Method and apparatus for shaping substantially flat continuous material

Abstract

The apparatus for shaping substantially flat continuous material comprises a shaping device (500) for gathering substantially flat continuous material transverse to a longitudinal direction of the continuous material to form a gathered continuous material. The apparatus further comprises a cooling device (75) for cooling the gathered continuous material. The shaping device and the cooling device are combined such as to immediately cool the gathered continuous material.

Claims

1. Apparatus for shaping substantially flat continuous material having a glass transition temperature of below 150 degree Celsius, the apparatus comprising: a shaping device for gathering substantially flat continuous material transverse to a longitudinal direction of the continuous material to form a gathered continuous material, the substantially flat continuous material having a glass transition temperature of below 150 degree Celsius; a cooling device for cooling the gathered continuous material, wherein the shaping device and the cooling device are combined such as to immediately cool the gathered continuous material, wherein the shaping device comprises at least a static shaping element, static with respect to a transport direction of the substantially flat continuous material, wherein the static shaping element is a garniture tongue for shaping a rod-shaped gathered continuous material, wherein the cooling device is arranged next to an outlet opening of the garniture tongue, wherein the cooling device comprises a contact surface for contacting and thereby cooling the rod-shaped gathered continuous material, and wherein the contact surface has a concave shape and the shape of the contact surface varies along the length of the cooling device; wherein a further static shaping element is provided, which further static shaping element is constructed as at least one structured surface, wherein the structure has a longitudinal extension in a transport direction of the substantially flat continuous material.

2. Apparatus according to claim 1, wherein the contact surface of the cooling device has a longitudinal concave shape.

3. Apparatus according to claim 1, wherein the shaping device comprises a dynamic shaping element capable of performing a movement in a transport direction of the substantially flat continuous material.

4. Apparatus according to claim 3, wherein the dynamic shaping element comprises at least one pair of shaping rollers, the shaping rollers of the pair of shaping rollers being rotatable in a transport direction of the substantially flat continuous material and having circumferentially arranged structures on a periphery of the shaping rollers.

5. Apparatus according to claim 3, wherein the shaping device comprises a conveyor unit for shaping the substantially flat continuous material into a round shape, the conveyor unit comprising at least two subsequently arranged dynamic shaping elements in the form of at least two gathering rollers having a rotational axis perpendicular to a transport direction of the substantially flat continuous material and having a circumferentially running groove for moving the substantially flat continuous material in the grooves and between each of the gathering rollers and an oppositely arranged guide element, wherein the at least two gathering rollers with oppositely arranged guide element are arranged at a distance to each other along the transport direction of the substantially flat continuous material.

6. Apparatus according to claim 5, wherein the guide element is provided with a groove having a form corresponding to a form of the groove of the oppositely arranged shaping roller.

7. Apparatus according to claim 1, further comprising a parting unit for creating an open channel in the gathered continuous material, the parting unit comprising a parting element, which is arranged relatively movable to a transport direction of the substantially flat continuous material and such as to extend at least partly into the gathered continuous material.

8. Apparatus according to claim 7, wherein the parting unit is arranged between the at least two subsequently arranged dynamic shaping elements, preferably between at least two subsequently arranged gathering rollers.

Description

(1) The invention is further described with regard to embodiments, which are illustrated by means of the following drawings, wherein:

(2) FIG. 1 shows a schematic overview of an embodiment of a filter making apparatus;

(3) FIG. 2 illustrates a static shaping device with cooling device;

(4) FIG. 3 shows a detail of the cooling device of FIG. 2;

(5) FIG. 4 shows an exploded view of a static shaping device with integrated cooling;

(6) FIG. 5 is a series of cross sections through the shaping device of FIG. 4;

(7) FIG. 6 shows a structured surface of the shaping device of FIG. 4;

(8) FIG. 7 shows a dynamic shaping device comprising shaping roller pairs;

(9) FIG. 8 shows a conveyor unit comprising pairs of gathering rollers;

(10) FIG. 9, 10 is a side view and a cross sectional view of a parting unit;

(11) FIGS. 11-13 show a dynamic insertion unit and details of the insertion unit;

(12) FIG. 14 shows a combination of shaping devices.

(13) In the filter making apparatus schematically shown in FIG. 1, a substantially flat continuous material such as a web of material 1 is provided on a bobbin 10. When unwound from the bobbin 10, the web 1 is crimped, gathered and cooled and wrapped in the apparatus. In this embodiment, the web 1, for example a polylactic acid (PLA) film, passes a corona module 2 directly after having been unwound from bobbin 10. In the corona module 2, both sides of the web 1 are subsequently corona treated in two corona module portions 21,22. Corona treatment enhances wettability of the web 1 with an adhesive for improving anchoring of the folded web in its wrapper. After corona treatment, the web 1 passes a crimping device 4, for example a set of two crimping rollers. The crimping device 4 provides the web with a crimping structure, for example with substantially parallel corrugations running, preferably, in longitudinal direction of the web, that is, in transport direction of the web 1. The crimping rollers may be cooled. The web 1 then passes a shaping device 5. The shaping device 5 comprises shaping rollers 50, preferably providing the crimped web 1 with a longitudinally running wave-like macro structure overlaying the crimping micro structure. Imposing the overlaying macro structure onto the web 1 causes the web 1 to be pushed together in a transverse direction of the web 1. In addition, a gathering of the web 1, for example into a rod shape, is supported by the longitudinal wave-like structure and may be performed in a more controlled manner. The shaping device also comprises a funnelling device 51 arranged downstream of the shaping rollers 50. In the funnelling device 51, the web 1 is further shaped into rod-shape, for example by gathering or pushing together. The shaping device 5 or parts of the shaping device are cooled. Preferably, when leaving the funnelling device 51, the web 1 has not yet achieved its final form, or is not entirely gathered, respectively. This facilitates the introduction of an object, such as for example a capsule or flavoured thread 71, into the endless rod of web material. A flavour application system 7 comprising an endless thread 71 and a flavour reservoir 72 is arranged downstream of the shaping device 5. The thread 71 is mounted on a bobbin 70. Preferably, the flavour reservoir 72 contains menthol. The thread 71 is unwound from the bobbin 70 and entrained with flavour before being transported to the gathered web 1. The flavour application system 7 may be provided with at least one of a flow meter, a valve, a temperature control and a pump for control of a defined amount of flavor to be applied to the thread 71. The flavour application system 7 is arranged above the web 1 in order for gravity to support the introduction of the thread into the web. Gravity may also support a flow of flavouring liquid along the thread 71. Alternatively, or in addition, flavour may be added separately from the thread 71 or may be entirely omitted. In that case, the presence of the thread may have mostly an aesthetic contribution to the aerosol-generating article.

(14) An endless wrap material 6, for example paper, is provided on a bobbin 60 and supplied from below the endless rod such that the endless rod of web material comes to lie on the wrap material 6. The wrap material 6 runs parallel to the endless rod when being joined with the rod. Before the wrap material 6 and the endless rod are joined, the wrap material is provided with glue. A glue reservoir 62 is in fluid connection with a seam nozzle 64 as well as with an anchor nozzle 63. Glue from the glue reservoir 62 is transported via a glue conduit, for example a tube, to the anchor nozzle and the seam nozzle. With the anchor nozzle 63, anchoring glue is applied to the wrap material such that the wrapper may securely be glued to the web material. With the seam nozzle 64, seam glue is applied to the wrap material 6, for gluing the wrap material to itself after the wrap material has been entirely wrapped around the endless rod of web material. In this embodiment, the glue reservoir 62 contains a glue, which may be used for both the anchoring and the seaming of the wrap material.

(15) However, if different glue shall be used, a reservoir each for the anchoring and for the seaming may be provided. Different glues may be advantageous, for example, if a wrap material is a paper wrapper and paper glue shall be used for the seam and if, for example, specific plastics glue shall be used for the anchoring of the wrapper to a plastics web material of the endless rod. Also, glues may vary with respect to the setting time for the glue. For example a polyurethane glue and a hot-melt glue may be used for different purposes.

(16) The wrapped endless rod of web material may be guided in a rod-shaped bed 52 passing a heating device 53 for heating the wrapped endless rod. The heating facilitates a distribution and fast drying of the glue. After the endless rod has been formed, it is cut in the cutting device 8 into rod segments of predefined length, for example single or double length segments (having the length or the double length of a final product). The cutting device or a cutting knife of the cutting device may be cooled. The rod segments may be transported to a tray or storage 91. The rod segment may also directly be transported to a combiner 92 for being combined with further elements, for example further filter elements or segments of, for example, aerosol generating articles.

(17) An online control unit 90 is provided after the endless rod has been cut into segments for a quality control of the manufactured segments. At the location of the tray 91, there may be provided an offline control unit 93. An online control unit 90 and offline control unit 93 may, for example, include a length control, diameter control, a weight control, ovality control, control for a resistance to draw (RTD), the thread centering and other visual quality aspects of the semi-finished or finished good. The offline control unit 93 may for example also be provided with a measuring device for a menthol content or other substances in the rod segment. In the tray 91, the segments may be labelled, for example with a batch number, production date or product code, for example, for tracking of the products.

(18) Preferably, tension rollers 30 and driving rollers 31 are provided in the apparatus for a controlled transport of the web of material 1 and a continuous, preferably constant, tensioning of the web. Synchronization means may be provided between crimping device 4 and a transport means such as a continuous belt, for example, at the position of the online control unit 90. By the synchronization means a linear speed of the endless rod and of the yet to be gathered substantially flat continuous material fed into the crimping device 4 may be synchronized.

(19) FIG. 2 is an embodiment of a static shaping device 500 comprising a cooling device in the form of an intercooled finger 75. A garniture tongue 510 as known in the art for shaping the web 1 into a rod-shape has a cut end portion 511. The intercooled finger 75 is arranged directly adjacent to and aligned with the cut end portion 511 of the garniture tongue 510. The intercooled finger 75 is provided with a cooling surface 752 directly contacting the web guided within the shaping device.

(20) The intercooled finger 75 comprises a cooling fluid inlet 750 and a cooling fluid outlet 751 for guiding a cooling fluid, for example air or liquid, into the intercooled finger 75. Preferably, the intercooled finger 75 is made of a thermally conductive material such that at least the cooling surface 752 is cooled via heat conduction from the cooling liquid to the cooling surface.

(21) The cooling surface 752 has a concave shape such as to keep the web 1 in contact with the cooling surface 752 in the rod shape. As shown in more detail in FIG. 3, the shape of the cooling surface 752 varies along the length of the cooling device 75. The cooling surface 752 is provided with a narrowing radius of curvature versus a downstream end 7520 of the surface such as to further form the web 1 into a rod shape. The cooling surface 752 has a continuously diminishing height 7521 along the length of the cooling device 75. Thus, the cooling surface 752 is arranged askew relative to a horizontal support 110 relative to the transport direction of the web. The web 1 is guided continuously in the garniture tongue 510 and the cooling device 75. A support 110 the web 1 is guided along comprises a longitudinal groove 1100 in the form of a half circle for receiving the rod-shaped web.

(22) The cooling surface 752 may also have a constant shape and orientation along the length of the intercooled finger 75.

(23) FIG. 4 shows another static shaping device 501 with integrated cooling system. The shaping device 501 comprises an upper and a lower shaping plate 515,516. The shaping plates comprise a plurality of longitudinally arranged structures 519,520 in the form of ridges and valleys. The ridges and valleys converge versus a downstream end of the plates. The structures 519 in the upper shaping plate 515 correspond to the structures 520 in the lower shaping plate. A continuous web of material 1 transported between the two shaping plates 515,516, for example a PLA foil, is progressively provided with a macro structure corresponding to the structures of the plates. A cover plate 517 and a base plate 518, by which the shaping device 501 may be assembled are preferably cooled by a refrigerated liquid (not shown). Preferably, all plates are made of a heat conductive material, such that the web 1 may be cooled by heat transfer via the plates 515,516,517,518. Preferably, the temperature of a PLA web is kept below 50 degree Celsius, preferably, below 40 degrees, most preferably, below 30 degrees.

(24) Air slots 755 are provided in the back side of the shaping plates 515,516. In addition, several lines of air passage holes 756 are provided in the shaping plates as can be seen in FIG. 6. These lines of passage holes 756 are arranged at a distance to each other and transverse to the longitudinal structures 519,520 in the shaping plates 515,516. The air holes are in fluid communication with the air slots 755. Compressed air may be introduced into the slots 755 and made to pass through the holes 756 to support an entering of the PLA foil between the shaping plates 515,516. In addition, friction between the shaping plates and the web may be reduced and the web may additionally be cooled by the air.

(25) In FIG. 5 several cross sections 525-529 through the closed shaping plates 515,516 are shown. From top to bottom the cross sections refer to different longitudinal positions of the shaping plates 515,516 when seen in a transport direction of the web 1 (indicated by arrow). The structures 519,520 in the shaping plates 515,516 are more expressed in the center 521 of the plates than at lateral sides 522 of the plates. A height of the structure (ridges) continuously grows also towards a downstream direction. In this example, distances 530 between individual ridges or valleys remain constant.

(26) The individual cross sections 525-529 may also correspond to cross sections of a series of individual static shaping elements arranged distanced to each other along the transport direction of the web 1. Several individual static shaping elements allow for, for example, a cooling by ambient air in between the individual shaping elements.

(27) FIG. 7 shows a dynamic shaping device 502, wherein a plurality of shaping roller pairs are arranged parallel to each other. The individual roller pairs are distanced from each other along the transport direction of the web. Upper and lower shaping rollers 531,532 comprise circumferentially running structures 535,536 corresponding to each other. The structures 535,536 defined by discs arranged in parallel along a length of a roller are more expressed in the center of the roller than at the lateral edges of the roller. The center of a web (midline) guided in between the shaping roller pairs is shaped more in the center than at the lateral edges of the web. A height of the structure 535,536 is increasing with progressing shaping of the web. In this example, a distance 540 between individual structures (discs) is decreasing from a center to the lateral edges of the shaping rollers 531,532.

(28) The rollers 531,532 rotate along the transport direction of the web moving between the rollers, thus reducing friction between the rollers and the web. A cooling of the shaping rollers 531,532 may be provided.

(29) The dynamic shaping device 503 of FIG. 8 comprises three gathering roller pairs. The pairs are arranged at a distance to each other along a transport direction of the web 1. Each of the pairs comprises two gathering rollers 541,542; 543,544; 545,546 arranged opposite each other and such as to rotate along the transport direction of the web. The gathering rollers each have a groove 5420,5410;5440;5460,5450 arranged in their circumference. The gathering rollers have a rotational axis perpendicular to the transport direction of the web 1 such that the web is guided and gathered in and by the grooves of the gathering rollers 541,542; 543,544; 545,546 when passing through the shaping device 503. Preferably, the grooves 5420,5410;5440;5460,5450 of each roller pair have a similar shape. Preferably, the grooves of different pairs of gathering rollers have a different radius of curvature. The more downstream the roller pair the smaller the radius of curvature of the grooves. In an alternative embodiment, the grooves of different gathering roller pairs have an equal shape but the two gathering rollers of a pair are arranged at different distances between each other. In this alternative embodiment, the distance between gathering rollers of a roller pair arranged further upstream is larger than the distance between a pair of gathering rollers arranged further downstream.

(30) The grooves 5410,5420 of the first and furthest upstream pair of gathering rollers 541,542 have an oval shape, the grooves 5440 of the second and middle pair of gathering rollers 543,544 have a half oval shape and the grooves 5450,5460 of the third and furthest downstream pair of gathering rollers 545,546 have a semi-circular shape. By this, the web of material 1 is stepwise gathered to an oval shape 12a up to a rod shape 14.

(31) An auxiliary roller 548 is arranged upstream of each of the gathering roller pairs. The auxiliary rollers 548 are arranged above the web 1 and extend over the width of the web 1. The auxiliary rollers 548 support a positioning of the web for insertion into the dynamic shaping device 503, in particular into the grooves of the gathering rollers 541,542; 543,544; 545,546.

(32) One gathering roller 542,544,546 of each pair of gathering rollers may be movable in a sideway direction. This may facilitate insertion of the web 1 into the shaping device 503 and maintenance of the device. Also a distance between rollers of a pair may thus be varied.

(33) Some or all of the gathering rollers may be cooled.

(34) A parting unit 65 is arranged between the second and the third gathering roller pair. With the parting unit 65, the not entirely rod shaped web material 13 is parted for insertion of a flavouring object, for example a thread or a capsule (not shown). In FIG. 9 and FIG. 10, the parting unit is shown in more detail. Two parting rollers 650, 651 are rotatable in transport direction of the web 1. The parting rollers 650,651 have a rotational axis arranged parallel to the web, parallel to each other and perpendicular to the transport direction of the web 1. The parting rollers 650,651 have a concave shape as may be seen in the cross sectional view of FIG. 11. The upper parting roller 650 has a circumferentially running disc 652 arranged in the center of the shaping roller 650. The partially gathered web 13 is guided in and through the space 653 spanned between and by the two splitting rollers 650,651. Thereby, the disc 652 of the upper roller 650 is inserted into the web and opens a channel in the web. The space 653 between the parting rollers 650, 651 may be varied and fixed in a defined position by adjustment knob 655.

(35) FIG. 11 shows an embodiment of a dynamic shaping device 506. Preferably, the shaping device 506 is arranged downstream of further shaping rollers, such that the web 1 entering the dynamic shaping device 506 of FIG. 11 already has a rod form or nearly rod form.

(36) The shaping device 506 comprises two pre-shaping rollers 560,561. The pre-shaping rollers 560,561 are arranged and rotate in line with the web transported through the dynamic shaping device 506. As may be seen in FIG. 12, the more upstream arranged pre-shaping roller 650 is symmetric with respect to its shape contacting the web. The web 1 passing the symmetric pre-shaping roller 650 is guided in the concave shape of the circumference of the symmetric pre-shaping roller. As shown in FIG. 13, the more downstream arranged pre-shaping roller 651 is asymmetric with respect to its shape contacting the web. Only about a quarter of the circumference of the substantially rod-shaped web 14 is guided by the asymmetric pre-shaping roller 561, thus reducing the contact between roller and web.

(37) A support 567 is provided with a longitudinal groove 567 having a concave shape, wherein the substantially rod-shaped web is transported in. The support 567 also comprises a covering 566, partially covering the support and the web arranged in the groove. Preferably, the cover does not contact the web but serves as retaining element keeping the web in the groove 567.

(38) An adjustment knob 565 is provided for adjustment and setting of the pre-forming rollers 560,561 to a defined diameter value of the web passing through the dynamic shaping device 506. In addition, the dynamic shaping device 506 may be removed by loosening the adjustment knob 565. By this, material jam in the device may be removed in a fast and convenient manner.

(39) The dynamic shaping device 506 may comprise further pre-shaping rollers arranged downstream of each other in the transport direction of the web. The further pre-shaping rollers may be of symmetric or asymmetric shape. One, several or all pre-shaping rollers 560, 561 may be cooled.

(40) Preferably, the static shaping device 500 as shown in FIG. 2 is used as alternative to the dynamic shaping device 506 of FIG. 11.

(41) In FIG. 14 an exemplary combination of different shaping devices is shown. A web having passed schematically indicated crimping rollers 4 subsequently passes the static shaping device 500 and the two dynamic shaping devices 501 and 506. After leaving the most downstream shaping device 506, the web is supplied to the rod forming zone 52 which may be designed as known in the art and which is not further described. The web 1 is subsequently shaped into a rod shape by the shaping devices. Individual shaping device may be replaced by different shaping devices. For example, static shaping device 500 may be replaced by the dynamic shaping device of FIG. 7. Both shaping devices provide the web with a macro structure. The two dynamic shaping devices 500,501 may for example be replaced by the one static shaping device comprising a garniture tongue as shown in FIG. 2.