Device for applying a hot-melt to a web of material

Abstract

The invention relates to a device for applying a hot-melt to a web of material. The device includes a driven roller and a nozzle with a nozzle channel arranged adjacent the driven roller for supplying a hot melt through the nozzle channel to the surface of the roller. The invention also relates to a combination of a device according to the invention and a web of material, which web of material is guided along the driven roller and wherein the nozzle channel exits in front of the nip of the web of material and the driven roller.

Claims

1. A device for applying a hot-melt to a web of material, wherein said device comprises: a driven roller for moving the web of material, wherein the driven roller has an outer surface and rotates in a first direction about a driven roller axis; a nozzle with a nozzle channel arranged adjacent the driven roller for supplying the hot-melt through the nozzle channel between the driven roller and the web of material directly to the surface of the driven roller, wherein the nozzle channel is bounded by a first channel wall, a second channel wall which is shorter than the first channel wall, and a part of the outer surface of the driven roller, wherein a portion of the nozzle channel is parallel to the outer surface of the driven roller from a point in the nozzle channel where the first channel wall extends past the second wall to a tip of the nozzle, and wherein the first channel wall directs the hot-melt against the outer surface of the driven roller in a flow direction that is a same direction the outer surface of the driven roller moves; and wherein the first channel wall of the nozzle and the driven roller outer surface form a layer of the hot-melt at a predetermined thickness which is then deposited to the web of material, the first channel wall extends from a point opposite the second wall to the tip of the nozzle where the hot-melt exits in front of a nip of the web of material and the driven roller, wherein at the tip of the nozzle the first channel wall is located directly between the driven roller and the web of material and the web of material at the nip moves in the same direction the outer surface of the driven roller.

2. The device according to claim 1, wherein the flow direction is tangential to the circumference of the driven roller.

3. The device according to claim 1, wherein the nozzle channel is bounded by the part of the outer surface of the driven roller, in the flow direction, over at least a twentieth of the circumference of the driven roller.

4. The device according to claim 1, wherein the nozzle channel is provided in transverse direction, perpendicular to the flow direction, at least one partition wall to apply the hot-melt in tracks to the web of material.

5. The device according to claim 4, wherein the at least one partition wall is provided by an elevation arranged in a nozzle channel wall.

6. The device according to claim 1, wherein the nozzle channel is in the flow direction, over at least a tenth of the circumference of the driven roller, parallel to the driven roller.

7. A combination of a device according to claim 1 and the web of material, wherein the web of material is guided along the driven roller and wherein the hot melt exits the nozzle channel in front of the nip of the web of material and the driven roller.

8. The combination according to claim 7, wherein the distance between the tip of the nozzle where the hot-melt exits the nozzle and the nip of the web of material and the driven roller is less than 10 mm.

9. The device according to claim 2, wherein the nozzle channel is bounded by the part of the outer surface of the driven roller, in the flow direction, over at least a twentieth of the circumference of the driven roller.

10. The device according to claim 1, wherein the nozzle channel is provided in a transverse direction, perpendicular to the flow direction, said nozzle channel having at least one partition wall to apply the hot-melt in tracks to the web of material.

11. The device according to claim 3, wherein the nozzle channel is provided in a transverse direction, perpendicular to the flow direction, said nozzle channel having at least one partition wall to apply the hot-melt in tracks to the web of material.

12. The device according to claim 2, wherein the nozzle channel is provided in a transverse direction, perpendicular to the flow direction, said nozzle channel having at least one partition wall to apply the hot-melt in tracks to the web of material.

13. The device according to claim 9, wherein the nozzle channel is provided in a transverse direction, perpendicular to the flow direction, said nozzle channel having at least one partition wall to apply the hot-melt in tracks to the web of material.

14. The device according to claim 1, further including the web of material.

15. The device according to claim 1, wherein the nozzle channel is provided in a transverse direction, perpendicular to the flow direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other features of the invention will be elucidated in conjunction with the accompanying drawings.

(2) FIG. 1 shows a side view of an embodiment of the device according to the invention.

(3) FIG. 2 shows an enlarged view of part of FIG. 1.

(4) FIG. 3 shows a perspective view of the embodiment of FIG. 1.

DESCRIPTION OF THE INVENTION

(5) FIG. 1 shows a side view of an embodiment of the device 1 according to the invention. The device 1 has a driven roller 2 along which a web of material 3, such as a paper web, is guided. The driven roller 2 is in contact with the web of material 3.

(6) Furthermore, a nozzle 4 is provided adjacent to the roller 2. The nozzle 4 has a nozzle channel 5 through which a fluid, such as a hot-melt, is supplied. The nozzle channel 5 has channel walls 6, 7. As the channel wall 6 is shorter than the channel wall 7, the nozzle channel 5 is also bounded by a part of the surface 8 of the roller 2 over a distance x of the circumference of the roller 2.

(7) As can be seen in more detail in FIG. 2, the fluid exits at the tip 9, or channel, of the nozzle 4 between the driven roller 2 and the web of material 3 and provides a layer 10 of fluid directly on the surface of the roller 2. As the fluid was already in contact with the roller 2 over the distance x and because the channel 5 has been parallel to the surface of the roller, a very even and thin layer 10 of fluid can be provided. The nozzle 4 and the driven roller 2 outer surface form a layer 10 of hot-melt having a predetermined thickness at the nip of the roller which is then deposited to the web of material 3. Furthermore, as seen in FIG. 2, the web of material 3 at the nip moves in the same direction as the material moved by the driven roller 2.

(8) Furthermore, when viewed in a direction perpendicular to the driven roller axis, the nozzle channel 5 is bounded by a first channel wall 6A, a second channel wall 6B being shorter than the first channel wall and part of the outer surface of the driven roller 2.

(9) When the fluid layer 10 arrives at the nip 11 between the roller 2 and the web of material 3, the fluid layer 10 is transferred onto the web of material 3.

(10) Preferably, the distance y between the tip 9 of the nozzle 4, where the fluid exits the nozzle 4, and the nip 11 is less than 10 mm. This ensures that the layer of fluid 10 is not disturbed between exiting the nozzle 4 and the nip 11, where the layer 10 is transferred onto the web of material 3.

(11) FIG. 3 shows a perspective view of the embodiment 1 of FIG. 1. The nozzle channel 5 is provided in transverse direction, perpendicular to the flow direction F, with a number of elevations 12, which provide partition walls, such that tracks of hot-melt can be applied to the web of material 3.