Device for automatically unwinding web-shaped materials and method for operating such a device

Abstract

A device for automatically unwinding web-shaped materials (8) from a master roll (3), and to a method for operating a device of this type are disclosed. The device has an infeed arm (2) and a first drive unit (6), wherein the master roll (3) by way of the winding core (4) thereof is rotatably mountable on the infeed arm (2), and the first drive unit (6) serves for introducing a driving force into the master roll (3). In order for high productivity to be achieved, the unwinder (1) has an outfeed arm (13) to which a second drive unit (14) for introducing a driving force into the master roll (3) is assigned, wherein the master roll (3) during an unwinding procedure is transferable from the infeed arm (2) to the outfeed arm (13). The material web (8) is then unwound from the master roll (3) which is mounted on the infeed am (2) down to a predefinable minimum diameter, wherein during the ongoing unwinding procedure the master roll (3) is subsequently transferred to the outfeed arm (13) and thereon is further actively unwound, wherein a new master roll (3) is received by the infeed arm (2). Unwinding without interruption is thus enabled.

Claims

1. An unwinder for automatically unwinding a material web from a master roll, having an infeed arm and at least one first drive unit, wherein the master roll by way of a winding core thereof is rotatably mountable on the infeed arm, and by way of the drive unit a driving force is introducible into the master roll, wherein the unwinder has an outfeed arm to which at least one second drive unit for introducing a driving force into the master roll is assigned, wherein the master roll during an unwinding procedure is transferable from the infeed arm to the outfeed arm, and wherein said unwinder has a contact roller which is placeable on a circumference of the master roll which is mounted on the infeed arm, wherein the material web by way of the contact roller is guided away from the master roll.

2. The unwinder as claimed in claim 1, wherein the first drive unit on the infeed arm is configured as a winding shaft drive which is attached to the end side.

3. The unwinder as claimed in claim 1, wherein the first drive unit on the infeed arm is configured as a first drive swing arm.

4. The unwinder as claimed in claim 3, wherein the first drive swing arm has one or a plurality of belt drives.

5. The unwinder as claimed in claim 1, wherein said unwinder has a cutting installation which is configured as a cutting blade having a counter-impact strip.

6. The unwinder as claimed in claim 1, wherein said unwinder has a roll storage stand from which the master roll is receivable by the infeed arm.

7. The unwinder as claimed in claim 1, wherein said unwinder has an outfeed installation by way of which the unwound winding core is removable from the outfeed arm.

8. The unwinder as claimed in claim 1, wherein the second drive unit on the outfeed arm is configured as a winding shaft drive which is attached to the end side.

9. The unwinder as claimed in claim 1, wherein the second drive unit on the outfeed arm is configured as a second drive swing arm.

10. The unwinder as claimed in claim 9, wherein the second drive swing arm has one or a plurality of belt drives.

11. A method for operating an unwinder for automatically unwinding a material web from a master roll, having an infeed arm and at least one first drive unit, wherein the master roll by way of a winding core thereof is rotatably mountable on the infeed arm, and by way of the drive unit a driving force is introducible into the master roll, wherein the unwinder has an outfeed arm to which at least one second drive unit for introducing a driving force into the master roll is assigned, wherein the master roll during an unwinding procedure is transferable from the infeed arm to the outfeed arm, wherein the material web is unwound from the master roll which is mounted on the infeed arm down to a predefinable minimum diameter, wherein during the ongoing unwinding procedure the master roll is subsequently transferred to the outfeed arm and thereon is further unwound, wherein a new master roll is received by the infeed arm, wherein an end of the material web that is unwound from the master roll which is mounted and driven on the outfeed arm is spliced to a lead end of the new master roll which is mounted and driven on the infeed arm, wherein to this end the material web emanating from the master roll which is mounted on the outfeed arm is pressed onto a circumference of the new master roll by a contact roller.

12. The method as claimed in claim 11, wherein for transferring the master roll, the infeed arm is moved toward the outfeed arm, or the infeed arm and the outfeed arm are converged, wherein driving by way of the first drive unit is performed at least until the master roll is driven by the second drive unit.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) The invention will be described in more detail hereunder by means of a preferred exemplary embodiment in conjunction with the drawings in which:

(2) FIGS. 1 to 9 show a side view of a device for automatically unwinding a material web at various points in time during an unwinding procedure.

DETAILED DESCRIPTION OF INVENTION

(3) A device for automatically unwinding a material web, that is to say an unwinder 1, which has an infeed arm 2 on which a master roll 3 having a winding core 4 is rotatably mounted is schematically shown in side view in the figures. A material web, for example from a non-woven material, is wound on the winding core 4. The master roll 3 is removed from a buffer or from a transfer region of a non-woven fabric production line, for example, and transferred to the infeed arm 2. A roll storage stand 5 on which a new master roll may be held in a standby position until the latter is acquired by the infeed arm 2 is provided for the transfer.

(4) A first drive unit 6 configured as a first drive swing arm which is disposed above the master roll 3 or above the infeed arm 2, respectively, serves for generating rotation of the master roll 3. The first drive swing arm 6 has one or a plurality of belt drives 7 and is placed on a circumference of the master roll 3, in order for a force which is directed in the circumferential direction to be transmitted. Unwinding of the master roll 3 is performed in this way, wherein the material web 8 is guided by way of a contact roller 9 and a deflection roller 10 to a downstream cutting line, for example, or to another processing line. Additionally, it may be provided that a winding shaft drive in the form of a center drive which is mounted on the infeed arm, for example, and which engages directly on the winding core 4 is provided for driving the master roll 3. This, however, is not illustrated in the figures.

(5) The contact roller 9 is pivotably mounted on an arm 11 and is capable of bearing on the circumference of the master roll 3 in order to provide contact pressure in particular. The infeed arm 2 is pivotably mounted, wherein a motion path 12 of a rotation axis of the master roll 3 is illustrated with dashed lines.

(6) The unwinder 1 furthermore has an outfeed arm 13 which is pivotably mounted. The master roll 3 may be transferred from the infeed arm 2 to the outfeed arm 13, which to this end are pivoted so as to converge. The outfeed arm 13 is assigned a second drive unit 14 which is configured as a second drive swing arm and which is then placeable on the circumference of the master roll 3 when the master roll 3 is mounted on the outfeed arm 13. Accordingly, it is possible for the master roll to be actively unwound in a continuous manner, irrespective of whether said master roll is mounted on the infeed arm 2 or on the outfeed arm 13. Like the first drive swing arm 6, the second drive swing arm 14 may also have one or a plurality of belt drives.

(7) A winding core 4 which has already been unwound and which is conveyed away from the unwinder 1 by an outfeed installation (not illustrated in more detail) is schematically illustrated in FIG. 1.

(8) In order for the material web to be severed, the unwinder 1 has a cutting installation having a cutting blade 15 and a counter-impact strip 16. In this way the material web is severable in a manner transverse to the web running direction when the master roll is mounted on the outfeed arm 13. The cut is then performed between the master roll 3, which is mounted on the outfeed arm 13, and the contact roller 9.

(9) The functional sequence of the unwinder will now be described in more detail, proceeding from FIG. 1.

(10) In FIG. 1 a master roll 3 is located on the infeed arm 2. The first drive swing arm 6 has been guided onto the circumference of the master roll 3, and the material web 8 is unwound by way of the contact roller 9 and of the deflection roller 10 and supplied to a cutting line (not illustrated). Once a diameter of the master roll has been reduced in a corresponding manner by unwinding of the master roll so as to make available sufficient space, a new master roll 3 is made available on the roll storage stand 5 (FIG. 2). Here, both the infeed arm 2 as well as the first drive swing arm 6 have already been pivoted in the direction of the outfeed arm 13, so as to enlarge the available space.

(11) The point in time at which the master roll 3 is acquired by the outfeed arm 13 is now illustrated in FIG. 3. To this end, the outfeed arm 13 grips projecting ends of the winding core 4 and acquires the master roll 3, without interrupting rotation of the master roll 3. Driving of the master roll 3 is assumed by the second drive swing arm 14 which is assigned to the outfeed arm 13. Optionally, both the first drive swing arm 6 as well as the second drive swing arm 14 may bear on the circumference of the master roll for a brief period, so as to guarantee a continuous transition.

(12) In FIG. 4 the master roll 3 is held by the outfeed arm 13 alone and is driven by the second drive swing arm 14, wherein drawing-off of the material web 8 continues to be performed via the contact roller 9 and the deflection roller 10. The infeed arm 2 is pivoted in the direction of the roll storage stand 5, so as to receive a new master roll 3. The first drive swing arm 6 has been upwardly pivoted, so as to enable introduction of the new master roll 3 into an unwinding position. This is illustrated in FIG. 5. The new master roll 3 is ready for participating in the unwinding procedure. However, the material web is still being unwound from the previous master roll 3.

(13) FIG. 6 now shows the beginning of a splicing procedure in which the material web emanating from the master roll 3 which is mounted on the outfeed arm 13 is spliced to the material web which is located on the new master roll 3. This is performed with the aid of the contact roller 9 which mutually compresses the material webs and which generates the pressure forces required for configuring the spliced connection. At the same time, the cutting installation having the cutting blade 15 and the counter-impact strip 16 is prepared in order for a cut through the material web to be produced.

(14) FIG. 7 now shows the actual splicing procedure, wherein an initially double-layered material web is drawn off downstream of the contact roller 9.

(15) It is now illustrated in FIG. 8 how the material web emanating from the previous master roll 3 is severed by the cutting blade 15. Accordingly, the master roll 3 is completely unwound and may be removed, as is shown in FIG. 9. A lead end of the material web which is wound on the new master roll 3 is automatically discharged by way of the contact roller 9 and of the deflection roller 10, without any interruption taking place. The unwinder here is in the same position as is illustrated in FIG. 1. Accordingly, a new unwinding cycle commences.

(16) Non-stop unwinding is possible by way of the method according to the invention and of the device according to the invention, respectively. It is provided here that active unwinding of the master roll is effected both on the unloading arm and on the infeed arm by way of respective drive units, that is to say that both positions are used for unwinding. In this way, a significant increase in efficiency results in particular in the case of offline plants such as employed in the manufacturing of non-woven fabrics. Downtime which to date has been necessary due to the changeover of the master roll may be entirely eliminated. Moreover, complete automation is possible.

(17) The invention is not limited to any of the above-described embodiments but may be modified in a variety of manners.

(18) All features and advantages, including construction details, spatial arrangements and method steps, which are derived from the claims, the description and the drawings may be relevant to the invention both individually and in various combinations thereof.

LIST OF REFERENCE SIGNS

(19) 1 Unwinder 2 Infeed arm 3 Master roll 3 New master roll 4 Winding core 4 Unwound winding core 5 Roll storage stand 6 First drive unit/First drive swing arm 7 Belt drive 8 Material web 9 Contact roller 10 Deflection roller 11 Arm 12 Motion path 13 Outfeed arm 14 Second drive unit/Second drive swing arm 15 Cutting blade 16 Counter-impact strip