ES2628416T3 - Napa comprising bicomponent or multicomponent curly fibers - Google Patents

Abstract

Napa comprising bicomponent or multicomponent curly fibers consisting of at least two sections, which comprise a polymer or a polymer mixture as a predominant component and which are arranged through the cross section of the fiber in a manner suitable to promote curling of the fiber during the fixing process and whose predominant components differ in the heat of crystallization (dHc), characterized in that the difference in the heat of crystallization dHc is in the range of 30 J / g to 10J / g, preferably 30 J / g at 20 J / g and that the predominant components differ, at least, in one of the other parameters selected from the flow index group, the degree of polydispersion and the flexural modulus, while the relative difference of the predominant components is: for the flow rate in the range of 100 g / 10 min to 5 g / 10 min and / or for the degree of polydispersion less than 1, but greater than 0.3, and / or for the flexural modulus in the range of 300 MPa to 50 MPa; in which the relative difference in the flow rate is not more than 100 g / 10 min, in the degree of polydispersity it is less than 1, in the flexural modulus it is not greater than 300 MPa; and in which said fibers have the degree of curling, at least, of 5 undulations per 20 mm of fiber.

Description

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DESCRIPTION

Napa comprising two-component or multi-component curly fibers Technical sector

The present invention relates to a sheet comprising bicomponent or multicomponent curly fibers consisting, at a minimum, of two materials comprising a polymer as a predominant component and which are arranged through the cross-section of the fiber in a manner suitable for promoting fiber curling during the fixing process and whose predominant polymer components differ in the heat of crystallization (dHc). The type of napa described in this document is especially intended for the production of nonwoven textiles that are mainly used for applications in the hygiene industry.

Background of the technique

The bulkiness of nonwoven textiles can be important for several reasons. Nonwoven textiles are often used as part of hygiene products, in which the bulkiness of the material can be used both for reasons of functionality (for example, as part of the loop part of the fastening system consisting of hooks and loops or, for example, for the improvement of the distribution of liquids in the core of the absorption products), as well as for sensory reasons, the volume of the material, in addition to other things, gives smoothness and can be positively accepted in contact with the skin. In certain cases, nonwoven textiles can be used as part of cleaning products such as, for example, wipes and sponges. The improvement in the bulkiness of such nonwoven textiles can also improve their effectiveness as a cleaning element.

In several cases, the effort was intentionally dedicated to creating or modifying certain properties of nonwoven textile materials with the aim of improving them. These efforts consisted of the selection and / or modification of various chemical compositions of fibers, the basis weight, the process of stratification of the fibers, the density of the fibers, the extrusion of various patterns, the use of various types of bonding.

The bulkiness of a nonwoven textile is directly related to the properties of the fibers that form it. Homogeneous continuous fibers are typical for fusion spun nonwovens. Subsequently, bulkyness can be increased through the use of joining procedures. One method consists in the use of such thermal bonding procedures, which retain the maximum part of loose fiber segments between the individual bonding points that are used to achieve the required strength of the final material. Another procedure consists in exposing the non-woven textile material, after calendering, to a water jet (hydrogenation or hydro-entanglement) in order to sponge the fibers and increase their specific thickness.

Another method consists in producing nonwoven textiles from "bicomponent" polymeric fibers, including stages in which these fibers are created under the row, placed to create a nap and, subsequently, linked using a selected embossing calender with the In order to achieve a certain stamped effect. Said bicomponent fibers can be produced using rows equipped with two adjacent sections, in which the first polymer is released through the first and the second polymer is released through the second in order to create a fiber having a part of the section cross section formed by the first polymer and the second part of the cross section formed by the second polymer (hence the term "bicomponent"). The respective polymers can be selected to have different characteristic properties, which allow, in the combinations of side or side geometry or asymmetric core / sheath, the bending of the two-component fibers during the spinning process as they cool and cool. extract from under the row. It is known that there are several documents that deal with the application of individual differences to achieve fiber winding. For example, European Patent EP0685579 of Kimberly Clark describes the combination of polypropylene and polyethylene. Another European Patent EP1129247 from the same company describes the combination of different polypropylene. The key here is the degree of difference of the individual properties described.

Next, the resulting rolled fibers can be placed to create a napa that is subsequently joined using various procedures to create a bulky nonwoven textile material.

EP2343406 discloses a nonwoven web of curly fibers, as defined in the preamble of claim 1.

Features of the present invention

A layer according to the present invention comprises bicomponent or multicomponent curly fibers consisting of at least two polymeric components, which are mutually arranged through the cross-section of the fibers, such that they promote the curling of the fibers during the fixing process and which differ in the heat of crystallization, in which the substance of the present invention is such that the difference in the heat of crystallization (dHc) is in the range of 30 J / g to 10 J / g, preferably from 30 J / g to 20 J / g and that the polymeric components described differ, as a minimum, in one of the other parameters selected from the group

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of index of fluidity, the degree of polydispersion and the flexion module, while the relative difference of the polymeric components is:

for the fluidity index in the range of 100 g / 10 min to 5 g / 10 min and / or for the degree of polydispersion in the range of 1 to 0.3, and / or for the flexural modulus in the range of 300 MPa to 50 MPa;

in which the relative difference in the flow rate is not more than 100 g / 10 min, the relative difference in the degree of polydispersity is not greater than 1, the relative difference in the flexural modulus is not greater than 300 MPa; and in which said fibers have the degree of curling, at a minimum, of 5 undulations per 20 mm of fiber.

The attached claims define, respectively, preferred and / or specific embodiments of the present invention. In a further aspect, the present invention relates to a method of producing such sheets.

Brief description of the drawings

Figure 1A - Examples of asymmetric arrangement (of curl stimulation) of the component sections through the cross section of a multicomponent fiber

Figure 1B - Example of a symmetrical arrangement of the component sections in the cross section of a multicomponent fiber

Figure 2 - Example of the fusion spinning production line Definitions

The term "napa" herein refers to materials in the form of fibers that are in the pre-bond state that is performed during the calendering process described, for example, in patent application WO2012130414. The "napa" consists of individual fibers between which a fixed mutual bond has not yet been formed, although they may be attached in certain ways, where this preunion can occur during fiber placement or shortly after it in the process of fusion spinning. This preunion, however, still allows a substantial number of the fibers to move freely, so that they can be repositioned. The "napa" mentioned herein may consist of several strata created by the deposition of fibers from various spinning beams in the fusion spinning process.

The terms "fiber" and "filament" are, in this case, mutually interchangeable.

The term "monocomponent fiber" refers to a fiber formed from a single polymer or polymer blend, which is distinguished from the bicomponent or multicomponent fiber.

"Bicomponent" refers to a fiber having a cross section comprising two discrete polymer sections, two discrete polymer mixing sections or a discrete polymer section and a discrete polymer mixing section. The term "bicomponent fiber" is included in the term "multicomponent fiber". A bicomponent fiber may have a global cross section divided into two or more sections consisting of different sections of any shape or arrangement, including, for example, a coaxial arrangement, core and sheath arrangement, side-by-side arrangement, radial arrangement.

The term "multicomponent" refers to a fiber having a cross-section that comprises more than one discrete polymer section or more than one polymer blend section or, at the very least, a discrete polymer component and, at the very least, a section of polymer mixture. The term "multicomponent fiber" thus includes, but is not limited to, "bicomponent fiber. A multicomponent fiber may have a global cross section divided into parts consisting of different sections of any shape or arrangement, including, for example, a coaxial arrangement. , nucleus and sheath arrangement, side-by-side arrangement, radial layout, island layout at sea.

As used herein, the term "nonwoven textile" means a structure in the form of a fleece or band made from randomly directed or oriented fibers, from which a nappa is initially formed and consolidated subsequently and the fibers are joined together by friction, effects of cohesive forces, gluing or similar procedures that create a single or multiple joint pattern consisting of joint footprints formed by a limited compression and / or the effect of pressure, heat , ultrasound or thermal energy, or a combination of these effects, if necessary.The term does not refer to fabrics formed by weaving or knitting or fabrics that use thread or fibers to form bond points.The fibers may be of origin natural or synthetic and may be staple fibers, continuous fibers or fibers produced directly at the processing site.The available fibers usually have diameters and n the range of approximately 0.0001 mm to approximately 0.2 mm and are supplied in several ways: short fibers (also known as staple or staple fibers), individual continuous fibers (filaments or monofilaments), unbraided bundles of continuous fibers ( also known as bast) and you make braided

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continuous fibers (thread). A nonwoven textile material can be produced using many methods, including technologies such as meltblown, continuous filament spinning, fusion spinning, solvent spinning, electrostatic spinning (electro-spinning), carding, film fibrillation, fusion film fibrillation, air deposition, dry deposition, wet deposition with staple fibers and various combinations of these processes as is known in the art. The basis weight of nonwoven textiles is normally expressed in grams per square meter (gm2).

The term "asymmetry", when used with respect to the perpendicular plane of the fiber cross section, means that the arrangement of the fiber sections is not symmetrical, particularly in relation to the central symmetry, where the center is considered to be the center of the fiber cross section. The term can also refer to axial symmetry, where it is necessary to evaluate, at a minimum, so many axes that pass through the center of the fiber cross section, since there are polymer sections present.

It is understood that the term "heat" means "heat of fusion" or "heat of crystallization" and is always understood to mean "latent heat".

Description of the preferred embodiments

In accordance with the present invention, a sheet may consist of continuous multicomponent fibers produced, for example, from the fusion spinning process. The fibers are extruded under a row and subsequently attenuated, cooled and deposited on a tape so that they form a fiber nap. During the course of the process, these fibers are automatically rolled up. Napa can become nonwoven fabric.

The individual fibers consist, as a minimum, of two polymeric components A and B, in which the polymeric components are supplied to the row separately and, in the resulting fiber, there is a section with a predominance of the polymeric component A and a section with predominance of the polymer component B and in which the sections in the cross-section of the fiber are arranged in a manner that supports the curling of the fibers already during the course of the fiber fixing process. These areas can be found, for example, on opposite sides of the cross section of the fiber and thus form a known arrangement in the bicomponent fibers under the name from side to side or, for example, a section may surround the second section. and thus forming an arrangement known as nucleo-sheath, in which in order to ensure fiber curling, the overall arrangement of both sections with predominant polymer components A, B is asymmetric in the cross section. In another arrangement, the fiber may contain three polymeric sections with predominant polymeric components A, B, C arranged, for example, in the arrangement called "segmented pie" or "islands in the sea", in which in order to ensure the Curled fiber, the general arrangement of both sections with components of predominant material A, B is asymmetric in the cross section.

Without intending to limit the theory, it is believed that the mutual arrangement of the sections with predominant polymer components in the cross section of the modified fiber to support the fiber curling has already been expressed, during the course of fiber fixation, for example, due to the degree of asymmetry of the polymeric components, which significantly affects the final result of curling, while it is not possible to simply assume that a greater asymmetry of the fiber arrangement will result in a more pronounced curl. On the contrary, it is also necessary to take into account the properties of the individual components, in which synergies of arrangement can arise and a fiber with a less pronounced asymmetric arrangement can promote a curl greater than a fiber with a more pronounced degree of asymmetry. One skilled in the art will appreciate that the optimum arrangement of the sections with polymeric component predominantly in the fiber can be determined in a laboratory test, for example, using a small laboratory row. Examples of the individual asymmetric arrangements and examples of arrangements that support the curling of the fibers, which are not limited to those presented herein, are shown in Figure 1A. Provisions that, based on the definition provided above, are not asymmetric or generally do not support fiber curling are shown in Figure 1B.

The formation of curly fibers resulting from a significant difference in the properties of the individual polymer components, usually expressed using the so-called contractibility of individual components, is well known in the industry. Fibers produced in this way are known under the name of chemically formed fibers. One skilled in the art will appreciate that the term contractibility of components primarily describes the change in volume during the transition from the liquid state to the solid state, which is affected by the various properties of the polymers. For example, for a two-component fiber, it is possible to use the combination of two polymers. For example, a polymer together with another polymer (polypropylene + polyethylene), copolymers (polypropylene + polypropylene copolymer) or a mixture (mixture of polypropylene + polypropylene and a polypropylene copolymer). When two polymers are used, it is always necessary to carefully consider the materials used and their mutual miscibility. The more they differ from each other, the more likely a lower level of cohesion of both sections is with the predominant polymer component in the fiber and fiber division can occur. Especially in hygiene applications, even a small degree of fiber division is very undesirable, since it can manifest itself as "fluff balls" on the surface of the textile material and thus appear on the surface of the product, what end customers see as a sign of inferior quality of

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product. It is also known that the same polymer with different properties can be used (for example, a difference in the index of fluidity, polydispersion, the degree of crystallinity of the material or its elasticity), where it is essential for success to have a significant difference, such as minimum, in one of the parameters.

For example, based on European Patent EP1129247 of Kimberly Clark, in the case of polydispersion a difference of at least 0.5 in the precisely determined area is necessary, the document indicates that the predominant component of one has a polydispersion of <2.5 and the second> 3, for crystallinity it is necessary that the predominant component of one section is amorphous and the other is crystalline, while the difference in heat of fusion must be at least 40 J / g ; while the fluidity index suitable for fusion spinning applications is in the range of a single digit at thousands of g / 10 min and for the elasticity a combination of elastic and non-elastic material is required.

The aim of the present invention is a curly multicomponent fiber in which the polymers used predominantly in sections are very similar to each other. Preferably, the polymers can be chemically equal, only slightly different in terms of physical properties, for example a combination of polypropylene-polypropylene. One skilled in the art will appreciate that, for example, polypropylene (polymer obtained from propylene monomer units) has basic characteristics, but, for example, the tacticity of the individual units or the length of the polymer chains or the Distribution of different polymer chains in the polymer can bring variability in physical properties, which is significant for the production of fibers and nonwovens. An expert in the sector will appreciate the wide range of commercial types of polymers available in the market and will also appreciate the various quantities and availability of individual types. Due to the distribution of demand, supply is also particularly concentrated in polymers in a relatively narrow area of properties. A considerable advantage derived from the use of significantly similar polymers is also that they are relatively available in the market.

It is necessary to underline that the mentioned polymer sections can be formed using a polymer or can be formed using a mixture of various compounds. It is known in the industry that there are also fibers consisting of multicomponent fibers based on the same polymer, the components varying only in the addition of a mixture. For example, US 6,203,905 by Kimberly Clark describes the addition of a nucleation additive in a bicomponent fiber section.

The principle of the present invention of the present inventors may consist solely of predominant polymer components or of predominant components and additives added.

The principle of the present invention of the present inventors may also contain the addition of additives (for example, dyes), but the addition of such an additive does not affect the curling of the fibers to a significant degree. The additive can, for example, be added to both sections symmetrically.

As the industry is known, some functional additives can induce a chemical reaction directly in the polymer melt immediately before spinning and its effectiveness can be affected, for example, by the melt temperature (for example BASF IRGATEC CR76 ). In this way, due to the various melt temperatures of both polymeric components for the sections, a significant difference in the resulting properties can be produced (for example, fluidity index, polydispersion) even when identical mixtures of polymers and additives in both sections. The principle of the present invention may contain the addition of functional additives, but this addition does not affect the curling of the fibers to a significant degree.

As is evident from the previous text, it is known in the industry that if the contractibility of the predominant components of the sections is sufficiently different, tension is produced in the fiber under the row that causes the curling. The curling of the fibers based on the present invention is the result of the combination of small differences, at least, in two, preferably three, polymer parameters.

The key variable is the latent heat of crystallization (dHc), which is an indicator of the amount of energy that needs to be taken from the system for the crystallization of the polymer components to occur. A well-known theory states that if the temperature difference is sufficient, the predominant component in a section will begin to be fixed first and, since said tension created has no opposite force in the form of a predominant component still liquid in the second section, the fiber will be rolled up. . It is always necessary to have a sufficient difference between both polymeric components, otherwise the effect will not take place.

A known document from Kimberly-Clark EP0685579 determines the minimum difference in heat of fusion, which is approximately equivalent to a heat of crystallization of 40 J / g. In contrast, according to the present invention, fiber curling occurs at smaller differences, when a surprisingly significant synergistic effect of other differences between the predominant component in the sections is used. The winding or curling of the fibers based on the present invention is the result of the combination of small differences in the heat of crystallization (dHc) and, at a minimum, in one, preferably in two more parameters of the polymer.

The predominant individual components differ in the heat of crystallization (dHc), in which the difference in

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the values are in the range of 30 J / g to 10 J / g and, preferably, from 30 J / g to 20 J / g. For a lower degree of curling, the heat of the crystallization difference (dHc) may be in the range of 24 J / g to 10 J / g and, preferably, 24 J / g to 20 J / g. In addition, the predominant individual components may differ in the level of fluidity index (MFI), in which the difference between the values is in the range of approximately 100 g / 10 min to 5 g / 10 min, better still 80 g / 10 minutes; preferably from 60 g / 10 min to 10 g / 10 min.

In addition, the predominant individual components may differ in the degree of polydispersion of the material, in which the difference in values is in the range of 1 to 0.3, better still 1 to 0.5 and, preferably, 1 to 0.75.

In addition, the predominant individual components may differ in the flexural modulus of the material, in that the difference in values is in the range of 300 MPa to 50 MPa, better still from 250 MPa to 80 MPa and, preferably, 200 MPa at 80 MPa.

Without being bound by theory, the present inventors assume that fiber curling is caused by tension in the fiber, when one section is already crystalline, while the other remains in a liquid state or that its degree of crystallization is less than the point given in time. In general, during the course of crystallization, the volume of the given section becomes smaller and if at that time the other section is still malleable, it does not have a very large resistance level and the fiber curls. From the aforementioned it may seem that, apart from the value of the latent crystallization heat (dHc) itself, also the temperature at which the crystallization begins and the crystallization speed can have an effect on the degree of winding. Respecting the fact that the objective of the present invention is the combination of two significantly similar polymers, they will probably also have similar crystallization temperatures. Examples of various commercial types of polypropylene homopolymers are shown in the table.

 Polymer / Manufacturer

 Crystallization temperature ° C Latent crystallization heat (dHc) J / g Crystallization rate (min)

 Mosten NB425 from Unipetrol

 124 108 1.36

 Tatren HT2511 from Slovnaft

 125 106 0.77

 MR 2002 of Total

 114 85 5.29

 Petrochemicals

 Exieve Achieve 3854

 113 91 8.19

 Moplen HM562S from Basel

 121 87 1.55

Without being bound to any theory, the present inventors assume that the differences in the crystallization time of the order of several minutes do not have a significant force in themselves to cause the fiber to wind, but also contribute to the degree of winding caused by the aforementioned differences, specifically in the heat of latent crystallization (dHc).

The predominant individual components of the sections may differ in the crystallization temperature, in which the difference in values is in the range of approximately 5-30 ° C, better still 5-25 ° C and, preferably, 8-25 ° C.

The predominant individual components of the sections may differ in the crystallization rate, in which the difference in values is at least 20 seconds, better still 50 seconds, better still 120 seconds and preferably 150 seconds.

The polymer components are dosed -1- in separate extrusion systems -2-, in which they melt, are heated to a suitable operating temperature and are still separated in rows -4- where the multicomponent fiber is formed. One skilled in the art will understand that the process for preparing spinning polymers in the form of a multicomponent fiber may, depending on the type of technology, encompass other specific steps, as well as the fact that various additives designed for this purpose can be added to the components. polymers in order to, for example, change the color of the fibers (dyes) or change the properties of the fibers (for example, hydrophilicity, hydrophobicity, flammability), where, according to the present invention, it is significant for the material that these additives do not affect the curling of the fibers and / or are dispersed symmetrically in the resulting fiber. The fiber -5- formed under the row -8- is exposed to a stream of cooling and attenuation air -6-, -7-, so that undulations are formed on the fibers before falling -8- on the mat of pickup -10-. Both the cooling and attenuation air -6-, -7- have approximately room temperature, preferably 10-30 ° C, more preferably 15-25 ° C. The collection mat -10- can be, for example, a mobile belt that draws the fiber sheet in formation -11-. During the trip on the collection mat -10- there is no additional heat input or mechanical energy to support the curling.

In this way, various spinning beams can be arranged in sequence, in which all can produce

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curly fibers or can put different layers (for example, simple fusion spinning fibers, for example, continuous or meltblown spinning, nanofibers, a film). For the design according to the present invention, it is advantageous that the layer / layers of curly fibers are deposited on other layers so that undesirable compression of the curly fibers does not occur. For other applications, it may be advantageous to make combinations in which the curly fibers are released from the first and last spinning bundles, so that the resulting material has the outer surfaces consisting of curly fibers and the inner layer can have different properties (by example, mechanical strength of the resulting nonwoven textile).

The fiber layer or layers are subsequently reinforced -12-, and several known methods can be used (for example, thermal bonding, thermal bonding by calendering, needle punching, hydro-entangling). Individual joining procedures have a significant effect on the resulting properties of the materials and an expert in the field will readily determine which procedure is suitable for their material. In the same way, this expert will also understand that the selection of a bonding procedure with a higher intensity or density of bonding point can even result in the denial of differences in the overall bulkiness of fibers containing non-textile fibers. resulting tissues based on the present invention and standard materials containing non-curly fibers.

The final nonwoven web can be used in various applications, such as in the non-limited list of the following examples: wipes for dust and hygiene, including wet wipes; furniture parts; parts of household equipment, including, for example, tablecloths, counterplead, cover materials; parts of absorbent hygiene articles for babies, feminine care and incontinence articles for adults, because, for example, it can create or be part of the non-woven storage area, ADL (acquisition distribution layer), lining, front laminate, side panels, core wrap, leg elastics.

Examples

Example 1: Design based on the present invention

One layer consists of continuous two-component fibers, in which one component consists of MR 2002 polypropylene from Total Petrochemicals and the second component consists of Mosipe NB425 polypropylene from Unipetrol. Both polypropylene homopolymeric materials are readily available in the market, both are inelastic and crystalline.

 MR 2002 from Total Petrochemicals Difference Mosten NB425 from Unipetrol

 Fluency index (MFI) (g / 10 min)

 15 10 25

 Polydispersion (POI)

 2.6 0.8 3.4

 Heat of latent crystallization (dHc J / g)

 85.00 J / g 23.1 J / g 108.1 J / g

 Material flexion module

 1,300 MPa 100 MPa 1,400 MPa

The fibers were produced in a Reicofil 3 production line for fusion spun nonwovens and were removed from the extended sheet before the material was joined.

Example 1A:

The continuous two-component fiber was of the side-by-side type and the individual sections formed in the 40:60 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Mosten NB425 polypropylene.

The average degree of curl reached was 13.4 undulations / 20 mm.

Example 1B:

The continuous bicomponent fiber was of the side-by-side type and the individual sections formed in the weight ratio of 30:70. The first section consists of MR 2002 polypropylene and the second section consists of Mosten NB425 polypropylene.

The average degree of curling reached was 15.8 undulations / 20 mm.

Example 1C:

The continuous two-component fiber was of the side-by-side type and the individual sections formed in the relationship in

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Weight 65:35 The first section consists of MR 2002 polypropylene and the second section consists of Mosten NB425 polypropylene.

The average degree of curling reached was 8.2 undulations / 20 mm.

Example 1D:

The continuous bicomponent fiber was of the side by side type and the individual sections formed in the 50:50 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Mosten NB425 polypropylene.

The average degree of curl reached was 11.7 undulations / 20 mm.

Example 2: Design based on the present invention

One sheet consists of continuous bicomponent fibers, in which one component consists of MR 2002 polypropylene from Total Petrochemicals and the second component consists of Tatvnaft Tatren HT2511 polypropylene. Both polypropylene homopolymeric materials are readily available in the market, both are inelastic and crystalline.

 MR 2002 from Total Petrochemicals Difference Tatren HT2511 from Slovnaft

 Fluency index (MFI) (g / 10 min)

 15 10 25

 Polydispersion (POI)

 2.6 0.1 2.7

 Heat of latent crystallization (dHc J / g)

 85.00 J / g 21 J / g 106.0 J / g

 Material flexion module

 1,300 MPa 100 MPa 1,400 MPa

The fibers were produced in a Reicofil 3 production line for fusion spun nonwovens and were removed from the extended nappa before joining the material.

Example 2A:

The continuous bicomponent fiber was of the side-by-side type and the individual sections formed in the 30:70 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Tatren HT2511 polypropylene.

The average degree of curling achieved was 15.9 undulations / 20 mm.

Example 2B:

The continuous two-component fiber was of the side-by-side type and the individual sections formed in the 40:60 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Tatren HT2511 polypropylene.

The average degree of curling reached was 12.8 undulations / 20 mm.

Example 2C

The continuous bicomponent fiber was of the side-by-side type and the individual sections formed in the 50:50 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Tatren HT2511 polypropylene.

The average degree of curling reached was 12.0 undulations / 20 mm.

2D example:

The continuous two-component fiber was of the side-by-side type and the individual sections formed in the 70:30 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Tatren HT2511 polypropylene.

The average degree of curling reached was 7.3 undulations / 20 mm.

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Example 3: Design based on the present invention - laboratory line

A sheet consists of continuous two-component fibers, fibers produced in a laboratory spinning line with compressed air filament that attenuates up to 0.9 MPa, 12-hole spinning die, 0.5 mm hole diameter, hole length of 0.8 mm Extrusion system with two independent extruders (diameter 16 mm). Line flow rate 0.5 grams per minute per hole. The line is available, for example, at the Synthetic Fibers Research Institute "VUCHV a.s. Svit", Republic of Slovakia.

Example 3A

The continuous two-component fiber was of the side-by-side type and the individual sections formed in the 40:60 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Tatren HT2511 polypropylene. The attenuation air pressure was 0.85 MPa.

Example 3B

The continuous two-component fiber was of the side-by-side type and the individual sections formed in the 40:60 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Mosten NB425 polypropylene. The attenuation air pressure was 0.85 MPa.

 Polymer predominates in the first section Polymer predominates. in the first section 3A Polymer predominates. in the first section 3B Difference 3A Difference 3B

 Material

 MR 2002 Mosten NB425 Tatren HT2511 Mosten / MR 2002 Tatren / MR 2002

 Fluency index (MFI) (g / 10 min)

 25 15 25 10 0

 Polydispersion (POI)

 3.4 2.6 2.7 0.8 0.7

 Heat of latent crystallization (dHc J / g)

 108.1 85 106 23.1 2.1

 Material flexion module

 1,400 1,300 1,400 100 0

 Fiber properties

   3A 3B

 Fiber thickness (dtex) STN EN ISO 1973

 2.2 2

 Traction (cN / dtex) STN EN ISO 5079

 2.7 2.8

 Elongation (%) STN EN ISO 5079

 393.5 376.3

 Degree of curling (undulations per 20 mm of fiber)

 14.5 14.5

Example 4: Design based on the present invention - including calendering

The continuous two-component fiber was of the side-by-side type and the individual sections formed in the 40:60 weight ratio. The first section consists of MR 2002 polypropylene and the second section consists of Tatren HT2511 polypropylene. Both polypropylene homopolymeric materials are readily available in the market, both are inelastic and crystalline.

 MR 2002 from Total Petrochemicals Difference Tatren HT2511 from Slovnaft

 Fluency index (MFI) (g / 10 min)

 15 10 25

 Polydispersion (POI)

 2.6 0.1 2.7

 Heat of latent crystallization (dHc J / g)

 85.00 J / g 21 J / g 106.0 J / g

 Material flexion module

 1,300 MPa 100 MPa 1,400 MPa

The fibers were produced in a Reicofil 4 SSS production line for fusion spun nonwovens.

The temperature of the attenuation air at 15-25 ° C, the cabin pressure in the area 2,800-3,200 Pa. The sheet was thermally joined using the pair of plain engraving rollers with Ungricht U2888M design (standard oval). The

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smooth roller temperature 170-1802C, engraving roller temperature 160-170 ° C, clamp 120-125 daN / cm.

The fibers removed from the extended nappa before joining the material had an average degree of curling of 15.7 undulations / 20 mm.

Properties of the final material:

 Number of samples measured Average value Standard deviation

 Base weight

   [gsm] 10 45.0 0.63

 Tensile strength, MD

 WSP 110.4 (09) [N / 50 mm] 10 67.5 20.73

 Tensile strength, CD

 WSP 110.4 (09) [N / 50 mm] 10 42.7 12.63

 Elongation at the peak, MD

 WSP 110.4 (09) [%] 10 43.5 11.18

 Elongation at the peak, CD

 WSP 110.4 (09) [%] 10 43.1 8.59

Test methodology

The "degree of curl" of the fiber is measured using the procedure described in standard CSN 80 0202 of 1969. The measurement is performed on individual fibers under standard conditions (an individual fiber is freely placed on a mat for 24 hours at a temperature of 20 ° C and a relative humidity of 65%.) The fiber is subsequently hung vertically and subjected to a deformation of 0.0076 g (for a fiber with a fineness of 1-5 den, that is, 0.111 - 0.555 tex) The number of undulations is 20 mm long.

The "polydispersion" of a polymer or also the "polydispersion coefficient (PDI)" expresses the heterogeneity of a material. It is identified by calculating the average molecular weight in number (Mn) and in weight (Mw) of the polymer, where PDI = Mw / Mn, as described, for example, in Modern Physical Organic Chemistry by Eric V. Anslyn and Dennis A Dougherty

The "fluidity index (MFI)" of a polymer is measured using a test methodology according to the German standard ASTM D1238-95; Specific test conditions (for example, temperature) vary for individual polymers, for example the test conditions for polypropylene are 230 / 2.16 and for polyethylene are 190 / 2.16.

The "flexion module" of a polymer is measured using the test methodology described in ISO 178: 2010.

"Crystallinity", "latent heat of crystallization", "crystallization temperature" and "melting temperature" are measured using the test methodology described in ASTM D3417 using DSC, where the temperature velocity is 2 ° C / min in the measured range of 200-80 ° C and the sample volume is 7-7.4 g.

The "crystallization rate" of a polymer is measured using the procedure ISO 11357-7-Determination of the kinetics of crystallization - isothermal crystallization, in which a sample is first maintained at the melting temperature of 210 ° C for 8 minutes and subsequently cooled to 120 ° C.

Industrial applicability of the present invention

The sheet produced in accordance with the present invention is applicable, in particular, to the production of nonwoven textiles, where they can form a production stage in an online production line. The non-woven textile produced from the nappa manufactured in accordance with the present invention is widely applicable in various fields, namely, in hygiene products, such as baby honeycombs, feminine absorption products or incontinence products. Curly fibers create a spongyness in the textile, which means that the material can be used advantageously in applications that require softness and silkiness (e.g., parts of absorbent products that are in direct contact with the user's skin) and in applications that require bulky (wipes, loop side of the “hook and loop” system).

Claims (12)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 1. Napa comprising bicomponent or multicomponent curly fibers consisting of at least two sections, comprising a polymer or a polymer mixture as a predominant component and which are arranged through the cross section of the fiber in a manner suitable to promote fiber curling during the fixing process and whose predominant components differ in the heat of crystallization (dHc), characterized in that the difference in heat of crystallization dHc is in the range of 30 J / g to 10J / g, preferably of 30 J / g to 20 J / g and that the predominant components differ, as a minimum, in one of the other parameters selected from the fluidity index group, the degree of polydispersion and the flexural modulus, while the relative difference of the predominant components is: for the fluidity index in the range of 100 g / 10 min at 5 g / 10 min and / or for the degree of polydispersion less than 1, but greater than 0.3, and / or for the flexural modulus in the interval from 300 MPa to 50 MPa; in which the relative difference in the fluidity index is not more than 100 g / 10 min, in the degree of polydispersity it is less than 1, in the flexion module it is not greater than 300 MPa; and in which said fibers have the degree of curling, at a minimum, of 5 undulations per 20 mm of fiber. 2. Napa comprising curly fibers, according to claim 1, wherein the relative differentiation of the predominant components in the flow index is in the range of 80 g / 10 min to 5 g / 10 min, preferably 60 g / 10 min at 10 g / 10 min. 3. Napa comprising curly fibers, according to claim 1 or 2, wherein the relative differentiation of the predominant components in the degree of polydispersion is in the range of 1 to 0.5, preferably 1 to 0.7. 4. Napa comprising curly fibers, according to any of the preceding claims, wherein the relative differentiation of the predominant components in the flexural modulus is in the range of 250 MPa to 80 MPa, preferably 200 MPa to 80 MPa. 5. Napa comprising curly fibers, according to any of the preceding claims, wherein the fibers are bicomponent fibers of the side-by-side type. 6. Napa comprising curly fibers, according to claim 5, wherein both predominant components of the bicomponent fibers are a propylene homopolymer. 7. Napa comprising curly fibers, according to any of the preceding claims, wherein said predominant components are arranged through the cross section of the fibers, centrally asymmetric and / or axially asymmetric with respect to a number of axes that pass to through the center of the fiber cross section, which equals the number of polymer sections in the fiber. 8. Napa, according to any one of the preceding claims, wherein the fibers comprise an additive, wherein the additive is present in the components in such a way that it does not affect the curling of the fiber to a significant degree. 9. Nonwoven textile characterized in that it comprises the nappa, according to any of the preceding claims. 10. Nonwoven textile according to claim 9, wherein the nonwoven fabric is of the spun yarn type. 11. Process for producing a sheet comprising multicomponent fibers, in which the process comprises the following steps: i. preparing, at a minimum, two materials comprising a polymer or polymer mixture as the predominant component, the materials being suitable for fiber formation; ii. then, to form multicomponent fibers from the materials prepared under a row, that is, multicomponent fibers comprising said materials arranged in sections, which are arranged through the transverse section of the fiber in a manner suitable to promote the curling of the fiber during the fixing and cooling process, and attenuating the fibers by cooling and attenuating the air; Y iii. forming a nappa from said multicomponent fibers; characterized by: said predominant components in sections are selected so that they differ in the heat of crystallization dHc in the range of 30 J / g to 10J / g, preferably from 30 J / g to 20 J / g and differ, at least, in another parameter selected from fluidity index group, the degree of polydispersion and the flexural modulus, where the relative differentiation of the polymeric components is: for the fluidity index in the range of 100 g / 10 min to 5 g / 10 min and / or for the degree of polydispersion in the range of 1 to 0.3, and / or for the flexural modulus in the range of 300 MPa to 50 MPa; in which the relative difference in the flow rate is not greater than 100 g / 10 min, in the degree of polydispersion it is not greater than 1, in the flexion module it is not greater than 300 MPa; Y wherein said fibers have the degree of curling, at a minimum, of 5 undulations per 20 mm of fiber. 10 12. Method according to claim 11, wherein said sections with predominant components are arranged through the cross section of the centrally asymmetric and / or axially asymmetric fiber with respect to a number of axes that pass through the center of the cross section of a fiber, which equals the number of sections present in the fiber. 13. Method according to claim 11, wherein said multicomponent fibers are bicomponent fibers Side by side 14. Method according to claim 11, wherein said polymer sections contain as a predominant component a polypropylene homopolymer. twenty