Winding device for reels of weblike material having means for obtaining compact reels and associated winding method

Abstract: The winding device comprises a support (1) for a reel (B) in the process of formation and a rotation system (3) for rotating the reel in the process of formation which winds up the weblike material (N) onto the reel. A tensioning member (61) is also provided in contact with the outer surface of the reel in the process of formation, whose peripheral speed is controlled so as to be able to exceed the winding-up speed.

Description: The present invention relates to a rolling-up or winding device for the production of reels of weblike material, such as, for example, though not exclusively, reels of nonwoven material. In the production of rolls of weblike material, such as, for example, reels of nonwoven, the material is wound up initially into reels of large diameter and substantial axial dimension, which are then subjected to successive processing operations, such as, for example, unwinding, lengthwise cutting and re-reeling to form rolls of lesser axial and/or radial dimensions. It is important in certain applications that the winding density of the reels should be adequate and consistent. This requires the weblike material to be tensioned during winding, in other words to be subjected to a certain tensile stress in the length immediately upstream of the reel in the process of formation. With some materials, these conditions cannot be satisfied, in that the material has inadequate tensile strength. Problems of this type are encountered in particular in the winding of certain types of nonwovens. EP-A-635445 discloses a device for winding reels of weblike material, including means for tensioning the weblike material, according to the preamble of claim 1. A method for winding reels of weblike material according to claim 10 is also disclosed in this prior art reference. Tensioning of the weblike material is obtained by rotating a winding roller contacting the reel being formed at a peripheral speed which is higher than the peripheral speed of a lay-on roll. The latter feeds the weblike material to said reel without contacting the reel. It is an object of the present invention to provide a winding device which allows sufficient compactness to be attained even in reels of weblike material that is not of particularly high tensile strength. This and other objects and advantages that will become apparent to those skilled in the art from reading the text that follows are substantially achieved by means of a winding or rolling-up device according to claim 1 and with a method according to claim 10. The device according to the invention includes a support for a reel in the process of formation and a rotation system for rotating the reel in the process of formation which winds the weblike material onto the reel at a winding speed. It also includes a tensioning member in contact with the outer surface of the reel in the process of formation whose peripheral speed is controlled so as to be able to exceed the winding speed, in other words the speed at which the weblike material is fed to the reel. The difference between the speed of the tensioning member and the feeding speed of the weblike material introduces a tension into said material that increases the compactness of the reel. Since the tension is applied to a more outward portion of the turn of the weblike material already wound up onto the reel, the risks of tearing and of excessive transverse contractions of the material are avoided, and therefore this device enables compact reels to be obtained even using weblike materials of low tensile strength. The compactness of the reels makes their subsequent handling easier and makes them less subject to damage. Using the device according to the present invention, it is possible to implement a winding method for producing a reel of weblike material of high compactness, maintaining the tension of the weblike material fed to the reel at a limit value, characterized in that the weblike material already wound around said reel is tensioned. The tensioning member may in principle be any member capable of transmitting motion peripherally to the reel, for example a band, a belt or the like. However, in accordance with a particularly advantageous embodiment of the invention, the tensioning member is a motor-driven cylinder. The rotation of the reel to wind up the weblike material may be obtained with a central transmission system, in other words one acting via the axis of the reel. However, peripheral or superficial winding systems are preferred, in other words systems in which the rotary motion is imparted by a peripheral winding means, in contact with the outer surface of the reel. This winding means may comprise a flexible member, for example one or more belts in parallel, side by side and pressed against the surface of the reel. According to a preferred embodiment, the winding means comprises a motor-driven winding roller, around which the weblike material is passed and fed to the reel in the process of formation. The reel is supported axially by said support. In order to ensure a reliable transmission of the motion by the tensioning member to the material to be tensioned, it is advantageous to provide for the outer surface of the tensioning member (in other words the surface in contact with the reel) to possess an outer surface having a high coefficient of friction. In order to introduce a sufficient tension into the weblike material, it is advantageous to provide for the tensioning member and the peripheral winding means to be in contact with the outer surface of the reel at points that are sufficiently far apart. For example, provision may be made for such points to be at an angular distance apart that is always approximately greater than 270°, even when the reel is at the beginning of the winding-up process. The invention will be better understood with reference to the description and the attached drawing, which shows a practical and nonlimiting embodiment of the invention. More particularly, Figs. 1 to 5 show diagrammatically a lateral view of the device at four different stages of processing. The device comprises a bearing structure 1 on which is mounted a motor-driven winding roller 3. The rotary motion of the winding roller 3 is provided in the example illustrated by a motor 4 and a transmission comprising a flexible member 6. Upstream of the winding roller 3 is disposed a series of cylinders 5, 7, 9 defining a feed path for the weblike material, generally designated N, which is fed in the direction of the arrow fN. The material N, fed with continuous and approximately constant motion, is passed around the winding roller 3 through an angle approximately equal to 180°. The winding roller is in contact with a reel B in the process of formation. The latter is wound around a central core C axially threaded onto a supporting mandrel M. The mandrel M is supported, during winding, by a dual support guide 11 solidly fixed to the bearing structure 1. A carriage 13 sliding on guides solidly fixed to the structure 1 and equipped with small arms 15 bearing small rollers 17 pushes the mandrel, and hence the reel B in the process of formation, against the winding roller 3, in a manner such that, via the frictional force, the rotation of the latter causes the reel B to rotate. The device is also equipped with a pair of oscillating arms, one of which is visible in the figures and designated 19 therein. The arms 19 are articulated about an axis coinciding with the axis of the winding roller 3 and are controlled in oscillation by a cylinder-and-piston actuator 21. The oscillating arms 19 bear a pair of cylinders 23, 25, one of which is mounted directly on the arms 19 while the other is mounted on small arms 27 controlled by a cylinder-and-piston actuator 29. The arms 19 additionally bear an oscillating blade 31 controlled by a cylinder-and-piston actuator 33. The components 19-33 serve to cut the weblike material N at the end of the winding of the reel B and act in the manner clearly indicated in Figs. 1 to 4. The completed reel B is caused to roll along the guides 11 as far as a brake 45, shown diagrammatically in the figures, which acts to stop the rotation by inertia of said reel, allowing it subsequently to be moved on by means that are not shown but are known per se. In the upper zone of the fixed structure is disposed a mechanism for the insertion of the new winding cores that replace the reels B progressively as the latter are completed. The mechanism for the insertion of the new cores comprises a pair of oscillating arms 47 controlled by a cylinder-and-piston actuator 49 to oscillate about an axis 50. The arms 47 possess jaws 51 whose opening and closing are controlled by a cylinder-and-piston actuator 53 and serve to grasp the individual cores C waiting in the upper zone of the structure 1 to carry them into the winding zone by means of oscillation of the arms 47, as can be seen in the sequence illustrated in the attached Figs. 1 to 4. The arms 47 release the new winding core C supported on the guides 11, in contact with the winding roller 3 and thrust against the latter by the carriage 13 with the associated small arms 15 and small rollers 17. The mechanism for cutting the weblike material and for winding up and braking the completed reel B, and the mechanism for the insertion of the new winding cores, are known per se and do not require any more detailed description here. Their modes of operation are apparent from the sequence shown in Figs. 1 to 4. They are merely given by way of example and could be replaced by various mechanisms having analogous or similar functions. Characteristically, according to the invention, the winding device has a motor-driven cylinder 61 supported by a pair of oscillating arms 63 pivoted at 65 on the structure 1 of the device. In the example, the pivot axis 65 of the oscillating arms 63 coincides with the axis of rotation of the winding roller 3. The motor-driven cylinder 61 is set in rotation by a motor 69, via a transmission belt 71 or other suitable flexible member. A different form of motor drive, for example by means of a motor coaxial with the cylinder 61 or a geared transmission or the like, is not excluded. The oscillation of the arms 63 bearing the motor-driven cylinder 61 is controlled by an actuator which, in the example shown, is a cylinder-and-piston actuator 73. The oscillating movement is such as to be able to cause the motor-driven cylinder 61 to assume a moved-apart position that allows the introduction of a new winding core, or a position such as to bring it side by side with and pressed against the reel B in the process of formation. The oscillating movement of the arms 63 in this case is such as to cause the motor-driven cylinder 61 to follow the growth of the reel B. In practice, the cylinder-and-piston actuator 73 can act as a simple pneumatic spring to keep the motor-driven cylinder 61 pressed with the necessary compressive force against the outer surface of the reel B in the process of formation during the entire winding cycle of said reel, while when it is retracted it brings the motor-driven cylinder 61 into the rearward position, in which it leaves the space free for the introduction of the new winding reel C by means of the oscillating arms 47 and the jaws 51. The motor 69 for the control of the motor-driven cylinder 61 is controlled by a central control unit which also provides the control of other parts of the device and in particular of the motor 4 for actuating the winding roller 3. The control is provided in a manner such that the peripheral speed of the motor-driven cylinder 61 is normally slightly greater than the feeding speed of the weblike material N, in other words the peripheral speed of the winding roller 3 and hence that of the reel B in the process of formation. The speed of the winding roller 3, on the other hand, is regulated in a manner such as to maintain on the weblike material N upstream of said winding roller 3 weblike material N upstream of said winding-up roller 3 a tension that is sufficiently moderate not to cause the tearing of said material. It follows from this that the final turn, that is to say the outermost turn of the reel B in the process of formation, is subjected to a tensioning determined by the difference between the peripheral speed of the motor-driven cylinder 61 and the peripheral speed of the winding roller 3. This difference in peripheral speed may be set as desired as a function of the winding requirements. Consequently, the outermost turn of the weblike material is tensioned and the winding is more compact. The greater the difference in speed, the greater the compactness of the reel B in the process of formation. The tension that is induced in the weblike material as a result of the difference between the abovementioned peripheral speeds does not cause the tearing of the weblike material, in that such tension is induced in the portion of the material already supported on the reel in the process of formation and not in the free weblike material. Furthermore, the tension that is induced in the weblike material as a result of the difference between the peripheral speeds of the motor-driven cylinder 61 and the winding roller 3 does not induce significant transverse narrowings of the weblike material, in that the latter is subjected to tensioning when it is already supported on the underlying coils of the reel B in the process of formation. In order to ensure a sufficient tensioning effect, and avoid phenomena of transverse narrowing and/or tearing of the weblike material, the motor-driven cylinder 61 is provided with a cylindrical surface having a high coefficient of friction, for example being covered with abrasive fabric or "grip", and furthermore it is located, relative to the winding roller 3, in a position such as to have a sufficient quantity of weblike material subjected to tensioning. In the example illustrated, the two elements 3 and 61 are located at an angular distance apart that is variable between approximately 270° and approximately 330°, depending on the diameter of the reel in the process of formation. From the above it is apparent that the reel in the stage of formation is supported axially, while the tensioning member 61 has no supporting function, interacts with the rotation system for rotating the reel (in other words the winding roller 3) to tension appropriately the turn of weblike material that is outermost at a given time. The arrangement is particularly useful in devices that wind up weblike materials of limited tensile strength, for example at the exit from the production line for said weblike material. The weblike material N is fed between the motor-driven cylinder 61 and the winding roller 3, thus permitting a good tensioning effect, in that the position of the elements 3 and 61 is such as to tension the weblike material along a very wide arc and almost over an entire turn. Advantageously, the diameter of the motor-driven cylinder 61 is less than the diameter of the winding-up roller 3.

Claims: A winding device for the production of reels (B) of weblike material (N), comprising: a support (11) for a reel in the process of formation; a rotation system (3) for rotating the reel in the process of formation which winds up the weblike material (N) onto the reel (B) at a winding speed; a tensioning member (61) in contact with the outer surface of the reel (B) in the process of formation whose peripheral speed is adjustable, characterized in that said rotation system for rotating the reel comprises a peripheral winding means (3) in contact with the external surface of the reel, and that said tensioning member is controlled so that its peripheral speed is able to exceed the winding speed. The device as claimed in claim 1, characterized in that said tensioning member is a motor-driven cylinder (61). The device as claimed in claim 1 or 2, characterized in that said winding means is a motor-driven winding roller (3), around which the weblike material is passed and fed to the reel in the process of formation. The device as claimed in claim 1 or 2 or 3, characterized in that said support for the reel supports the reel at its axis. The device as claimed in one or more of the preceding claims, characterized in that said tensioning (61) member possesses an outer surface having a high coefficient of friction. The device as claimed in one or more of the preceding claims, characterized in that said tensioning member (61) and said peripheral winding means (3) are in contact with the reel (B) in the process of formation in two zones angularly offset by an angle equal to or greater than 270°. The device as claimed in one or more of the preceding claims, characterized in that said tensioning member (61) is supported by a pair of oscillating arms (63). The device as claimed in claim 7, characterized in that said oscillating arms (63) also support a motor (69) for the actuation of the tensioning member (61). The device as claimed at least by claims 2 and 3, characterized in that the motor-driven cylinder (61) has a lesser diameter than the winding roller (3). A method for the production of reels (B) of weblike material (N) of high compactness by maintaining the tension of the weblike material fed to the reel at a limit value, wherein: the weblike material is fed in a continuous manner to a rotation system (3) for rotating the reel (B) in the process of formation; at the end of the winding of a reel, the reel formed is removed and the weblike material fed in a continuous manner is wound up on a subsequent reel; the weblike material already wound up around said reel being tensioned during formation of said reel, characterised in that : said rotation system (3) includes a peripheral winding means (3) in contact with the external surface of the reel; said weblike material is tensioned by a motor-driven tensioning member (61) contacting said reel; and the peripheral speed of said tensioning member (61) is maintained higher than the peripheral speed of said peripheral winding means (3), to introduce a tension into said weblike material (N).

Inventors: ACCIARI GIUSEPPE, ACCIARI, GIUSEPPE
Applicants: CELLI NONWOVENS SPA, A. CELLI NONWOVENS S.P.A.
Application year: 2001
Main classification: B65H18
IPC codes: B65H23, B65H18, B65H19