DE10232148B4 - Process for the liquid-permeable perforation of a fleece - Google Patents

Abstract

method for producing a perforated nonwoven fabric (2), wherein in the nonwoven fabric Perforating means intervene, the perforating means on one first roller (8) are arranged and the perforating means the fleece in a surface (15) engage a second roller (10) and the perforating means Fibers of the fleece can displace, wherein the perforating means into a material on the second roller (10) intervene that they can displace upon intervention, characterized that by the intervention of the perforating contours in the material of the second roller (10) are formed and the perforating in these contours intervene repeatedly.

Description

The The present invention relates to a process for producing a perforated nonwoven, wherein in the nonwoven perforating, in particular Intervene needles of a roller calendar. Affected is also affected a perforated nonwoven material produced by a process has been.

From the EP 1 048 419 A1 as well as from the EP 1 046 479 A1 go out calenders, each having a needle roller and a perforated roller. The needles of the needle roller engage with the corresponding opposite openings of the perforated roller and thereby are able to perforate materials passed through the gap formed by the perforated roller and the needle roller. Materials that can be perforated are plastic film, paper or non-woven fabrics. The latter should be up to a few millimeters thick.

In EP 0 214 608 A2 For example, perforated spunbonded nonwoven webs of polypropylene fibers and bicomponent fibers are described, which discloses a method of perforating a nonwoven web in which the positive roll has numerous perforating needles which are brought into contact with a backing roll. The fleece is perforated in that the perforation needles enter the recesses of the counter roll and thereby penetrate the fleece. The web has perforations with diameters between 0.015 to 0.125 inches but only 20% to 55% of the entire surface is perforated.

Out EP 1046479 A1 A method for perforating and deforming a fabric is known, wherein with a device consisting of a needle element with a plurality of needles and a counter element of rubber or metal with a plurality of holes for receiving the needles, the respective hole edge on the fabric in a controlled manner is formed. The needles engage in the hole and deformation each in a hole of the counter element and thereby punch the fabric. The perforation and deformation of the fabric takes place at elevated temperature, with a very accurate fit in the hole and deformation area is required to keep the wear on the backing roll low.

Out WO9967454 A1 For example, a process for making a web of fibers having a plurality of hole structures extending across the cross-section of the web is disclosed. The hole structures are produced by laying the fibers on a wire belt to form a batt, then perforating the batt into a hole structure production unit and solidifying it into a web in a consolidation unit. In this case, the hole structure generating unit has two elements. One element has a multiplicity of barbs directed toward the batt. The second element has openings into which the spikes of the first element partially submerge and displace its fibers non-destructively as they pass through the batt and form the hole structures. The openings of the second element communicate with a source of negative pressure / overpressure which allows the fibers in the area of the openings to be sucked into or blown out of the openings. Nonwovens produced therefrom have hole structures with a diameter of 0.5 to 5 mm and 40 to 120 bonding points per square centimeter, the bonding area being only 10 to 40% of the nonwoven area.

In DE 100 05 306 C1 a calender for the production of nonwovens is described, which allows the changing of the rollers from a working position to a parking position, the rollers are very expensive stored on separate pivot lever on a frame and are brought about this pivot lever in the respective position. The change of rolls is achieved in that the first roll from a working position in which it forms a nip with a third roll, is displaceable in a first parking position, the second roll from a working position, in which they are the nip with the third roll forms, is displaced into a second parking position and the parking position of each roller is far removed from the third roller, that a movement of the other roller from the working position to the parking position and vice versa is possible.

Out DE69210403 T2 A device and a method for producing a perforated sheet, for example a membrane material forth. The web passes through two counter-rotating cylinders, wherein the first cylinder is smooth and the second cylinder has projections and the second cylinder rotates at a peripheral speed greater than the peripheral speed of the smooth cylinder. The smooth cylinder consists of an elastically yielding envelope of rubber material or textile fibers. Disadvantageous effect of the different peripheral speeds of the cylinder, which lead to a slip, which holes are produced in the track and around these lobes are formed by partially separated material.

The object of the present invention is to provide a method which provides the Her position of a perforated nonwoven fabric with a low technical complexity at the same time allows high production speed.

These Task is using a method of making a perforated Fleece solved with the features of claim 1. Further advantageous embodiments are given in the respective subclaims.

In order to the wear is on kept low the second roll and produces stable perforations in the web.

One inventive method for producing a perforated nonwoven provides that in the nonwoven Perforating, in particular needles intervene. The needles are arranged on a roller, with the needles through the fleece in a surface engage a second roller. The needles displace fibers of the nonwoven, wherein the needles engage in a material. The material is selected so that the needles displace the material can. In particular, you can the needles displace the material so that contours form in the material. To reach into these contours the needles preferably repeatable. The contours will be particular first formed by the intervention of the perforation. Preferably the perforating means at least partially engage in fibrous Material, which preferably at least partially a surface of the second roller forms. In particular, the displaceable material is a felt material.

According to one Continuing education are the perforating needles. The needles can have different geometries and have cross sections. For example, the needles can be pointed or run dull, have undercuts, cylindrical as well be conical. The geometry as well as the cross section can over the Length of Change needle. In addition to needles Pyramids, stumps, especially truncated cones, Mushroom geometries, elongated Geometries with heads, For example, be used at least partially round heads. The Perforation agents can milled from solid, etched or be eroded. But the perforating agents can also later be introduced, for example, glued, clamped or on other form-fitting and / or non-positive Wise.

Preferably the perforating means, in particular needles, engage in felt material one which the surface the second roller forms. Due to the fact that the felt material on the Second roller is arranged, the felt material forms the needles opposite Counterpart which preferably on the one hand have an elastic behavior can, on the other hand over a certain hardness features. Preferably, the felt material is capable of the nonwoven on the stabilize the second roller, so that the rollers when sliding in the fleece can displace nonwoven fibers laterally.

According to one Embodiment is the felt material which on the second roller is used, under mechanical tension standing on the second Roller arranged. On the one hand, this offers a certain amount in particular Strength of the felt material over one through the needles or the first roller pressure exerted. On the other hand, this makes felt fibers capable of a certain elastic To exhibit behavior.

According to one Embodiment of the method is the first roller with the needles driven while the second roller having the felt material on the surface, not driven directly. Rather, a movement of the first roll for that by the intervention of the needles in the nonwoven material, the second Roller is dragged. In this way it succeeds that the first Roller and the second roller synchronously with each other. Preferably the felt material is selected that upon intervention of the needles in the felt material this always done in about the same places. This will be within the felt material openings formed, in which the needles intervene again and again. In this way manages to wear the felt material when used on to restrict the second roller.

According to a further embodiment, the needles are heated. Preferably, the heating is carried out up to a temperature which is below a melting temperature of the web or a destruction temperature of the felt material. For example, a needle surface temperature may be such that fibers of the nonwoven are melted or softened without, however, destroying the fiber structure as such. A development of the method provides that the felt material is applied to the second roller as a shrink tube. Preferably, this shrink tube is seamless. The second roller preferably has a metal surface. It may, for example, be smooth on its surface or have a ridge. The ridge is applied, for example, spirally or in the form of axially parallel grooves. There is also the possibility that the surface of the second roller has left-handed or right-handed screw-like grooves. A connection between the particular metal surface of the second roller and the Felt material preferably takes place in that the tube exerts a contact pressure on the metal surface of the second roller. Furthermore, an adhesive may additionally be applied between the felt material and the metal surface. This adhesive is preferably redissolvable, for example, by the action of alcohol or the like. As a result, the connection between the film material and the second roller is releasable again. If the felt material is worn too far, it is exchanged for a new felt material. The remaining parts of the second roller need not necessarily be replaced.

A Continuing education, which also represents an independent thought, provides that the felt material is applied to a carrier. The felt material with the carrier will then be followed applied to the roller, for example wound up. Preferably is the carrier an exchangeable sleeve. The exchange sleeve is preferably attached to the roller. A connection between the exchange sleeve and the roller is made via conventional connections, which are in particular non-positive and / or positive fit. For example, groove / spring systems, screw or similar be used. The felt material is preferably interchangeable on the carrier applied, leaving the carrier is reusable. The carrier, especially the exchangeable sleeve, allows a quick felt material change. A downtime of the calender becomes thereby minimized. A connection between felt material and carrier takes place for example, as above in connection with the compound of Felt material has been described with the roller. Preferably for the change cover a plastic material used. A shrink tube only needs still on the exchangeable sleeve be raised. The rollers of the calender can remain unchanged. By using several exchange sleeves can also shorter Service life of the felt material to be bridged quickly. By adequate Stocking can be a replacement of the removable sleeve at the same time Changing a roll from the unwinder done.

According to one further also independent Thought of the invention is provided that the roll calender is constructed so that the mating roll made so accessible on one side can be that, for example, an exchangeable sleeve can be replaced. This is preferably done while the other side remains in its position, for example in a storage. If the weight of the counter roll are compensated must, can to the calender support be provided. The support takes the weight on, otherwise by a clamping of the now free Side of the counter roll is done. Preferably, the support is at least partially movable, so that when removing and mounting the exchange sleeve a sufficient hedging takes place. In particular, part of the support movable along the axis of the counter roll. According to a further training will the counter roller on the free side by an attachable weight supported. The weight is screwed example and extends along the axis of the counter roll. The power is in particular so long that the sleeve can be moved up and down.

Another equally independent thought provides that the calender has a roll changer for the counter roll. For example, if a first felt material worn so far that it is to be replaced, the first mating roll is continued with the first felt material from the perforation and a second counter roll of the calender with a second felt material is brought into contact with the perforation. The first mating roll can now be removed, for example, to replace the first felt material. For example, a roll changer for a calender goes from the DE 100 05 306 C1 in the context of this disclosure with particular reference to the calender, the roll change and the operation of the rollers.

A Good contact force when using a felt tube results for example, in that the felt tube over the cleaned surface of the second roller or the cleaned carrier is drawn and then with about 60-80 ° C warm Water is soaked evenly. It may be advantageous to the water an additional Wetting agents, for example, this can be a detergent be. As a result, a shrinkage of the felt tube is accelerated. Subsequently the felt tube is quenched with cold water and at a Temperature of, for example, 30-40 ° C dried on the second roller. The resulting connection between felt material and second Roller or carrier is sufficient that no slippage when penetrating the needles in the felt material between the felt material and the second roller he follows.

A surface the felt material itself can continue to be processed as well. This is necessary, for example, when the felt material surface disturbing elevations or signs of wear having. There is also the possibility the surface either roughen or edit them so that their roughness degree decreases. The latter, for example, with a slight Absengen überstehender Felt material fibers and subsequent Remove for example by means of a brush.

Preferably, a felt material is used, which has wool as a pulp. For certain applications, however, it may also be useful to use other fibers as felt material. These may be, for example, flax or cotton, viscose, polyamide, polyacrylonitrile, polyester, polypropylene, aramids, polytetrafluoroethylene, polyimides or Polyphenylenesufide. While wool has a long-term temperature resistance of around 100 ° C, at a higher needle temperature, polyamides, polyester or aramid fibers are used, for example. A particular durability of the shrink tube used has been found if this has a hardness of the group F according to DIN 61 200. Preferably, the felt material has a bulk density between 0.32 and 0.48 g / cm ³ . Preferably, the felt material has a felt thickness which is greater than 5 mm, in particular greater than 8 mm, preferably 10 mm and more, for example up to 15 mm. Preferably, a felt tube is used which has a wool felt according to F 2 with a wall thickness of about 10 mm and a density of 0.36 g / cm ³ .

A Use of a felt tube or a felt material has a further advantage that on a thermal expansion of a needle or the first roller takes little consideration. In particular if the first roller entrains the second roller, there is an automatic synchronization between the needles and the points of engagement in the felt material. Furthermore, an embodiment provides the material of the second roll has a lower elasticity, as the felt material forming the surface of the second roll. Preferably, the second roller is made of a metal, in particular made of an alloyed steel. Another embodiment sees in that the second roller has plastic, preferably made a plastic predominantly consists. Furthermore, the second roller may also be a hollow roller.

One The gap between the first and second rollers is preferably adjusted so that the needles that penetrate into the fleece, the Displacing fibers of the fleece and push against the felt material, wherein the fibers are compacted and stabilized an opening in the web becomes. Depending on the speed of the rolls or the fleece, of the applied pressure, temperature and other parameters the possibility, that the openings for example, accept funnel shape. Furthermore, the use allows a felt material on the second roller the use of different Needle geometries. these can pointed, conical, dull or otherwise shaped. Their cross sections can rectangular, star-shaped, round, semicircular, figure-shaped or mixtures of everything.

According to one Further development, the needles are shaped in particular so that when Intervention of the needles at least partially fibers are forced out of the web. The fibers form a structure that they correspond to one Shape the geometry of the needle. Preferably, it lifts up after passing through of the nonwoven through the first and the second roller the structure of a fleece surface from. Another embodiment of the method provides that when Penetration of the needles into the felt material at least partially fibers be pulled into the felt material. This can be at a subsequent Peel off the fleece from the second roller cause the existing structuring of the nonwoven surface is additionally evaluated. For example, you can the fibers are pulled out by the adhesion in the felt until, until the connection felt fiber is interrupted.

According to one Another idea of the invention is a roll calender for perforation a fleece available The roller calender has a first and a second roller having. The first roller has perforating means by a surface stand out the first roller. Form the first and second rolls a gap through which a nonwoven to be perforated is passed. The second roller has a felt material as a surface, wherein the gap between the first and second rollers is set that the perforating means engage in the felt material. A Continuing provides that the gap between the first and second roller changeable is. In particular, it can be set to use Needles not complete but only up to a certain area in the felt material as well in the performed Intervene nonwoven.

Preferably, the needle roller has a circular needle shape. A needle diameter preferably has a value between 1 to about 3 mm. A needle surface is in particular between 1.5 and 5 mm ² , a needle density is preferably between 8 and 25 per cm ² , wherein a needle surface portion between 30% to 70% is preferably. An immersion depth of the needles in the felt material is preferably between 2 mm to 6 mm. Preferably, the gap between the first and second rollers is adjusted so that the needles do not fully immerse themselves in the felt material and in the web. A further embodiment provides that the gap has a size such that a nonwoven fabric carried therebetween is compressed simultaneously with the perforation. For example, for this purpose, the nonwoven can be subjected to a pressure and / or a temperature which are exerted on the nonwoven by the first roller or parts thereof.

The following table shows data of an exemplary needle roller with which various nonwovens have been perforated in cooperation with a felt material on the second roller. Needle shape in supervision Needle diameter [mm] Needle surface [mm ² ] Needles [number / cm ² ] Needle area fraction [%] circular 1.95 2,987 15.36 45.86

• A: PP-Spinnvlies
• B: PP-Spinnvlies + PE/PP-Bico-Spinnvlies

The following table gives an example of measurement data from various tests, which were determined using a needle roller and a felt-coated counter roller: Template material A A A B B B B Basis weight [g / mm ² ] 30 30 30 30 30 40 40 Needle immersion depth [mm] 4.5 4.5 5.0 4.5 5.0 4.5 5.0 Hole area [mm ² ] 0.63 0.68 1.09 0.73 0.84 0.91 0.95 Open area [%] 9.7 10.6 18.3 12.3 14.2 15.1 15.7

• A: PP spunbonded fabric
• B: PP spunbond + PE / PP bico spunbond

The Siebbandgeschwindigkeit was 95 in the experiments shown m / min.

Preferably the perforating means, in particular the needles, are designed that the fleece perforated liquid throughout is. As a used nonwoven has been found to be particularly suitable, a pre-consolidated nonwoven to use.

Preferably, a single-ply web is used. For example, a spunbonded nonwoven predominantly polypropylene is used, which is single-layered. Preferably, this spunbonded web has a weight between 20 g / m ² to 40 g / m ² . Preferably, the basis weight is 30 g / m ² . For example, a preconsolidated web had a consolidation area in the form of a thermobonding of 14.49%. Preferably, the web has a bonding area between 10% to about 60%. In addition to a thermobonding, the nonwoven can also be obtained by other solidification processes its stability and strength, for example by hydroentanglement, adhesive, adhesive fibers, ultrasonic welding, etc. The hole sizes that were prepared, for example, were 1.09 mm ² as a hole area, with a length in MD 1 , 35 mm on average and a length in CD averaged 1.04 mm. The needle roller used was heated from the inside with a thermal oil, wherein a surface temperature of the needle roller between 105 ° C and 130 ° C was set. Hole sizes were obtained with the single ply web having an MD to CD ratio of about 1. In this case, speeds of up to 95 m / min have been driven.

Further experiments were carried out, for example, on a two-ply nonwoven. A first layer consisted of a spunbonded polypropylene, a second layer of a bicomponent material. The two-ply web was preconsolidated and had a bonding area of about 17%. Particularly good, stable circular perforations resulted for a basis weight which was between 30 and 40 g / m ² .

Preferably is used for perforating a pre-consolidated nonwoven, which a connection surface in particular between 8% and 25%.

Next the materials shown PP as well as PE, the nonwovens other materials For example, polyamides, polyesters, glass fibers, PET, Viscose, acetates, polyacrylics, polystyrene, polyvinyl chlorides, their Copolymers and mixtures thereof. The use of biko or multi-component nonwovens, in particular from these materials possible.

Further advantageous embodiments and developments are apparent from the following To take drawing. The features shown there are with the pre-described embodiments of the invention to further independent training combinable, without the invention as such in its embodiment limited by the drawing becomes. Show it:

1 a first device for producing a perforated nonwoven fabric,

2 a section from 1 .

3 a single ply fleece before the perforation,

4 the one-ply fleece 3 after perforation,

5 a two-ply fleece in front of a perforation,

6 the two-ply fleece off 5 after perforation,

7 a material, in particular felt material, on an exchangeable sleeve,

8th a schematic view of a roll calender, in which a roller, can engage in the perforation, for the exchange of a surface material is laterally accessible and

9 a schematic view of another roll calender, in which an exchange of rollers is possible.

1 shows a first device 1 for producing a perforated nonwoven fabric 2 , A pre-consolidated fleece 3 is from a handler 4 over different track guides 5 and a tension measuring roller 6 to a roll calender 7 guided. The roller calender 7 has a first roller 8th with needles 9 as a perforating agent and a second roller 10 on. The second roller 10 is preferably made of metal and has on its surface a felt material 11 on. The felt material 11 is preferably a shrink tube 12 , The shrink tube 12 is about the second roller 10 pushed over, leaving an inner surface 13 of the shrink tube 12 in contact with a metal surface 14 the second roller 10 stands. The surface 15 of the shrink tube 12 therefore simultaneously forms an outer surface of the second roller 10 , Into this surface 15 grab the needles 9 the first roller 8th one. The pre-consolidated fleece 3 now becomes the roll calender 7 led it first on the second roller 10 to come to rest. Preferably, the preconsolidated web has 3 a wrap around the second roller 10 greater than 90 °, in particular greater than 120 ° and preferably greater than 180 °. This allows tensions in the web to be perforated by the needles 9 due to settling on the felt material 11 be reduced. In particular, the not yet perforated nonwoven can be 3 even in this way. Preferably, a defined tensile stress is exerted on the nonwoven. For example, the tension over the Zugmesswalze 6 at least detectable, preferably also adjustable via a position control.

Out 1 continues to show that a gap 16 between the first roller 8th and the second roller 10 is adjustable. At least one of the two rollers 8th . 10 can be changed in his position. In this way, a Lochungstiefe the needles 9 in the felt material 11 adjustable. An adjustment of the perforation depth, for example, directly after the perforation by checking the perforation image of the perforated nonwoven 2 checked. This can be done automatically in particular. For example, a quality can be checked immediately via a detection unit, preferably a camera and predefinable parameters, and corresponding settings can be made in the event of deviations. For example, can be displayed in addition, if the felt material must be changed. After the unperforated fleece 3 through the needles 9 was perforated, according to another independent thought, the perforated fleece is not immediately out of the gap 16 withdrawn and wound up by means of an unwinder. Rather, the fleece remains on the first roll 8th and is carried along according to the direction of rotation indicated by the arrow. Preferably, the perforated web becomes 2 over a wrap angle greater than 90 °, in particular greater than 120 ° and preferably in a range of 160 ° to 270 ° entrained. Only then does the perforated nonwoven take off 2 from the first roller 8th and with it the needles 9 , Such a nonwoven guide has several advantages: On the one hand, the needles can be heated to such an extent that they stabilize the perforations made in the nonwoven. Stabilization can be achieved by a more uniform, especially slower heat supply to the needles 9 surrounding nonwoven fibers. This allows, for example, to soften non-woven fibers, not only directly in direct contact with the needles 9 stand. Rather, a large wrap angle also allows to at least soften at least adjacent nonwoven fibers arranged thereon. Softening preferably results in easy adhesion of the surfaces of adjacent fibers. This allows stabilized structures and geometries to stabilize. On the other hand allows such a nonwoven guide that by the engagement of the needles 9 into the perforated fleece 2 and the continuation of the fleece on the surface of the felt materials 11 the nonwoven fibers compress each other. This also leads to a stabilization of the through the needles 9 generated perforation structure in the fleece. The perforated fleece 2 gets from the first roller 8th to a second tension measuring roller 17 guided. From there the perforated fleece arrives 2 over web guides 5 to a rewinder 18 , The tension measuring rollers 17 make it possible, during the perforation process, to check again and again the stresses acting on the fleece and accordingly, for example, the rewinder 18 or unwinders 4 to adjust in their speed. Furthermore, the speed of the first roller can also be 8th or the second roller 10 be controlled so that a desired tensile stress acts on the nonwoven.

2 shows a section 1 , You can see the engagement of the needles 9 in the felt material 11 of the shrink tube 12 , Schematically indicated is an exemplary construction of the first roller 8th , The needles 9 are in a surface of the first roller 8th admitted. The possibilities of constructive solution, needles or other perforating means in the first roll 8th to provide, are known in the art. By way of example, reference is made to the documents set forth above in the prior art within the scope of this disclosure.

3 shows a single-layer fleece 19 which is in 4 perforated is shown. The single-layer fleece 19 is preferably a spunbonded nonwoven. The perforations are in particular designed in such a way that non-woven fibers projecting from the surface form funnel-shaped structures.

5 and 6 show a two-ply fleece 20 which has either been laminated together prior to perforation or laminated together by the perforating process. A first location 21 and a second location 22 are perforated at the same time. An embodiment of funnel-shaped structures of the first layer 21 preferably extend into the second layer 22 in such a way that the latter has a nearly smooth surface without further elevations. However, depending on the penetration depth of the needles can also from the first layer 21 or second layer 22 Nonwoven fibers extending from a surface of the two-ply web 20 take off.

7 shows a removable sleeve 23 , which is preferably made of plastic. On the change sleeve, for example, a shrink tube is applied, which in particular has a felt material 11 , The felt material 11 can from the exchange sleeve 23 be removed again, so that then a new heat shrink tubing on the exchange sleeve 23 can be put back on. Preferably, the exchange sleeve 23 a certain elasticity or deformability. For example, this can be a pressure that acts from the heat shrink tubing to the change sleeve 23 , from the exchangeable sleeve 23 acting on a counter-roll of a calender arranged opposite a perforating roller. In particular, the pressure can be so great that thereby attaching the exchange sleeve 23 supported on the counter roll at least.

8th shows a schematic diagram of a calender 24 which is accessible from the side. This allows a change of a surface on the second roller 10 without the second roller 10 must be expanded. In particular, this can be a holder 25 and / or cover are folded laterally or be moved up or down. This allows free lateral access to the second roller 10 , In particular, the roller construction of the second roller 10 and a corresponding dimensioning and weight design be such that a one-sided bracket in the calender 24 sufficient for the weight of the second roller 10 catch. This may apply if the calender 24 not in operation, but also if the calender 24 is in operation. For example, the second roller 10 be a hollow cylinder, be made of lightweight construction material and / or for example at least partially made of plastic or aluminum. With the possibility of only one-sided clamping, the second roller 10 be pulled out of the calender frame and the surface of the second roller 10 be changed.

In the 9 illustrated schematic diagram corresponds to the structure and operation of the forth 1 known arrangement. Additionally is in 9 a principle shown in which by a change mechanism, the second roller 10 through a third roller 26 can be replaced. As a result, for example, the second roller 10 be exchanged while the third roller 26 engaged with the first roller 8th located. For this purpose, the roller calender 7 next to the third roller 26 for example, a lever mechanism 27 on, over which the second roller 10 and the third roller 26 connected to each other. Will the lever mechanism 27 as indicated by the arrows, for example, moves about an axis not shown, the second roller moves away 10 from the first roller 8th , The third roller 26 on the other hand will be on the first roller 8th moved. A fine adjustment of the distance of the respective roller 10 . 26 to the first roller 8th may preferably be independent of the lever mechanism 27 respectively. Is the third roller 26 engaged with the first roller 8th , the web to be perforated, as indicated by dashed lines along the third roller 26 to first roller 8th be guided. The tension measuring roller 17 may preferably be in position to that of the third roller 26 be adjusted. This will ensure that even when operating the third roller 26 a tension measurement takes place.

Claims (11)

Process for producing a perforated non-woven fabric ( 2 ), in which the fleece perforating means engage, the perforating means on a first roll ( 8th ) are arranged and the perforating through the fleece in a surface ( 15 ) a second roller ( 10 ) and the perforating means can displace fibers of the nonwoven, the perforating means being in a material on the second roll ( 10 ) that they can dislodge upon engagement, characterized in that by the engagement of the perforating contours in the material of the second roll ( 10 ) are formed and the perforating agents intervene repeatedly in these contours. A method according to claim 1, characterized in that the perforating means engage in an at least partially fibrous material, which preferably the surface of the second roller ( 10 ) forms and wherein contours are formed in the material. Method according to claim 1, characterized in that that the perforating means are heated up to a temperature below a melting temperature of the web or a destruction temperature the contour-forming material is located. A method according to claim 1, 2 or 3, characterized in that a felt material ( 11 ) is used. Method according to claim 4, characterized in that the felt material ( 11 ) on the second roller ( 10 ) is applied as a shrink tube. Method according to one of the preceding claims, wherein the perforation means displace the fibers of the fleece and against the material ( 11 ) and wherein the fibers are compressed and an opening in the nonwoven fabric is stabilized, characterized in that at least partially fibers are forced out of the nonwoven upon engagement of the perforating means, wherein the fibers form a structure corresponding to a geometry of the perforating means, which after passing through of the fleece through the first ( 8th ) and the second ( 10 ) Roll lifts off a nonwoven surface. Method according to Claim 6, characterized that at least when penetrating the perforating means in the material Partial fibers are fed into the material. Method according to one of the preceding claims, characterized in that the perforated fleece ( 2 ) is detected. Perforated nonwoven material produced by a process according to claim 1, characterized in that the nonwoven material has a basis weight between 20 g / m ² and 40 g / m ² , has a bonding area of between 8% and 25% and has perforations approximately are circular, with a diameter of a perforation between 0.1 cm and 2.0 cm in size. Perforated nonwoven material according to claim 9, characterized characterized in that the nonwoven material is a single-layer spunbonded nonwoven is that at least predominantly made of polypropylene. Perforated nonwoven material according to claim 9, characterized in that the nonwoven material is a two-ply spunbonded nonwoven is, wherein a first layer has a spunbonded, the polypropylene and a second layer of at least a bicomponent material having.