DE3634146C2 - Nonwoven and its manufacture - Google Patents

Description

The invention relates to a nonwoven fabric containing a plurality of fibers or individual threads made of a thermoplastic material. In particular, the invention relates to nonwoven fabrics which Fibers or single threads with a two-lobed cross-section point. The invention further relates to a method for Production of such non-woven fabrics.

Nonwoven materials are known and have been predominant developed in the 50s and 60s, although at least a corresponding publication dates back to 1943 goes; see. US 2,336,743 (Manning).

One of the most important industrial applications for Nonwovens are made for the one times consumption of certain disposable items. Typical case games for such products are disposable diapers, disposable Sanitary articles for women, disposable clothing for surgical Purposes, disposable wipes for industrial purposes and The like. Because the nonwovens in these applications as a fabric Substitute efforts have been undertaken taken to ver the properties of nonwovens and improve the properties of fabrics as much as possible approach. Soft procurement is of particular interest found of non-woven fabrics, d. H. an attempt was made to The nonwovens' resistance to folding or bending increases decrease as well as the feeling of touch or the softness in Touch to improve. Another important area is the improvement of tensile strength and tear strength of Non-woven fabrics. With the exception of some listed below With the help of examples, efforts were concentrated almost to improve the properties of nonwovens exclusively on the use of circular fibers shaped cross section.  

US 2,336,743 (Manning) describes one method and one Device for solution spinning or melt spinning Non-woven fabrics. According to the description, the spinning material are extruded through orifices of a spinneret, wherein the openings are slit-shaped, circular or openings with a different cross section.

US 3 314 840 (Lloyd et al.) Relates to a method and a device for the production of nonwovens. Although the disclosure of this document is obvious mainly refers to solution spinning, the enamel spinning processes are obviously not excluded. The Spinneret is preferably circular or slotted shaped openings, although these openings also others Can have shapes, e.g. B. circles, triangles, crescents and the like.

US 3,508,390 (Bagnall et al.) Relates to modified threads and fabrics made from it. Although this publication the production of conventional knitted textile works fabrics, fiber fleeces are also mentioned. The strings have a cross section that is essentially full of three constantly connected, essentially symmetrical thighs, which is essentially a uniform, Y-shaped cross section of defined ab measurements are created.

US 3 509 009 (Hartmann) relates to a nonwoven fabric which by melt spinning fiber-forming high molecular weight Polymers in a directional gas stream of high Ge speed with the formation of a uniform nonwoven of high Strength is produced. Although according to this Description manufactured threads typically a circle have a shaped cross-section, other cross cuts mentioned, for example star-shaped and Y-shaped Cross sections or combinations thereof.  

A device for producing nonwoven fabrics is in US 3,528,129 (Hartmann). This patent be obviously hits an improvement on an existing one Device, with details of the openings find in the spinneret that has a branched cross section exhibit. U-shaped and T-shaped openings are special mentioned.

DE-OS 16 60 623 (Rottenbacher et al) relates to fibers and threads with special cross-sections, as well as a process and nozzle plates for their manufacture. The fibers and threads are in one Melt spinning processes through spinnerets extracts their opening cross-sections that consist of two ver tied legs, which have an angle between 90 ° and 160 ° include, or consist of curved parts. The so Fibers and threads obtained have speci fish cross-section improved brilliance and a verbes they whiteness and are silky to the touch.

Finally, US 3 630 816 (Parker) relates to threads Rectangular cross-section made of non-woven fabrics. Of the Rectangular cross section of these threads is intended to be a length ver have a ratio of at least 3: 1.

The object of the invention is to provide nonwovens with improved To provide softness. In particular, fiction according to nonwoven top layers for disposable diapers with ver better softness are provided. Another special object of the invention is the ready provision of non-woven fabrics for menstrual hygiene articles with improved softness.

The solution to the problem according to the invention results from Providing a nonwoven fabric with a plurality of Fibers or individual threads made of a thermoplastic material, which is characterized in that the bevels or threads have a two-lobed cross-section, wherein two-lobed refers to a form that one essentially rectangular area, at the ends which are further apart from each other there is an enlarged area. This area is typical circular and its diameter larger than that Rectangle thickness.

It was found according to the invention that from such non-woven fabrics made of two-lobed threads are of significantly increased soft nature as well have other desirable properties.  

According to a preferred embodiment of the invention the nonwoven fabric substantially comprises a plurality of identically produced continuous and essentially Chen arbitrarily filed single threads from a thermo plastic polymer. Furthermore, the nonwoven is through discrete densified areas of thermally induced Thread ties that span much of the thickness of the nonwoven article extend, stabilized, wherein these densified areas in an intermittent, regular patterns are distributed and about 10 to about Make up 30 percent of the area of the fleece. There is also the thermoplastic material preferably made of a poly olefin. In particular, the polyolefin is Propylene, polyethylene or an ethylene-propylene copoly merisat.

According to a further preferred embodiment, a Nonwoven cover sheet provided for a disposable diaper, whose nonwoven largely that described above Embodiment corresponds, but the polyolefin A threads are spiked around the deck location, which in and of itself is hydrophobic, in a way to make it hydrophilic or wettable. He can do this follow that one before the wetting agent with the polymer mixed after extrusion or preferably a solution of the wetting agent on the fiber fleece already formed brings.

According to a further preferred embodiment of the Er is a fiber fleece for menstrual hygiene items in the same way as the nonwoven top layer made wettable for disposable diapers.

The process for producing the fiber according to the invention Fleece consists of the following stages: The polymer is in the molten state by a spinning nozzle plate with a plurality of openings of the desired ten-lobed cross-section extruded, creating a more  Number of single threads formed with a two-lobed cross-section becomes. These individual threads are then preferably on stretched pneumatically. After stretching the individual threads are deposited on a moving belt. To at this point the individual threads are essentially in arbitrarily oriented towards each other. Subsequently the individual threads are preferably gently put together expresses it by putting it in an opposite way Direction of rotating pair of rollers leads. Then will stabilize the fleece by heating it through two Rolls leads, one of which has a smooth surface and the others have a raised pattern. That way he you keep a fleece that is thermal in discrete areas is interconnected, these areas in one Patterns are arranged that match the raised pattern on the corresponds to a heated roller. Preferably that is Pattern of the thermally bonded areas formed so that it's about 10 to about 30 percent of the surface of the Fiber fleece.

The invention will be described in more detail below with reference to the drawing explained. Show it:

Figure 1 is a schematic representation of a preferred device for producing the inventive fiber fleece.

Figure 2 is a bottom perspective view of a spinneret plate with two-lobed openings through which a single thread of two-lobed cross-section are extruded.

Fig. 3 is an enlarged bottom view of two two-lobed openings of the spinneret plate of Fig. 2;

Fig. 4 is a partial cross-sectional view of an inventive non-woven fabric with monofilaments of zweilappigem cross-section;

5a to 5c show various pattern of an intermittent heat bonding, which can be guided in the inventive non-woven fabric through.

Figure 6 is a cross-section produced by using the inventive non-woven fabric liner A wegwindel. and

Fig. 7 is a cross-section through a made using the inventive nonwoven fabric menstrual hygiene product.

Thus, the invention broadly encompasses a fiber fleece, which is made up of a plurality of individual threads or fibers comprises a thermoplastic material, the one individual threads or fibers form a two-lobed cross have cut.

In particular, the cross section of these individual threads can be describe it as an elongated, essentially Rectangular area that covers at each other ends further away each have an enlarged one and typically has a circular area whose Diameter is greater than the thickness of the rectangle. This Form can also be described as a "dog bone" or "barbell" become.

In general, such non-woven fabrics (webs, Mats) of non-continuous fibers, continuous Produce single threads or combinations of these. The time are continuous individual threads, as they are, for example wise through nonwoven techniques (spunbonding techniques) are available, preferred. Another way be stands in the application of blow molding techniques, which are used for bil lead of non-continuous fibers.

The thermoplastic material can be any Trade materials that form fibers or single threads can be spun or blown. Although the Verwen of materials, such as glass, in practice  comes, polymeric materials are preferably used. Examples of such materials are polyolefins, poly amides, polyester, polyvinyl acetate, polyvinyl chloride, poly vinyl alcohol, polyurethane, polyacrylonitrile, polymethyl methacrylate, polyacrylate, cellulose acetate, viscose and the like. Furthermore, the thermoplastic Ma material around homopolymers, copolymers or mixtures act from two or more polymers. Ho copolymers, copolymers and polymer mixtures of Polyolefins preferred, copolymers and homopoly merisates are particularly preferred. Particularly preferred Homopolymers are polypropylene and polyethylene. As Copolymers will be ethylene-propylene copolymers particularly preferred.

Fig. 1 shows a schematic representation of a preferred device for the production of nonwoven fabrics from such polymers. This device is manufactured in accordance with US Pat. No. 4,405,297 and is operated in accordance with US Pat. No. 4,340,563 (Appel and Morman in each case), reference being made in full to the disclosure of these publications. Although this device and the corresponding method for producing nonwoven fabrics are preferred, other devices and methods are also available. For example, according to a further embodiment, nonwovens are produced using the device and the method according to US Pat. No. 3,692,618 (Dorschner et al.), Reference being made in full to the disclosure of this publication.

Briefly summarized, the device of Fig. 1 comprises a spinneret housing 11 which receives the polymer in the molten state. The temperature of the polymer melt is chosen so that the melt is sufficiently flowable for the spinning process. The preferred temperature when spinning polypropylene is about 238 ° C (460 ° F). Pressure is applied to the polymer melt in order to press it through the holes or openings in the spinneret plate 12 and in this way to form a “curtain” of individual threads 13 . The curtain 13 falls through a quenching chamber 14 in which it is brought into contact with quenching air. The quenching air is supplied at a relatively low pressure, the pressure being sufficient, however, to cause a specific stretching of the individual threads when they pass through the stretching nozzle 16 . After leaving the lower end of the drawing nozzle 16 , the individual threads are deposited on a moving surface 17 provided with holes, for example an endless wire or belt, to form a nonwoven web 18 . The web 18 passes through two compacting rollers 19 which slightly compact the individual threads in the web, where the cohesion of the web increases and further processing is facilitated.

Subsequently, the web 18 passes through two heated binding rollers 21 and 22. These rollers are preferably manufactured and operated in accordance with US Pat. No. 3,855,046 (Hansen and Pennings), the full disclosure of which is disclosed. Briefly summarized, the apparatus and method described in this patent involves the use of two rollers 22 and 21 , at least one, and preferably both, of which are heated. The lower roller 22 has a smooth surface, while the upper roller 21 has a raised, intermittent pattern on its surface. When the web 18 between the two heated rolls 21, 22 is performed, the web 18 is stabilized by the formation of discrete compacted areas of thermally induced bonds thread extending over a large part of the thickness of the web 18. These densified regions are distributed in an intermittent pattern corresponding to the raised pattern of the roller 21 , with unbonded thread areas therebetween.

FIGS. 5a to 5c show three patterns, the nonwoven web on the roller 21 to produce the corresponding pattern on the fiber 18 may be used. FIG. 5a includes circular portions 61 which are arranged in hexagons and triangles. According to Fig. 5b, the circular Be rich 62 are arranged as a repeating Sanduhrfiguren. Figure 5c, which shows the currently preferred pattern, includes areas 63 in the form of equilateral diamonds arranged in staggered rows.

Two important parameters related to the specific, ver turned patterns are the size of the compacted formed Areas and the distance between the areas. This both parameters together give the percentage the area of the fleece that is bound. It is important, that the percentage of bound area is large is enough to ensure sufficient strength of the fleece for to ensure the intended purpose. Furthermore, it is important that the percentage of bound area is not too big, because of a larger bound area the softness of the fleece is generally reduced. Currently, a bound area between about 10 and about 30 percent of the area of the nonwoven is preferred. Especially more preferred is a range from about 12 to about 20 Pro percent and in particular about 17 percent.

Another important factor in the bonding of the web is the temperature at which the rollers 21 and 22 are maintained. Naturally, no bond is achieved with any polymer below a certain temperature, while temperatures above a further temperature limit lead to excessive melting of the fleece. It was also observed that the temperature of the rollers can influence both the tensile strength and the softness of the nonwoven formed. In particular, within a certain range, higher temperatures result in a fleece with higher tensile strength. However, at the same higher temperatures, nonwovens with reduced softness can also result. This is believed to be due to a higher or lower level of binding that occurs within this temperature range. This means that at higher temperatures it is likely that a higher degree and a higher intensity of inter filamentary bonds result, which has a favorable effect on the tensile strength and on the softness to a certain extent. Currently, the preferred bonding temperature when using polypropylene is about 104 to about 160 ° C (about 220 to about 320 ° F). A temperature of about 135 ° C (275 ° F) is particularly preferred.

According to the invention it was found that two-lobed Nonwovens made from single threads compared to sol chen from circular individual threads in general at low higher temperatures can be bound. This poses an important advantage in so far as lower ones Binding temperatures typically get softer nonwovens become.

According to further embodiments, the nonwoven can according to whose procedures are stabilized. For example the nonwoven according to another method or as Part of another process in a different Production line to be bound by heat. Furthermore, the nonwoven fabric by adding an adhesive that a certain interfilamentary bond, stabilized become. Methods for stabilizing Nonwoven fabrics are known by removing the matting of the threads strengthened and thereby a certain degree of interfila mental bond.

According to the preferred embodiment shown in FIG. 1, the nonwoven web 18 is wound on the winding roller 23 after the binding by means of the rollers 21 and 22 . Another possibility is to design this device so that it is connected to the production line of an end product.

The basis weight of the nonwoven fabric can be varied in a simple manner depending on the intended use. For example, nonwoven fabrics can be made from about 10.2 to about 102 g / m ² (about 0.3 to about 3.0 oz / sq. Yard). A preferred basis weight for cover sheets for disposable diapers is about 27.1 g / m ² (0.8 oz / sq. Yard). For nonwoven fabrics for menstrual hygiene articles, the basis weight is preferably about 13.6 g / m ² (0.4 oz / sq. Yard).

Fig. 2 is a bottom perspective view of the spinneret plate 12 with two-lobed openings 24. Through the openings 24 , the polymer is extruded. The individual threads formed thus have a cross section of two lobed shape or of bone or barbell shape. The spinning nozzle plate 12 is made in a width that is slightly larger than the width of the product. The preferred web width varies depending on the end use of the product. For example, topsheets for disposable diapers preferably have a width of about 31.8 cm (12.5 in).

The number of openings and their arrangement on the plate at the prescribed intervals, the choice is such that the desired density of the individual threads in the nonwoven results. Currently, about 30 to about 100 are preferred Openings in the spinneret plate per 2.54 cm (1 in) web wide provided. About 85 openings are particularly preferred per 2.54 cm (1 in) web width. For example, points a 31.8 cm spinneret plate, d. H. a spinneret plate to make a 31.8 cm (12 in) wide nonwoven preferably 1020 openings.

Fig. 3 illustrates in an enlarged view of the preferred an arrangement, two of the openings 24 of the spinneret plate 12. It is not known that the dimensions and acts nep the bilobal orifices are critical, provided that they according to the invention for the formation of individual threads with the two-lobed cross-section to lead. The following form is currently preferred for the openings. The shortest dimension is the thickness a of the elongated area. The diameter b of the essentially circular regions 25 and 26 is approximately twice the thickness a. The length c of the opening 24 is approximately 10 times the thickness a. According to a particularly preferred embodiment, the thickness a is 0.215 mm, the diameter b is 0.430 mm and the length c is 2.15 mm. Of course, these dimensions and ratios in other embodiments, depending on various factors, e.g. B. depending on the specific polymer to be extruded and the desired properties of the nonwoven, can be varied.

As already mentioned, the preferred distance between the openings depends on the density of the nonwoven fabric to be produced. According to a preferred embodiment, the distance d between the openings is 7.25 mm. The openings are preferably aligned such that all of the openings are arranged parallel to one another and their length c is aligned in the direction of movement of the belt 17 (ie in the running direction).

Fig. 4 illustrates a present invention produced non-woven fabric 51 is in cross section. It will be appreciated that the fiber fleece a number of continuous monofilaments 52 to sums that are aligned with each arbitrary. There is preferably a high degree of loop formation and overlap in the nonwoven in the individual threads. These properties are influenced by various factors, e.g. B. affects the density of the deposited individual threads, the speed at which the individual threads are deposited, and the like.

It can be seen that the individual threads of this fleece 51 have a two-lobed cross section. It is not known that the dimensions of the two-lobed cross-section are critical if the basic features of such a cross-section are present. This means that the cross-section of the individual threads comprises a substantially rectangular area, each of which has enlarged areas at its more distant ends, which are typically essentially circular.

As already mentioned, the individual threads are stretched after the extrusion through the spinneret plate 12 . As a result, they typically have dimensions that are smaller than the dimensions of the openings 24 . The extent of this reduction depends on various factors, e.g. B. the special extruded polymer, the quenching speed of the individual threads, the tensile force applied to the individual threads and the like. According to the preferred embodiment, in which polypropylene is used, the individual threads at the end typically have a cross-sectional length of about 30 to about 60 µm. A cross-sectional length of approximately 40 μm is particularly preferred, although this size varies depending on the desired properties of the fiber fleece.

Fig. 6 shows a disposable diaper 71 in cross section. The fiber fleece topsheet 72 is on the side of the diaper 71 , which rests on the child's body. The majority of the diaper consists of a layer 73 of an absorbent material, e.g. B. flakes of cellulose pulp. Naturally, the function of layer 73 is to absorb moisture. A moisture-impermeable layer 74 is also provided.

An important property of the top layer 72 is its soft nature. In particular, it is important for the cover layer 72 that it is extremely supple and feels soft to ensure the child's well-being. According to the invention, it was surprisingly found that a nonwoven cover layer made of individual threads of two lobed cross-section compared to conventional nonwoven cover layers, which are made of single threads with a circular cross-section, have a significantly improved soft nature.

A test according to the invention for determining softness of nonwovens is the so-called "Smeltnik- Stiffness test ". In this test, a test piece is a Nonwoven ge on top of an open cylinder sets. A hemispherical test piece whose diameter is slightly below the inside diameter of the cylinder, is then dropped from a standard height, the Nonwoven is pressed into the cylinder. The route that the test piece migrates into the cylinder is then measured and as a measure of softness, d. H. the supplication density and conformability of the textile material give. A nonwoven top layer for diapers made from circles shaped individual threads is produced at a ver at the same time attempt a hike of 155 mm in the Cylinder, while a nonwoven diaper topsheet made of single threads of the same material, but a two-lobed Cross-section exists, a hiking distance of 370 mm gives. The material according to the invention thus leads to a considerable increase in soft texture.

Another aspect of softness, especially for What is important is the softness of the diaper topsheet Touch. A special test to determine this Eigen shaft is currently not available, but have the inventors as well as other people in the nonwovens from single threads with a two-lobed cross-section a considerable one Festge increases the soft texture poses.

Another property of nonwovens, in particular important when used for top layers of disposable diapers is the wettability of the top layer. Depending on the structure  the diaper is generally desired to have a topsheet that is at least partially wettable to the passage of Lighten moisture to the absorbent layer. Each However, there are numerous polymers that are suitable for production of non-woven fabrics are suitable, of hydrophobic nature. In particular, the two particularly preferred polymers sate, namely polypropylene and polyethylene, completely hydrophobic. It may therefore be desirable to take measures take to the wettability of from such poly Merisaten manufactured nonwovens.

It is known that the wettability by adding Wetting agents, e.g. B. surfactants can be increased can. In particular, cationic, anionic and not ionogenic surfactants added to the materials to make them wettable. According to a preferred one Embodiment of the invention, polypropylene are single threads by adding a non-ionic surfactant Made wettable by. This can be done by the surfactant before extrusion with the poly merisat mixed, d. H. it will be an "internal encore" carried out. This measure is preferably a non-ionic surfactant used. The Wetting agent is preferably combined with the polymer in one Ver up to about 5.0 percent by weight of the polymer mixes. It was also found that Polymeri Saten, such as polypropylene, is advantageous, the nonwoven to warm up at any stage and thereby hike bring the wetting agent to the surface of the individual threads. In U.S. 3,973,068 and U.S. 4,070,218 (Weber), to the full as regards content, this heating level is detailed added in connection with the addition of lubricants a nonwoven explained. Naturally, the temperature, to which the nonwoven is heated, below the melting point of the individual threads lie.

Another option is to put the wetting agent in  Form a solution to the nonwoven already formed set, d. H. an "external application" is carried out. This can be done by placing the nonwoven in a solution of the wetting agent and then the solvent evaporates, leaving a certain amount of surfactant Remains on the surface of the fleece. Given in case the fleece can be heated to the solvent evaporate faster. Another option is the surfactant solution by spraying or by gravure. In both cases it can Evaporate the solvent by heating the fleece be accelerated. It is naturally desirable that the evaporation process is ended before the fleece on the Winding roller is wound. In all three procedures for external application is the use of a non-iono gene surfactant preferred. The non-ionic surfactants can be up to about 5.0 percent by weight of the fleece.

Another important property of nonwoven top layers for diapers and for nonwovens in general, their pull is strength, d. H. the resistance to tearing. This Property is within the scope of the present invention measured a device in which a sample of the Fiber fleece clamped in two jaws and then out is pulled together. The force required to tear the fleece is indicated as gripping tensile strength. This test is typically carried out twice. To next, the nonwoven fibrous web in the jaws is made this way directed that the applied force is parallel to the direction in which the web has been deposited (running direction, MD) ver running. All tensile strength values specified here pull on a pulling process in the direction of travel.

Fortunately, according to the invention it was found that Non-woven fabrics made of double-lobed single threads Nonwoven fabrics made of the same material with circular  Individual threads increased tensile strength in both directions show. Without being committed to any particular theory it is currently believed that this increased tensile strength on the increased contact area between the individual threads that is available when the threads are on the way described thermally connected who which is due. This probably also helps Reduction in the formation of nonwoven webs with sufficient cohesion required bonding temperatures at.

Another property that gave way to nonwoven top layers is their opacity or opacity. It's nam It is often desirable that the top layer is opaque. It corresponds to normal practice, subordinate to the polymer melt Add nete shares of titanium dioxide to the opacity of the To increase the nonwoven fabric. It was found that he nonwovens according to the invention have an increased opacity, probably due to the increase in surface area of the individual threads that can thus reflect more light lead is.

Fig. 7 shows a cross section through a typical menstruation hygiene article, e.g. B. A sanitary napkin 81. As shown, the pad consists of a nonwoven cover 82 surrounding an absorbent region 83 . Much of the properties that are desired for nonwoven cover sheets for disposable diapers are also desirable for nonwoven covers for menstrual articles. In particular, it is important that, according to the invention, a non-woven fabric of increased softness, ie both conformability and soft texture when touched, is provided. It is also important here to increase the wettability of the casing 82 . This can be achieved by adding a wetting agent to the cover according to the methods described above in connection with diaper cover layers. It is also important that according to the invention a non-woven fabric cover is provided with improved tensile strength and opacity.

The invention will now be illustrated by examples purifies.

example 1

This example is carried out on the device described above. In particular, the web width is 31.8 cm (12 in), and the spinneret plate has 40 two-lobed openings per 2.54 cm (1 in) width. Polypropylene is extruded at a melting temperature of approximately 260 ° C (500 ° F). The basis weight of the nonwoven web is 27.1 g / m ² (0.8 oz./sq. Yard). The nonwoven web is bound using the pattern shown in FIG. 5a, the binding area being approximately 17.5 percent of the area of the nonwoven web. In order to test different patterns, the nonwoven webs are connected outside the device (off-line), ie the webs are formed and rolled up on a winding roller. They are then unwound in a separate device and subjected to the binding treatment. The temperature of the bonding rollers is about 132 ° C (270 ° F).

The nonwoven web obtained shows the Smeltnik stiffness test (SST) a value of 230 mm. Furthermore, the griffin tensile strength of the nonwoven web of this example measured, by moving a piece of the track between two in opposite directions brings pulling gripping devices. The Force used to tear the web in the direction in which it has been discarded (running direction or MD) 6.8 kg (15 lb).

Example 2

This example is similar to Example 1 performed with the modification that the binding temperature Is 116 ° C (240 ° F). The nonwoven web obtained has  an SST of 320 mm and an MD tensile strength of 1.59 kg (3.5 lb).

Example 3

This example is similar to Example 1 performed, with the modification that the binding tempera The temperature is 143 ° C (290 ° F). The nonwoven web obtained has an SST of 150 mm and an MD tensile strength of 2.27 kg (5.0 lb).

Example 4

This example is similar to Example 1 performed, with the modification that the binding pattern is reduced to 10.5 percent. The nonwoven fabric obtained bahn has an SST value of 260 m and an MD tensile strength from 5.44 kg (12 lb).

Example 5

This example is similar to Example 1 performed, with the modification that the bond area Is 35 percent. The nonwoven web obtained has one SST value of 150 mm and an MD tensile strength of 8.16 kg (18 lb).

Example 6

This example is carried out in a manner similar to Example 1, except that polyethylene is extruded at about 191 ° C (375 ° F) through a spinneret plate with about 14 two-lobed openings per 2.54 cm (1 in) width. The basis weight is 27.1 g / m ² (0.8 oz./sq. Yard). The web is bound at about 107 ° C (225 ° F) with a share of bound area of about 14 percent. The nonwoven web obtained has an SST value of more than 700 mm, ie the fall distance of the test piece corresponds to the full cylinder length.

Although the invention has been specifically discussed in connection with  len embodiments have been described, it is apparent lich that many alternatives, modifications and varia tions are possible. In particular, the fiction like non-woven fabrics in connection with cover layers for once diapers and menstrual hygiene items described wor the. However, other types of products also come in Question of how surgical and other disposable garments, Wipes for industrial use and the like the invention encompasses all such applications, age native, modifications and variations.

Claims (21)

1. Nonwoven fabric containing a plurality of fibers or individual threads made of a thermoplastic material, characterized in that the fibers or individual threads have a two-lobed cross-section, two-lobed referring to a shape which comprises a substantially rectangular area, at the further apart from each other There is an enlarged area at the ends. 2. Nonwoven fabric according to claim 1, characterized in that the thermoplastic material is a Polyolefin. 3. nonwoven fabric according to claim 2, characterized in that the polyolefin is polypropylene, Polyethylene or an ethylene-propylene copolymer acts. 4. Nonwoven fabric according to one of the preceding claims, characterized in that the individual threads or Fibers are wettable. 5. Nonwoven fabric according to one of claims 1 to 3, characterized characterized in that there are a plurality of im essentially identical manufactured, continuous and essentially arbitrary  deposited single threads from a thermoplastic Polymer contains. 6. nonwoven fabric according to claim 5, characterized in that a certain degree of interfilamentary Binding is present, the nonwoven stabilizing is. 7. nonwoven fabric according to claim 6, characterized in that the interfilamentary bond a plurality of discrete, densified areas of thermal induced thread bindings, which extend over the Extend most of the thickness of the nonwoven, comprises, the compressed areas in one intermittent, regular patterns are distributed and there are unbound thread areas in between. 8. nonwoven fabric according to claim 7, characterized in that the densified areas are about 10 to about 30 Make up percent of the area of the fleece. 9. nonwoven fabric according to claim 7, characterized in that the densified areas are about 12 to about 20 Make up percent of the area of the fleece. 10. Nonwoven fabric according to claim 9, characterized characterized in that the individual threads are wettable. 11. Nonwoven fabric according to one of claims 5 to 9, characterized characterized in that the length of the cross section is approximately 30 to about 60 microns. 12. Nonwoven fabric according to one of claims 5 to 9, characterized characterized in that the length of the cross section is approximately Is 40 µm.   13. nonwoven diaper topsheet, characterized in that that they are made of nonwoven fabric according to one of claims 7 or 8. 14. Nonwoven cover for menstrual hygiene articles, characterized in that they follow the nonwoven contains one of claims 1 to 12, wherein the Individual threads are wettable. 15. Multi-layer absorbent article, the one Top layer, a liquid-impermeable underlay and one sandwiched between them absorbent wadding layer, thereby characterized in that it is a nonwoven fabric according to one of the Claims 5 to 12 contains. 16. A method for producing a nonwoven article, in which one

• 1. a thermoplastic polymer is extruded through a spinneret with a plurality of openings to form discrete individual threads,
• 2. the individual threads are stretched,
• 3. the individual threads are deposited in an essentially arbitrary manner on a moving support to form a nonwoven web and
• 4. stabilizes the fleece by interfilamentary bonds,

characterized in that a spinneret is used which has two-lobed openings so that monofilaments with a two-lobed cross-section are formed, two-lobed referring to a shape which comprises a substantially rectangular area, at the ends of which are more distant from one another enlarged area. 17. The method according to claim 16, characterized in that that the interfilamentary bonds were made by pulling the nonwoven web through two guides rollers rotating in the opposite direction, at least one of which is heated and at least one a raised pattern to form a plurality of discrete, densified areas of thermal induced thread bindings that spread over a Extend most of the thickness of the nonwoven, the densified areas in one intermittent pattern that matches the sublime pattern on at least one of the rollers are and between the intermittent pattern unbound thread areas are formed. 18. The method according to claim 17, characterized in that that the densified areas are about 10 to about 30 Make up percent of the total area of the fleece. 19. The method according to claim 17, characterized in that the densified areas are about 12 to about 20 Make up percent of the area of the fleece. 20. The method according to any one of claims 16 to 19, characterized characterized in that it is the thermoplastic Polymer is a polyolefin. 21. The method according to claim 20, characterized in that the polyolefin is polypropylene, Polyethylene or an ethylene-propylene copolymer acts.