced from the first and the second sources toward the extrusion tool only by the delivery roller, and the extrusion tool is further configured to process several sources of filter material simultaneously to create one filter rod. A method for forming filter rods for aerosol-generating articles is also provided.

Claims

1. An apparatus for forming filter rods for aerosol-generating articles, the apparatus comprising: a first source and a second source, the first source being configured to supply filter material in a form of a first tow, and the second source being configured to supply filter material in a form of a second tow; a single driven delivery roller configured to advance the first tow and the second tow; and an extrusion tool configured to process the first tow and the second tow, wherein the delivery roller is arranged such that the first and the second tows are advanced from the first and the second sources toward the extrusion tool only by the delivery roller, and wherein the extrusion tool is further configured to process several sources of filter material simultaneously to create one filter rod.

2. The apparatus according to claim 1, further comprising a first non-driven aligning roller arranged to align the first and the second tows in the extrusion tool after the first and the second tows are advanced by the delivery roller.

3. The apparatus according to claim 2, wherein the first non-driven aligning roller and the delivery roller are arranged such that the first and the second tows are aligned in an s-shaped pathway.

4. The apparatus according to claim 1, further comprising second and third non-driven aligning rollers configured to align the first tow, wherein the second and the third non-driven aligning rollers are arranged to align the first tow before the first tow is fed into the delivery roller.

5. The apparatus according to claim 4, wherein the second and the third non-driven aligning rollers and the delivery roller are arranged such that the first tow is aligned and overlaying the second tow when advanced by the delivery roller.

6. A method for forming filter rods for aerosol-generating articles, comprising the steps of: (a) providing, by means of a first source, filter material in a form of a first tow, and, by means of a second source, filter material in a form of a second tow; (b) advancing the first tow and the second tow only by means of a driven single delivery roller; and (c) extruding the first tow and the second tow in an extrusion tool, wherein several sources of the filter material are processed in the extrusion tool simultaneously to create one filter rod.

7. The method according to claim 6, further comprising providing a first non-driven aligning roller and arranging the first non-driven aligning roller to align the first and the second tows in the extrusion tool after the first and the second tows are advanced by the delivery roller.

8. The method according to claim 7, further comprising arranging the first non-driven aligning roller and the delivery roller such that the first and the second tows are aligned in an s-shaped pathway.

9. The method according to claim 6, further comprising providing second and third non-driven aligning rollers configured to align the first tow, and arranging the second and the third non-driven aligning rollers so as to align the first tow before the first tow is fed into the delivery roller.

10. The method according to claim 9, further comprising arranging the second and the third non-driven aligning rollers and the delivery roller such that the first tow is aligned and overlaying the second tow when advanced by the delivery roller.

Description

(1) The invention will be further described, by way of example only, with reference to the accompanying drawing in which:

(2) FIG. 1 shows an illustrative cross-sectional view of the inventive apparatus for forming filter rods for aerosol-generating articles.

(3) The apparatus shown in FIG. 1 comprises a first source 1 and a second source 2. Both of these sources comprise filter material.

(4) Cellulose acetate may be employed as the filter material. For the purpose of providing uniform density and overall cohesive character to the filler, the filaments may be subsequently treated with a plasticizer to thereby promote interfiber bonding of the various filaments comprising the tow. The tow may be comprised of a plurality of filaments of cellulose acetate extending longitudinally and coextensively of the tow mass. The cellulose acetate may have a total denier of 25,000 to 75,000 but more preferably in the range of 30,000 to 50,000 the foregoing being based on a fiber denier of about 1 to 16 and preferably 3 to 6 denier. Other materials are suitable for use as filler and can include polyalkenes, polyethylene, and paper tows.

(5) As a preliminary to forming a filter rod, the filter material which is described in representative form as being a tow of filaments of cellulose acetate may be fed through a blooming and coating chamber (not shown) wherein the filaments may be coated with a plasticizer comprising by way of example, a solution of 3%-12% triacetin. The plasticizer may be employed to promote interfiber bonding in the tow at the points of crossing or contact of the respective fibers and thereby produces cohesiveness in the mass of the tow.

(6) The filter material is pulled from the first source 1 and second source 2. In this regard, a first tow 3 is pulled from the first source 1 and a second tow 4 is pulled from the second source 2. The provision of two sources is to be understood illustrative. Multiple sources and respective multiple tows may be employed in the invention.

(7) The first tow 3 and the second tow 4 are pulled by a single driven delivery roller 5. The delivery roller 5 may be driven by a conventional means such as an electromotor.

(8) The delivery roller 5 is arranged such that the first tow 3 and the second tow 4 are both pulled by the delivery roller 5 from the first source 1 and the second source 2. Thus, a uniform pulling action is performed by the delivery roller 5 with respect to the tows 3, 4.

(9) Before reaching the delivery roller 5, the tows 3, 4 are provided separate from each other and do not interact with each other. Upon reaching the delivery roller 5, the first tow 3 overlays the second tow 4 or the second tow 4 overlays the first tow 3. Thus, both tows, overlaying each other, are pulled by the delivery roller 5.

(10) After being pulled by the delivery roller 5, the tows are together delivered towards an extrusion tool 6. The extrusion tool 6 is provided as a conventional extrusion tool comprising a funnel-shaped entrance (not shown) and a barrel (not shown) for extruding the first tow 3 and the second tow 4 and to create a filter rod which can be used in an aerosol-generating article.

(11) After exiting the extrusion tool 6, the filter rod is conveyed by conventional conveying means 7 towards a filter making device (not shown).

(12) Between the delivery roller 5 and the extrusion tool 6, a first non-driven aligning roller 8 may be provided. As can be seen in FIG. 1, the first aligning roller 8 is arranged such that the combined tows form an s-shaped pathway between the delivery roller 5 and the extrusion tool 6. The s-shaped pathway guarantees a high contact area between the tows 3, 4 and the surface of the delivery roller 5. Also, the tows 3, 4 are straight delivered into the extrusion tool 6 along the extrusion axis, thereby preventing a disturbance of the tows 3, 4.

(13) To facilitate the separation of the first tow 3 and the second tow 4 before the delivery roller 5, a further second aligning roller 9 and a further third aligning roller 10 are provided between the first source 1 and the delivery roller 5. The second and third aligning roller 9, 10 facilitate the separation and proper alignment of the first tow 3 before the first tow 3 is fed towards the delivery roller 5. The second aligning roller 9 is displaced with respect to the pathway of the first tow 3 and the third aligning roller 10 so that the contact area between the first tow 1 and the second and third aligning roller 9, 10 as well as the delivery roller 5 is increased, thereby facilitating a safe aligning of the first tow 3 and an optimized pulling action of the delivery roller 5.

(14) The above described features with respect to the invention are to be understood illustrative. The skilled person understands that the above described features can be combined with each other within the scope of the invention.