FR2598102A1 - METHOD AND DEVICE FOR APPLYING FLUID MATERIAL TO A STRIP - Google Patents

Abstract

THE INVENTION CONCERNS THE APPLICATION OF A FLUID MATERIAL ON A TAPE CONSISTING THAT THE MATERIAL IS WITHDRAWN FROM A RESERVE 4, BY MEANS OF A ROTARY CONVEYOR WITH SAMPLE 7, IN THE FORM OF A LAYER AND TRANSPORTED TO TAPE 1 WITH A VIEW TO BEING TRANSFERRED TO IT, WHILE MATERIAL NOT TRANSFERRED TO TAPE IS RETURNED BY THE SAMPLE CARRIER TO THE RESERVE REGION; THE LAYER OF MATERIAL NOT TRANSFERRED AND RETURNED ON THE SURFACE OF THE SAMPLE CONVEYOR 7 IS TRANSPORTED THROUGH CHANNEL 11 THROUGH WHICH FRESH MATERIAL IS BACKFLOWED.

Description

1; Method and device for applying a fluid material to a

  The present invention relates to a method for applying a fluid material to a strip, in

  which the material is removed from a reserve, by means of a rotary pick-up conveyor, in the form of a layer and transported to the strip, and the material which is not transferred to the strip is returned, by the direct debit transporter in the reserve region.

  The invention further relates to a device for applying a fluid material to a strip, which comprises a rotary sample conveyor for removing a layer of material from a reserve, transporting the layer of material & the strip and turning the material n 'not having

  been transferred to the band in the reserve area.

  The object of the invention is to improve the application of fluid materials, in particular liquids, to a strip by means of a method and a device of the kind mentioned above, such that in particular gaseous occlusions in material not transferred to the web and returned to the reserve area is disposed of before the pick conveyor removes

  a new layer of reserve material.

  This object is achieved according to the invention - as regards a method for applying a fluid material to a strip, in which the material is removed from a reserve, by means of a rotary pick-up conveyor, under the shape of a layer and transported to the belt, and the material not transferred to the belt is returned by the sample conveyor in the region of the reserve by the fact that along the layer of material not transferred and returned to the The surface of the sample conveyor is transported, in the opposite direction, a layer of fresh material. The non-transferred material can then be ment. As a pick-up conveyor, provision should be made in particular for a pick-up cylinder with which a metering roll can advantageously be associated in such a way that the slot thus formed between the two

  cylinders influences the thickness of the layer, that is to say it maintains this thickness as much as possible constant. In the immediate vicinity of the slot can then be provided a doctor blade bearing on the dosing cylinder and 10 serving & sealing the reserve.

  In the material which is not transferred to the strip and which is returned to the region of the reserve, there are frequently, particularly in the case of high viscosity of the material, gaseous occlusions, in particular of air, which during the removal of a new layer and / or the transfer of this layer on the strip can have disruptive effects. These air bubbles which, when particularly small, are also called micro-foam, can be eliminated in an expansion zone which, for an observer looking in the direction of transport of the

  transporter & removal, is arranged in front of the canal.

  This means that this expansion zone is located, with respect to the direction in which fresh material is forced through the channel and thus collects residual material, behind the channel so that, in particular at atmospheric pressure, the small gas bubbles can come together to form larger bubbles which are

  then removed from the material in the expansion zone.

  If the pressure to which the material in the supply is subjected is relatively high, then it is

  it is advantageous that the relaxation takes place from the reserve space to the relaxation zone in at least two steps.

  The first step can then take place in the channel according to the invention; for the remaining expansion from an intermediate reserve space 35 can serve another channel according to

  transported through a channel through which fresh material is forced back in the opposite direction (countercurrent).

  A preferred embodiment of the invention is that the material is removed by the surface of the sample conveyor, preferably a sample cylinder, and is transported to the belt and that non-transferred material is transported in the direction of the channel, the surface of the sample conveyor forming in O10 in this respect a surface limiting the channel. In this case, the material discharged in the opposite direction to the direction of movement of the surface of the sample conveyor and which risks containing at least part of the returned material can, according to a variant of the invention, reach a pumping equipment. which returns material to the reserve where the direct transporter withdraws material

in the form of a layer.

  If the material in the reserve, from which the sample conveyor removes material in the form of a layer, is kept under pressure, it is advantageous, according to a development of the invention, to reduce the pressure, through the channel by which material is forced backward as well as through at least one

  other channel, preferably at atmospheric pressure.

  As for a device which, for applying a fluid material to a strip, comprises a rotary sample conveyor for removing a layer of material from a reserve, transporting the layer of material to the strip and turning the non-transferred material over the 30 band in the region of the reserve the object of the invention

  is achieved by the fact that the surface of the sample conveyor forms with a boundary wall a channel whose inlet is contiguous to the pressure reserve, in such a way that material is discharged through the channel in the opposite direction to the direction of transport from transporter to sample

  the invention. In this case this other intermediate space can be sealed by means of another doctor blade taking

  support against the surface of the sample conveyor.

  The sampling cylinder can be produced in the form of an engraved cylinder, also called a screened cylinder, which, depending on the configuration in which liquid material is applied to the strip, has various profiles. As a result, we could call them

  cylinders also form cylinders.

  -The application device according to the invention can find a preferred use in a machine known as placement of filter tips in which tobacco sticks are joined, by means of glued cuffs, with filter tips to form cigarettes. 15 filter tip. For this a strip of covering paper, from which the sleeves are continuously detached, can be provided with liquid adhesive, preferably with an aqueous solution of polyvinyl acetate, by means of a device.

of application according to the invention.

  The advantage offered by the invention consists in that it makes it possible for small air bubbles, for example micro-foam, to harm neither the removal of a layer of material from the reserve by the transporter & removal or transfer of material onto the strip. In addition, there is no more or only a little old material left on the periphery of the sample conveyor when the latter removes new material from the reserve, so that in this respect an improvement is also obtained. The old detached material, from which the 30 small air bubbles can escape, may, if only because of their relatively small quantity, be

  added to the fresh material, if desirable.

  The invention is explained below in more detail with the aid of exemplary embodiments illustrated in the appended drawings in which: FIG. 1 represents an embodiment of the invention with pressure reduction in a single step between the reserve and relaxation area; FIG. 2 represents an embodiment of the invention with pressure reduction in two stages between the reserve and the expansion zone; FIG. 3 represents a cylinder engraved as a sampling cylinder; 4 shows, on a larger scale, O10 details of the profile of the cylinder according to arrows IV-IV of Figure 3; FIG. 5 shows another embodiment of an engraved cylinder as a sampling cylinder; FIG. 6 represents, on a larger scale, details of the profile of the cylinder according to the arrows VI-VI of FIG. 5; and Figure 7 shows, in an enlarged view, details of a device for sealing the surface of a shaped cylinder to prevent liquid material from

flow in the axial direction.

  In Figure 1 is shown an application device according to the invention. The fluid material, in particular liquid material, to be applied to a strip 1 in the form of a ru25 ban, which may for example be made of paper, cardboard, plastic material, textile material, fibers or the like, is supplied by a pump 2 via a supply conduit 3. In the end portion of the supply conduit 3 is formed a reserve 4 of material subjected to pressure, so that a sample conveyor presented in the form of a sample cylinder 7 rotating in the direction of the arrow 6 can take material from its periphery and transport it in the direction of the strip 1. From the material removed in the form of a layer is then transferred from the material to the strip. By 8 is designated a doctor blade which bears elastically against the sampling cylinder 7 and seals the reserve in the direction of transport of the sampling cylinder 7. The material not transferred to the strip 1 may contain small air bubbles 5, for example example what is known as micro-foam, which in the case of the usual return to a reserve space for material can no longer be released and may, during the formation of a new layer of material or when transferring it to the tape, to give rise to malfunctions. In addition, it is desirable to enrich the so-called old material or

  as much residual fresh material as possible.

  This is obtained according to the invention in a particularly advantageous manner by a channel situated between the reserve 4 and an expansion zone presented in the form of an expansion chamber 12. A movable limit surface of the channel 11 is formed by the surface 13 of the sampling cylinder 4, while the other limiting surface, fixedly mounted, is formed by a fixed wall 14 limiting the channel. 20 Thanks to channel 11 there is now a flow of material from the reserve 4 towards the expansion chamber 12, which flow has a shearing action and evacuates small bubbles, in particular micro-foam, still adhering to the old material towards the expansion chamber 12. As a result of shearing forces, the old material can also, at least in the region of the boundary layer, come off and be evacuated towards the expansion chamber. This shearing effect is particularly advantageous in the case of shaped cylinders such as those shown in FIGS. 3 to 6. Passing through the channel 11 which is widening, micro-foam and old material reach the expansion chamber 12 which is produced so as to produce a pronounced vortex (indicated by the arrow 15). 35 The walls of the chamber are adapted to the whirlpool. The air in the micro-foam follows the flow of material due to the smallness of the bubbles. As a result of the wetting of the wall and under the effect of the forces in the vortex, the small air bubbles come together to form larger air bubbles which, following the upward force, are then drawn upwards. along the wall of the expansion chamber 12 and parallel to the vortex. The rate of rise of these large air bubbles is limited so that an increase in the gas volume of each bubble becomes possible. The upper part of the expansion chamber 12 has an inclination which leads to an automatic evacuation of large air bubbles. The discharge duct 16 for the material is located behind or above the expansion chamber. A support cylinder 15 18 is located at the application location A. The material

  flowing from the expansion chamber 12 is transported, passing through the discharge duct 16, to a reservoir 17 for fresh materials, from which the pump 2 transports substantially fresh material and to a large extent free from foam towards the reserve 4.

  The width of the channel 11 as well as the discharge pressure of the pump 2 are adjustable since it is advantageous to adapt these two values to one another according to the consistency of the material, in particular its viscosity , in order to obtain an optimal shearing action. FIG. 2 shows a development of the invention in which a metering cylinder is provided and the pressure in the reserve space is lowered in several (two) steps up to the expansion chamber. Construction elements which conform to the corresponding elements in FIG. 1 have the same reference numbers,

  increased by 100, and are no longer specially described.

  In the sampling region E, from which the sampling cylinder 107 withdraws material from the reserve 104, there is associated with the sampling cylinder a metering cylinder 121. The doctor blade 108 is disposed in the immediate vicinity of the slot 129 between the cylinders 107 and 121. The material arrives, passing through recesses in the form of channels formed in the fixed wall of the channel, from the prechamber 122 in the reserve space proper 104 from which the sampling cylinder 107 removes of the material which is metered by the metering cylinder 121. The metered layer is transported by the sampling cylinder to the band 101 guided 10 in the opposite direction by means of a deflection pulley 123. The excess material (material old, residual material) not transferred and remaining on the surface of the sampling cylinder 107 returns to the expansion chamber 112. In this expansion chamber also arrives the material which, flowing through the channel 111 in the opposite direction to the direction of transport 106 of the sampling cylinder 107, detaches the micro-foam found on the returned old material. The material flowing through the channel 111 can also detach from the old material, at least in the separating layer thereof. The detached micro-foam and / or the material arrive first in the intermediate space 124 and from there, passing through another narrow channel 126, into the expansion chamber 112. Another doctor blade 127, which bears elastically against the periphery of the sampling cylinder 107, closes the intermediate space '124 in a sealed manner with respect to the expansion chamber 112. From the expansion chamber 112 the material

  returns, passing through the discharge duct 116, to the reservoir 117 for fresh material.

  According to the particularly advantageous embodiment, shown in FIG. 2, of the invention of the material is brought by the pump 102, passing through the supply conduit 103, to the reserve space 128 formed by the doctor blade. 108, the sampling cylinder 107 and the metering cylinder 121 and in which the material reserve is under pressure. Through the slit 129 between the cylinders 107 and 123 a layer of material on the surface of the sampling cylinder 107 is transported to the strip 101. The old non-transferred material is returned to the region of the reserve o of the old material containing air is first removed by the additional doctor blade 127 so as to reach the expansion chamber 112. The remains of material still remaining on the surface of the sampling cylinder 107, in particular in the hollows thereof , arrive in the channel 111 under the action of the shearing forces which are exerted by the material flowing at a relatively high speed in the opposite direction to the direction of rotation 106 of the sampling cylinder 107 through the relatively narrow channel 111. The material flowing in the opposite direction to that of arrow 106 first arrives in the intermediate space 124 where there is an intermediate pressure between the pressures prevailing in the reserve space 128 and in the cham trigger 112. Passing through the additional channel 126, the material then arrives in the

  expansion chamber 112 from which it returns practically free of air, passing through the evacuation duct 116, to the reservoir 117. The degassing mechanism in the expansion chamber 112 is the same as that described in connection with the 25 relaxation room 12.

  Thanks to the operating mode described above

  the sampling cylinder 107 can, in the region of the reserve space, take up a new layer of material, which is dosed in the slot 129, without this process being prejudiced by bubbles air / micro foam and / or old material.

  Consequently, it is obtained thanks to the invention a good wetting, filling, in the absence of air, of the whole system conveying material, a continuous cooling of the material and a safe elimination of the

  old material. If the speed of rotation (peripheral speed) of the sampling cylinder 107 varies, it is to be expected that the pressure of the material in the prechamber 122 and the reserve space 128 will be multiplied by the square of the factor of this variation.

  It is also for this reason that the use of a forced feed pump 102 is recommended. The pressure difference between the prechamber 122 and + 0 is decisive for the slit 129. For a constant slit area the flow velocity varies, on the one hand, as a function of this pressure difference linearly and, on the other hand On the other hand, also depending on the wetting force ratios at the surfaces of the cylinders 107 and 121. By matching suitable materials, it is possible to obtain practically constant layer thicknesses on the sampling cylinder 107, the speed of rotation of the cylinder. dispenser 121 which can be practically maintained unchanged. This is valid for the relatively high speed range. In the case of dosing cylinder rotation speeds 121 near 20, it is necessary to reckon with a variable layer thickness which can however be equalized by varying

  the speed of rotation of the pump 102.

  In Figures 3 and 4 is shown a cylinder

  said engraved 7, 107 (also called screened cylinder) having a fine threaded profile extending obliquely. The inclination of the multi-pitch thread can be approximately 45.

  An outer ring 131 with the profile 132 then rests by means of an intermediate ring 133 in copper on

a steel cylinder 134.

  Figures 5 and 6 show an engraved cylinder

  (also called screened cylinder) 7, 107 with another profile 135 which resembles a network of truncated pyramids. The shaped ring 136 is made of chromic oxide and rests by means of an intermediate ring 133 made of leather on a cylinder 134 of steel.

1 1

  FIG. 7 shows an advantageous device for sealing an engraved cylinder (FIGS. 3 to 6) intended to prevent the material from flowing in the axial direction.

  A fixed sealing wall 138 is connected by the intermediary of a layer of cellular material 139, which serves as a spring, to the sliding seal itself 142, preferably made of plastic (Teflon). Sealing device details are not shown

in Figures 1 and 2.

  The application device according to the invention makes it possible to apply materials of different types continuously to strips. A particularly advantageous example consists in applying liquid glue to a strip, for example of paper, plastic or cardboard, in particular when it is a question of obtaining a special sizing pattern. Thus, the application device according to the invention can be provided in a so-called filter tip placement machine, in order to apply liquid glue to it, for example an aqueous glue solution based on polyvinyl acetate, (for example with a water content of 50%), continuously on a so-called covering paper tape, which is then cut into small covering sheets. By means of the small glued covering sheets (also called cuffs), cigaret25 tes (tobacco sticks) are then connected to filter tips to form filter-tip cigarettes. A machine for fitting filter tips of this kind, which is known in the cigarette manufacturing industry under the name MAX from the firm HauniWerke Kôrber & 30 Co. KG, 2050 Hamburg 80, Kampchaussee 8 to 32, is described. in American patent 4249547. The adhesive application device provided in the latter can be replaced by the application device according to the invention. This applies not only to the sizing pattern shown in the aforementioned US patent but to any sizing patterns, i.e. for glue applied flat with or without an unglued middle ribbon s' extending in a longitudinal direction or for gluing patterns having recesses in the form of fields in the glued surfaces.

  The device according to the invention also makes it possible to apply glue to a strip of cigarette paper or to a ribbon forming an envelope for a rod of filtering material from the tobacco processing industry or to a ribbon of material. forming an envelope in packaging machines.

2598 1 02

Claims (10)

RESELL ICATIONS   1 - Method for applying a fluid material to a strip, in which the material is removed from a reserve, by means of a rotary sample conveyor, 5 in the form of a layer, and is transported to the web, and the material not transferred onto the web is returned by the sample conveyor in the region of the reserve, characterized in that along the layer of non-transferred material returned on the surface of the sample conveyor is transported , in the opposite direction, a layer fresh material.   2 - Method according to claim 1, characterized in that the layer of material not transferred and returned on the surface of the sample conveyor is transported through a channel through which the material   fresh is driven back & against the current.   3 - Method according to claim 2, characterized in that the material is removed by the surface of the sample conveyor, preferably a sample cylinder, and transported to the belt and in that non-transferred material is transported towards of the canal, the surface of the sample conveyor forming a surface limiting the channel.   4 - Method according to any one of the preceding claims, characterized in that the material discharged through the channel in the opposite direction to the direction of movement of the surface of the sample conveyor, which material may contain at least part of the material returned , arrives at pumping equipment which returns material & the stock where the sample conveyor removes material in the form of a layer.   - Method according to any one of the preceding claims, characterized in that the material in the reserve, from which the sample conveyor removes material in the form of a layer, is kept under pressure   and in that the pressure is reduced, through the channel through which the material is discharged against the current as well as through another channel, preferably at atmospheric pressure. 6 - Device for applying a fluid material on a strip (1, 101), which comprises a rotary sample conveyor (7, 107) for removing a layer of material from a reserve (4, 104), transporting the layer of material to the belt and return the non-transferred material 10 to the belt in the region of the reserve, characterized in that the surface (13, 113) of the sample conveyor (7, 107) forms with a boundary wall (14, 114 ) a channel (11, 111) the inlet of which is contiguous to the reserve (4, 104) under pressure, so that material is forced through the channel in the opposite direction to the direction of   transport (6, 106) of the direct conveyor.   7 - Device according to claim 6, characterized in that the sampling conveyor is produced in the form of a sampling cylinder (7, 107) with which 20 can be associated, in the region of the reserve, a metering cylinder (121 ).   8 - Device according to claim 7, characterized in that a doctor blade (108) intended to seal the reserve (104) is mounted in the immediate vicinity of the slot 25 (129) between the metering cylinder (121) and the cylinder of direct debit (107).   9 - Device according to any one of claims 6 to 8, characterized in that, for an observer looking in the direction of transport (6, 106) of the sample transporter (7, 107), is located in front of the channel ( 11,   111) a relaxation zone (12, 112) for occlusions gaseous in matter.   - Device according to any one of claims 6 to 9, characterized in that between the reserve (104), 35 from which the sample conveyor removes a layer and   in which the material is under pressure, and the expansion zone (112) is provided, in addition to the channel (111), at the minus another channel (126).   11 - Device according to claim 10, caracté5 risé in that the space (124) between the channels (111 and 126) is sealed by means of another doctor blade (127) taking   support against the surface of the sample conveyor.   12 - Device according to any one of claims 6 to 11, characterized in that the sampling cylinder is relaised as an engraved cylinder.   13 - Device according to any one of the preceding claims, characterized in that the device is part of a machine for placing filter tips for cigarettes, by means of which glue, preferably glue based polyvinyl acetate,   is applied to a covering paper tape intended to join tobacco sticks and filter tips.