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DE-102024003660-A1 - Protective device for protecting a movable conveyor belt, device for producing a non-woven fabric and method for protecting the movable conveyor belt

DE102024003660A1DE 102024003660 A1DE102024003660 A1DE 102024003660A1DE-102024003660-A1

Abstract

The present disclosure relates to a protective device (1) for protecting a movable lay-up belt (2) for laying down stretched filaments (3) for forming a nonwoven fabric (4), comprising a belt (5) that can be wound onto a gathering shaft (6) and, if necessary, laid down onto the lay-up belt (2) and positioned below a spinneret (7) that extrudes the filaments (3) from a melt, so that the melt extruded from the spinneret (7) falls onto the belt (5). The present disclosure further relates to a device for producing a nonwoven fabric (4) with such a protective device (1) and a method for protecting a movable lay-up belt (2) of such a device for producing a nonwoven fabric (4).

Inventors

  • Sebastian Kohl

Assignees

  • OERLIKON TEXTILE GMBH & CO. KG

Dates

Publication Date
20260513
Application Date
20241108

Claims (10)

  1. Protective device (1) for protecting a movable depositing belt (2) for depositing stretched filaments (3) for forming a nonwoven fabric (4), comprising a belt (5) that can be wound onto a collecting axis (6) and, if necessary, laid down on the depositing belt (2) and positioned below a spinneret (7) that extrudes the filaments (3) from a melt, so that the melt extruded from the spinneret (7) falls onto the belt (5).
  2. Protective device (1) according to Claim 1 , characterized in that the protective device (1) has a release device (8), wherein the belt (5) can be unwound from a state (Z1) wound on the collecting axis (6) towards the discharge belt (2) by activating the release device (8).
  3. Protective device (1) according to Claim 1 or 2 , characterized in that the band (5) is connected to the collecting axis (6) at an inner end of the band (5) in the rolled-up state (Z1).
  4. Protective device (1) according to one of the preceding claims, characterized in that the release device (8) has a spring element, in particular a torsion spring, and a retaining element, wherein the collecting axle (6) with the belt (5) can be locked in the wound-up state (Z1) by means of the retaining element, wherein the spring element is pre-tensioned in the wound-up state (Z1) of the belt (5), wherein activating the release device (8) includes releasing the retaining element, wherein the belt (5) can be unwound towards the discharge belt (2) by means of a rotation of the collecting axle (6) generated by means of the spring element.
  5. Apparatus for producing a nonwoven fabric (4) with a protective device (1) according to one of the preceding claims, with a spinneret (7) for extruding filaments (3) from a melt and with a depositing belt (2) for depositing stretched filaments (3) to form a nonwoven fabric (4).
  6. Device according to Claim 5 , characterized in that the collecting axis (6) of the protective device (1) is arranged in a depositing direction (RA) of the depositing belt (2), namely in a movement direction of the depositing belt (2) in a depositing area (9) of the depositing belt (2) for the filaments (3) and/or the melt, in front of the spinneret (7).
  7. Device according to Claim 5 or 6 , characterized in that the belt (5) is designed to be such a length that, in an unwound state (Z2), it extends from the end connected with the collecting axis (6) to beyond the depositing area (9) formed on the discharge belt (2), wherein, in the unwound state (Z2), the belt (5) projects beyond the depositing area (9) on the side facing away from the collecting axis (6) with a safety area (10) of a certain length and/or that a free space with a height (H) of 4mm to 6mm, in particular 5mm, is formed above the discharge belt (2) in its depositing area (9).
  8. device according to one of the Claims 5 until 7 , characterized in that a control and/or regulating device (11) is provided, wherein the control and/or regulating device (11) is connected to the protective device (1), in particular the release device (8), in particular the holding element, in a control-technical manner, wherein the control and/or regulating device (11) is configured to detect a malfunction of the device for producing a non-woven fabric (4), in particular the spinneret (7) and/or the lay-up belt (2), and thereafter to trigger an unwinding of the belt (5), in particular to activate the release device (8), in particular to release the holding element.
  9. Method for protecting a movable depositing belt (2) of a device for producing a nonwoven fabric (4) according to one of the Claims 5 until 8 , in which the following steps are preferably carried out in the order mentioned: • Detecting a malfunction of the device for producing a non-woven fabric (4), in particular the spinneret (7) and/or the lay-up belt (2), • Unwinding the belt (5) from the gathering axis (6), • Laying the belt (5) on the lay-up belt (2), • Conveying the belt (5) into the unwound state (Z2) by means of the lay-up belt (2) by contact with the lay-up belt (2), wherein the belt (5) in the unwound state (Z2) covers the lay-up area (9) formed on the lay-up belt (2).
  10. Procedure according to Claim 9 , characterized in that , after detecting a malfunction of the device for producing a non-woven fabric (4), in particular a malfunction of the spinneret (7) and/or the lay-up belt (2), the lay-up belt (2) is braked to a standstill, the braking of the lay-up belt (2) being monitored, the unwinding of the belt (5) being triggered and/or the release device (8) for unwinding the belt (5) being activated, in particular the holding element being released, if, due to the then current speed The tape (5) is subsequently unwound by contact with the tape (2) until the tape (5) is in the unwound state (Z2) and the achievement of the unwound state (Z2) of the tape (5) essentially coincides in time with the standstill of the tape (2).

Description

The present invention relates to a protective device for protecting a movable depositing belt for depositing stretched filaments to form a nonwoven fabric, a device for producing a nonwoven fabric with such a protective device, and a method for protecting the movable depositing belt of this device for producing a nonwoven fabric. In the prior art, devices for the production of nonwoven fabrics are known which operate according to the spunbond process or the meltblown process. From the DE 10 2019 004 969 A1 A device for producing nonwoven fabrics is known, comprising a tool with a spinneret for extruding a multitude of filaments and a lay-up belt designed as a screen belt, onto which the filaments can be laid down to form a nonwoven fabric. The device for producing nonwoven fabrics includes a drip guard with a drip tray, which can be moved from a waiting position to a protective position between the spinneret and the screen belt to protect the screen belt. The drip guard thus forms a protective device for the movable lay-up belt. Positioning the drip tray in the protective position is particularly necessary if, for example, due to problems in the extrusion process, filaments are no longer being extruded, but rather droplets that would reach the screen belt in liquid form. This must be avoided, as such droplets adhere to the screen belt and are difficult to remove, potentially only at the cost of damaging the screen belt. The drip tray, positioned in the protective position, catches any droplets before they reach the screen belt. It is designed in such a way that the drops can be easily removed from it. The drip tray is attached to the side of the tool facing the wire belt. The drip tray itself is made of serrated and perforated sheet metal. It is guided in two drip tray guides on opposite sides. The movement of the drip tray from its waiting position to its protective position between the wire belt and the spinneret is achieved by actuators, which are automatically operated by a control unit. The known drip guards, especially the drip tray with its associated drip tray guides and actuators, are very complex in design, which entails corresponding costs. Furthermore, when designing the drip guard, it is crucial to ensure that the drip guard, particularly the drip tray guides, does not impede the proper operation of the nonwoven fabric production equipment or any maintenance or conversion work on this equipment. Additionally, such a complex drip guard requires a correspondingly large installation space, specifically a clearance of at least 100 mm above the conveyor belt if the drip guard is not in place. The present invention is therefore based on the objective of providing a protective device for protecting a movable depositing belt, a device for producing a non-woven fabric with such a protective device, and a method for protecting the movable depositing belt, which reduce or eliminate the problems of the prior art, in particular reducing the design and control engineering effort. This problem is solved by a protective device according to claim 1. More precisely, the task is solved by a protective device for protecting a movable depositing belt for depositing stretched filaments to form a nonwoven fabric, which has a belt that can be wound onto a collecting axis and, if necessary, placed on the depositing belt and positioned below a spinneret that extrudes the filaments from a melt, so that the melt extruded from the spinneret falls onto the belt. Such a protective device is particularly simple and can be implemented with minimal design effort, especially because the belt is flexible and can therefore perform complex movements without the need for elaborate actuators. For example, after being placed on the discharge conveyor, the belt can be conveyed along with the conveyor, meaning it can be moved into the desired position or brought into the desired state. The belt of the protective device is preferably air-permeable, but the openings formed in the belt for this purpose are so small that the melt, which is to be captured by the belt, cannot pass through them. This is possible due to the viscosity difference between the air and the melt. The belt has a very small thickness, so that it can also be positioned below the spinneret if there is a shallow clearance above the discharge conveyor in its discharge area. Preferably, the protective device includes a release mechanism. The belt, wound onto the collecting axis, can be unwound towards the discharge conveyor by activating the release mechanism. The release mechanism is designed to unwind the belt from the collecting axis until a specific section of the belt rests on the discharge conveyor, at which point further transport of the belt can occur through contact with the moving discharge conveyor. The release mechanism is preferably activated by an automatically controlled actuator. However, manual activation of the release mechanism would also be conceivable.