WO2000071797A1

WO2000071797A1 - Method for the production of spunbonded or melt blown fibers/filaments, method for the production of foils and spundbonded or melt blown fibers/filaments, foils and nonwoven fabric

Info

Publication number: WO2000071797A1
Application number: PCT/DE2000/001635
Authority: WO
Inventors: Joachim Bauer; Indra Roy
Original assignee: Corovin Gmbh
Priority date: 1999-05-21
Filing date: 2000-05-18
Publication date: 2000-11-30
Also published as: DE19923344A1; DE10081377D2; AU5962300A; ES2245942T3; DK1187949T3; DE50010760D1; EP1187949A1; ATE299961T1; EP1187949B1

Abstract

The invention relates to a method for manufacturing a product, especially spunbonded or melt blown fibers/filaments, whereby at least one substance altering the surface properties of the fibers/filaments is applied on the surface of said fibers/filaments, e.g. during a time interval ranging from the emergence of the fibers/filaments to the storing of said fibers/filaments.

Description

Process for producing spunbonded or meltblown fibers / filaπients, process for producing films and spunbonded or meltblown fibers / filaments, films, nonwoven

The invention relates to a method for producing products, in particular spunbonded or meltblown fibers / filaments, according to the preamble of claim 1.

For the production of chemical fibers using melt spinning technology, in particular spunbonded or meltblown fibers / filaments, polymers are usually used in the form of granules as the starting material, which are shaped into fibers / filaments by means of an extrusion process via suitable spinnerets and after targeted cooling in the production of Nonwovens can be processed in-line (e.g. spunbond, meltblown) or off-line (e.g. carded nonwovens) to form a nonwoven. In order to specifically influence the cooling process of the fibers / filaments formed during and after their formation, an additional cooling (quench) liquid in the form of small drops (mist) can be sprayed onto the fibers / filaments after the molten polymer has emerged from the spinnerets are placed before the threads in the in-line nonwoven fabrication as a fiber / filament layer on a laying tape and then optionally a consolidation process z. B. be subjected to heat embossing or needling. In the meltblown process in particular, this form of process control offers (use of a quench liquid) the advantage that the fiber / filament cross-section is influenced favorably, the formation of fiber bundles is reduced and the formation of drops at the fiber ends can be suppressed. An increased cooling rate in the production of continuous filaments (eg spunbonded process) is also advantageous.

The selection of the raw materials for the processes mentioned (spunbond and meltblown production) has been sufficiently described in the relevant literature. For the products in question, one or more polyolefins (polypropylene, polyethylene or mixtures of the aforementioned among themselves or with other polyolefins) or other thermoplastic plastics (such as, for example, polyethylene terephthalate, polyamide, polymers and condensates based on natural and / or renewable raw materials) are often used or addition products, degradable polymers, etc.) or mixtures of the groups mentioned.

A barrier effect of the formed nonwoven fabric against liquids is described in the first approximation by the Laplace equation and results for untreated spunbonded or meltblown fibers / filaments from the pore structure (pore size and pore shape) of the formed nonwoven fabric and the surface chemistry (interfacial tension) of the material ser / filament formation used polymer.

2 • γ ^■ cos $

AP ΔP: pressure difference across the porous structure that is necessary around the

Pressing liquid through the pore with radius r (wetting of the pore) γ: free interfacial enthalpy ("interfacial tension") of the polymer / liquid / air system

9: Wetting angle: pore radius

By applying additives (substances) to the surface of the fibers / filaments, the barrier properties against liquid media can be specifically changed.

In the production of spunbonded or meltblown fibers / filaments, two methods are known for applying the additives to the surface of the fibers / filaments, which are described in US Pat. No. 5,178,931.

Procedure A:

Additives are added to the polymer melt before the fibers / filaments are shaped. The additives in the fibers / filaments formed are distributed over the fiber / filament cross section, with only a part of the additive influencing the surface chemistry (eg interfacial tension) of the fibers / filaments. Depending on the additive used, the proportion of the additive active on the surface can change due to migration from the fiber cross-section. This method offers the advantage that the entire fiber surface is reliably detected regardless of the pore size of the nonwoven fabric formed. Disadvantages of this process are that the addition of an additive to the polymer melt directly affects the melt spinning process with the change in the internal structure of the melt and thus changes the fiber shaping behavior, fiber structure, fiber properties and deposition behavior of the fibers (and thus the nonwoven structure). This goes hand in hand - especially in the meltblown process - for example frequently with an enlargement of the pores in the nonwoven fabric formed, which reduces the barrier effect against liquids. Furthermore, only a small proportion of the additive reaches the fiber / filament surface, which can contribute to the desired increase in the barrier effect against liquids.

Procedure B:

US Pat. No. 5,178,931 mentions the surface application of at least one substance for changing the surface properties of the nonwoven fibers, the application being carried out on the finished nonwoven fabric.

The substance is used in an amount sufficient to impart at least one property to the fibers of such a nonwoven that differs from the surface properties of untreated fibers.

Various methods are specified for applying the substance, which relate to the finished nonwoven, including immersing the nonwoven in a liquid containing the additive and then squeezing the Fleece, or spraying the fleece with the same liquid.

A disadvantage of this process is that in the case of nonwovens, which in their entirety are said to have the changed surface properties, the entire structure of the product must be wetted with the liquid.

This is usually done by immersing the fleece in an immersion bath that is filled with the liquid containing the additives.

However, penetration of the fleece with the liquid is particularly difficult to achieve if the wetting of the fleece is not sufficiently good. The application of the additive in narrow-pore areas (e.g. at crossover points of individual fibers) of the fleece proves to be particularly critical.

Another disadvantage of the immersion baths is the extremely slow processing speed.

Following the wetting of the fleece, the carrier substance must be dried off safely and, if necessary, crosslinked with high energy input. This takes place in complex dryers so that a sufficient evaporation or crosslinking time is available. The temperature in the ovens is limited by the limited temperature stability of the raw materials of the fleece. The complex technology and slow processing speed are the reason for the high process costs of this equipment technology.

Other methods such as spraying the nonwoven have the disadvantage that only the upper layer of the nonwoven is treated. The desired change in the surface properties of the entire nonwoven cannot be achieved. This leads to individual imperfections in the treated nonwoven fabric where the barrier effect against liquids is not at the desired level.

From EP 0 550 029 A1 it is now known to apply a conductive substance to the meltblown fibers in a meltblown process before the meltblown fiber appears on a conveyor belt and is removed with it.

Starting from EP 0 550 029 AI, the object of the invention is to create a method and a device for producing a product in which a selected surface property of the product is changed uniformly on the surface, taking into account a fluid to be applied later in use of the product without an undesirable influence on the internal structure of the product and the associated influence on the product storage properties. This object is achieved with a method with the features of claim 1, with a nonwoven fiber / filament with the features of claim 15, with a film with the features of claim 16 and with a device with the features of claims 25 and 26, respectively . Further developments and advantageous refinements result from the subclaims.

According to the invention, for the production of a product in which at least one polymer is processed as a starting liquid to form a melt liquid, this is deposited as a layer through a nozzle as a melt polymer. At least one substance that changes a surface property of the product is applied to the surface of the product in a period of time from product creation to product deposition. A substance is used with which a barrier property of the product is increased, an interfacial tension of the product being reduced.

By applying at least one substance which changes the surface properties of, for example, fibers / filaments, also referred to as an additive, within a period of time from when they are formed until the fibers / filaments are deposited, it is achieved that the substance before further processing, e.g. is distributed over the entire surface of the fibers / filaments before nonwoven formation. The same applies analogously to a method for producing a film.

Compared to the admixing of the substance to the polymer melt, it is achieved that the application has no influence on the inner Structure of the polymer has and does not affect a spinning process. The properties resulting from the polymer structure in the interior of the fibers / filaments or the film, such as, for example, strength, extensibility and others, are retained. By selecting suitable substances, it is even possible to support such properties. For example, a substance can be applied that achieves a surface softness while reducing the interfacial tension, while the core of the product still has high strength values.

In comparison to the subsequent application of the substance to the finished fibers / filaments, possibly even only after it has solidified to form a fleece, the fibers / filaments or the film are still close to their melting or softening temperature in the period between their formation and their deposition. In this state, they have a particularly good affinity or binding force on their surface for the substance supplied. This later results in better adhesion and durability of the substance on the surface of the fibers / filaments or the film.

In addition, this application of the substance allows the use of several substances to set different properties on the product. The substances can be applied simultaneously, for example in the form of a mixture, or in succession. Another advantage results from the small amount of substance that is required to obtain the desired surface properties of the fibers / filaments or the film. This primarily means inexpensive production.

It is also advantageous that, compared to the admixture of the additive to the polymer, there is no negative / undesirable influence on the deposition behavior and the associated nonwoven structure - visible e.g. in an enlargement of the pore diameter - the spunbond or meltblown.

The application of the substance within a period of time from the formation to the deposition of the fibers / filaments also has the advantage that desired surface properties of the fibers / filaments are considerably easier and more precise to set, regardless of the migration behavior of individual additives in different polymers. In particular, this type of order allows the interfacial tension to be set in a defined manner depending on the area in which the product is used. If a fluid that comes into contact with the product later is known, the parameters attributable to this fluid, such as surface tension, are thus also known, at least approximately.

It has been found that the desired interfacial tension on the product can be matched to the fluid in a precisely defined manner by applying a substance that increases the barrier property. This can be done by selecting the Concentration of the substance, the volume of the order and, for example, the surface wetting of the product surface with the substance can be achieved. The definition of the interfacial tension can be set so precisely that it is possible that the surface of the product has an interfacial tension that has a difference of approximately 3 mN / m compared to an interfacial tension of a fluid subsequently wetting the surface. A difference between 3 mN / m and 5 mN / m is preferably set. In the case of fluids whose interfacial tension is not always uniform, for example due to fluctuations in the composition, the difference can also be set so that it is between 10 mN / m and 20 mN / m. In the case of usable polymers, the interfacial tension is between, for example, 25 mN / m and more than 60 mN / m at 20 ° C., the interfacial tension also being dependent on whether a pure polymer or a polymer mixture or one or more additives, for example as a batch in the molten liquid Phase before exiting the nozzle.

With regard to possible interfacial tensions, existing as well as to be achieved and usable polymer materials, it is expressly referred to on Tables 1, 2 and 3, Chapter Vl / Page 524ff from "Polymer Handbook ^" _/ Publisher: Brandrup, Immergut, Grulke, Verlag John Wiley & Sons, 4th editions, 1999, the content of which is included here. It also shows that the interfacial tension can be significantly reduced by, for example, a fluorocarbon group or silicone group. Other substances with which the interface Tension can be set as desired in the "Handbook of Chemistry and Physics ^" _/ edited by Robert C. Weast, CRC Press, 68th edition, 1987. A wide variety of substances can be found on pages F-33 to F-37, with which a desired barrier effect can be set by reducing the interfacial tension depending on the polymer used and the fluid used later. These substances and their interfacial tensions are expressly referred to in the context of this disclosure and also included here.

If the fluid used later should contain water or mainly water, an interfacial tension must be set below that of this fluid, thus below about 70 mN / m. With other fluids such as blood or saline solutions, however, their interfacial tension can also be much lower, for example around 40 mN / m. The nature of the order allows, due to the accuracy as well as the leveling of the order, that the interfacial tension of the product can be set to, for example, 35 mN / m or 28 mN / m. The error tolerance range can be set so that it is below 5%, preferably below 2.5%.

Compared to the subsequent application of the substance to the finished nonwoven fabric, it is achieved that, for example, an additive is applied and / or distributed evenly on the entire surface of the fibers / filaments. This results from the fact that the surface of the fibers / filaments during the pull is still completely exposed and is therefore easily accessible for applying the substance. Flaws in places of the nonwoven fabric where fibers / filaments overlap (ie narrow-pored areas), and the resulting non-uniform surface properties do not result. The properties "evenly applied and / or distributed" as well as the term "imperfections" are not to be evaluated here by absolute standards but in a macroscopic sense related to the wetting medium. The application is preferably set in such a way that a surface is wetted which is proportionately more than 2%, in particular in a range between 5% and 85%. For example, in the case of a film, this can also be further shaped later, so that, for example, areas between 25% and 40% result in proportion to the end product. The order is also selected depending on the mode of action of the substance. In doing so, variables such as molecular size, viscosity or other factors are included. The uniformity of the application due to the method of production also allows the surface to be wetted with a substance in a range from about 2% to about 15% in order to achieve a sufficient reduction in the interfacial tension.

A further development provides that the substance is sprayed onto the surface of the fibers / filaments or the film. This ensures that the surface of the fibers / filaments or the film is evenly covered by the substance even when the substance is used in small quantities. It is further provided that the substance is applied unmixed as a solution or as a dispersion (emulsion / suspension / aerosol) or from the gas phase to the surface of the fibers / filaments or the film.

This ensures that substances are also applied to the surface of the fibers / filaments or the film, which are not suitable for a previous admixture to the starting material, for example, because they show poor migration behavior or interfere with the inner processability of the polymer melt in the spinning process , or on the other hand, are not suitable for subsequent application to the nonwoven or the film, since the nonwoven or the film cannot be wetted to a sufficient extent.

A further development provides that the solvent or dispersion medium is water.

This ensures that the substance is optimally dissolved or dispersed and that the fiber / filament mass or film mass is wetted in a suitable manner.

According to a further development, it is possible to dissolve or disperse the substance in the coolant sprayed against the fibers / filaments or the film.

This ensures that the substance is applied evenly to the entire surface of the fibers / filaments or the film with little technical effort. Moreover the cooling properties are preserved during the manufacturing process.

Furthermore, it is provided that the coolant evaporates after the wetting of the fibers / filaments or the film, and the substance contained in the coolant remains on the surface of the fibers / filaments or the film.

This ensures that the substance is evenly distributed over the path of wetting on the surface of the fibers / filaments or the film, remains there after the evaporation of the coolant and thus covers the entire surface of the fibers / filaments or the film. Another advantage is that after the substance has been applied to the surface of the fibers / filaments, no further complex and energy-intensive post-treatment steps are absolutely necessary for the finished nonwoven. The post-treatment steps required when applying additives to non-woven fabric by means of an immersion bath, such as pressing out the non-woven fabric and drying, and the associated cost-intensive, extremely slow processing times are eliminated.

A further development provides that the coolant with the substance contained therein is sprayed in very fine droplets against the fibers / filaments or the film.

This ensures that the coolant and thus the substance contained therein is finely distributed over the entire surface of the fibers / filaments or the film, also wets them and distributes them evenly.

It is also advantageous that the droplets on impacting the fibers / filaments or the film have no undesirable negative influence on the fiber / filament or film structure, and that the coolant after wetting the fibers / filaments or the Film evaporates quickly.

The substance can be applied to the product at different heights along a product formation path, for example directly at the nozzle or in the case of nonwoven manufacture with stretching of the material after a stretching zone or also in this. It is also possible to choose a location for the application of the material depending on the temperature of the product. The substance is preferably applied at a point in time at which the product has stored so much thermal energy that there is no need for subsequent drying of the product. According to a further development, the product can also have a certain residual moisture content of below 10%, in particular in a range between 2.5% and 5%.

It is also possible that the fibers / filaments or the film are sprayed from different directions with the coolant and the substance contained therein. For this purpose, the coolant and the substance can partly be introduced via nozzles against a direction of movement of the product, so that turbulence for an adequate distribution of the sub- punch ensures. According to a further development, turbulence vortices are generated by means of corresponding constructive devices such as baffle plates, deflections and / or by means of a corresponding inflow of the coolant or another carrier medium for the substance in such a way that the substance is distributed evenly. For this purpose, the substance can be supplied on one or more sides, in particular on two sides.

It is thereby achieved that, compared to the spraying of the fibers / filaments or the film from only one direction, the fibers / filaments or the film are wetted even more effectively and the additive application is improved uniformly.

A further development provides that the wettability of the fibers / filaments or the film against wetting media, in particular water, alcohols, surfactants, lipids, organic solvents, proteins or against dissolved substances contained in wetting media is specifically adjusted by the substance. This makes it possible to set a barrier effect against liquids that is optimized for the respective application.

For example, it can be achieved that, depending on the additive applied, a nonwoven fabric becomes more permeable or impermeable to certain wetting media than the untreated nonwoven fabric under the same test conditions. The permeability or its inverse value, the barrier effect depends on the test method used, in particular the Pressure difference of the medium loaded on the nonwoven and the residence time, depending. The same applies accordingly to porous foils.

In a targeted manner, substances can be applied to the fibers / filaments or the film, which evenly cover their surface and thereby make them less or more wettable compared to a wide range of wetting media compared to untreated fibers / filaments or films.

Dissolved substances contained in wetting media can undesirably change the wetting properties and thus the permeability or the barrier effect of the fibers / filaments or foils in comparison to the same media in pure form, that is to say without the dissolved substances. The measure according to the invention also makes it possible to specifically change the effects on the wetting properties caused by the dissolved substances.

The fiber / filament layer can be solidified after application of the substance which changes the surface properties of the fibers / filaments to form a nonwoven.

As a result of the application of the substance upstream of the solidification process, the substance is already present uniformly on the fibers / filaments and thus also in areas which become inaccessible to subsequent treatment with substances in the course of the solidification. Otherwise, the explanations given for the procedural features also apply accordingly to the material features.

In the case of a product such as a nonwoven fabric made of spunbonded or meltblown fibers / filaments, in which the fiber / filament layer has been solidified after application of the substance which changes the surface properties of the fibers / filaments, the surface of the fibers / filaments is now uniform and uniform covered by additives. As a result, the nonwoven has the desired surface chemistry throughout, ie also at the closely spaced intersections of the fibers / filaments. The internal structure of the fibers / filaments and the resulting properties of the nonwoven, in particular its pore size, are not adversely affected.

In an advantageous embodiment of a nonwoven fabric, the substance that changes the surface properties of the fibers / filaments is a pseudocationic fatty amide with a proportion of 4 percent by weight. The nonwoven has a basis weight of 11.5 g / m ² and a pore size of 16 μm.

In this embodiment it is achieved that even with water as the wetting medium, the barrier effect of the nonwoven is not reduced by surfactant-containing ingredients dissolved in the water, which would be the case with an untreated nonwoven. The nonwoven fabric or the film can be part of a two or more layered inline or offline composite made of further textile materials and / or films.

By combining it with other textiles and / or foils, the wetting properties achieved and the resulting permeability and barrier effect for liquid media can also be used for other fabrics. The combination with these textiles and / or foils can also lead to synergy effects with other properties, which can then be used for applications.

Due to the properties obtained through surface chemistry, the nonwoven or the film is used in the hygiene industry as a barrier material, in particular as a textile backing in diapers, incontinence products or feminine hygiene products, in the textile industry, in particular as a material for protective clothing in the medical field and for drapes and Wipers, as a starting material for protective clothing in technical applications, as a barrier material for materials that are permeable to diffusion, in particular in the construction sector.

In these applications, either the breathable properties, i.e. the barrier effect against liquid media and permeability for vaporous or gaseous media, are used or, conversely, the absorbency for media through increased wettability. In the case of a film in particular, the application of the substance enables the polymer to be perforated by stretching the film material. For this purpose, the film material has, for example, polypropylene with chalk and / or a beta-nucleating agent. The nucleating agent is preferably added in a concentration between 0.1 ppm to 100 ppm and extracted before stretching, in particular stretching the film. In addition to chalk, other fillers can also be added to the thermoplastic film material. In addition to fillers, it is also possible to add miscible additives that separate out during crystallization. Due to the phase separation that occurs, openings arise in the film material.

The invention is explained below on the basis of an exemplary embodiment which is illustrated in the drawing.

In this show:

1 shows a schematic representation of the method according to the invention for producing (spunbonded or) meltblown,

Fig. 2 is a schematic cross-sectional view of a fiber / filament with the substance applied to the surface, and

Fig. 3 shows a nonwoven manufacturing device. The schematically illustrated process is optimized here especially for a meltblown process. However, it is also suitable for the spunbonded nonwoven process or, with minor modifications, for the film process. A device 18 for producing the melt 6 from polymers 4, one or more (spinning or) meltbown nozzles 8 (here for the sake of clarity) is used to produce (spunbonded or) meltblown fibers / filaments as product 2 individual nozzle shown) with capillary openings 20, air nozzles 22, a laying tape 12 and a spraying device 24, which is preceded by a dissolving or dispersing device 26 in which the substance 14 and the solvent or dispersion medium 16 can be mixed with one another.

For the production of (spunbonded or) meltblown fibers / filaments 2, polymers 4 are usually used in the form of granules as the starting material. This polymer granulate 4 is processed in a device 18 to form a melt 6, from which the fibers / filaments 2 for forming the nonwoven fabric are produced via spinning or meltblown nozzles 8.

For this purpose, melt drops 28 emerge from the capillary openings 20 of the nozzle 8, to which a sharp air flow is directed from the air nozzles 22, which produces threads (fibers / filaments) 2 from the melt drops 28.

The fibers / filaments 2 formed from the (spinning or) meltblown nozzles 8 are laid on a laying tape 12 as fiber or Filament layer 10 deposited. If appropriate, this filament layer 10 is subjected to a suitable consolidation process.

When the fibers / filaments 2 are formed from the melt drops 28, the poor cooling of the fiber / filament mass can lead to the formation of drops when the fibers / filaments 2 are formed and to fiber bundles when cooling or drawing. These disadvantages are eliminated by introducing a coolant, preferably water, in the form of very small droplets into the fibers / filament jet 2 via a spraying device.

In the method according to the invention, at least one substance 14 which changes the surface properties of the fibers / filaments 2 is now applied to the surface of the fibers / filaments 2, specifically within a period of time from the point in time until the fibers / filaments 2 are deposited as fibers / filament layer 10.

For this purpose, the substance 14 is either unmixed, as a solution or as a dispersion, preferably sprayed onto the surface of the fibers / filaments 2 by means of a spray device 24. If the substance 14 is sprayed in the form of a solution or dispersion, the substance 14 is mixed beforehand in the dissolving and dispersing device 26 with the solvent or dispersion medium 16. One possibility of applying substance 14 to fibers / filaments 2 with the least possible technical outlay is to add substance 14 to a coolant sprayed to cool the fibers / filament mass. Accordingly, the coolant then represents the solvent or dispersant 16.

In this case, the substance 14 is mixed with the coolant 16 via the dissolving or dispersing device 26 and introduced into the fibers / filaments jet 2 via the spraying device 24. The coolant 16 and the substance 14 contained therein uniformly wet the surface of the fibers / filaments 2, the coolant 16 evaporating and the substance 14 remaining on the surface of the fibers / filaments 2.

The spraying device and the number of spraying devices 24 are varied depending on the type of process used, the polymer 4 and the substance 14 to be applied in such a way that optimal wetting of the fibers / filaments 2 and, as a result, a uniform distribution of the substance 14 the entire surface of the fibers / filaments 2 takes place. The spraying device 24 is preferably adjustable in height. A jet applied from the spraying device 24 for wetting the fibers / filaments 2 is preferably applied via a nozzle bar. The shape of the nozzle itself can be slit, cross or circular. A variable nozzle geometry is preferably also selected in order in this way to apply the jet to the to be able to adapt the respective process. Further adjustments of the jet take place, for example, via different mixing ratios in the dissolving and dispersing device as well as via the variation of the pressure. Furthermore, the angle of the direction of the beam onto the fibers / filaments 2 can be changed. There is also the possibility that this angle is very flat in relation to air emerging from the air nozzles and surrounding the fibers / filaments 2, for example between 10 ° and 35 °. Then the substance 14 is mainly applied by micro-swirls and a disturbance of the air flow is avoided.

The choice of substance 14 depends on the desired surface property of the fibers / filaments 2. In this case, substances 14 are selected which determine the wettability of the fibers / filaments 2 or the finished spunbonded fabric or meltblown compared to certain wetting media such as water, alcohol, Adjust surfactants, lipids, organic solvents, proteins etc. ie specifically affect the barrier effect against the liquids in question.

FIG. 2 schematically shows the cross section of a fiber / filament 2, on the surface of which at least one substance 14 which changes the surface properties of the fiber / filament 2 is applied.

This substance 14 is applied evenly over the entire surface of the fiber / filament 2. example

To compare the various processes, several nonwovens were produced based on the same meltblown process settings and their barrier effect against wetting liquids was measured using different processes.

Fleece 1

A polypropylene granulate (manufacturer Himont, Grade Valtec HH442H, MFI 800 manufacturer's specification) was used. A standard meltblow nozzle (manufacturer Accurate Products) was used. The extrusion and spinning temperatures were in the range usual for PP as well as air temperature and quantities. In the production of the fibers, the cooling of the fibers was supported by adding a quench liquid. The fleece produced has a weight of 11.5 g / m ² . The product properties are listed in Table 1.

Fleece 2

In addition to the PP used for the production of fleece 1, 1.0 percent by weight of the total product of an additive (nonionic fluorochemical compound, grade FX1801, manufacturer 3M) was added to the polymer melt.

The fleece produced also has a weight of 11.5 g / m ² . The product properties are listed in Table 1. Fleece 3

This material was produced analogously to fleece 1. Here, an additive (pseudocationic fatty amide, grade BK2047FL, manufacturer Henkel KGaA) was added to the quench liquid, so that the nonwoven is equipped with 4 percent by weight on the nonwoven.

The fleece produced also has a weight of 11.5 g / m ² . The product properties are listed in Table 1,

Results

Table 1

(a) measured with deionized H ₂ 0, surface tension 70 mN / m

(b) measured with test liquid, surface tension 45 mN / m (a) + (b) measured according to Corovin method CM108A in accordance with DIN 53886

It can be seen that the additive in fleece 2 reduces the extensibility of the fibers and thus with the same process Positions leads to enlarged pores compared to fleece 1. As a result, a lower value was measured according to (a).

Fleece 3 shows no change in pore size due to the surface application of the additive. The measured values according to (b) demonstrate an increased barrier effect of the fleece 2 compared to fleece 1 due to the addition of the additive to the melt, despite the enlarged pore diameter.

By maintaining the small pore diameter of fleece 1 in the case of fleece 3 and the surface treatment with the additive added to the quench liquid, a significantly increased barrier effect according to (b) is achieved, even compared to fleece 2.

FIG. 3 shows a nonwoven manufacturing device 30, which also produces meltblown fibers 32, which are deposited on a sieve 34. The screen 34 is transported further in accordance with the direction of the arrow. Furthermore, the device 30 has an encapsulation 36. This preferably surrounds the meltblown fibers 32 not only in the area where the substance 14 is applied, but also, as shown, beyond. However, the substance 14 can be supplied additionally or only exclusively via the air nozzles 22, indicated by the arrows. Furthermore, a two-sided substance supply 38 is shown. A carrier 40 and / or the substance 14 is conditioned, for example tempered, by means 40 for setting a fluid state of a fluid supply 42 indicated by arrows. pressurized, mixed, etc. The fluid supply 42 also allows metering of the fluid flow flowing into the encapsulation, for example depending on the setting of certain turbulent flow conditions. For example, a secondary air inflow to the meltblown fibers 32 can be controlled or regulated in this way via a fan. According to an embodiment which is not shown in detail, the substance can also be supplied by means of high pressure, ie a pressure which is higher than that of the air flowing out of the air nozzles 22, for example 80 bar and more. The encapsulation 36 itself can, however, also have corresponding ventilation slots into the surroundings, through which the necessary secondary air can be drawn in. By appropriate selection of the arrangement of the ventilation slots, for example depending on the fluid supply 42 and / or substance supply 38, this is preferably done automatically.

Furthermore, flow distribution means such as the flow guide plates 44 shown can be present in the interior of the encapsulation 36. With these, the substance 14 and / or the carrier fluid can be conducted and swirled in such a way that the surface of the meltblown fibers 32 is applied uniformly. For example, the substance 14 can preferably also be passed through the meltblown fibers 32 one or more times with these flow distribution means. As indicated by dashed lines, the substance supply 38 can also be arranged at different locations, either individually or in addition. The substance supply is preferably in its Angularity adjustable so that the substance 14 can also be introduced into the encapsulation 36 against the flow direction of the meltblown fibers 32. The encapsulation 36 itself has, for example, a conical shape or an hourglass shape. It can terminate at the top and bottom with the nozzle or the screen 34 or at least partially also be open, for example in the form of slots. An embodiment of an encapsulation 36 is preferred which detects a stretching zone of the meltblown fiber after it has emerged from the nozzle. For example, the encapsulation is between 5 and 10 centimeters long. A fan is preferably arranged below the sieve 34, which generates a negative pressure in the encapsulation 26. As a result, the fluids flowing in and through the encapsulation are laminarized.

Nonwovens such as films described in this way are used in the hygiene industry as a barrier material, for example as a textile backing in diapers, incontinence products or feminine hygiene products, in the textile industry for example as a material for protective clothing in the medical sector, for example as a material for drapes and wipes or also as a starting material for protective clothing in the technical fields of application as barrier material for materials that are open to diffusion, for example in the construction sector, but in each case not restricted to the examples mentioned in the respective segment and also not restricted to the segments. Inline / off-line combinations with other materials (such as other spunbonded fabrics, meltblowns, foils, textile materials in the white test senses, tissues, etc.) conceivable to show synergy effects.

Claims

P ate nt p rü c he

1. A process for producing a product (2), in which at least one polymer (4) is processed as a starting material to form a melt liquid (6) from which the product (2) is produced, the melt liquid being produced from at least one nozzle (8) Polymer (4) emerges and is deposited as a layer (10), preferably on a sieve belt (12), at least one substance (14) changing the surface properties of the product (2) in a period of time from product formation to product deposition on the Surface of the product (2) is applied, characterized in that the substance (14) increases a barrier property of the product (2), whereby an interfacial tension of the product (2) is reduced.

2. The method according to claim 1, characterized in that an interfacial tension is set which has a difference of at least 3 mN / m from the fluid interfacial tension subsequently wetting the product (2).

3. The method according to claim 1 or 2, characterized in that an interfacial tension is set, which is 5 mN / m lower compared to a product (2) without such applied .Substance.

4. The method according to any one of claims 1, 2 or 3, characterized in that the product (2) is applied when the product (2) has a surface temperature of at least

110 ° C, preferably more than 130 ° C, in particular more than 150 ° C and preferably less than 180 ° C.

5. The method according to any one of claims 1 to 4, characterized in that a film is produced as the product (2).

6. The method according to any one of claims 1 to 4, characterized in that a spunbonded fabric is produced as the product (2) that is deposited on a screen belt.

7. The method according to any one of claims 1 to 4, characterized in that a meltblown nonwoven is produced as the product (2) and placed on a screen belt.

8. The method according to claim 6 or 7, characterized in that a pore size of a fleece is set, which is at least approximately the same with the applied substance (14) compared to setting an identical barrier effect in a fleece with the substance (14), the the polymer (4) is added in the melt, or a pore size of a nonwoven is set which is smaller with the substance (14) applied compared to setting an identical barrier effect in a nonwoven without the substance (14).

9. The method according to any one of claims 1 to 8, characterized in that the substance (14) is applied unmixed to the surface of the product (2).

10. The method according to any one of claims 1 to 8, characterized in that the substance (14) as a dispersion (emulsion / suspension / aerosol) is applied to the surface.

11. The method according to any one of claims 1 to 10, characterized in that the substance (14) is applied as a gas to the surface.

12. The method according to any one of claims 1 to 8, 10, characterized in that the substance (14) is dissolved or dispersed in a coolant (16) sprayed against the product.

13. The method according to any one of claims 1 to 8, 10, 11, characterized in that the product from different directions with the coolant (16) and the substance contained (14) is applied.

14. Product (2), produced by a process according to one of claims 1 to 1, in particular for taking up a surfactant-containing solution.

15. Nonwoven fiber / filament (2), which consists of a melt liquid (6) made of polymer (4) as the starting material by emerging from at least one nozzle (8) and then being pulled off and deposited as a nonwoven fiber / filament layer (10) on egg- nem sieve belt (12) is produced, at least one substance (14) changing the surface properties of the fiber / filament (2) being arranged on the surface of the fiber / filament (2), which in a period of fiber / filament formation up to for fiber / filament deposition on the surface of the fiber / filament (2), characterized in that the substance increases a barrier property of a nonwoven, the substance reducing an interfacial tension of the nonwoven.

16. A film which is produced from a melt liquid with a polymer as the starting material by exiting from a slot nozzle and then removing and depositing, further processing or winding up, characterized in that at least one substance which changes the surface properties of the film is arranged on the surface of the film which was applied to the surface of the film in a period of time from the film formation until the film was deposited.

17. fleece fiber (2) or film according to claim 15 or 16, characterized in that the surface is wetted in a range between 3% and 85% with the substance.

18. Nonwoven fiber (2) or film according to one of claims 15 to 17, characterized in that the surface is wetted approximately uniformly in gussets of superposed nonwoven fibers / filaments or films with the substance (14).

19. Nonwoven fiber (2) or film according to one of claims 15 to 18, characterized in that the substance (14) is applied in droplet form to the surface of the fiber / filament (2) or the film.

20. fleece fiber (2) or film according to one of claims 15 to 19, characterized in that the substance (14) the wettability of the fleece fiber / filament (2) or the film against a wetting medium, in particular water, Alcohols, surfactant-containing solutions, lipids, organic solvents, proteins or, compared to dissolved substances contained in a wetting medium, are lowered in order to increase a barrier effect against the respective wetting medium.

21. Nonwoven fiber (2) or film according to claim 20, characterized in that the surface property changing substance (14) is a pseudo cationic fatty amide.

22. Film according to one of claims 16 to 19, characterized in that the substance (14) contains the wettability of the film with respect to a wetting medium, in particular water, alcohols, surfactant-containing solutions, lipids, organic solvents, proteins or in a wetting medium solute increased to lower the barrier effect against the respective wetting medium.

23. fleece fiber (2 Y according to one of claims 15, 17 to 21 or film according to one of claims 16 to 22, thereby indicates that the fleece fiber (2) or the film is part of a two- or multi-layer inline or offline composite made of other textile materials and / or films

24. Use of a product produced according to one of claims 1 to 13 and / or a fleece and / or a film according to one of claims 15 to 23 m in the hygiene industry as a bar material, in particular as a textile backing in a jacket, in an incontinence product or in a women's hygiene product, in the textile industry, in particular as a material for protective clothing, in the medical field as well as for a curtain, wrapping, packaging, an insert and / or a wipe, in a technical application, as a bar material for a diffusion-open material , especially in the construction sector.

25. Nonwoven fabric setting device for a method according to one of claims 1 to 13 and for a nonwoven fiber (2) according to one of claims 15, 17 to 23, characterized in that a substance is supplied by means of a stretching air.

26. Device for applying a substance to a product that is made from a melt liquid (6), which has polymer (4) as the starting material and is produced by exiting from at least one nozzle (8) and then depositing, wherein on the surface of the Product (2) is arranged at least one substance (14) which changes the surface properties of the product (2) and which is in a Time span of product formation until the product is deposited on the surface of the product (2), characterized in that the device has an at least partial encapsulation of the melt liquid emerging from the nozzle.

27. The device according to claim 26, characterized in that a fluid supply via the device to the product is provided.

28. The device according to claim 26 or 27, characterized in that a substance supply is coupled to the fluid supply.

29. Device according to one of claims 26, 27 or 28, characterized in that the device has a means for setting a fluid state.

30. Device according to one of claims 26 to 29, characterized in that the substance feed has a high-pressure feed.

31. Device according to one of claims 26 to 30, characterized in that the fluid supply and / or the substance supply is adjustable in height.

32. Device according to one of claims 26 to 31, characterized in that the substance supply takes place in the immediate vicinity of the nozzle.