Device and method for laser cutting a web of fibrous material

Patent metadata

Field	Value
Publication number	US-10610418-B2
Application number	US-201515305054-A
Country	US
Kind code	B2
Filing date	Apr 14, 2015
Priority date	Apr 18, 2014
Publication date	Apr 7, 2020
Grant date	Apr 7, 2020

Abstract

A device for cutting a web of fibrous material including movement means for moving a web of fibrous material to be cut, defining a feed surface for the web and having at least one first cutting zone, at least one laser source configured to generate a laser beam extending along its operating direction towards the first cutting zone to make, on the web, at least one incision extending along a predetermined cutting line, where a portion of the laser beam passes through the web of fibrous material at the first cutting zone. The device also includes recovery means for recovering the portion of the laser beam and at least partly located along the operating direction, at the first cutting zone, in such a way as to intercept the portion of the laser beam and direct it towards a second cutting zone to make a further incision or cut.

First claim

The invention claimed is:

1. A device for cutting a web of fibrous material, comprising:
the web of fibrous material;
a rotatable drum for moving the web, where the web includes a variable density material having a discrete distribution of fibers defining solid zones and empty zones free from material, the rotatable drum also defining a feed surface for the web and including a first cutting zone;
a laser source configured to generate a laser beam extending along an operating direction towards the first cutting zone to make, on the web, an incision extending along a predetermined cutting line interposed between a first edge and a second edge of the web, wherein, at the first cutting zone, the laser beam is partly absorbed by the solid zones to make the incision and a portion of the laser beam passes through the web via the empty zones;
a recovery system including at least one chosen from a mirror and a permeable portion of the rotatable drum for recovering the portion of the laser beam and at least partly located along the operating direction, at the first cutting zone, in such a way as to intercept the portion of the laser beam and direct the portion of the laser beam towards a second cutting zone to make a further incision on the web;
wherein the laser source and the recovery system are configured to:
use the laser beam at the first cutting zone to make the incision along the predetermined cutting line without separating the first edge from the second edge;
use the portion of the laser beam at the second cutting zone to make the further incision along the predetermined cutting line by which the first edge is completely separated from the second edge.

2. The device according to claim 1 , wherein the feed surface is operatively interposed between the laser source and the recovery system.

3. The device according to claim 2 , wherein the mirror is associated with the rotatable drum to at least partly define the feed surface and is oriented to reflect the portion of the laser beam on the cutting line at the first cutting zone.

4. The device according to claim 1 , wherein the recovery system comprises the mirror located along the operating direction and oriented in such a way as to reflect the portion of the laser beam towards the second cutting zone.

5. The device according to claim 4 , wherein the first cutting zone and the second cutting zone are coincident.

6. The device according to claim 1 , wherein the rotatable drum comprises, for the web, at least one supporting element provided, at the first cutting zone, with a permeable portion permeable to the laser beam “F” to allow through the permeable portion the laser beam portion which passes through the feed surface; the recovery system being operatively located downstream of the permeable portion, with reference to an optical path of the laser beam, to intercept the laser beam portion which passes through the permeable portion and direct the laser beam portion towards the second cutting zone.

7. The device according to claim 6 , wherein the permeable portion is defined by a through slot.

8. The device according to claim 6 , wherein the permeable portion is defined by an insert or window which is transparent to the laser beam; the device comprising a cleaning device, including at least one chosen from a pneumatic device, an ultrasound device and a contact device, for cleaning the insert or window, configured to remove dirt produced by sublimation of the fibrous material.

9. The device according to claim 6 , wherein the mirror is operatively located downstream of the permeable portion, with reference to an optical path of the laser beam, and oriented in such a way as to reflect the portion of the laser beam onto the second cutting zone which is distinct from the first cutting zone.

10. The device according to claim 1 , wherein the rotatable drum establishes a feed direction for the web, with the web being at least partly wound around the rotatable drum during operation of the device.

11. A method for cutting a web of material, comprising the steps of:
providing a device for cutting a web of fibrous material, comprising:
the web of fibrous material;
a rotatable drum for moving the web, where the web includes a variable density material having a discrete distribution of fibers defining solid zones and empty zones free from material, the rotatable drum also defining a feed surface for the web and including a first cutting zone;
a laser source configured to generate a laser beam extending along an operating direction towards the first cutting zone to make, on the web, an incision extending along a predetermined cutting line interposed between a first edge and a second edge of the web, wherein, at the first cutting zone, the laser beam is partly absorbed by the solid zones to make the incision and a portion of the laser beam passes through the web via the empty zones;
a recovery system including at least one chosen from a mirror and a permeable portion of the rotatable drum for recovering the portion of the laser beam and at least partly located along the operating direction, at the first cutting zone, in such a way as to intercept the portion of the laser beam and direct the portion of the laser beam towards a second cutting zone to make a further incision on the web;
wherein the laser source and the recovery system are configured to:
use the laser beam at the first cutting zone to make the incision along the predetermined cutting line without separating the first edge from the second edge;
use the portion of the laser beam at the second cutting zone to make the further incision along the predetermined cutting line by which the first edge is completely separated from the second edge;

preparing the web;
positioning the web at the first cutting zone;
generating the laser beam directed towards the first cutting zone;
making in the web, using the laser beam, the incision extending along the cutting line in such a way that the portion of the laser beam, not used in making the incision, passes through the web at least through the empty zones;
recovering the portion of the laser beam which has passed through the web;
positioning the web at the second cutting zone;
directing the recovered laser beam portion towards the second cutting zone to make the further incision in the web.

12. The method according to claim 11 , wherein the cutting line is interposed between the first edge and the second edge of the web; the power of the laser beam being such that the step of making the incision does not completely separate the first edge and the second edge from each other.

13. The method according to claim 11 , wherein the cutting line is interposed between the first edge and the second edge of the web; the directing step being accomplished by directing the recovered laser beam portion along the cutting line in such a way as to separate the first edge from the second edge thereby completing the cutting of the web along the cutting line.

14. The method according to claim 11 , wherein the step of recovering the portion of the laser beam comprises at least a sub-step of at least one chosen from reflecting and concentrating the portion of the laser beam on the second cutting zone.

15. The method according to claim 11 , wherein the first cutting zone and the second cutting zone are substantially coincident.

16. The method according to claim 11 , wherein the step of recovering and directing the portion of the laser beam are defined by a step of directly reflecting the portion of the laser beam onto the same cutting zone from which the portion of the laser bea

Assignees

• Gdm Spa
• Univ Degli Studi Di Bergamo
• Univ Di Bergamo

Inventors

• Piantoni Matteo
• Soli Valerio
• Russo Davide
• Carrara Paolo

Classifications

• B23K2101/22

  Nets, wire fabrics or the like · CPC title

• A61F13/15764

  Transferring, feeding or handling devices; Drives · CPC title

• B23K26/0846

  for moving elongated workpieces longitudinally, e.g. wire or strip material · CPC title

• B23K26/38

  by boring or cutting · CPC title

• B23K26/03

  Observing, e.g. monitoring, the workpiece · CPC title