WO2016124321A1

WO2016124321A1 - Passive, directed transport of liquid perpendicular to a surface

Info

Publication number: WO2016124321A1
Application number: PCT/EP2016/000149
Authority: WO
Inventors: Helga KRIEGER; Thomas Gries; Sabrina JANDREY; Anna-Christin JOEL; Ingo Scholz; Philipp COMANNS; Werner Baumgartner
Original assignee: Rheinisch-Westfälische Technische Hochschule (Rwth) Aachen
Priority date: 2015-02-05
Filing date: 2016-01-28
Publication date: 2016-08-11
Also published as: EP3253350A1; DE102015001461A1

Abstract

The present invention relates to a device for unidirectional transport of liquid substantially perpendicular to a surface, to a method for producing the device according to the invention, and to the use of such a device.

Description

"Passively directed liquid transport perpendicular to a surface"

description

The present invention relates to a device for unidirectional liquid transport substantially perpendicular to a surface, a method for producing the device according to the invention, and the use of such a device.

The development of unidirectional liquid transport devices for use in a variety of applications, e.g. As a diesel fuel filter, Wundaufläge, incontinence product or for the separation of, for example, emulsions, is the subject of considerable economic interest. Particularly advantageous in this respect would be a product which generally permits a directed, passive liquid transport, in particular a transport substantially perpendicular to a material surface, so that a liquid can be conveyed towards or away and / or held on a target side. For example, can be avoided by a wound dressing with directed removal of the wound fluid a pathological softening of the sore tissue.

A passive directed liquid transport has already been observed in the animal world in humid lizards. With their scale structure, they can collect even the smallest amounts of water from the environment and wet their skin with it. A network of fine capillaries in their surface then transports the water to the mouth of the lizards (Beilstein Journal of Nanotechnology, 20 1, Issue 2, pp. 204-214, Zoomorphology, 2007, Issue 126, pp. 89-102, Journal of Herpetology, 1993, Issue 27, No. 3, pp. 265 to 270). In this process, the special property of a capillary is exploited. Their fine, elongated cavity can outweigh any surface effects of liquid contained therein from viscosity and inertial effects. The resulting transport of a liquid is determined by the surface tension of the liquid itself and the interfacial tension between the liquid and the solid surface. In the case of a vertical orientation, the liquid in a capillary rises until the capillary force equals the counteracting gravity of the liquid. This special property of capillaries for directional liquid transport has already been exploited in the prior art, for example in the patent application DE 10 2012 021 603 A1. It describes the use of at least two capillaries that are connected to one another via at least one passage channel, so that an at least partially passive directed capillary transport of a liquid takes place along a surface or along a fiber through the at least two capillaries. However, such a device, which allows a liquid transport along a surface (ie substantially parallel thereto), requires a costly and time-consuming preparation or processing of the required complex surface structure. In addition, the fields of application described at the outset require transporting a liquid substantially perpendicularly to a surface, which according to the cited prior art is not feasible.

The present invention is therefore based on the object to provide a device for unidirectional liquid transport, which has a directional transport of a liquid substantially perpendicular to a surface.

This object is achieved by the embodiments of the present invention characterized in the claims.

According to a first aspect of the present invention, in particular, a device for unidirectional liquid transport is provided, which has at least one layer of a base material (1), wherein at least partially narrowing capillaries (2) from a first main surface (3) of the respective layer to a second main surface (4) extend the respective layer, and wherein the capillaries (2) are formed such that a passive directed capillary Trans- Port of a liquid through the at least partially narrowing capillaries is substantially perpendicular to the Hauptoberfiächen (3, 4) of the respective layer (s). As used herein, the term "unidirectional liquid transport" means that there is no or greatly reduced transport in the apparatus of the present invention against the preferred direction of the liquid, that is, the liquid is substantially from the first major surface toward the second major surface of each The term "essentially" is understood to mean that at least 51%, preferably at least 60% or 70%, particularly preferably at least 80% or 90% and most preferably at least 95% of the transported liquid per unit time in the preferred direction is transported. According to the invention, the term "first main surface of the respective layer" refers to the boundary surface of a layer into which the liquid to be transported enters, for example by the geometry of the capillary opening, a coating or by means of a liquid from a capillary The term "second main surface of the respective layer" denotes the boundary surface of the same layer opposite the first main surface, in the direction of which the liquid is transported through the capillaries and through which the liquid optionally exits. According to a particular embodiment, the main surfaces are characterized in that the first main surface has capillary openings with a larger cross section and the second main surface has capillary openings with a smaller cross section.

According to the invention, the term "capillaries" is understood to mean fine, usually elongated cavities which extend from the first main surface to the second main surface of the respective layer.

The term "narrowing" in accordance with the present invention means that the Cross-sectional area of the respective capillaries in the longitudinal course, ie from the first main surface in the direction of the second main surface of the respective layer, reduced. According to the present invention, this constriction of the capillaries is formed at least in sections from the first main surface in the direction of the second main surface of the respective layer. Here, the term "at least in sections" is understood to mean that the cross-sectional area in the direction of the second main surface does not have to reduce continuously or steadily, but a narrowing of the cavity to at least 51%, preferably at least 60% or at least 70%, particularly preferably at least 80% or at least 90%, based on the capillary transport path, is required because of the constriction of the capillary, at least in sections, in a preferential direction of the liquid transport in the direction of the narrowing capillary A constriction present over the entire capillary transport path lies, for example, in a funnel-shaped 7, (5)), for example, however, it is also possible to carry out liquid transport in the preferred direction if a constriction of the capillary is not continuous but at least abs is present chnittsweise within each layer (see Figure 7, (6) to (18)). In this case, a partial widening of the cavity of the capillary to, for example, at most 49%, at most 40%, at most 30% or at most 20%, based on the capillary transport path, are present. The expansion can also include the boundary to the room, starting from the capillary.

The partial expansion slows down the liquid transport. With a strong expansion of Fiüssigkeittransport comes to a standstill. A slow liquid transport or the complete stopping of a liquid transport can be overcome for example with a liquid from a spatially close interconnection / cross connection. Alternatively, the slow transport or the stopped transport can be used selectively by a targeted adjustment of constriction and widening of the cavity, taking advantage of the relationship of the ratio of the contact angle of the liquid to the angle of the capillary inner wall, locally the transport direction is reversed. As a result, locally a liquid transport can take place counter to the at least partially narrowing capillary (ie from the second main surface in the direction of the first main surface) and thus a particularly efficient control of the liquid transport, for example to keep the liquid within one layer or between several layers.

The liquid transported in the device according to the invention is not subject to any particular restriction. According to the present invention, the liquid is selected from the group consisting of water, aqueous emulsions, aqueous liquids, aqueous solutions, in particular body fluids, liquid long-chain hydrocarbons, organic solvents and mixtures thereof. The term "body fluids" according to the present invention is not particularly limited and includes, for example, liquids such as blood, sacs, cerebrospinal fluid, secretions, saliva and urine.Furthermore, the term "liquid long-chain hydrocarbons" includes, for example, lipophilic substances such as oils, lubricants, Plant active ingredients, essential oils and flavorings.

The base material in the device according to the invention is not subject to any particular restriction. In this case, the base material may contain a single component or consist of a mixture of different components. Examples of components usable for the base material according to the present invention are polymers, metals, ceramics, glasses, etc. Here, the term "polymer" according to the present invention is not particularly limited and includes, for example, biopolymers and synthetic polymers Biopolymers are cellulose, starch and polylactide According to a preferred embodiment, the base material comprises a plastic or a plastic mixture Examples of such plastics are acrylonitrile-butadiene-styrene (ABS), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), Polyolefins, such as polyethylene (PE) or polypropylene (PP), polyurethane (PU), polystyrene (PS), polyamide (PA), polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC) and modifications of such plastics such as a plastic supplemented with a composite material , as well as copolymers or mixtures thereof. The form in which the base material is also subject to no particular restriction, as long as this allows a liquid transport as mentioned above. For example, the base material can be present as a film or a plate, as a fiber or wire or in the form of particles. According to a preferred embodiment of the device defined above, the base material consists of substantially parallel asymmetric fibers, a film and / or particles. As used herein, the term "film" is not limited thereto and includes films of various thicknesses, including plates and blocks, The term "substantially parallel" means that at least 60%, preferably at least 70%, or at least 80%, especially preferably at least 90% of the asymmetric fibers are aligned parallel to each other. For example, the term "parallel" here includes not only a completely parallel orientation of the longitudinal edges of the asymmetrical fibers relative to one another, but also a deviation of, for example, at most 25 ° or at most 20 °, preferably at most 15 ° or at most 10 ° preferably at most 5 °, from this fully parallel orientation.

Moreover, the term "asymmetric fiber" according to the present invention is not particularly limited and includes all fiber forms having such cross-sections which, by their shape and / or arrangement with one another, allow capillaries to form in a layer according to the present invention As used herein, the term "asymmetric" includes not only cross-sectional shapes that are completely asymmetrical but also those that have some symmetry. In accordance with the present invention, the term "asymmetric fiber" also includes the use of asymmetric cross-section wires in that the wires can have very different dimensions with regard to their length and their cross section, as long as the capillary structure according to the invention can be obtained by a corresponding arrangement.

Another embodiment relates to a device as defined above, wherein the cross-sectional shape of the asymmetric fiber is selected from a group consisting of triangular to trilobate, quadrangular to trapezoidal, pentagonal or otherwise polygonal, star-shaped, freeform and semicircular, or any combination of at least two of these shapes. In this case, due to the geometric configuration, a structured arrangement of such asymmetrical fibers can lead directly to the formation of capillaries in the position (cf., for example, FIGS. 2 to 4). The shape of the capillaries can be adjusted in an advantageous manner by the cross section of the fibers used.

According to a further embodiment of the device according to the invention, the shape of the particles is selected from a group consisting of truncated pyramidal, kugelseg- mentförmig, triangular pyramidal, quadrangular-pyramidal, drop-shaped or completely asymmetric. In this case, due to the geometric configuration, a structured arrangement of such particles can lead directly to the formation of capillaries in the position. The shape of the capillaries can be adjusted by the choice and arrangement of the particles in an advantageous manner.

The base material may be selected according to the purpose of use of the corresponding device. According to another embodiment, a layer consists exclusively of a base material, for example in the form of a plate, a film or arranged particles or fibers (textile) or wire. According to a further specific embodiment, the layer may comprise, in addition to the base material, further components which may influence the properties such as wetting behavior, dimensional stability, durability, etc. of the layer. The transition from a constriction to an expansion in the course of the capillary may for example be discontinuous (see Figure 7, (16)) or continuous (see Figure 7, (17) and (18)). The longitudinal cross-section of the capillary is not necessarily rotationally symmetric. The dimensions, ie the capillary length and the number of capillaries per unit area of the device according to the invention are not subject to any particular restriction, with both parameters influencing, for example, the transport speed and transport quantity. The minimum and maximum cross-sectional area is limited insofar as capillary liquid transport must be enabled. According to the invention, the term "passive directed capillary transport of a liquid through the at least partially narrowing capillaries substantially perpendicular to the main surfaces of the respective layer (s)" means that a transport of a liquid without the use of external energy sources (eg. Temperature) is generated substantially perpendicular to the above-described main surfaces of the respective layer (s) by the capillaries.

According to a further embodiment, the device defined above has at least two layers which are arranged parallel to one another. A further embodiment of the invention relates to the above-defined device with at least three layers, at least four layers or at least five layers which are arranged parallel to one another. The layers are preferably arranged in such a way that the constriction of the capillaries present at least in sections within a respective layer (starting from the first main surface in the direction of the second main surface) is oriented in the same direction in all layers. According to the above-mentioned embodiment, the sheets are stacked so that the second main surface of an upper layer and the first main surface of the adjacent lower layer are aligned with each other. The ply stack of the present invention may in this case be produced using various measures known in the art, for example by gluing, fusing, sewing, welding or pressing individual layers. In this case, the connection of the layers takes place in such a way that a liquid transport through the layer stack while retaining respective capillary paths through the individual layers is still possible. The term "capillary paths" also includes the volume between two layers in which the liquid can collect, whereby the transition of the capillary cavity to the volume located between two layers also constitutes a widening in the sense of the invention The terms "top" and "bottom" according to the invention are not limiting in terms of space, but merely to be understood in terms of a relative arrangement of two adjacent layers relative to one another Stacking of multiple layers, a device can be provided, which allows a relation to a single layer more efficient liquid transport with further reduced reflux. From an arrangement of a plurality of layers as defined above to form a device according to the invention, a discontinuity occurs between two adjacent layers, ie at the transition of a second main surface of an upper layer to a first main surface of a lower layer due to abrupt widening of the capillary cross-sectional areas (see Figure 3, (8)). Moreover, in accordance with the present invention, such a point of discontinuity is also present in the transition region of the second main surface to the space, that is to say, for example, when using a single layer.

A further embodiment of the present invention relates to the device as defined above, wherein two adjacent layers are arranged offset to one another. According to a further preferred embodiment, the adjacent layers are displaced relative to one another in such a way that the capillaries have a lateral offset in their arrangement relative to one another in adjacent layers (cf., for example, FIG. 4, left-hand illustration). According to another embodiment, adjacent layers form a rotational offset relative to one another (cf., for example, FIG. 4, right illustration). This rotational offset is not particularly limited in its extent and may for example be in the range of less than 1 ° to nearly 360 °. If the device according to the invention is in the form of a layer stack, then each individual layer can have a different lateral offset and / or a different rotational offset relative to the preceding layer.

According to another embodiment of the present invention, the device comprises a functional material. The arrangement of the functional material in the device is in no particular way restricted and may be present in sections. For example, the functional material may be on the first major surface, on the second major surface or on the opening of the capillaries be arranged in the respective main surfaces, in the capillary interior or at any combination of the aforementioned locations.

A preferred embodiment of the present invention relates to a device as defined above which has at least two layers arranged parallel to one another, further comprising a functional material arranged at the transition of a second main surface of an upper layer to the first main surface of a lower layer , In this case, the said functional material can be arranged, for example, on the second main surface of the upper layer, on the first main surface of the lower layer, on the opening of the capillaries of these main surfaces or on any combination of the aforementioned points.

By using a functional material, for example, the liquid to be transported can more effectively overcome the discontinuity, or the liquid can be collected by means of the functional material.

The functional material may be provided, for example, by modifying the base material or by adding another material to the base material. In this case, the base material, for example, chemically, mechanically or thermally modified by coating, structuring or plasma treatment or supplemented by the additionally introduced or applied material to functions. According to the present invention, the functional material comprises, for example, lacquers, nanocoatings, plasma coatings, adhesives, nanoparticles, superabsorbers, microstructures and / or nanostructures. For example, a defined wettability of the base material or a defined roughness of the base material can be provided by the functional material or the base material can be modified in its magnetic property. The use of, for example, a wettable material in the device according to the invention is advantageous in that the liquid can overcome the above-mentioned point of discontinuity by wetting the wettable material. This makes it possible to increase the capabilities of the respective layers for passive capillary liquid transport combine and thus provide a particularly effective liquid transport. In this case, for example, the functional material can ensure the entry of the liquid into the capillary opening of a first main surface and / or the exit of the liquid from the capillary opening of a second main surface. Furthermore, by modifying the magnetic property of the base material by means of the functional material, the arrangement of the base material in layers in the manufacturing process can be facilitated in an advantageous manner.

According to a particular embodiment of the present invention, as the above-mentioned asymmetric fiber, for example, a bicomponent fiber may be used which may have the above-described functional material. According to the invention, the term "bicomponent fiber" is understood to mean a fiber which has two components, ie a first component and a second component, whereby the division of the fiber into the two components is likewise not restricted The preferred embodiment is such that a first component forms the first main surface of the respective layer and a second component forms the second main surface of the respective layer The respective components can be selected with regard to the desired properties of the layer (s) thus obtained Selection of the respective components is not restricted and may include those components which improve the transport of the desired liquid through the layer (s), increase the physical integrity of the layers and / or the adhesion of the layers to one another or the production simplify or allow the device itself. According to a further example of the present invention, the components may be selected such that transport improves with respect to the desired liquid, but transport with respect to one or more undesired liquids is reduced.

As another example, the bicomponent fiber may include electrostatic material and / or paramagnetic material, such as nanoferrite, in a lower portion of the fiber, thereby using an electric field or a magnetic field Magnetic field, the fibers can be arranged to form a layer (see, for example, Figure 5).

According to a particular embodiment, the first and second components of the bicomponent fiber may comprise thermoplastics with different melting points or a thermoplastic and a non-thermoplastic material to allow a controlled point melting or melting.

According to a specific embodiment of the above-defined device according to the invention, the first component, the second component or both components may comprise the functional material. According to a preferred embodiment, only one of the components comprises a functional material.

According to a further embodiment of the present invention, the base material may also be present in the form of a bicomponent film, the division of the respective film into the two components and the property of said components corresponding to those of the above-defined bicomponent fiber.

Another embodiment of the present invention relates to a device as defined above comprising a base material having particles, wherein a particle may comprise two components (bicomponent particles). When using such bicomponent particles, the distribution of the respective particles into the two components and the property of said components corresponds to those of the bicomponent fiber defined above.

According to the present inventive device, layers of the same or different material and structure can be combined with each other. The respective layers of the device according to the invention can be constructed, for example, only of asymmetrical fibers or wire, only of particles, only of films or plates, or any combination thereof, wherein the respective layers independently of one another may have a functional material as mentioned above. According to a preferred embodiment of the device defined above, one or both of the main surfaces of one or more layers are at least partially coated with the functional material.

According to another embodiment, the device according to the invention comprises a layer which is arranged on the first main surface of the first (i.e., uppermost) layer or on the second main surface of the final (i.e., lowest) layer. Examples of such layers are layers which allow a transport parallel to the surface, spacer layers, which maintain any necessary intervals, or layers comprising an absorbent material.

According to a further embodiment, two devices according to the invention can be arranged in a system against each other. In this case, they can be arranged, for example, such that a liquid is transported in and collected in the space located between the two devices. The collected liquid can then be held there, further transported or otherwise processed. Furthermore, the devices can be arranged such that a liquid located between the devices is transported to the outside through the devices bordering this space.

A further aspect of the present invention relates to a method for producing the device according to the invention, comprising the steps:

(i) providing asymmetric fibers,

(ii) arranging and / or joining the asymmetric fibers into a layer, at least partially narrowing capillaries being produced, and

(iii) optionally placing a plurality of the sheets obtained in step (ii) into a sheet stack; or

(a) providing a film,

(B) introducing holes into the film, wherein a layer is produced with at least partially narrowing capillaries, and (c) optionally arranging a plurality of the layers obtained in step (b) into a layer stack; or

(1) providing particles,

(2) arranging the particles into a layer, wherein at least partially narrowing capillaries are produced, and

(3) optionally, arranging a plurality of the sheets obtained in step (2) into a sheet stack

The preparation or provision of the asymmetric fibers in step (i) of the process according to the invention is not subject to any particular restriction. According to a preferred embodiment of the present invention, the asymmetric fibers are prepared by melt spinning, solvent spinning, electrospinning, wet spinning, rolling, pressing or by a 3D printing process. Asymmetric fibers with a wide variety of cross-sectional shapes, such as, for example, fibers with a triangular to trilobal, quadrangular to trapezoidal, pentagonal to polygonal, star-shaped and semicircular cross-section, freeform or a combination thereof can be provided by the abovementioned methods. According to the present invention, the preparation or provision of the asymmetric fibers, for example, by melt spinning or solvent spinning, not only in terms of the fiber form almost arbitrarily configurable, but also with regard to the fiber composition is not limited in any particular way. For example, the provision of the asymmetric fibers may involve the preparation of asymmetric bicomponent fibers by melt spinning. In this case, both the asymmetrical fiber and the asymmetric bicomponent fiber can have a functional material. The functional material can be introduced or applied as described above. According to a preferred embodiment, the step (i) of providing asymmetric fibers comprises the substantially parallel arrangement of the respective fibers relative to each other. As already mentioned, the functional material for this purpose may comprise, for example, an electrostatic material or paramagnetic material, whereby by means of an electric or magnetic field, a uniform orientation or an essentially parallel arrangement of the respective asymmetric fibers to each other favors or supported. The fibers can be pulled to align, for example via a rail.

The arrangement / joining of the asymmetric fibers to a layer according to step (ii) of the method according to the invention is likewise subject to no particular restriction. According to a specific embodiment of the method according to the invention, the asymmetrical fibers are joined together to form a scrim, fabric, knitted fabric, knitted fabric, fleece, spunbonded fabric, braid, tapestry or leno fabric. According to a further embodiment, the asymmetric fibers are thermally bonded together, for example by laser welding, or by gluing.

According to a further embodiment, steps (i) and (ii) are carried out simultaneously, for example by means of a 3D printing process, wherein the fibers are produced as desired and arranged according to the present invention.

The arrangement of several of the layers obtained in step (ii) of the process as defined above in optional step (iii) is not particularly limited. According to the present invention, the respective layers are preferably joined together, for example by a chemical compound (eg gluing), a mechanical connection (for example sewing or pressing) or a thermal connection (for example welding or fusion).

According to an alternative embodiment of the method according to the invention, the provision or provision of a film in step (a) is not subject to any particular restriction. For example, the film is produced by calendering, casting, injection molding or 3D printing.

The introduction of holes into the film in step (b) of the method according to the invention as defined above is not subject to any particular restriction and can be realized by any method known to the person skilled in the art. For example The holes can be introduced into the film by means of embossing rollers, punching, a laser, using correspondingly profiled needles or by etching.

Alternatively, steps (a) and (b) can also be carried out simultaneously by means of an original molding process, for example by injection molding. According to a particular embodiment, steps (a) and (b) may be carried out simultaneously by means of a 3D printing process.

The arrangement of the films obtained in step (b) in optional step (c) of the process according to the invention is likewise subject to no particular restriction. According to the present invention, the respective layers are preferably joined together, for example by gluing, fusing, sewing or pressing, etc. According to a further embodiment of the method according to the invention, the provision of particles in step (1) is not particularly limited. For example, the particles are prepared by polymerization, milling, machining (grinding), spraying, cutting fibers or by means of a 3D printing process.

The arrangement of the particles to a layer according to step (2) of the method according to the invention is not subject to any particular restriction. According to a specific embodiment of the method according to the invention, the particles are individually targeted to layers by self-organization, shaking, shaking, laser sintering or in the case of a bicomponent particle with electrostatic or magnetic material by means of an electric or magnetic field. In this case, the arrangement of the particles can be fixed, for example by means of sintering or laser sintering. According to a further embodiment, steps (1) and (2) are carried out simultaneously, for example by means of a 3D printing process, wherein the particles are produced as desired and arranged according to the present invention. The arrangement of the layers obtained in step (2) in optional step (3) of the method according to the invention is likewise subject to no particular restriction. According to the present invention, the respective layers are preferably connected to one another, for example by gluing, fusing, sewing or pressing, etc.

A further aspect of the present invention relates to the use of the device according to the invention for unidirectional liquid transport for transporting a liquid away from and / or holding the liquid on the target side.

In particular, the device according to the invention can also be used to evaporate, transport or otherwise process the liquid transported on the destination side.

For example, the device according to the invention is advantageous when used in a diesel fuel filter. In many countries biodiesel serves as a blend component with a share of 7 to 12% by volume for conventional diesel fuel. However, the water contained in the biodiesel causes corrosion on the engine components and hydrolytic decomposition of the fuel. Currently used filters have the disadvantages that they have only a low water absorption capacity, have no water-conducting properties and often need to be changed. Due to the advantageous use of the device according to the invention, directed water transport is possible, so that the water is separated and transported to a collecting container, which can be emptied. Thus, the use of the device of the invention in a diesel fuel filter allows the reduction of filter changes, resulting in lower costs for car manufacturers and motorists. The device according to the invention can alternatively serve as an impregnation aid for fiber composite plastics (FRP). In the manufacturing process of FRP high pressures and long process times are required to complete the component with a thermoplastic, Duromer, metal or monomer to soak. The advantageous use of the device according to the invention in the form of an auxiliary layer, the material could be distributed quickly and selectively, so that advantageously also air pockets can be avoided.

Furthermore, the device according to the invention is advantageous, for example, when used as an incontinence product, since the body fluid can be transported away from the skin and held on the target side, so that a barrier is created between the liquid-filled device and the skin. The disadvantageous use of superabsorbers in conventional incontinence products can be reduced or avoided by the advantageous functionality of the device according to the invention, so that the use of the device according to the invention reduces or substantially eliminates the occurrence of superabsorbers as hazardous waste.

The figures show:

FIG. 1 shows a base material (1) of the device according to the invention. For example, the base material takes the form of an asymmetric fiber, in particular the shape of a triangular or trapezoidal fiber.

Figure 2 shows the structure of a layer comprising a base material (1) with narrowing capillaries (2), the capillaries extending from the first major surface (3) of the layer to the second major surface (4) of the layer. Such an arrangement results in a preferred direction for the liquid transport (5).

Figure 3 shows the construction of a device consisting of two layers of a base material (1) with narrowing capillaries (2) with the preferred direction for liquid transport (5), wherein the transition between the second main surface of the upper layer (6) to the first main surface the lower layer (7) has a discontinuity (8) at which the capillary of the upper layer widens. Figure 4 shows mutually staggered layers (9) with Kapiiiaren having a lateral offset, or two adjacent layers, which form a rotation sversatz with each other (10). FIG. 5 shows examples of bicomponent fibers (11) with a first component (12) and a second component (13).

Figure 6 shows examples of shapes of the particles (14). In this case, a particle is, for example, truncated pyramidal or has a spherical segment shape, the shape of a pyramid with a triangular base or the shape of a pyramid with a quadrangular base.

FIG. 7 shows examples of shapes of the capillaries narrowing at least in sections. The shape is, for example, funnel-shaped (15) and both capillary openings have a different size. But the capillary openings can also be the same size and the capillary can narrow and widen in sections ((6) to (18)).

The present invention provides an apparatus that enables unidirectional, passive liquid transport substantially perpendicular to a surface. The unidirectional transport allows the transport of a liquid to and fro and / or the holding of the liquid on the target side. Due to this special property, the device according to the invention has a high application potential, for example as a diesel fuel filter, wound dressing or incontinence product. In addition, the production method of the device according to the invention advantageously makes use of established and cost-effective production methods.

LIST OF REFERENCE NUMBERS

1 base material

2 capillaries 3 first main surface

4 second main surface

5 preferred direction for liquid transport

6 second main surface of an upper layer

7 first main surface of a lower layer

8 discontinuity

9 staggered layers

10 with rotational offset arranged layers

11 bicomponent fiber

12 first component

13 second component

14 particles

15 funnel-shaped capillary cross section

16 Capillary cross-section with discontinuous widening area

17 Capillary cross-section with continuous expansion area

18 Capillary cross section with free form

Claims

claims

Device for unidirectional liquid transport, comprising at least one layer of a base material (1), at least partially narrowing capillaries (2) extending from a first main surface (3) of the respective layer to a second main surface (4) of the respective layer, and

wherein the capillaries (2) are formed such that a passive directed capillary transport of a liquid through the at least partially narrowing capillaries is substantially perpendicular to the main surfaces (3, 4) of the respective layer (s).

A device for unidirectional liquid transport according to claim 1, which has at least two layers which are arranged parallel to one another.

A device for unidirectional liquid transport according to claim 1 or 2, wherein two adjacent layers are arranged offset to one another.

Device for unidirectional liquid transport according to one of claims 1 to 3, wherein the base material (1) consists of substantially parallel aligned asymmetric fibers, a film and / or particles.

A device for unidirectional liquid transport according to claim 4, wherein the cross-sectional shape of the asymmetric fiber is selected from a group consisting of triangular to trilobal, quadrangular to trapezoidal, pentagonal to polygonal, star-shaped, semicircular, freeform, or any combination thereof.

6. A device for unidirectional fluid transport according to any one of claims 1 to 5, further comprising a functional material.

The unidirectional liquid transport device of claim 6, wherein the asymmetric fiber is a bicomponent fiber (11), the film is a bicomponent film, and the particles are bicomponent particles comprising the functional material.

8. A device for unidirectional liquid transport according to claim 6 or 7, wherein one or both of the main surfaces (3, 4) in each case one or more layer (s) at least partially coated with the functional material.

9. A device for unidirectional liquid transport according to any one of claims 6 to 8, wherein the functional material corresponds to a modified portion of the base material or in addition to the base material introduced material.

10. A method for producing the device for unidirectional liquid transport according to one of claims 1 to 9, comprising the steps

(i) providing asymmetric fibers,

(a) providing a film,

(B) introducing holes into the film, wherein a layer is produced with at least partially narrowing capillaries, and

(c) optionally arranging a plurality of the layers obtained in step (b) into a layer stack; or

(1) providing particles,

(2) arranging the particles into a layer, wherein at least partially narrowing capillaries are produced, and (3) optionally, arranging a plurality of the gene obtained in step (2) into a sheet stack.

Use of the device for unidirectional liquid transport according to one of claims 1 to 9 for transporting a liquid away from and / or keeping the liquid on the target side.