Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H19/00—Changing the web roll
  • B65H19/22—Changing the web roll in winding mechanisms or in connection with winding operations
  • B65H19/26—Cutting-off the web running to the wound web roll
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H19/00—Changing the web roll
  • B65H19/22—Changing the web roll in winding mechanisms or in connection with winding operations
  • B65H19/2238—The web roll being driven by a winding mechanism of the nip or tangential drive type
  • B65H19/2269—Cradle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H19/00—Changing the web roll
  • B65H19/22—Changing the web roll in winding mechanisms or in connection with winding operations
  • B65H19/26—Cutting-off the web running to the wound web roll
  • B65H19/267—Cutting-off the web running to the wound web roll by tearing or bursting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H19/00—Changing the web roll
  • B65H19/22—Changing the web roll in winding mechanisms or in connection with winding operations
  • B65H19/30—Lifting, transporting, or removing the web roll; Inserting core
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2301/00—Handling processes for sheets or webs
  • B65H2301/40—Type of handling process
  • B65H2301/41—Winding, unwinding
  • B65H2301/414—Winding
  • B65H2301/41419—Starting winding process
  • B65H2301/41425—Starting winding process involving blowing means, e.g. air blast
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2301/00—Handling processes for sheets or webs
  • B65H2301/50—Auxiliary process performed during handling process
  • B65H2301/51—Modifying a characteristic of handled material
  • B65H2301/515—Cutting handled material
  • B65H2301/5153—Details of cutting means
  • B65H2301/51533—Air jet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2408/00—Specific machines
  • B65H2408/20—Specific machines for handling web(s)
  • B65H2408/23—Winding machines
  • B65H2408/235—Cradles

Definitions

• Rewinding machine method for producing logs of web material
• the present invention relates to a rewinding machine for winding a web material to form logs for producing, for example but not exclusively, small rolls of toilet paper, kitchen towels and the like. More specifically, but not exclusively, the invention relates to a "peripheral" rewinding machine, i.e. in which logs are formed by winding the web material in a winding cradle composed of winding members in contact with the outer surface of the log. The invention also relates to a winding method and more specifically, although not exclusively, a "peripheral" winding method. State of the art
• rewinding machines are used to which the material to be wound is fed, and which produce logs with a pre-established quantity of wound material.
• the web material is typically fed from unwinders, i.e. machines that unwind one or more reels of large diameter coming, for example, from a papermill.
• the logs can be sold "as is”, or can undergo further conversion operations; typically they are cut into rolls of smaller axial length, equivalent to the final dimension of the small rolls to be sold.
• rewinding is performed by central rewinding machines, i.e. in which the logs are formed around motorized spindles, on which winding cores made of cardboard or similar materials, can be inserted, which cores remain inside the logs.
• the latest rewinding machines are based on the peripheral or surface winding concept.
• the log is formed in a winding cradle, defined by rotating winding rollers or other winding members, such as belts, or a combination of rollers and belts.
• Rewinding machines both of the peripheral and central type, are machines that operate in automatic and continuous mode, meaning that the ⁇ web material is fed continuously therein without stopping and substantially at a tendentially constant speed.
• the web material is provided with transverse perforation lines that divide the material into individual portions, which can be separated from the roll for final use. Typically, an effort is made to produce rolls with a specific and precise number of said portions or sheets.
• the exchange phase When a roll or log has been completed, the exchange phase must be performed, during which the log is unloaded and the web material is severed, forming a final end of the completed log and an initial end of the subsequent log. The initial end starts to wind to form a new log.
• Severing preferably takes place at the level of a perforation line, so that the finished product contains a full and predetermined number of portions of web material.
• GB-A-1435525 describes a rewinding machine in which severing of the web material takes place by means of a blade or jet of compressed air that tears the web material or produces a loop that wedges between the new winding core inserted in the winding cradle and one of the winding rollers.
• the nozzles that produce the jet of air are positioned downstream of the nip for insertion of the cores, defined by two opposed winding rollers, belonging to a peripheral winding cradle.
• US-A-4327877 describes a rewinding machine in which severing of the web material takes place through the combined action of suction through the surface of one of the winding rollers and of pinching of the web material between the new core inserted in the winding cradle and the suction winding roller. Suction forms a loop of material which is pinched and pulled in the opposite direction to the direction of feed of the web material being wound around the log reaching completion.
• GB-A-2150536 and US-A-5368252 describe methods and rewinding machines in which the web material is torn after winding has terminated solely by controlled acceleration of one of the winding rollers.
• the same system based on the principal of tearing the web material along a perforation line by acceleration of one of the winding rollers is described in EP-A-1.219.555.
• GB-A-2105687 describes a method and a rewinding machine, in which severing of the web material takes place by cutting carried out by a blade in a channel of one of the winding rollers.
• US-A-5137225 and EP-A-0199286 describe methods and rewinding machines in which tearing takes place by cooperation between a winding core and a fixed surface against which the core pinches the web material causing it to stop or temporarily slow down.
• IT-B-1.275.313 describes a device in which tearing of the web material is obtained by a core inserter, which cooperates with the main winding roller.
• US-A-6056229 describes a rewinding machine, in which the web material is severed by pinching it between a fixed surface and a moving member, which also inserts the winding cores in the machine. Particularly reliable and flexible machine and method are described in
• WO-A-2004/096684 describes a rewinding machine which uses the same tearing system of the web material already described in the British patent 1435525, i.e. a jet of compressed air which, by acting on the web material, causes tearing thereof along the perforation line.
• the system with - A - jets of pressurized air is positioned inside the cylindrical surface of the principal winding roller, around which the web material is driven.
• This configuration is particular complex and difficult to produce, and not devoid of defects.
• the system of compressed air nozzles is positioned inside the cylindrical casing of the roller, the latter must have a wide perforated area to obtain an adequate tearing effect on the web material.
• the winding roller has annular grooves, positioned inside which are curved tubes terminating in blowing nozzles. This construction is complex and not very efficient. Moreover, in both embodiments the winding roller cannot have a smooth and regular surface, but must be provided with holes or annular grooves, which damage the web material during winding, decreasing the quality of the finished product.
• the object of the invention is to produce a winding method and a rewinding machine which are particularly efficient, economical and reliable and which guarantee a high level of production flexibility.
• a rewinding machine for producing logs of web material of the type illustrated in GB-A-1435525, comprising: a winding system with at least a first winding roller and a second winding roller defining therebetween a nip through which the web material is fed; a feed path of the web material towards said winding system; and a severing member which produces a jet of air to sever the web material after winding of each log has terminated.
• the severing member is positioned along the feed path of the web material, upstream of said nip.
• the jet of air applied in a manner synchronized with the remaining machine functions and for a short period of time to the web material along the feed path causes a force orthogonal to the web material, which is under tension due to winding and which consequently tears.
• the nozzles producing the jets of air can be associated with an opposing surface on which the belts of the flexible member rest and run.
• the severing member can have one or more openings, in the form of holes, windows, slots or of any other suitable configuration, a series of aligned nozzles, a single nozzle per slot or a plurality of nozzles per slot, to apply one or more jets of compressed air to the web material.
• the jet of air is phased with the position of the perforation line along which the web material is to be severed after winding of each log has terminated.
• a number of perforation lines are obtained, and therefore a number of individual sheets of web material on each log is determined precisely.
• the perforation line represents a stress riser point, with decreased tensile strength, which facilitates tearing.
• the rewinding machine thus produced has considerable advantages with respect to known devices. In fact, it is characterized by the same operating flexibility and by the same reliability as the machines described in US-A- 5979818, but does not require the rotating mechanical member, which performs tearing of the web material. A smaller number of mechanical parts make the machine more economical, easier to run and also more reliable. Furthermore, elimination of the mechanical action of the device to tear the web material reduces wear, vibrations and noise.
• the machine according to the invention has advantages of cost, reliability and production speed, besides increased winding precision, with the possibility of more accurate and reliable adjustment of the position of the severing or tearing point of the web material, even at very high speeds.
• the principal winding roller around which the web material is driven can have a smooth surface devoid of holes, or can have annular grooves.
• belts, with a smooth exterior defining, with the roller, a continuous cylindrical contact surface with the web material can be driven inside the annular grooves.
• the wall of the winding roller is no longer interposed between the compressed air nozzles and the web material, obstructing the effect of the air.
• the inventive concept defined above can be applied both in rewinding machines producing rolls or logs with a winding core that is left inside the finished product, such as a cardboard or plastic core, and in machines producing rolls or logs without a winding core, in which the log is formed around a spindle or core that is subsequently removed from the wound product before it is cut into small rolls.
• the finished product is in this case devoid of central core but has an axial hole.
• the rewinding machine has a winding core feeder, to feed winding cores to a feed path towards the winding cradle.
• a feed member for said cores can advantageously be provided along the feed path of the winding cores.
• the feed member can, for example, be composed of a flexible member comprising one or more belts defining a closed path.
• the nozzles of the severing member are advantageously positioned in the spaces between parallel belts. These belts can also be positioned at a considerable distance from each other, so that the severing system of the web material is composed of a very extensive line of compressed air nozzles with only a few interruptions and therefore very efficient.
• a rolling surface for the cores can be provided along the feed path thereof, forming with the feed member a channel for insertion of the winding cores.
• the cores fed to the feed path roll between the feed member and the fixed rolling surface.
• the rolling surface and the feed member of the cores forming the channel for insertion of the winding cores are positioned so that the web material is fed between the core and the feed member when the core is in the feed path. In this way the core starts to roil along the feed path and, once the web material has been severed, the initial free end produced is wound around the core already in rotation.
• the compressed air severing device can be positioned along this channel and can be synchronized to sever the web material in front of the core, i.e. downstream thereto with respect to the direction of feed.
• the nozzles, or other equivalent blowing members can be placed at a distance from the winding rollers.
• this makes it possible to utilize alternative systems rather than glue, for example jets of air or electrostatic charges, to wind the initial free end of web material around the winding cores. This makes it possible to obtain a higher quality product, in which the innermost turns are also wound with increased regularity and less or even no creases. Moreover, the cost of expendable materials is reduced.
• the rewinding machine comprises an opposing surface, along which the web material and the feed member of the cores slide, and along which the severing member can be positioned.
• the winding cradle can be produced in various ways preferably providing at least a first winding roller and a second winding roller.
• at least one flexible member, on which the web material fed to said winding cradle is in contact, can be driven around the first winding roller.
• the invention relates to a method for producing logs of wound web material, comprising the steps of: - feeding the web material to a winding cradle, comprising at least a first winding roller (1) and a second winding roller (2), the web material passing through a nip (5) between said winding rollers (1 , 2);
• Figures 1A to 1C show an operating sequence of a machine according to the invention in a first embodiment
• Figures 2A to 2D show an operating sequence of a machine according to the invention in a second embodiment
• Figure 3 shows a side view of a machine according to the invention in a further embodiment
• Figures 4A-4E schematically show the sequence of the phase to tear or sever the web material and to start forming the first turn of the new log around the new core, with the aid of jets of air and without glue;
• Figures 5A-5D schematically show the operating phases of a variant of the embodiment in Figures 2A-2D;
• Figure 6 shows a variant of the embodiment in Figure 3;
• FIGs 7 and 8 show two variants of the embodiment in Figure 6;
• Figures 9 and 10 show two variants of embodiment of the severing member in a configuration in which it is provided with a movement to "follow" the perforation on which severing of the web material is to take place.
• the winding machine comprises a winding cradle formed of three winding rollers and more specifically: a first winding roller 1 , a second winding roller 2 and a third winding roller 3.
• the three rollers 1 , 2, 3 rotate about axes parallel to one another and with peripheral speeds which - during the winding cycle - are substantially the same as one another, while they can vary, in a way known per se, at the end of winding to unload the completed log and/or to insert the new core, around which winding of the subsequent log has started, through a nip defined between the winding rollers 1 and 2.
• the winding roller 3 is supported on a pair of oscillating arms 7, hinged about an oscillation axis 7A.
• the oscillating movement allows increase in the roll R being formed inside the winding cradle 1, 2, 3 and unloading of the completed roll along a chute 9.
• the web material to be wound to form the logs R is indicated with N. It is fed along a feed path that passes through a perforator unit (not shown) which, in a known way, perforates the material N along perforation lines substantially orthogonal to the direction fN of feed of the material N. Downstream of the perforator unit the web material N is driven around a guide roller 11 , revolving about an axis parallel to the axis of the winding rollers 1, 2 and 3. The feed path of the web material then continues along a portion tangent to the rollers 1 and 11 , defined by a flexible feed member 13, composed of a plurality of belts, preferably flat and parallel with one another, driven around the rollers 1 and 11.
• the purpose of the feed member is above all to insert and feed the winding cores A around which the logs R are wound, as will be explained hereunder.
• the belts forming the feed member 13 are driven around the rollers 1 and 11 , they are fed at the same speed as the web material N and therefore there is no relative movement between said material and the belts.
• One opposing shoe for each belt is positioned above the lower portion of the belts, to prevent deformation of the belts, which would nullify the driving effect of the core in the channel during transfer thereof.
• a curved rolling surface 15 defined by a sheet or a folded section, by a plurality of sheets or folded sections parallel with one another, or by a comb structure.
• a channel for insertion and feed of the winding cores indicated with 17, which has an inlet on the left side in the figures and an outlet substantially at the level of the nip 5 between the winding rollers 1 and 2.
• the terminal part of the channel is thus defined between the rolling surface 15 and the outer surface of the winding roller 1 around which the feed member 13 is driven, the rolling surface being curved to be approximately coaxial with the surface of the roller 1.
• the terminal part of the surface 15 penetrates annular grooves produced in the winding roller 2, to facilitate feed of the cores rolling on the surface 15 towards the nip 5 and from this to the winding cradle 1 , 2, 3.
• a core inserter is provided in the vicinity of the inlet of the channel 17, composed of a rotating element 19 which, at the right moment, inserts a winding core A into the channel 17.
• the cores are conveyed to the inserter 19 by a chain conveyor 21. Operation of the core insertion mechanism is known to those skilled in the art, for example from one or more of the patents cited in the introduction of this specification and will not be described in more detail.
• the core insertion mechanism indicated schematically in Figures 1A-1C, can be of the type shown and described with reference to Figure 6.
• the height of the channel 17 is the same as or slightly less than the outer diameter of the winding cores A, which therefore, when inserted in said channel by the inserter 19 are angularly accelerated and roll on the surface 15 fed by the movement of the feed member 13.
• the web material N remains pinched between the belts forming the feed member 13 and the core inserted in the channel.
• a severing member of the web material is provided, indicated as a whole with 23 and including for example a series of blowing nozzles aligned according to a direction orthogonal to the plane of the drawing, i.e. orthogonal to the direction of feed of the web material and parallel to said material.
• the individual nozzles can be arranged in the free space between adjacent belts forming the feed member 13 of the winding cores A. These belts can also be spaced at a relative distance from one another, as a limited number of relatively narrow belts are sufficient to feed the cores by rolling along the fixed surface 15. Alternatively, or in combination, the nozzles can define a continuous row also at the level of the belts.
• the nozzles can be nozzles with a circular or elliptical hole or, in any case, suitable to produce a flow of compressed air of modest dimension, or can be laminar in shape and produce a narrow and elongated jet. In this latter case, one or more elongated nozzles can be provided.
• the nozzles of the member 23 that produce jets of air can be associated with an opposing surface 24 on which the belts of the flexible member rest and run.
• the opposing surface 24 will preferably extend for the entire free lower portion of the belts 13A and can be composed of individual portions at the level of the belts, or of an element of the same width as the overall width of the belts 13 adjacent with one another, and optionally provided with guide grooves of the belts. In general, and preferably, however, the opposing surface 24 is produced so that it does not come into contact with the web material running parallel to and along it, to avoid obstructing the movement thereof.
• the severing member 23 produces jets of pressurized air against the web material N in the exchange step, i.e.
• Figure 1A shows the instant immediately prior to tearing or severing of the web material.
• the log R wound around the winding core indicated with A1 is ready to be ejected from the winding cradle, while a new core A2 has just been inserted in the channel 17 by the inserter 19.
• the core is rapidly angularly accelerated to take the point of contact thereof with the web material to the same feed speed as the web material.
• the rolling surface 15 has a comb structure or at least a series of notches which allows the inserter 19 to complete rotation about the axis of rotation thereof and to position itself for insertion of a subsequent core.
• the letter P indicates the position of a transverse perforation line, produced on the web material N by the perforator (not shown), along which severing by tearing of the web material will take place.
• the perforation P is at the level of the severing member 23.
• the jets of air are controlled and phased to act when the perforation line P is in the position indicated in Figure 1A, or slightly downstream or slightly upstream in the direction of feed of the web material N. In this way, when the jets of air are activated, the web material is torn.
• the core A2 is already in contact with the web material N upstream of the tearing area and has already been made to rotate. It constrains the web material N against the belts forming the feed member 13 and thus prevents the initial free end Li of the material N which was formed by tearing from being lost.
• the final free end Lf of the log R is finished being wound on said log, which is ejected by varying the peripheral speed of the roller 2 and/or the roller 3, in a way known per se.
• one or more series of blowing nozzles can be used, suitably positioned around the area in which the core receives the free end. This solution is facilitated particularly by the fact that there are no mechanical members under the rolling surface 15 to tear the web material, as is instead the case in other known machines. Moreover, the severing device or member 23 with its blowing nozzles is positioned at a distance from the winding rollers 1 and 2, so that there is ample space available to provide means other than glue to make the first turn of web material wind around the core.
• FIGS 2A-2D show a second embodiment of the machine according to the invention, with a respective operating sequence.
• the same numbers indicate parts the same as or corresponding to those in the previous Figures 1A-1C.
• the main difference with respect to the previous example of embodiment consists in the increased distance between the rollers 1 and 11, the increased length of the surface 15 and the increased extension of the opposing surface 24 and of the portions of the belts 13A parallel to the rolling surface 15. The rest of the arrangement and operating sequence is substantially the same.
• the core performs a complete rotation in the channel 17 before severing of the web material, as can be observed by comparing Figures 2A and 2C.
• the line of glue is indicated with C.
• the core is inserted with a device of the type shown in Figure 6, which prevents the core A2 from rotating around itself due to the inserting movement, and guarantees the angular position of the line of glue with respect to the web material.
• Figure 2A shows the instant in which the line of glue C comes into contact with the web material.
• the letter P again indicates the position of the perforation line along which tearing of the web material will take place. In Figures 2A and 2B this perforation line is upstream of the core A2.
• Figure 2C shows the jets of air which tear the web material N along the perforation line P, which at this point has moved beyond the position of the winding core A2, and is downstream thereof with respect to the direction of feed of the web material. This is due to the fact that the axis of the core A2 moves along the channel 17 at half the feed speed of the web material, so that the point of contact between core A2 and web material N is also fed along the channel at a speed substantially equal to half the feed speed of the perforation line P.
• the line of glue C is in the lower part of the core. To prevent the glue from soiling the rolling surface 15 during this movement, this surface can be made of sections positioned at a distance from one another, and the line of glue C can have breaks at the level of the sections.
• an auxiliary glue dispenser composed of an oscillating element 20 which can be immersed in a glue reservoir 22, is indicated with a broken line.
• the oscillating element is shaped so that it can be inserted between the plates forming the surface 15 to touch the core A2 to apply in the desired position thereon a line of glue C, which can superimpose the line applied previously (or can be angularly staggered with respect thereto) and partly transferred in C1 to the final free end of the roll in the completion phase.
• the quantity of glue is re-established and a glue is applied that can have different qualities with respect to the glue previously applied and at least partly transferred to the final free end.
• a suction system can be provided acting between the belts 13A and respective opposing members 24, to keep the web material adhering to the belts 13 during the tearing phase performed by the jet of air and, subsequently to tearing, to constrain the final end in contact with the belts 13A also after tearing has been performed, to prevent creases from forming or loss of control of said final end.
• This suction system can advantageously be provided for all the examples of embodiment of the machine of the present invention, also illustrated in the continuation of this description.
• the suction system is indicated with a broken line and marked with the number 26, while in the other figures it is omitted for simplicity.
• the system 26 can, for example, act through the free space between adjacent belts 13.
• Figures 4A -4E show - limited to the tearing area of the web material N, an example of embodiment in which winding around the new core A2 of the initial free end Li produced by tearing of the web material takes place without the use of glue.
• the severing member 23 is produced as already described.
• the jet or jets of air produced thereby per se form an element that facilitates starting to wind the initial free end Li around the new winding core.
• a further series of nozzles is positioned under the rolling surface 15. While the nozzles of the severing member 23 are fixed, the series of nozzles 85 oscillates about a horizontal axis, transverse with respect to the direction of feed of the web material N. The oscillating movement is represented in the sequence in Figures 4A-4E.
• Operation of the machine in this example of embodiment is as follows.
• the core A2 is upstream of the nozzles forming the severing member 23, these are activated and the web material is torn or severed at the level of the perforation line P, which is approximately at the level of said nozzles.
• the jets produced by the severing member 23 push the free end 23 downwards, i.e. towards the rolling surface 15. In this way the free end Li tends to wind around the core A2.
• the jets of air produced by the nozzles 85 urge the free end to wedge between the core A2 and the surface 15.
• the first turn, i.e. the innermost turn, of the log formed is devoid of fold, i.e., is not folded back in the opposite direction with respect to the direction of winding of the remaining part of the web material, as is the case in the embodiments described in the previous examples.
• this advantageous conformation of the log is also obtained in the case of combined use of glue and air nozzles, obtaining an advantageous result which was previously impossible when gluing was performed with a longitudinal line of glue.
• the machine can also be adapted more easily to different diameters of winding core.
• the winding cores are inserted in a channel 17 delimited by a rolling surface 15 which is for the most part rectilinear and optionally has a curve only in a terminal portion. It is therefore possible to adapt the machine to cores of variable diameter simply by translating the sections forming the rolling surface 15, together with the lower roller in the example shown, in particular in the configuration in Figures 6, 7 and 8.
• the rolling surface 15 could be composed of a simple sheet, optionally interrupted to allow passage of the inserter 19, while it does not require to have a comb structure for the entire extension thereof. This also prevents damage to the first turn of the web material, caused by the mark left by the plates of the comb structure.
• a pneumatic severing system of the web material makes operation more regular and less subject to wear, noise and vibrations, with respect to those in which the web material is severed by pinching the material against a winding roller or a belt by means of a mechanical member moving at a different speed to the feed speed of the web material. Moreover, all the advantages of reliability and flexibility of previous systems are maintained.
• the ample space available for the nozzles of the member 23 allows a decrease in the flow rate and pressure of the air, resulting in energy saving and further reduction in noise and vibrations with respect to systems which house the severing nozzles of the web material inside the cylindrical surface of the winding roller.
• the surface of the web material is not damaged by the presence of holes or grooves in the winding roller.
• the severing member can be regulated in a position along the extension of the channel 17. This facilitates regulation and calibration of the machine, as it makes it simpler to phase the action of the blowing system with respect to the position of the perforation line.
• the position of the severing member 23 forms an added regulation parameter with respect to control of opening and closing of the blowing nozzles. This is easy to obtain as the distance between the rollers 1 and 11 is considerable with respect to the portion traveled by the web material N during the very short activation time of the blowing nozzles of the severing device 23. Consequent advantages are obtained with respect to conventional solutions in which the jets of air are inside the winding roller.
• the slots or holes through which the jets of pressurized air pass can also act progressively on the web material N in the direction of feed thereof. This is obtained by making the jets of air produced by the severing member move in the direction of feed of the web material, so that the jets of air act along a thin line moving in the same direction of feed of the belts 13A and of the web material N, allowing said jets of air to act in a concentrated area and for a longer time.
• Figures 9 and 10 show two possible configurations of the severing member provided with this function.
• Figure 9 shows a diagram in which the severing member 23 is produced in a block provided with a first chamber 51 in which pressurized air is contained, delimited inferiorly by a wall 61 provided with slots or holes 62, which can be opened and closed by a sliding valve 67, provided with slots or holes 68, which can be moved alternatively to the level of the holes or slots 62 or staggered with respect thereto.
• Under the sliding valve 67 is an opening 53 (continuous or discontinuous, which extends transverse to the direction of feed of the web material N and which is closed inferiorly by a plate 54 provided with an alternating movement according to the double arrow f54.
• the plate 54 has a slot 55 transverse to the direction of feed of the web material N, which moves forward in concurrence with the web material N when the severing member 23 must perform severing.
• a blade of air (closely adjacent to or at the level of the perforation line P) acts on the web material, advancing with said material and therefore characterized by a longer action time on the web material and in particular on the perforation P than the time obtained when using a fixed jet of air. Severing of the web material can therefore be obtained with lower air pressures and flow rates.
• slot 55 can also be discontinuous or replaced by a series of aligned holes.
• FIG. 10 shows a severing member 23 comprising a plurality of nozzles
• FIG. 23A aligned transverse to the direction of feed of the web material N and oscillating about a transverse axis A.
• Figure 10 shows three distinct positions taken by the oscillating nozzles 23A in the operating phase are indicated with a broken line and with a continuous line. The direction of oscillation is indicated with f23. In this way too a jet or blade of air acting for a longer time on the perforation line or in proximity thereto is obtained, to further ensure correct tearing.
• This principle can also be adopted advantageously in rewinding machines of other types, in which compressed air is used to sever the web material.
• the jets of air are produced inside the winding roller around which the web material is driven, it is possible for oscillating nozzles or other means to be provided inside the winding roller (which has a perforated surface) to produce a jet which follows, for a certain curve, the rotational movement of the roller.
• nozzles coaxially to the roller, housed inside the annular grooves produced in said roller, nozzles can be provided which have a rotational or oscillatory movement synchronized with the position of the perforation line, again to follow the perforation line on which they must act.
• this offers the advantage of improving severing of the web material also at high speeds and optionally decreasing air consumption. This has an advantage also in terms of economizing and reducing machine noise.
• the invention also relates to a rewinding machine comprising a peripheral winding unit with a system to sever the web material after winding has terminated with a severing member which produces at least one jet of air to sever the web material after winding has terminated, wherein said severing member produces a jet moving in the direction of feed of the web material during the web material-severing phase, to track the perforation line on which the web material is to be severed.
• FIGs 5A to 5D show a variant of execution of the machine in Figures 2A-2D.
• the same numbers indicate the same or corresponding parts.
• the parts of the machine which remain the same are not described again.
• the substantial difference consists in the presence of electrostatic bars to make the initial free end Li of the web material torn by the blowing nozzles adhere to the new winding core, with consequent elimination of the glue.
• in the configuration in Figure 5 it is also possible to obtain wound logs in which the first turn, i.e. the innermost turn against the core, is devoid of fold.
• an electrostatic charging bar is positioned in the space inside the closed path formed by the feed member 13.
• a second bar, indicated with 503, is positioned under the rolling surface 15.
• These bars and the high voltage generators connected thereto are known per se in the art and are used, for example, to electrostatically charge plastic films, or - in contrast - as ionizers to eliminate electrostatic charges from plastic films or other products.
• Electrostatic charging devices which can be used in this application can, for example, be the devices marketed by Haug GmbH & Co KG (Germany) or by Haug Biel AG (Switzerland) with the codes ALS-A and ALS-R.
• the bars 501 and 503 apply charges of the opposite sign, so that the web material N is charged with charges of one sign and the cores are charged with the opposite sign.
• the sign of the charges can depend on the material of which the web material N and the cores A are made.
• Figure 5A shows the initial instant of insertion of the new core A2 in the channel 17, on which winding of a new log will start after completion of the log R wound around the core A1.
• Figure 5B shows the subsequent instant in which the core A2 is in contact with the rolling surface 15 and with the web material N which is pinched between said core and the member 13. The core is rolling on the surface 15 and is angularly accelerated to take the point of contact thereof with the web material N to the same feed speed of said material.
• Figure 5C shows the instant immediately prior to tearing or severing of the web material.
• the log R wound around the winding core A1 is ready to be ejected from the winding cradle, while the new core A2 is traveling between the two bars 501 , 503 and is electrostatically charged by the bar 503, while the bar 501 charges, with the opposite sign, a portion of the web material adjacent to the area in which it will be severed and in which the initial free end that must adhere to the new core A2 will be formed.
• the rolling surface 15 has a comb structure formed of non-metal elements (or in any case in which the rolling surface of the winding cores is made of or covered with insulating material), or at least a series of notches which allows the inserter 19 to complete rotation about the axis of rotation thereof and position itself to insert a subsequent core.
• the letter P indicates the position of a transverse perforation line, produced on the web material N by the perforator (not shown), along which the web material will be severed by tearing.
• the perforation P is substantially at the level of the severing member 23.
• the nozzles of the severing member 23 are controlled and phased to act when the perforation line P is in the position indicated in Figure 5C, or slightly downstream or slightly upstream in the direction of feed of the web material N. In this way, when the jets are activated, the web material is torn or severed.
• the core A2 is already in contact with the web material N upstream of the tearing area and has already been made to rotate and been electrostatically charged by the bars 501, 503.
• the core A2 constrains the web material N against the belts forming the feed member 13 and consequently prevents the initial free end Li of web material N formed by severing from being lost.
• the final free end Lf of the log R terminates winding thereon, and is ejected as described previously.
• the electrostatic charge applied to the core A2 immediately prior to tearing or during tearing of the web material N makes the initial portion of web material electrostatically attract to the core and adhere thereto, as if a glue had been applied to the core (Figure 5D).
• the immediate spatial and temporal vicinity between electrostatic charge of the core and tearing of the web material N prevent dispersion of the electrostatic charges and make electrostatic attraction very efficient.
• FIG. 6 shows a modified embodiment, in which the electrostatic charges are used in combination with glue.
• the same numbers indicate parts the same as or corresponding to those of the embodiment illustrated in the previous figures.
• the terminal part of a chute 601 for the winding cores A is positioned upstream of the mouth of the channel 17.
• the first core of the row is engaged by an inserter composed of a member 603 rotating about an axis 603A, which supports a fixed jaw 605 and a moving jaw 607 operated by an actuator 609 supported by the rotating member 603, the operation of which will be described hereunder.
• a glue applicator 611 Positioned under the chute 601 is a glue applicator 611 comprising a glue reservoir 613, dipped into which is an element 615, provided (in the example shown) with an alternate movement to be dipped into the glue and removed from the glue to apply a line of glue to the core which is in the position Ax.
• A is inserted in the channel 17, and therefore also the position of the line of glue applied to the core, are controlled in a reliable way and are therefore precise.
• the position of the line of glue is phased with respect to the perforation line P along which the web material N is to be severed, so that when the core starts to roll on the surface 15, the line of glue touches the web material immediately downstream of the perforation line P, at the level of the area of material which, after severing, will form the final free end Lf of the completed log R.
• a line of glue is applied to the final free end Lf to close the final free end without the need for a gluing unit downstream of the rewinding machine.
• the subsequent core can be temporarily constrained by a constraining system, such as a moving stop.
• Severing of the web material can take place as described above by means of blowing nozzles forming the severing device or member 23.
• the glue can also be applied to the web material at the level of the final free end Lf using different methods, such as direct application, with a spray system or the like.
• Figure 7 shows an embodiment similar to with one in Figure 6, with a modification in the arrangement of the machine members.
• the same numbers indicate parts the same or equivalent to those in Figure 6.
• Different consecutive positions taken by the new winding core in the insertion phase are visible.
• the substantial difference with respect to the configuration in Figure 6 consists in the fact that the positions of the members 23 and 501 are reversed so that the winding core can be charged before or during tearing, while the web material can be charged during or after tearing.
• two electrostatic bars 501 can be positioned respectively upstream and downstream of the blowing device 23 and over the channel for feed of the cores and two electrostatic bars 503 can be positioned thereunder.
• This solution is shown in Figure 8.
• an electrostatic bar is mentioned, but it is understood that the term electrostatic bar can mean a single bar or a series of electrostatic bars placed adjacent to one another.

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• Replacement Of Web Rolls (AREA)
• Preliminary Treatment Of Fibers (AREA)

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• 2005
  • 2005-05-23 IT IT000108A patent/ITFI20050108A1/it unknown
• 2006
  • 2006-05-19 CA CA002608969A patent/CA2608969A1/en not_active Abandoned
  • 2006-05-19 BR BRPI0611168-8A patent/BRPI0611168A2/pt not_active IP Right Cessation
  • 2006-05-19 KR KR1020077029697A patent/KR20080033170A/ko not_active Application Discontinuation
  • 2006-05-19 US US11/920,778 patent/US20090302146A1/en not_active Abandoned
  • 2006-05-19 WO PCT/IT2006/000375 patent/WO2006126228A2/en active Application Filing
  • 2006-05-19 JP JP2008513012A patent/JP2008542151A/ja active Pending
  • 2006-05-19 EP EP06745355A patent/EP1888442A2/en not_active Withdrawn

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