WO2024227651A1 - Method and device for producing a flexible web-type composite material - Google Patents

Abstract

In order to produce a flexible web-type composite material (2) from a web-type substrate (3) and a web-type nonwoven material (4), discrete particles (7) are applied to the substrate (3) or the nonwoven material (4) by applying the particles (7) to a heated release surface (6) and softening them thereon and then transferring them from the release surface (6) to a surface (3a, 4a) of the substrate (3) or the nonwoven material (4). Optionally, the particles (7) are cooled and the substrate (3) and the nonwoven material (4) are brought together, wherein the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) with the adhered particles (7) faces a surface (4a, 3a) of the nonwoven material (4) or the substrate (3), followed by optionally heating the particles (7) and pressing the substrate (3) and the nonwoven material (4) together, whereby the particles (7) connect the facing surfaces (3a, 4a) of the substrate (3) and the nonwoven material (4) together.

Description

Method and device for producing a flexible web-shaped composite material

The invention relates to a method for producing a flexible web-shaped composite material, according to the preamble of claim 1.

The invention further relates to a device for producing a flexible web-shaped composite material, according to the preamble of claim 17.

The document EP 3 463 805 B1 describes non-slip, flexible materials and methods for their production and use. In these methods, individual thermoplastic particles heated to a sticky state are applied to a surface of a thermoplastic flexible carrier which can be used as a non-slip flexible packaging material. Non-slip flexible packaging bags are also disclosed, the outer surface of which has roughening projections, as well as methods for their production and use. If such bags lie on top of one another, the roughening projections prevent mutual slipping, even if the material of the bags is not non-slip per se, because the projections interlock with one another. It is also mentioned that these projections produce an effective, non-slip mechanical lock with a fibrous engagement material, such as a commercially available fleece, which is placed between two bags, for example. The fleece can be lifted vertically from the rough surface. This document further describes that the bag can consist of a film and/or a fabric and/or a nonwoven fabric. Fig. 12a of EP 3 463 805 B1 shows a tubular web of plastic film in which roughening projections are applied to one surface and a nonwoven strip is fixed to the opposite surface, either by a fiber-sprayed hot melt adhesive or by extrusion lamination, in which a continuous application of narrow strands of an extruded polyolefin polymer is carried out in order to encapsulate the fibers of the nonwoven and fix them to the film, and the sandwich arrangement of film/melt/nonwoven is pressed between a pair of metal rollers.

The disadvantage of the film-nonwoven composite material produced in this way is that the mechanical properties of the fleece are changed by the hot melt adhesive or the extruded polyolefin polymer, as the hot melt adhesive or the extruded polyolefin polymer coats the fibers of the fleece and is then pressed against the film. the hot melt adhesive or the extruded polyolefin polymer penetrates the fleece to its surface facing away from the film, making it stiff and impairing the mechanical locking with the rough surface of the film. The described methods of fixing the fleece to the film also require a high material consumption of hot melt adhesive or polyolefin polymer, which is not necessary for the desired mechanical locking function of the fleece. The use of hot melt is also disadvantageous because hot melt adhesives are expensive and make it difficult to recycle objects made from the film-nonwoven composite material.

The document US 2015/0036952 A1 describes the production of a packaging bag with an anti-slip coating. An easily extrudable olefinic elastomer is applied from an extrusion head to a woven polypropylene packaging bag and immediately flattened with rollers in several spaced-apart strips with the aim of increasing the friction coefficient of the surface of the bag.

From the document US 2019/02913337 Al, a non-slip, heat-sealable plastic packaging bag and a method and a device for its production are known. The bag is made of a flexible plastic material, on the surface of which a large number of separate, anti-slip projections made of a thermoplastic polymer are applied. The material of the anti-slip projections should be different from the material of the bag.

DE 40 33 499 A1 discloses a method for equipping a thermoplastic film web for further processing into sacks, wherein the sacks have perforated areas that are covered with fleece strips. The fleece strips are attached to the film web with a connecting means, wherein the film web, the fleece strip and the connecting means are made of the same thermoplastic. This method solves the problem that plastic bags coated with adhesives can no longer be recycled or can only be recycled for inferior applications. When producing the sacks, the melted connecting means is applied along the edge areas of the fleece strip between the fleece strip and the film web and connecting pressure is exerted on the fleece strip, connecting means and film web so that the thermoplastic of the connecting means at least partially penetrates the fleece strip and connects the fleece strip to the film web while the thermoplastic hardens. The method described in DE 40 33 499 A1 has the disadvantage described above that the partial or complete Penetration of plastic into the fleece impairs its mechanical locking with rough surfaces of adjacent bags. In addition, the fleece strip is only attached to its edges, so that the fleece is freely movable between its edges due to its elastic properties, which means that it is not suitable for preventing bags lying on top of one another from slipping. This problem is not addressed in DE 40 33 499 A1 because the fleece strips in the bags disclosed only serve to cover perforations in the bag body made from the film web. For this reason alone, it would not be possible to attach the fleece strip over the entire surface of the film web by applying the melted connecting agent and then applying connecting pressure, because this would close the perforations in the film web.

A method for producing a sack is known from the document WO 2011/018318 A1, wherein the sack contains a plastic nonwoven material. The method comprises providing a flat sheet material with at least two layers, with a first layer of a plastic nonwoven material and a second layer of a plastic coating, forming a tube from the flat sheet material by laying the side regions of the flat sheet material on top of one another to form an overlap and connecting them to one another, wherein after the tube has been formed, the plastic coating faces outwards and the plastic nonwoven material layer faces inwards, separating the tube into tube pieces and forming a base on at least one end of a tube piece. Before separating the tube into tube pieces, the flat sheet material with at least two layers or the tube produced from it is perforated. This is necessary because the plastic nonwoven material layer is permeable to air, which is important when filling the sacks so that the air can escape from the inside of the sack, but the plastic coating prevents the air from escaping. The disadvantage of perforating the flat sheet material that includes the plastic fleece material layer and the plastic coating is that the plastic fleece material layer is also perforated. A fleece layer forms a labyrinth with its many fibers that allows air to pass through but holds back the filling material contained in the bag, usually granular or powdery, and thus prevents the filling material from escaping from the bag. If the fleece layer is now perforated, the perforation forms a straight passage through the entire flat sheet material, so that the fleece layer can no longer prevent the filling material from passing through the flat sheet material that forms the bag wall. The object of the present invention is to propose a method and a device for producing a flexible web-shaped composite material which overcomes or at least mitigates the above-mentioned disadvantages of the prior art. In one aspect of the invention, the flexible web-shaped composite material produced according to the invention is used to produce sacks.

The invention solves the problem by providing a method for producing a flexible web-shaped composite material with the features of claim 1 and a device with the features of claim 17. Advantageous embodiments of the invention are set out in dependent claims, the description and the drawings.

The method according to the invention for producing a flexible sheet-like composite material comprises providing a sheet-like substrate which at least partially contains a first thermoplastic polymer, providing a sheet-like nonwoven material which at least partially contains a second thermoplastic polymer, applying discrete particles containing a third thermoplastic polymer to the sheet-like substrate or to the sheet-like nonwoven material by providing a release surface, providing and arranging a plurality of the discrete particles on the release surface, wherein the release surface has a temperature which is above a softening temperature of the third thermoplastic polymer, heating the particles arranged on the release surface above the softening temperature of the third thermoplastic polymer, bringing a surface of the substrate or the nonwoven material into contact with the release surface and the softened particles arranged thereon so that the particles adhere to the surface of the substrate or the nonwoven material, then removing the surface of the substrate or the nonwoven material with the particles adhering thereto. Particles from the release surface, and optionally cooling the particles adhering to the surface of the substrate or the nonwoven material below the softening temperature of the third thermoplastic polymer, bringing the substrate and the nonwoven material together, wherein the surface of the substrate or the nonwoven material with the particles adhering thereto faces a surface of the nonwoven material or the substrate, pressing the substrate and the nonwoven material together, whereby the particles bond the mutually facing surfaces of the substrate and the nonwoven material to one another, optionally before pressing the substrate and the Nonwoven material, heating of the particles adhering to the surface of the substrate or the nonwoven material above the softening temperature of the third thermoplastic polymer takes place, and optionally cooling the composite material thus produced from the substrate and the nonwoven material.

This method connects the substrate and the nonwoven material to one another by means of a large number of discrete connection points made of particles containing the third thermoplastic polymer, with the connection points being distributed as evenly as possible over essentially the entire connection surface between the substrate and the nonwoven material, so that the overall effect of a "full-surface" connection with homogeneous connection properties is created. In contrast to the connections of a substrate and a nonwoven by means of extrusion lamination or bonding known from the prior art, according to the invention the cavities of the nonwoven material remain largely intact, so that they are retained both for the positive connection with a material made slip-resistant by the application of plastic particles and for the retention of powdery or granular material through the labyrinth channels formed by the cavities of the nonwoven.

Advantageously, the method according to the invention makes it possible to dispense with expensive equipment such as extruders or hot melt melting devices. In addition, the material consumption of the connecting agent, i.e. the particles, is significantly lower than when connecting a substrate to a fleece using hot melt adhesive or extruded polymer. Another positive effect of the invention is the possibility of recycling the substrate and fleece together.

In a further development of the invention, after the substrate and the nonwoven material have been pressed together, discrete particles containing a fourth thermoplastic polymer are applied to the surface of the substrate opposite the nonwoven material by providing a release surface, providing and arranging a plurality of the discrete particles on the release surface, wherein the release surface has a temperature which is above a softening temperature of the fourth thermoplastic polymer, heating the particles arranged on the release surface above the softening temperature of the fourth thermoplastic polymer, bringing the surface of the substrate opposite the nonwoven material into contact with the release surface and the softened particles arranged thereon so that the particles adhere to the surface of the substrate, and then removing the surface of the substrate with the particles adhering thereto from the Detachment surface, and optionally cooling the particles adhering to the surface of the substrate below the softening temperature of the fourth thermoplastic polymer. In this text, "cooling" is understood to mean active cooling using a cooling device or passive cooling by allowing it to cool, e.g. in the ambient air.

The flexible web-shaped composite material produced in this way therefore meets all the requirements to be processed into bags that are characterized by high slip resistance when stacked on top of one another, in that the particles applied to a surface of the substrate that forms an outer surface of the bag engage in a form-fitting manner in the cavities of the nonwoven material of the composite material, which is arranged on an outer surface of the bag that is opposite the outer surface of the bag with the particles. Since the nonwoven material is connected to the substrate over the entire connection surface by a large number of connection points, it does not come loose when shear forces occur when a stack of bags lying on top of one another, in which one side with nonwoven fabric of a bag faces one side with particles on the substrate of an adjacent bag, is tilted. This means that high tilt angles, typically of 35° and more, are possible without the bags slipping; instead, the stack of bags will fall over first. This means that when stacking bags, there is no need for stretch film, shrink film or covers or other means of securing the load.

If the substrate or the composite of the substrate and the nonwoven material is turned over before the application of the particles containing the fourth thermoplastic polymer on the surface of the substrate opposite the nonwoven material and this surface of the substrate is turned towards the release surface which also serves for applying the particles containing a third thermoplastic polymer, the device on which the web-shaped composite material is produced according to the method according to the invention can be considerably simplified because a single release surface is used for applying the particles on both sides of the composite material.

The web-shaped substrate may be tubular for the production of bags, whereby, depending on the type of bags to be produced from the composite material, the tubular substrate is optionally provided with side folds.

In a preferred embodiment of the invention, the substrate has at least one layer of a plastic ribbon fabric, preferably made of PP, HDPE or PET. The plastic ribbon fabric can have an optionally printed coating or a have a laminated plastic film, which serves, for example, as a carrier for printing or as a barrier layer, e.g. as a moisture barrier layer.

In an alternative embodiment of the invention, the substrate is a single- or multi-layer, optionally printed plastic film, preferably made of PP, LLDPE, LDPE, HDPE or PET.

For certain applications, the composite material produced according to the invention must be permeable to air, for example when valve bags are made from the composite material which are filled with powdery or granular filling material by means of an air stream, whereby the air must be able to escape from the bag. For such applications, the substrate is perforated before it is combined with the fleece material. It is important that only the substrate and not the fleece material is perforated, because otherwise the fleece material would lose its retention function for the filling material, for example very fine-grained/fine-dust cement.

Preferably, the nonwoven material is a spunbonded nonwoven or a carded nonwoven or a spunlace material or a meltblown material or a spunbond material or a composite material of the materials mentioned.

It has proven to be effective if the first and/or the second thermoplastic polymer is selected from: PET, PP, PE, or a co- or terpolymer containing two or three of the following monomers: ethylene, propylene, vinyl acetate, alkyl acrylate, maleic anhydride, alpha-olefin. The first and the second thermoplastic polymer can be selected from the same material or from different materials.

Preferably, the third and/or fourth thermoplastic polymer are selected from: PET, PP, PE, or a co- or terpolymer containing two or three of the following monomers: ethylene, propylene, vinyl acetate, alkyl acrylate, maleic anhydride, alpha-olefin. The third and fourth thermoplastic polymers can be selected from the same material or from different materials.

In a preferred embodiment of the invention, the particles containing the third thermoplastic polymer have an average particle size of less than or equal to 1000 pm. In a further preferred embodiment of the invention, the particles containing the fourth thermoplastic polymer have an average particle size between 80 and 800 pm, preferably between 100 and 500 pm, whereby for largely homogeneous bonding and slip resistance properties, particle sizes that are as uniform as possible, in particular with size differences of less than a factor of 3, are particularly preferred. The particles containing the fourth thermoplastic polymer are selected by sieving with sieves of defined mesh width, which ensures good, uniform particle sizes.

According to the invention, it is preferred if the particles are applied to the substrate and/or the nonwoven material with a basis weight of between 1 g and 20 g per m ² , preferably between 3 g and 5 g per m ² . These basis weights are far below the basis weights of extrusion connections, but still ensure sufficient bonding strength, whereby the bonding strength can be adjusted by selecting an appropriate basis weight so that the nonwoven material does not detach from the substrate due to the action of shear forces, but can be pulled off the substrate by applying force perpendicular to the bonding surface, e.g. by hand. If the basis weight of the particles is in the specified range, this also ensures that the particles do not clog the cavities in the nonwoven material.

According to the invention, it can be provided that the particles are set to a temperature above their softening temperature but below their melting temperature when bonding to the substrate or the nonwoven material. This means that the particles are embedded in the substrate or the nonwoven material, the nonwoven material or its fibers remain essentially non-destructive, but good adhesive properties are nevertheless created between the substrate and the nonwoven material (through positive locking). In this procedure, the particles do not form large, undefined areas that change the mechanical properties of the substrate or nonwoven material, as is the case when plastic extrudate or hot melt is applied over the entire surface. It should be mentioned that it has proven to be expedient if the heating of the particles on the release surface takes place to a higher temperature, which can also be above the melting temperature of the particles, than when the substrate and nonwoven are bonded using the particles.

In a further embodiment of the method according to the invention, in which the web-shaped substrate is provided as a flat web, the web-shaped composite material is formed from the substrate and the nonwoven material into a tube by placing the side regions of the flat, web-shaped composite material on top of one another to form an overlap and connecting them to one another, the nonwoven material forming an inner layer of the tube. Such a tubular Composite material can be formed into bags in which the nonwoven material forms an inner layer that prevents the contents, such as fine-grained/dusty cement material, from escaping to the outside by separating the tube into tube pieces and forming a base at at least one end of the tube pieces. This is particularly advantageous if the substrate has been perforated before being connected to the nonwoven material.

The invention is explained in more detail below with reference to the drawings by means of non-limiting embodiments.

Fig. 1 shows schematically a first embodiment of an apparatus for producing a flexible web-shaped composite material according to the invention.

Fig. 2 shows schematically a second embodiment of an apparatus for producing a flexible web-shaped composite material according to the invention.

Fig. 3 shows a turning device of the device of Fig. 2.

Fig. 4 shows schematically a simpler embodiment of the device shown in Fig. 1 for producing a flexible web-shaped composite material. Fig. 5 shows the production of a hose from a flat web-shaped composite material according to the invention.

A first embodiment of the invention will now be explained with reference to the schematic representation in Fig. 1. Fig. 1 shows a device 1 for producing a flexible web-shaped composite material 2. This device 1 is provided with a web-shaped substrate 3, which at least partially contains a first thermoplastic polymer, wound up on a roll. The web-shaped substrate 3 can be a flat material or a tubular material, optionally with side folds. The device 1 is also provided with a web-shaped nonwoven material 4, which at least partially contains a second thermoplastic polymer, wound up on a roll. During operation of the device 1, the web-shaped substrate 3 is unwound from its roll by means of feed means (not shown), such as driven roller pairs, pulled through a perforation device 5 where it is perforated, and fed to a release surface 6. The release surface is designed as a heated endless conveyor belt circulating around rollers, which is preferably equipped with a surface made of polytetrafluoroethylene (PTFE), known under the brand name "Teflon", or a material with similar properties to PTFE. PTFE has a high chemical and thermal resistance, a low coefficient of friction and is anti-adhesive. Discrete particles 7 containing a third thermoplastic polymer are discharged from a container 8, for example by means of a spreading roller, applied in large numbers in as even a distribution as possible to the release surface 6. The heated release surface 6 has a temperature which is above a softening temperature of the third thermoplastic polymer. The particles 7 heat up on the release surface above the softening temperature of the third thermoplastic polymer and, in the softened state, adhere sufficiently to the release surface 6 that they do not fall off the release surface 6 even when they are transported on the rotating release surface 6. The substrate 3 and the release surface 6 run through a pair of rollers 9 so that the particles 7 on the release surface 6 face a surface 3a of the substrate 3. The pair of rollers 9 presses the particles 7 against the surface 3a of the substrate 3, whereby the softened particles 7 adhere to the surface 3a of the substrate 3. The surface 3a of the substrate 3 with the particles 7 transferred to it then moves away from the release surface 6, which is then ready for the renewed application of particles 7. The surface 3a of the substrate 3 is now cooled until the particles 7 have a temperature below the softening temperature of the third polymer. In this embodiment, cooling is carried out actively by means of a cooling device 10. Depending on the ambient temperature, transport speed and transport length of the substrate 3, passive cooling, e.g. by ambient air, can also be provided, in which the particles 7 are allowed to cool on the substrate 3. If the substrate 3 with the particles 7 adhering to it is processed directly, cooling below the softening temperature can be omitted.

In the next step, the web-shaped nonwoven material 4 is fed by unwinding it from its roll by means of feed means (not shown), such as driven rollers, and the nonwoven material 4 is brought together with the substrate 3 via a roller 21, wherein the surface 3a of the substrate 3 with the particles 7 adhering to it faces a surface 4a of the nonwoven material 4. The superimposed layers of substrate 3 and nonwoven material 4 are then heated by means of a heating device 11 above the softening temperature of the third thermoplastic polymer of the particles 7 adhering to the surface 3a of the substrate 3, followed by the pressing together of the substrate 3 and the nonwoven material 4 by means of a pair of rollers 12, whereby the softened particles 7 connect the mutually facing surfaces 3a, 4a of the substrate 3 and the nonwoven material 4 to one another. The flexible web-shaped composite material 2 produced in this way is finally cooled either actively by means of a cooling device 14 or passively by being allowed to cool in the ambient air during transport through the device 1, and can be wound onto a roll for further processing. An embodiment of the device 1 for producing the flexible web-shaped composite material 2, which comprises the parts described so far and in which the composite material 2 is wound onto a roll for further processing, is shown schematically in Fig. 4.

The main advantage of the device 1 and the method carried out thereon is that the substrate 3 and the nonwoven material 4 are connected to one another by a large number of discrete connection points made of the particles 7 containing the third thermoplastic polymer, wherein the connection points are distributed as evenly as possible and extend essentially over the entire connection surface between the substrate 3 and the nonwoven material 4, so that the overall effect of a "full-surface" connection with homogeneous connection properties is created. The cavities of the nonwoven material 4 remain largely intact.

In the embodiment of the device 1 shown in Fig. 1 and Fig. 4, the substrate 3 is first fed in and, after the particles 7 have been applied, is brought together and connected to the nonwoven material 4. It should be mentioned, however, that the device 1 is also suitable for first feeding the nonwoven material 4 and, after the particles 7 have been applied to the nonwoven material 4, bringing it together with the substrate 3 so that their surfaces 3a, 4a are connected to one another by a plurality of connection points consisting of the particles 7.

In the embodiment of the device 1 for producing the flexible web-shaped composite material 2 shown in Fig. 1, the composite material is further treated immediately after its production by applying discrete particles 17 containing a fourth thermoplastic polymer to the surface 3b of the substrate 3 opposite the nonwoven material 4, i.e. facing away from it, after the substrate 3 and the nonwoven material 4 have been pressed together by the pair of rollers 12. The particles 17 are applied by applying the particles 17 from a container 18, for example by means of a spreading roller, in a large number in as even a distribution as possible to a heated release surface 16. The heated release surface 16 has a temperature which is above a softening temperature of the fourth thermoplastic polymer. The particles 17 heat up on the release surface 16 above the softening temperature of the fourth thermoplastic polymer and, in the softened state, adhere sufficiently to the release surface 16 that they do not fall off the release surface 16 even when they are transported on the rotating release surface 16. The release surface 16 is designed as a heated endless conveyor belt rotating around rollers, which is preferably covered with a surface made of PTFE or a material with similar properties to PTFE. The composite material 2 and the release surface 16 pass through a pair of rollers 19 so that the particles 17 on the release surface 16 face the surface 3b of the substrate 3. The pair of rollers 19 presses the particles 17 against the surface 3b of the substrate 3 of the composite material 2, whereby the softened particles 17 adhere to the surface 3b of the substrate 3. The surface 3b of the substrate 3 of the composite material 2 with the particles 17 transferred thereto then moves away from the release surface 16, which is thus ready for new application of particles 17. The composite material 2 is now cooled actively by means of a cooling device 14 or passively by being allowed to cool, e.g. in the ambient air, until the particles 17 have a temperature below the softening temperature of the fourth polymer. The web-shaped flexible composite material treated in this way is then wound onto a roll for further use, for example for the production of bags.

Examples of preferred materials for the first, second, third and fourth thermoplastic polymers are given above in the text.

Fig. 2 shows schematically a further embodiment of a device 20 for producing a flexible web-shaped composite material 2, which essentially carries out the same process steps as the device 1 of Fig. 1. The same or similar device parts as in the embodiment of Fig. 1 are provided with the same reference numerals in Fig. 2 and for their explanation reference is made to the description of the device of Fig. 1. The essential difference between the two devices 1, 20 is that in the device 20 of Fig. 2 only one release surface 6 is used, with which both surfaces 3a, 3b of the substrate 3 are provided one after the other with particles 7, 17. For this purpose, the substrate 3 is turned in a turning device 30 after the particles 7 have been applied to its first surface 3a. The nonwoven material 4 is then brought together with the first surface 3a of the substrate provided with the particles 7. By applying heat and pressure in the heating device 11 and the pair of rollers 12, the substrate 3 and the nonwoven material 4 are connected to one another at their mutually facing surfaces by a plurality of connection points, as described in detail above with reference to Fig. 1. The composite material 2 produced in this way is then fed again to the release surface 6, in such a way that the surface 3b of the substrate 3 opposite the nonwoven material 4, i.e. facing away, faces the release surface 6. Discrete particles 17 are applied to this surface 3b of the substrate 3 opposite the nonwoven material 4 and then in the cooling device 14. The composite material 2 treated in this way is then wound into a roll.

Fig. 3 shows an embodiment of a turning device 30, as can be used in the device 20 of Fig. 2, in plan view. To make the drawing easier to understand, some device parts not necessary for the explanation have been omitted. The representation in Fig. 3 shows the substrate 3, which has already been subjected to the particles 7 containing the third thermoplastic polymer on the pair of rollers 9, the particles 7 being applied from the container 8 to the release surface 6. The substrate 3 provided with the particles 7 is turned by 180° on a first deflection roller 24, then fed to a first fixed deflection rod 22, where it is deflected by 90°, then fed to a second fixed deflection rod 23, where it is deflected again by 90°. The substrate 3 is then turned again by 180° around a second deflection roller 25 and is thereby guided in the direction of the heated release surface 6. Before the substrate 3 comes into contact with the release surface 6, it is brought together with the nonwoven material 4 on the roller 21, as described above. The substrate 3 is then exposed to the particles 17 containing the fourth thermoplastic polymer on the pair of rollers 19, the particles 17 being applied from the container 18 to the release surface 6.

Fig. 5 shows schematically the forming of a tube 15 from the composite material 2, which is designed as a flat material. For this purpose, the side areas 2a, 2b of the flat, web-shaped composite material 2 are placed on top of one another by deflection means (not shown) to form an overlap 2c and connected to one another, so that the nonwoven material 4 forms an inner layer of the tube 15. The connection of the side areas 2a, 2b of the flat, web-shaped composite material 2 takes place by introducing a plastic extrudate into the overlap 2c by means of an extruder 26 and an extrusion nozzle 27 and then passing the overlap 2c through a pair of rollers 28 and thereby pressing it together. Bags can then be formed from the tube 15 by separating the tube 15 into tube pieces and forming a base at at least one end of the tube pieces. However, the composite material 2, if it has a tubular substrate 3, can also be separated into tubular pieces and a base can be formed at at least one end of the tubular pieces. This makes it possible to produce cross-bottom bags, valve bags, pouches or form-fill-and-seal bags, the shapes of which are well known to those skilled in the art. The composite material 2 used is preferably a material whose substrate 3 has been perforated before being connected to the nonwoven material 4.

Claims

Claims: 1. A method for producing a flexible web-shaped composite material (2), comprising providing a web-shaped substrate (3) which at least partially contains a first thermoplastic polymer, providing a web-shaped nonwoven material (4) which at least partially contains a second thermoplastic polymer, applying discrete particles (7) which contain a third thermoplastic polymer to the web-shaped substrate (3) or to the web-shaped nonwoven material (4), by Providing a release surface (6), providing and arranging a plurality of the discrete particles (7) on the release surface (6), wherein the release surface (6) has a temperature which is above a softening temperature of the third thermoplastic polymer, heating the particles (7) arranged on the release surface (6) above the softening temperature of the third thermoplastic polymer, bringing a surface (3a, 4a) of the substrate (3) or the nonwoven material (4) into contact with the release surface (6) and the softened particles (7) arranged thereon, so that the particles (7) adhere to the surface (3a, 4a) of the substrate (3) or the nonwoven material (4), then removing the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) with the particles (7) adhering thereto from the release surface (6), and optionally cooling the particles (7) on the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) adhering particles (7) below the softening temperature of the third thermoplastic polymer, characterized by bringing the substrate (3) and the nonwoven material (4) together, wherein the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) with the particles (7) adhering thereto faces a surface (4a, 3a) of the nonwoven material (4) or the substrate (3), pressing the substrate (3) and the nonwoven material (4) together, whereby the particles (7) connect the mutually facing surfaces (3a, 4a) of the substrate (3) and the nonwoven material (4) to one another, wherein, if appropriate, before pressing the substrate (3) and the nonwoven material (4) together, heating the particles (7) adhering to the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) above the softening temperature of the third thermoplastic polymer, and the optional cooling of the composite material (2) thus produced from the substrate (3) and the nonwoven material (4). 2. Method according to claim 1, characterized in that after pressing together the substrate (3) and the nonwoven material (4) on the nonwoven material (4) opposite surface (3b) of the substrate (3) discrete particles (17) are applied which contain a fourth thermoplastic polymer, by Providing a release surface (16), providing and arranging a plurality of the discrete particles (17) on the release surface (16), the release surface (16) having a temperature which is above a softening temperature of the fourth thermoplastic polymer, heating the particles (17) arranged on the release surface (16) above the softening temperature of the fourth thermoplastic polymer, bringing the surface (3b) of the substrate (3) opposite the nonwoven material (4) into contact with the release surface (16) and the softened particles (17) arranged thereon, so that the particles (17) adhere to the surface (3b) of the substrate (3), and then removing the surface (3b) of the substrate (3) with the particles (17) adhering thereto from the release surface (16), and optionally cooling the particles (17) adhering to the surface (3b) of the substrate (3) below the softening temperature of the fourth thermoplastic polymer. polymers. 3. Method according to claim 2, characterized in that the substrate (3) or the composite (2) of the substrate (3) and the nonwoven material (4) is turned over before the application of the particles (17) on the surface (3b) of the substrate (3) opposite the nonwoven material (4) and this surface (3b) of the substrate (3) is turned towards the release surface (6), which also serves for the application of the particles (7) containing a third thermoplastic polymer. 4. Method according to claim 2 or 3, characterized in that the web-shaped substrate (2) is tubular, wherein the tubular substrate is optionally provided with side folds. 5. Method according to one of the preceding claims, characterized in that the substrate (3) has at least one layer of a plastic ribbon fabric, preferably of PP, HDPE or PET. 6. Method according to claim 5, characterized in that the plastic ribbon fabric has an optionally printed coating or a laminated plastic film. 7. Method according to one of claims 1 to 4, characterized in that the substrate (3) is a single- or multi-layer, optionally printed, plastic film, preferably made of PP, LLDPE, LDPE, HDPE or PET. 8. Method according to one of the preceding claims, characterized in that the substrate (3) is perforated before it is combined with the nonwoven material (4). 9. Method according to one of the preceding claims, characterized in that the nonwoven material (4) is a spunbonded nonwoven or a carded nonwoven or a spunlace material or a meltblown material or a spunbond material or a composite material of the said materials. 10. Process according to one of the preceding claims, characterized in that the first and/or the second thermoplastic polymer is selected from: PET, PP, PE, or a co- or terpolymer containing two or three of the following monomers: ethylene, propylene, vinyl acetate, alkyl acrylate, maleic anhydride, alpha-olefin. 11. Process according to one of the preceding claims, characterized in that the third and/or the fourth thermoplastic polymer is selected from: PET, PP, PE, or a co- or terpolymer containing two or three of the following monomers: ethylene, propylene, vinyl acetate, alkyl acrylate, maleic anhydride, alpha-olefin. 12. Method according to one of the preceding claims, characterized in that the particles (7) containing the third thermoplastic polymer have an average particle size of less than or equal to 1000 pm, and/or that the particles (17) containing the fourth thermoplastic polymer have an average particle size between 80 and 800 pm, preferably between 100 and 500 pm, wherein for the particles (17) containing the fourth thermoplastic polymer, particle sizes that are as uniform as possible, in particular with size differences of less than a factor of 3, are particularly preferred. 13. Method according to one of the preceding claims, characterized in that the particles (7, 17) are applied to the substrate (3) and/or the nonwoven material (4) with a surface weight between 1 g and 20 g per m ² , preferably between 3 g and 5 g per m ² . 14. Method according to one of the preceding claims, characterized in that the particles (7, 17) are set to a temperature above their softening temperature when bonding to the substrate (3) or the nonwoven material (4). 15. Method according to one of claims 1 to 3 and 5 to 14, characterized in that the web-shaped substrate (3) is a flat web and the web-shaped composite material (2) is formed from the substrate (3) and the nonwoven material (4) into a tube (15) by placing the side regions (2a, 2b) of the flat, web-shaped composite material (2) on top of one another and connecting them to one another to form an overlap (2c), the nonwoven material (4) forming an inner layer of the tube (15). 16. Method according to one of the preceding claims, characterized in that the hose (15) produced according to claim 15 or a composite material (2) comprising the tubular substrate (3) according to claim 4 is separated into hose pieces and a base is formed at at least one end of the hose pieces. 17. Device (1, 20) for producing a flexible web-shaped composite material (2), comprising Feeding means for feeding a web-shaped substrate (3) which at least partially contains a first thermoplastic polymer, Feeding means for feeding a web-shaped nonwoven material (4) which at least partially contains a second thermoplastic polymer, a device for applying discrete particles (7) which contain a third thermoplastic polymer to the web-shaped substrate (3) or to the web-shaped nonwoven material (4), wherein the device for applying particles (7) comprises a heatable release surface (6), a container (8) from which a plurality of the discrete particles (7) can be applied to the release surface (6), wherein the release surface (6) can be heated to a temperature which is above a softening temperature of the third thermoplastic polymer, a pair of rollers (9) for bringing a surface (3a, 4a) of the substrate (3) or of the nonwoven material (4) into contact with the release surface (6) and the softened particles (7) arranged thereon, so that the particles (7) adhere to the surface (3a, 4a) of the substrate (3) or of the nonwoven material (4), and optionally comprises a cooling means (10) for cooling the particles (7) adhering to the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) below the softening temperature of the third thermoplastic polymer, characterized in that the device (1, 20) further comprises: Means (21) for bringing together the substrate (3) and the nonwoven material (4) so that the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) with the particles (7) adhering thereto faces a surface (4a, 3a) of the nonwoven material (4) or the substrate (3), optionally a heating device (11) for heating the particles (7) adhering to the surface (3a, 4a) of the substrate (3) or the nonwoven material (4) above the softening temperature of the third thermoplastic polymer, and a pair of rollers (12) for pressing the substrate (3) and the nonwoven material (4) together so that the softened particles (7) contact the mutually facing surfaces (3a, 4a) of the substrate (3) and the nonwoven material (4) together, and optionally coolant (14) for cooling the composite material (2) thus produced from the substrate (3) and the nonwoven material (4). 18. Device according to claim 17, characterized by a device for applying discrete particles (17) containing a fourth thermoplastic polymer to the web-shaped substrate (3), wherein the device for applying particles (17) comprises a heatable release surface (6, 16), a container (18) from which a plurality of the discrete particles (17) can be applied to the release surface (6, 16), wherein the release surface (6, 16) can be heated to a temperature which is above a softening temperature of the fourth thermoplastic polymer, a pair of rollers (19) for bringing a surface (3b) of the substrate (3) into contact with the release surface (6, 16) and the softened particles (17) arranged thereon, so that the particles (17) adhere to the surface (3b) of the substrate (3), and optionally coolant (14) for cooling the particles (17) on the surface (3b) of the substrate (3) adhering particles (17) below the softening temperature of the fourth thermoplastic polymer. 19. Device according to claim 18, characterized by a turning device (30) for turning the substrate (3) or the composite (2) of the substrate (3) and the nonwoven material (4) prior to applying the particles (17) containing a fourth thermoplastic polymer to the surface (3b) of the substrate (3) opposite the nonwoven material (4) and means for feeding the turned composite (2) to the release surface (6), which also serves for applying the particles (7) containing a third thermoplastic polymer, so that the surface (3b) of the substrate (3) opposite the nonwoven material (4) faces the release surface (6).