Cement bags

[0001] The present invention relates to a bag for building materials, in particular a flexible bag for building materials for bulk material, especially a cement bag, for transporting and storing specific portions of bulk material, preferably at least 15 kg to 50 kg.

[0002] Various types of cement bags are known so that cement can be transported and stored in specific portions. Different sack designs meet different points, but different requirements may apply depending on the field of application, cement composition and environmental conditions. Points such as sufficient mechanical strength depending on the size of the bag, a sufficient barrier against small particles (dust) to prevent migration of fine cement components through the packaging material, a sufficient moisture barrier and / or sufficient air permeability may be relevant here. guarantee pressure equalization when filling and cooling the cement bag.

[0003] Depending on the specific requirements, different material concepts for bags for building materials can be used, which have different advantages as well as disadvantages:

Ordinary bags of one or several layers of paper that are partially perforated to ensure air permeability. This results, for example, from DE 36 13 749 A1. Although this concept has the lowest costs, it is difficult to ensure sufficient mechanical strength and moisture protection. Despite this, due to the favorable price, the use of these materials is still widespread. There are also further developments enabling the use of so-called kraft (sulfate) papers also in the case of wholesale sacks, as is apparent from DE 698 06 168.

[0004] Bags with one or several layers of paper and one perforated plastic film. Compared to paper bags alone, this design gives a clearly improved moisture / liquid barrier. A suitable bag that can be used for building materials is known from AT 413 273 B. [0005] There are also bags made of woven plastic ribbon fibers, most often of polypropylene, with a perforated plastic film as a liquid and dust barrier. This design ensures very high mechanical strength, water resistance and high water barrier. Therefore, these bags are often used in countries where the mechanical load during transport and storage is highest, for example in Arab countries.

[0006] Due to the price of polypropylene compared to paper, and also the production of a woven bag, the costs of this material are, however, clearly higher compared to paper bags. Many technological steps are needed, which are labor-intensive, such as the production of ribbon fiber, weaving tapes to form a surface structure, the production of a perforated film and the combination of materials into a surface structure with multiple layers. [0007] From WO 2005/012121, a cement bag is known in turn, which as a wall is to comprise one plastic layer and a supporting layer connected thereto, wherein the support layer can be a fabric and the plastic layer applied to this fabric with an adhesive hot melt, which is either perforated or porous. The wall shall be gas-permeable and water-impermeable.

[0008] From DE 10 2004 013 469 A1 a material combination of a film and a nonwoven is known, in which the nonwoven is used as an inner layer. A film that is air-permeable is used as the outer layer. The bag has an overlap region of the foil in which the underlying region of the foil is perforated. The hermetic pleat closure extending from the side creates a venting path through which air can escape when the bag is being filled. Outside the venting area, the outer layer itself is impermeable to air and water. The bag thus formed is to be filled through the filling nozzle. This bag can be used for cement, plaster, dry mixes containing cement or plaster, flour, feed or similar materials.

[0009] From CN-Y-219 6086 a cement bag is known which uses a waterproof laminate.

[00010] The object of the present invention is to create a bag for building material that will be easy to manufacture.

[0010] The solution to this task is a sack for building material, especially a flexible sack for building material for loose material, especially a sack for cement, for transporting and storing specific portions of bulk material, preferably at least 15 kg to 50 kg, the sack for material construction as the wall of the bag has at least one laminate with at least one first and one second layer, the first layer is foil and the second layer is a nonwoven fabric, which are connected with each other, the outer wall and the inner wall of the laminate being air permeable. [0011] It has surprisingly been found that the use of non-woven fabric and film, which are in particular air-permeable, provides a sufficient liquid barrier effect. In this way, the non-woven fabric's ability to provide high strength can be particularly utilized, while the film is able to further enhance the non-woven barrier effect. Preferably, a monolayer film as well as a monolayer nonwoven is used. Multilayer films or multilayer nonwovens can also be used. For example, as the preferred nonwoven material, pure nonwoven fabric (from under the spunbond), spunbond-meltblown material, hereinafter referred to as SM material, in particular SMS material is used. Perforated films are a suitable form of making air-permeable films.

[0012] According to a further embodiment, the construction material bag has an inner layer and an outer layer, each of which is air-permeable. Preferably at least one of both layers is formed of the laminate, in particular both layers, however. Further development envisages that the nonwoven fabric is located outside and the foil inside. Another further development envisages that the nonwoven fabric is positioned inside and the film outside. For example, the film may have a higher specific gravity than the nonwoven or vice versa.

[0013] The laminate preferably has a structure such that the nonwoven fabric provides higher strength than the film. For example, it can be provided that, with equal strength, the nonwoven fabric elongates less than the film. It is advantageous when the nonwoven fabric at the same load stretches you at least by a factor of 2, especially at least by a factor of 4 less than the film.

[0014] The use of pure hydrophobic non-woven fabric from underneath the cloth, for example polypropylene, in cement bags is only possible to a very limited extent, because the delicate hydrophilic cement dust components partially penetrate into the nonwoven and can give the structure hydrophilic properties. Thanks to this, the barrier effect of the non-woven fabric "from under the filament" against water is completely abolished and there is a "sponge effect" that absorbs liquid and even promotes the penetration of liquid. However, thanks to the combination of nonwoven materials proposed here, especially the nonwoven nonwoven, with a permeable foil, particularly preferably a perforated foil, it is possible to produce a very economical material for cement bags with good moisture barrier properties and high mechanical strength. Surprisingly, very good barrier properties are obtained when the film and nonwoven fabric are perforated simultaneously with needles, the needles pierce the material through the film towards the nonwoven fabric and form conical holes that are stabilized by the nonwoven fabric. A further embodiment envisages that perforation will occur, preferably the perforated material, especially the film, however, preferably does not tear completely. According to one embodiment, it is rather provided that, as a result of perforation, a hole is formed, but this preferably closes back, e.g. under pressure, when filling a bag for building materials with loose material, especially free-moving material, such as cement. For example, the perforating device may have punches intended for this that slide into the perforation matrix and only partially form an opening. [0015] According to one embodiment, the permeability of the laminate is selected in such a way that particles with a diameter larger than 300 μη cannot pass through. Thanks to this, it is possible to design a bag for building material so that it is impermeable to building material and especially to dust particles.

[0016] The permeable film can be produced in various ways. And so a filled film is made, which is then stretched. By stretching, micro perforations are created that ensure air permeability. The film is preferably stretched in the machine direction (web advance) as well as in the direction transverse to the machine direction. As a result, the laminate may contain a microporous film. For this purpose, the film is, for example, filled with filler at least 20% by weight, in particular at least 30% by weight and preferably up to 50% by weight By stretching, it is also possible to rupture predetermined cracking points, which were previously made in the foil material, which also allow air permeability.

A microporosity can also be provided in addition, for example in the case of a film which has closable openings.

[0017] If, for example, mechanical perforation of the laminate with needles is made, it advantageously causes the foil to penetrate into the nonwoven interior. The nonwoven fibers can also stabilize the geometry created by the perforation. According to one embodiment, it is provided that the conical perforation extends from the film into the interior of the nonwoven fabric. A further development provides that the perforation forms a semi-permeable membrane, in which the liquid cannot penetrate into the bag for building material, however, air can escape from the bag for building material. In addition, it may be provided that the perforations are micro-perforations.

[0018] Perforation may occur in various ways. In addition to water jet perforation, needle perforation can be performed. There is also the possibility of perforation by supplying energy, e.g. in the form of ultrasound. However, perforation can also be done by electron discharge. For example, not only foil, but also nonwoven and / or other layers may be perforated during perforation. According to one embodiment, it is provided that a connection between the layers is created by this. The connection can be caused by force and / or shape connection mechanisms. In this way, materials of different layers can get caught together, as well as thermal bonding of these materials. The thermoplastic multilayer structure may be perforated, for example, as is known from DE 101 32 196 A1, to which we refer in full in the context of the present disclosure. [0019] In addition or as an alternative to joining the laminate layers together, according to a further embodiment it is provided that the laminate layers are glued together. Bonding can occur by applying hot melt adhesive. For example, the adhesive is sprayed. It can also be applied by roller application. The adhesive can be prepared in the form of particles, liquids, fibers or other forms.

[0020] A further embodiment provides that the laminate for sacks for building material is produced in such a way that the film is extruded onto a nonwoven fabric. It is also possible that the non-woven fabric is deposited directly onto the prefabricated film and connected to it.

[0021] To enable marking of the bag for the building material, it may be provided to provide it with one or more labels. You can also print the outside of the bag for building material. Another option is to print one layer of laminate, on which the outer layer of the bag for building material is applied. For this purpose, it can be advantageous, for example, when the nonwoven material is at least opaque. For example, the nonwoven can cover the printed foil layer. It is also possible for the laminate to have layers of different color. This can also be used to mark a bag for building material regarding its content. Another possibility is that the laminate or one of its layers has some relief. This relief can be created, for example, by appropriate embossing. For example, for a sidewall in special areas, the surface can be selectively changed under the action of heat. A special effect can be achieved by creating a relief, especially by underlining the printed area.

[0022] A further development provides that the material has a reinforcement, preferably a mesh material. The mesh material may contain thermoplastic material. However, it can also be another plastic material. It is also possible to use other high strength mesh material.

[0023] The bag for the building material preferably contains a laminate that has an air permeability of at least 20 l / m according to EDANA 140.1²/ S. This allows you to fill the bag for building material with the possibility of an outlet for air contained in the bag.

[0024] A particularly close connection of the bag for the building material is obtained when the non-woven material and the film material are glued together at least under the action of heat, in particular welded. The thermal joining step can be used for this purpose. But also the possibility of hot stamping of the film material allows at least surface gluing, but especially at least partial penetration into the gaps between the nonwoven fibers.

[0025] It is preferred that at least the laminate is biodegradable. The nonwoven and / or film can for example be made for this purpose from a starch-based polymer as well as from PLA. The sack for building material can be folded, in particular rolled up, and thus flexible; however, the material may also have some stiffness so that the bag for the building material will retain its shape even after being filled with building material and emptied of it.

[0027] According to a further idea of ​​the invention, a method is provided for producing a bag for building material, especially a flexible bag for building material for bulk material, in particular for a cement bag, preferably for the above-mentioned bag for building material, using air-permeable but impermeable to water laminate, in which non-woven fabric and foil are used.

[0028] A further development provides that the method produces a laminate which in the unfilled state of the construction material bag is first at least water vapor permeable, however preferably water permeable, but becomes water-impermeable when the building material bag is filled . Also after filling, the laminate can also be approximately vapor-impermeable. A further development provides that the method produces a laminate which in the unfilled state of the construction material bag is at least water vapor permeable, possibly also air permeable, but preferably water permeable, however, after filling the building material bag, it becomes at least impermeable to water. After filling, the laminate may also be approximately impervious to steam. You can use a foil that closes its holes after filling and is preferably no longer air-permeable. So, for example, you can use a shrink film, which, as a result of heating from the cement poured under the action of heat, closes the holes it contains. As a result of the funnel shape, the film holes can also close under the effect of cement pressure.

[0029] The laminate is preferably further processed, wherein the inner surface of the building material bag is formed by a film and the outer surface of the building material bag is formed from a nonwoven fabric. For example, it is foreseen that a laminate is produced at the first station and a bag of building material is made of laminate at the second station, with the laminate being transported between the first and second stations at the plant site, especially in the building, and the bag being filled with loose material construction material takes place in the third position, the third station compiles a large number of bags for building material to be automatically equipped with a non-automatic filling machine.

[0030] A further development provides that in the first station using a non-woven fabric production plant, a "non-woven fabric" is produced, and in the laminating installation it is combined with a foil material, followed by giving the laminate air permeability properties.

[0031] With this method, the laminate is preferably perforated under the action of heat, the needle perforating device being heated in its needle area to a temperature exceeding the glass transition temperature, in particular the softening point of the film, and the glass transition temperature of the nonwoven. Devices with which perforation can be made are known, for example, from EP 1 425 143 A1 and EP 1 425 161 A1, to which we refer in this respect in full in this disclosure.

[0032] The laminate is perforated, for example, up to a maximum opening diameter of max. 2 mm. Another embodiment provides for perforating the laminate up to a maximum opening diameter of 0.4 mm. [0033] The method may for example be carried out in such a way that a nonwoven is used in which at least one first polymer and one second polymer form a nonwoven fiber, and wherein at least one of the two polymers is at least glued, preferably heat-sealed, due to heat film, with funnel-shaped holes stabilizing.

[0034] During the production of the laminate or at another stage in the production of the bag for the building material, it is preferably provided to form holes in the laminate that close under pressure. When loading the film from the inside, as a result of filling the bag for building material, the holes in the film preferably close. When filling the bag for building material, there is preferably a positive pressure acting on its internal space. Air can escape through the pores or holes in the laminate. Depending on the state of filling with poured cement, it is only necessary, for example, to open those pores or openings that are not yet at the height of the cement filling, but above it. By adjusting the geometrical shapes in the film and / or nonwoven fabric, you can influence whether they remain open, for example, or can be closed by cement. The holes may be at least partially closed, for example by squeezing the foil material. For this purpose, for example, tubular geometric shapes can be formed in the film material. They close if they are weighed down by pressure from the side. However, such tubes can also be produced without a perforation step. For example, by adhering to a certain surface, especially a roller, the foil material can obtain a micro surface in the form of volcanoes. These micro-volcanoes are empty. The structures formed in this way can also run cylindrical or otherwise, in particular protruding from the surface of the foil material. It is also possible that, for this purpose, the foil material is partially recessed, especially pressed, into the matrix surface provided with appropriate negative geometric shapes. Various possible basic types of construction for this type of device are described in DE 198 43 109 A1, DE 101

501 A1, DE 100 35 597 A1 and / or DE 100 36 780 A1. EP 1 198 339 B1 gives various materials and devices in this respect, information on the state of the art, where reference is made to this publication and to the state of the art mentioned therein. According to further development, such cones can also extend from the inside to the outside. This allows closing them, for example at the latest under pressure from the outside, such as when storing filled bags one on top of the other or next to each other. Geometric shapes can also close on their own under the influence of cement when it enters these geometrical shapes and clogs them. For example, cement can be introduced as hot and as a result sintered in the holes. Thanks to this, the cement cannot go further and the geometric shape fills up.

[0035] It has proved advantageous to make the laminate from only one layer of nonwoven and only one layer of film. The laminate preferably has a dynamic barrier property which is greater than> 95% against water, the laminate preferably also having an air permeability according to EDANA 140.1 exceeding 20 l / m²/ S. The measurement methodology for determining the dynamic barrier property of liquids will be further described below:

Preferably, holes are made in the laminate, in order to produce in one technological step the perforated laminate is produced by a combination of a nonwoven fabric production plant with a film extruder, calender, needle perforation roller and winder. The nonwoven fabric production plant is preferably a nonwoven fabric production plant. Another embodiment provides for the laminate perforation that the calender has a smooth roll facing the foil and an engraved roll facing the nonwoven fabric.

[0036] A bag for building materials may have one or more layers of nonwoven fabric. You can use the same type of nonwoven or different types of nonwoven for this. For example, nonwoven nonwoven fabric, carded nonwoven material, SMS material, airlaid material, spunlace material, meltblown material, elastic nonwoven material, two-component material and / or nonwoven fabric whose fibers or filaments have specific geometric shapes, e.g. three-plane (e.g. trilobal), or they have other geometrical shapes, especially they do not have a round shape in cross-section.

[0037] The preferred shape of the bag for the building material and its manufacture envisages that it uses a laminate with a surface weight of at least 30 g / m², especially at least 40 g / m2², preferably between 40 g / m2² a 150 g / m2². At least one handle is preferably attached to the side wall of the bag for building material, in particular by welding. The material for the handle can be a nonwoven fabric "from under the fille", with a surface weight of at least 70 g / m2², preferably between 80 g / m2² a 100 g / m2².

[0038] Especially thermoplastic materials are considered as materials for the sack for building materials. The polymer used can be isotactic or atactic. According to one embodiment, it is possible that the majority of the construction material bag is made of polypropylene, a polypropylene-containing polymer or copolymer, as well as of a two-component or multi-component material. Preferably, the two-component material has on the surface at least partially, preferably on the entire surface, polyethylene, while another polymer, preferably polypropylene, is arranged in the interior. In this way, polypropylene can give high strength, while polyethylene is suitable for providing particularly pleasant wearing comfort when the bag for building material needs to be transported by hand. Secondly, the use of polyethylene allows a better combination with other similar foil material. The outer material of the fibers is preferably at least matched to the laminate foil material, preferably it is even compatible with it.

[0039] According to a further embodiment, it is provided that the laminate, foil and / or non-woven fabric are made of a material that contains at least one of the following group members: PO, PET, biocompatible polymer, PP, PE, copolymers, antimicrobial additive, additive with hydrophilic action, phosphorescent additive, fluorescent additive, antistatic additive and anti-dirt additive.

[0040] Further development envisages that as a result of extrusion, the nonwoven web has increased tearing strength. Preferably, the embossing surface occupies from 10% to 70% of the surface of the nonwoven web, especially from 15% to 30%, preferably with a single embossing surface from 0.05 mm² up to 3 mm². The embossing is preferably made using a thermal bonding step. The embossing is especially made so that the tensile strength of the nonwoven web is more strongly increased in the machine direction MD (web direction) than in the CD direction (transverse to the web direction). For this purpose, it is provided, for example, that the main axis of the extrusion area is located in the CD direction (transverse to the web direction).

[0041] The embossing, especially the thermal bonding, is preferably carried out by means of an embossing calender that has corresponding elevations. For example, the smooth roll and embossing roll form a calender gap, wherein at least one of both rollers is heated to a temperature that in particular causes the nonwoven fabric to melt through the calender gap. In addition to heat embossing, it is also possible to thicken the nonwoven fabric by suitable means such as, for example, ultrasound, heat radiation, water jetting and / or the use of adhesives such as, for example, adhesive fibers or the like.

[0042] The laminate, especially the opposite side walls in at least one area are connected to each other, especially welded. It has proved beneficial when in the welding area, especially when making edges, at least the material therein is a copolymer. The copolymer may contain, for example, polypropylene and polyethylene. By using a copolymer, it is achieved that a better bonding of materials occurs during welding. When PP and / or PE are used, the frequency of 10,000 Hz to 30,000 Hz is preferably used for ultrasonic welding to introduce energy into the material.

[0043] The ends of the laminate can be joined, for example, by way of an overlap. For this purpose, for example, wide areas can be welded together. Another possibility is that the edges opposite each other are adjacent to each other in contact. In addition, for example, a nonwoven material or polymeric material may be added to allow the laminate to bond together. The laminate bond can be located, for example, in the area of ​​one side wall. However, it is also possible to locate the seam on the transverse side of the bag for building material. According to a further embodiment, it is provided that in the bottom area there is one bond with the laminate or no bond. For this purpose, for example, the laminate can be pulled up into the side wall or the transverse wall of the bag for building material, so that the bonding of the laminate only takes place there. In addition, it is possible that the bag for the building material has one or two areas where a laminate is used which includes a section in which only non-woven material or only foil is present. [0044] Bonding together can, for example, also take place using foil material. For example, the film can provide additional polymer material that is additionally used in the area of ​​weld formation. In addition to welding, in addition to welding or instead of welding, you can also use gluing, as well as other joining techniques. [0045] In addition, it is preferably provided that, in particular in the region of the side edges being bonded together, for example by welding, greater elongation is provided than in the rest of the laminate area. This can for example be provided by the appropriate shape of the embossing or by the appropriate shape of the weld edges. The material used in the region of the weld edge may have a buffer or damping effect. The material used there is, for example, more flexible or stretchy than in other areas of the construction material bag.

[0046] The weld or edge of the material on the bag for building material preferably does not extend in a straight line from one end to the other. Rather, it has a wavy structure, changing its direction many times, zigzag structure or other waveforms. This creates a larger, especially longer joint or edge, and therefore a stronger connection. [0047] In addition to joining one or more flat layers to make a bag for building material, the laminate is preferably coated either before or after. It is also possible for the nonwoven web to have a barrier effect. The nonwoven fabric forms, for example, a barrier of this type that it is water vapor permeable and water impermeable, the nonwoven web preferably having a water column of at least 200 mm, in particular up to 1000 mm. For this purpose, the nonwoven can, for example, be constructed as a laminate of meltblown and nonwoven from under the fabric. The nonwoven fabric is also preferably air permeable in such a way that the air permeability is between 100 and 5000 l / m²/ s, preferably between 1000 and 3000 l / m²/ S.

[0048] In one or more places or areas, the bag for building material can also preferably have reinforcement. One area can be a grip area. For example, a carrying aid, in particular an ear or handle, may be attached to it. Strengthening may also be provided in some areas of the bottom. This reinforcement can, for example, take place through an insert, which can also be a particular element that gives shape to a sack for building material. This reinforcement can be flexible as well as rigid. It can be made of one or more layers. The reinforcement material may be a plastic, especially a polymer, from which the laminate is made and in particular the nonwoven. Laminate or nonwoven can also be used as reinforcement. In the case of a handle, the handle reinforcement may, on the one hand, provide a seam area between the appropriate carrying bag and the handle. For example, additional material may be prepared that allows connection to the handle material. In addition, it is possible that the reinforcement prevents one or several handles from being pulled out. For this purpose, the reinforcement can be appropriately additionally connected to the handle and one side wall of the bag for building material. It is also possible to plan the reinforcement in the area of ​​the proper gripping area. This type of reinforcement may consist, for example, in widening the gripping area, which avoids cutting the grips into the palm surface. The reinforcement can also be used especially to enable widening the bearing surface of the carrying handles and thus the support in the hand. To this end, the reinforcement may be made of, for example, cardboard, paper, foam or similar material.

[0049] The method for producing a bag for building material is implemented, for example, such that the laminate is prepared using a nonwoven web, the laminate being folded in the MD direction of the nonwoven, i.e. in the direction of the machine, in the direction of the nonwoven in the machine, and opposite the sides of the laminate are processed into the side walls of the bag for building material, while the laminate is processed in such a way, that the non-woven fabric extends in the CD direction (transverse to the machine direction of operation) from the bottom of the building material bag towards the filling opening.

The following figures show further embodiments and features of the invention which, with the features described above, can be combined into further developments not described in more detail. However, the relevant figures should not be construed as limiting. The details contained in the respective figures, respectively, can also be combined with other features in isolation from a given configuration. The figures show:

Fig. 1 an exemplary view of a first configuration of a bag for building materials, Fig. 2 a first exemplary configuration of a first and second laminate production station which is used to produce a bag for building material, Fig. 3 a second configuration of a laminate production installation, Fig. 4 nonwoven for making the laminate, Fig. 5 feeding the pre-perforated material, which then goes into the laminate, Fig. 6 determination of the dynamic laminate barrier, Fig. 7 another installation for the production and filling of a bag for building material, and Fig. 8 an example schematic view of the laminate surface.

[0051] Fig. 1 shows an exemplary view of a first embodiment of a bag 1 for building material. The building material bag 1 may in particular have a longitudinal extent, with an approximately cuboid shape. Laminate 2 is used to produce building material 1. Bag 1 for building material is preferably made exclusively of laminate 2. An exemplary configuration of laminate 2 is shown in an enlarged view. There is a first layer 3 of foil material, which is connected to the second layer 5 via a connection 4, shown in the form of crosses. The first layer is preferably a thermoplastic film. This layer can be formed, for example, three-dimensional. The second layer is preferably a nonwoven, in particular a nonwoven web. The first layer 3 as well as the second layer 5 are respectively air-permeable. The laminate 2 thus formed is therefore also air-permeable in total. Preferably, the laminate 2, but at least one layer thereof, has a water column of at least 30 cm. The joint 4 can be made, for example, by using an adhesive layer, but also by melting and bonding the first and second layers 3, 5 together. The laminate forms at least one wall 6 of the illustrated bag 1 for building material. Preferably, the film forms the inner layer 7, while the nonwoven fabric forms the outer layer 8 of the bag 1 for the building material. The building material bag 1 preferably has a gripping area

9. It allows improved, especially manual transport of the bag 1 to the building material, especially when the bag is filled. The gripping area 9 can be made in the most diverse way. It may occur at one upper end of the bag 1 for building material as shown. However, it is also possible that there are at least one gripping area on two opposite long sides of the construction material bag 1. However, the gripping area can also be on the transverse side of the bag 1 for building material. The grip area is preferably also manufactured from laminate 2. In addition, the grip area 9 can also have additional reinforcement. Laminate 2 is preferably air-permeable over the entire used area of ​​the building material bag 1. For this purpose, the foil may have one or several holes 10. The holes 10 may be formed by perforation but also by microporosity. If perforations are made, they are arranged in the form of a regular pattern. According to another embodiment, the perforations are irregular. In addition, the holes can also extend through the joint 4 and attached in a nonwoven fabric. This is achieved, for example, thanks to the perforation that passes through all the layers. However, according to a further embodiment, only the film can contain such openings, wherein the air permeability of the nonwoven is ensured by the material properties of the nonwoven.

[0052] Fig. 2 shows a first exemplary configuration of a first station 11 and a second station 12, with which a laminate and a bag for building material are produced. At the first station 11, laminate is produced. In the presented embodiment, the produced material is temporarily stored. At the second station 12, it is further processed into a sack for building material. According to this embodiment, the first station 11 comprises a first uncoiler 13 and a second uncoiler 14. Non-woven fabric is fed from the first uncoiler, and film material from the second uncoiler 14. They are fed to the first calender unit 15. There, for example, under the influence of heat, the layers brought together can be joined. For example, perforating laminate can be made in another processing unit 16. You can use a calender with needle rollers, perforation with water jets or other suitable equipment. As shown, the entire laminate is perforated at the first station 11. The perforation can be carried out in particular in such a way that stabilization, preferably of three-dimensional geometry, which is similar, for example, to a cone, occurs by penetrating the materials. Then the perforated laminate is wound onto a winder 17. The perforated laminate roll produced in this way can then be stored in a transitional warehouse. The production of bags for the building material can take place by using the laminate roll formed in this way in a device for making bags for the building materials, which as the second station 12 is only schematically represented. The laminate roll 18 continuously provides material for further processing in the bag making apparatus 19. From there, the bags for building material produced are made available in the form of a transitional warehouse 20. Bags for building materials can, for example, be placed in a cardboard box separated from each other and / or at least partly connected to each other. When the bags for building materials have a connection between them, it is also possible to roll them up, as indicated by a roller drawn with dashed lines. The advantage of this kind of first and second stations 11, 12 is that each special mode of operation can be carried out continuously. The disturbance in this continuous operating mode can be compensated for by the fact that as a result of transient storage of the necessary material by appropriate transient storage, time buffers can be created. Therefore, if one station working in continuous mode is stopped, one or more of the next positions may still work. It is particularly advantageous when such positions are located together in one factory area, especially even in one hall building, when they are subject to the same regulations, especially hygiene regulations and requirements regarding the purity of production. In this way, long travel times as well as decontamination of the material can be avoided.

[0053] Fig. 3 shows a second configuration of the laminate production machine. The extruder 21 melts the polymer material for the device 22 for the production of nonwovens by the "under the filament" method 22. The extruder 21 can be a single extruder or a double extruder. It is also possible to add modifying additives to the extruder if it has not occurred as a result of appropriate compaction of the polymer material. The twin extruder makes it possible to produce, in particular, two-component materials, preferably core fibers. The exemplary device 22 for the production of nonwovens by the "under the filament" method may be an installation for the production of nonwovens by the "under the filament" method. Various manufacturers supply this type of installation as turnkey installations. Producers can be the companies Neumag, Reifenhauser, STP Impianti, as well as others. The device 22 for the production of nonwovens by the "under the filament" method can, however, also be replaced by another device for the production of nonwovens, such as a carding or similar installation. Through the operation of the device 22 for the production of nonwovens by the "under the filament" method, the thickness of the filaments or fibers as well as the basis weight of the nonwoven layer are regulated, and thus especially such properties as air permeability and water column. According to the installation shown in fig. 3 the uncured nonwoven fabric is deposited on a sieve belt and then fed to the film extruder 23. The material is melted by the extruder and then applied to the uncured nonwoven fabric. During this polymer coating, the adhered film, which is still liquid or still very hot, adheres, so that the non-woven fibers and the film are at least tacked together, possibly also fusing together. The laminate thus formed is then cured in the thermal bonding calender 24.

It is advantageous here that the smooth roll 25 presses against the film and the extrusion roll 26 into the nonwoven fabric. The non-woven laminate cured in this way is fed to the perforation assembly 27. As shown schematically, the perforation assembly is preferably a needle roller calendering device. The needle roller is preferably heated, whereby the needle surface temperature can be kept constant. The temperature is set depending on the nonwoven polymer material and / or film used. The needles preferably enter the material on the foil side to create a conical structure facing the nonwoven layer. During perforation, the nonwoven fibers are subject to this reorientation and are not damaged by the perforation process. If the needle surface temperature is set, for example, so that the glass transition temperature of the nonwoven polymer is exceeded, the nonwoven forms a support structure for the conical hole directed towards the nonwoven, which in turn is important for the barrier function of the liquid. According to one embodiment, it is therefore provided that the polymer material of the film melts at a higher temperature than the non-woven polymer material. According to another embodiment, it is provided that the polymeric material of the film melts at a lower temperature than the nonwoven polymeric material. In this way, one can advantageously choose which of the two layers is to support the second layer by appropriate melting and in particular by joining various structures. The advantage of the installation shown in fig. 3 is a continuous production process, because thanks to sufficient supplementation of the output granulate for the production of non-woven fabric or film, this type of installation can work round the clock without interruption. A winding unit 28 is provided downstream of the perforation assembly. It preferably includes an automatic changer, therefore coil replacement can take place without interrupting the laminate production process. [0054] Fig. 4 shows the feeding of non-woven fabric in a semi-linear process using prefabricated rolls of film.

The device 22 for producing nonwovens by the "under the filament" method continuously produces the nonwoven fabric. Foil material is made available through the development team 29. Behind it can be further processing stations such as, for example, a thermal bonding calender 24 and a perforation unit 27. In addition to this configuration, it is also possible to produce the film layer continuously, while the nonwoven fabric is made available through a suitable unwinding unit. The very design of the installation also allows the inclusion of additional machining units 30. They are marked with dashed lines and can be used in various places in the installation. For example, machining units can apply coatings, emboss materials, dry, wet materials, or otherwise change the chemical, physical, or geometric structure of a layer or laminate.

[0055] Fig. 5 shows the supply of pre-perforated material, which is then converted into a laminate. For this purpose, for example, between the pre-hardened non-woven fabric 31 and the pre-perforated film 32, a reinforcing layer 33 is introduced. The reinforcing layer may in particular be an additional layer in nonwovens but in particular also a mesh. The mesh can thus provide especially high strength laminate. The mesh is usually made of a polymer material, therefore at the thermal bonding stage, which has been marked by the thermal bonding calender 24, it can be combined with either of the other two layers. Due to the further heat input, e.g. in the form of a calender 34 with smooth cylinders, the laminate and its layers can be better bonded by suitable heating of the materials at least to the adhesion temperature. Then the material is rolled up and remains ready for further processing. The plant structure according to Fig. 5 may also provide that the film layer will not be pre-perforated. Moreover, the foil layer can also be a foil filled with filler. Chalk or similar material is suitable as a filler. For example, after passing through the thermal bonding calender 24, a so-called annular roller calender 35 may be provided instead of the smooth roller calender 34. In this technology, the laminate is preferably stretched in at least one direction, especially in the CD direction (transverse to the web advance) as well as in the MD direction (web advance). There are cracks in the connection between the filling material and the polymer material of the film, so that the film layer becomes air-permeable. The ring-roller calender may have a disk structure for this purpose, with the shields coming into each other. Opposite waltzes may also have deep or high positive / negative structures, between which the material is partly restrained and partly stretched between them. In addition, it is also possible to use pre-stretched film in the installation. If the stretching is only carried out after lamination, as for example by the respective stretching frames 36 marked with a dashed line, then the nonwoven fabric is preferably glued to the foil material. As a result of this stretching, the adhesive layer breaks, provided that it was applied not intermittently but continuously. Thanks to this also air-permeable areas are created in this connection.

[0056] Fig. 6 shows a possible measurement method for determining the dynamic barrier against liquids. According to fig. 6 illustration

a) a 15cm x 15cm sample is mounted on a 20cm x 20cm plate on which an absorbent 14cm x 14cm filter paper is centrally attached, with only the top edge of the sample clamped onto the filter paper to prevent it from moving, wherein the substrate has an angle of inclination of 30 °. At the lower end, the sample protrudes beyond the filter paper by 1 cm. Remember that the sample should come into direct contact with the filter paper.

[0057] Using a piston or syringe with a 0.5 mm hole from a height of 10 cm, spot 1 cm³ centrally distilled water per sample, adjust the piston stroke so that individual drops break off. Repeat this procedure in 4 places of the sample, which have a distance of at least 1 cm from each other, so that a total of 4 cm is spotted on the sample³ distilled water. When performing the test, make sure that the filter paper is not wetted by dripping water (the sample must protrude at least 1 cm from the filter paper at the lower end).

[0058] By weighing the filter paper before and after dropping the water, the proportion of water that has penetrated into the sample is determined. The dynamic barrier is defined as the result of the equation:

(α - b) / a * 100 where a = total amount of liquid in the sample [g] (4cm³ responds

g) b = weight gain of the filter paper (amount of liquid that has penetrated, in [g]) [0059] Fig. 7 shows a schematic view of another installation for producing and filling a bag for building material. The first station 11 and the second station 12 are schematically represented. The third station schematically shows an example of filling bag 1 for building material. The advantage of the laminate 2 used is that an antistatic coating can be applied or a modifying additive which has an antistatic effect can be used. Since very fine-grained powder is also introduced into the building material 1 during filling, the use of antistatic materials allows the filling characteristics to be improved. In addition, unwanted static electricity in installation areas is avoided. After filling the bag for building material, the bag is closed.

The closing also preferably takes place automatically. Laminate 2 allows various methods to produce a bag 1 for building material. Closure as well as a change in geometry can occur by means of gluing, welding or otherwise.

[0060] Fig. 8 shows two possibilities how a laminate can be designed to be air permeable. While the left illustration of Fig. 8 shows the laminate 2, in which in the first layer 3 the perforations led to the formation of volcano-like shapes 37 which are directed from the foil to the non-woven fabric, the laminate on the right has micro-perforations, which are indicated schematically. The perforating effect need not automatically be volcano-like shapes or comparable capsizing in the film material. After perforation, the film material can also remain approximately flat. The layers of laminate 2 are joined, for example, by means of a degree, adhesion or welding, as is indicated, for example, by the thermal bonding area 38. The thermal bonding area 38 strengthens the nonwoven fabric on the one hand and forms a bond between the nonwoven layer and the film layer on the other. This can occur by mutual surface adhesion as well as by mutual penetration.

ABTS-Advanced Bag Technology & Service GmbH

Proxy: