Device and method for thermal bonding of a textile web

Abstract

The invention relates to a device and a method for the bonding of a textile web, whereby the textile web is guided over an idler drum into a bonding plant, led around a through-air drum and over a cooling drum and then led out again, whereby heated fresh air flows through the web and the through-air drum and the exhaust air is extracted from the bonding plant. According to the invention, it is intended that cooling air is directed onto the web ahead of the detachment point of the web from the through-air drum onto the web.

Claims

1. A device for thermal bonding of a textile web, whereby the textile web is led over an idler drum into a bonding plant, led around a through-air drum and led out again over a cooling drum, whereby heated fresh air flows through the web and the through-air drum and exhaust air is extracted from the bonding plant, wherein cooling air is directed onto the web ahead of a detachment point of the web from the through-air drum, whereby the cooling air is directed onto the web by means of a channel and/or a nozzle and wherein the cooling air flows through the web and the through-air drum.

2. The device according to claim 1, wherein the cooling air is separated from the fresh air and hot air inside the through-air drum by means of an air system.

3. The device according to claim 2, wherein the air system is structured as an at least partially closed redirection arranged inside the through-air drum with which the cooling air is again led off from the bonding plant.

4. The device according to claim 2, wherein the air system comprises at least one channel or one shielding plate.

5. The device according to claim 4, wherein the cooling air is led from the bonding plant via a channel that is arranged in an area between the idler drum and the cooling drum.

6. The device according to claim 5, wherein the channel is arranged so that it can swivel.

7. The device according to claim 4, wherein the shielding plate is formed as a concave or convex dished design.

8. A method for the bonding of a textile web, whereby the textile web is led over an idler drum into a bonding plant, led around a through-air drum and led out again over a cooling drum, whereby heated fresh air flows through the web and the through-air drum and exhaust air is extracted from the bonding plant, wherein the web is cooled by cooling air ahead of a detachment from the through-air drum, and wherein the cooling air that forms a closed redirection within the through-air drum is extracted from the bonding plant by an air system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is explained in more detail by means of the accompanying drawings; in these is shown

(2) FIG. 1 A schematic representation of a first embodiment of an invention-related bonding plant;

(3) FIG. 2 A schematic representation of a second embodiment of an invention-related bonding plant.

DETAILED DESCRIPTION OF THE INVENTION

(4) FIG. 1 shows an Omega design bonding plant operated with hot air. The web 1 to be bonded runs in the run-in section 4 over an idler drum 2 that can be embodied as extraction drum into the bonding plant, runs around the air-permeable-designed through-air drum 5 in the clockwise direction and then runs over a cooling drum 3 in the run-out region 6 of the bonding plant. The through-air drum 5, the idler drum 2 and the cooling drum 3 can be arranged in a common housing 7 into which hot fresh air 8 is fed via one or more inlet flow openings. The hot fresh air 8 flows through the web 1, so heating the web; the air is then extracted by a fan, not shown in the figure, located in the end face of the through-air drum 5. In this, the through-air drum 5 is operated at negative pressure so that different flow conditions occur in the bonding plant.

(5) To prevent the web 1 adhering to the through-air drum 5, the invention provides for the web 1 to be cooled shortly before the detachment from the through-air drum 5. For this, a channel 10 in the run-out region 6 is arranged over which cooling air 9 is fed by fans not shown in the figure, onto the web 1. The cooling air 9 flows through the web 1 across the working width and along the axis of the through-air drum and cools this. In this, the cooling air flows through the through-air drum 5 in a locally limited area and redirected via a further channel 10a arranged within the through-air drum 5. The cooling air then 9 then flows through the through-air drum 5 for a second time and is extracted again via a channel 10b which lies between the idler drum 2 and the cooling drum 3. An inlet for fresh air 8, amongst other things, is arranged in the region of the cooling drum 3. As a separate air system is used for web cooling, and is completely separated from the fresh air and hot air of the bonding plant, the air balance of the bonding plant is not affected. The air system in this embodiment example comprises at least the channel 10a that separates the various air streams within the through-air drum 5 from each other and from the run-out region 6 up to the area between the idler drum 2 and the cooling drum 3. The channel 10a is formed as a channel closed at the circumference, which also stretches over the working width of the bonding plant parallel to the longitudinal axis of the of the through-air drum and has two openings whereby one opening with channel 10 and the other opening with channel 10b interact. A shielding plate 13 closes flush with channel 10a and reaches into the run-in region 4 into the area above the idler drum 2. The shielding plate 13 is designed and located parallel to the inner side of the through-air drum and separates the hot air and fresh air within the bonding plant from the ambient air.

(6) An extraction 11 using a fan not shown in the figure, which lies underneath the bonding plant in the region of the idler drum 2 and of the cooling drum 3 can be so arranged that it extracts the cooling air 9 from the channel 10b. The channel 10b located between the idler drum 2 and the cooling drum 3 can be designed so that it can swivel, which facilitates the introduction of a web 1 when starting up the plant. The bonding plant can also be converted very quickly to working with webs using normal fibers that have no or only a very slight tendency to adhere. An adjustment of the cooling output to the web 1 to be processed can take place by means of a device in which the cross section of the channel 10 is changed and/or the fans transporting the cooling air 9 have a variable power that can be controlled, e.g. using frequency inverters. As an alternative with this embodiment, the cooling air 9 can also be fed via the channel 10b, be redirected in the channel 10a within the through-air drum 5 and extracted via the channel 10. This flow direction assists the detachment of the web 1 from the through-air drum.

(7) In the second embodiment example according to FIG. 2, in which the bonding essentially has the same structure and the same function, an already known shielding plate 13 is used to extract the cooling air 9 from the bonding plant. The air system in this embodiment example comprises at least the shielding plate 13 that separates the various air streams within the through-air drum from each other and from the run-out region 6 up to the area between the idler drum 2 and the cooling drum 3. The purpose of the shielding plate 13 is to separate the surroundings outside the bonding plant into the run-in and run-out sections 4, 6 in flow terms from the through-air drum 5, as this is at negative pressure and the air flowing in this region between idler drum 2 and cooling drum 3 does not heat up the web 1. The shielding plate 13 can be a convex or concave dished design that is aligned parallel to the inner diameter of the through-air drum. It has the task, on the one hand, of screening off the cooling air 9 from the airflow in the through-air drum 5 but, on the other hand, also to redirect the cooling air 9. In this, the cooling air flows through a nozzle 12 up and through the web 1 into an edge region of the through-air drum 5 and cools the web 1. By means of the nozzle 12, a very narrow strip or area can be cooled whereby the cooling air is directed precisely onto the edge region of the shielding plate 13. Through the shielding plate that can have a dish-shaped convex or concave form, a redirection of the cooling air 9 out of the bonding plant takes place in which this is extracted between the idler drum 2 and the cooling drum 3 via an extraction 11. In a preferred embodiment, a channel 10b that can be swiveled can be located between the idler drum 2 and the cooling drum 3. The bonding plant can therefore be converted very quickly to working with material webs using normal fibers that have no, or only a very slight, tendency to adhere. Furthermore, the channel 10b that can be swiveled facilitates the introduction of a web 1 when starting up the plant.

(8) In both embodiment examples, the channel 10 or the nozzle 12 is limited to a small local area, but directed parallel to the longitudinal axis of the through-air drum 5 over the entire working width onto the web 1, shortly before the web 1 is guided tangentially onto the cooling drum 3. The detachment point of web 1 from through-air drum 5 is formed from the intersection point of the verticals through the center point of through-flow drum 5 with the tangent between through-air drum 5 and cooling drum 3. As the detachment point of web 1 from the through-air drum depends, amongst other things, on the diameters and the arrangement of the through-air drum 5 and the idler drum 2 or cooling drum 3, the arrangement of the channel 10 or the nozzle 12 can vary. With a through-air drum diameter of, for example 2650 mm, the cooling air 9 can be directed onto the circumference of the through-air drum between 50 mm and 1200 mm in front of the detachment point of the web 1. If the through-air drum 5 is rotating at high speed, the cooling air 9 must be directed at a greater distance from the detachment point on the web 1 as that for a lower speed. The adherence angle of the web 1 has naturally also to be taken into consideration here.

REFERENCE NUMBERS

(9) 1 Web 2 Idler drum 3 Cooling drum 4 Run-in region 5 Through-air drum 6 Run-out region 7 Housing 8 Fresh air 9 Cooling air 10 Channel 10a Channel 10b Channel 11 Extraction 12 Nozzle 13 Shielding plate