JP2016507012A - A bat made of crimped bicomponent or multicomponent fibers - Google Patents

Abstract

It consists of a polymer or polymer blend as the main component and is arranged across the fiber cross-section to promote fiber crimping during the setting process, and the main component has a difference in heat of crystallization (dHc), at least Provided is a vat composed of two regions of crimped bicomponent or multicomponent fibers. The difference in heat of crystallization (dHc) ranges from 30 J / g to 5 J / g, the main component of which is at least one of the other parameters selected from the group of melt flow index, polydispersity and flexural modulus. There are differences, the relative differences of the main components are: in the range of 100 g / 10 min to 5 g / 10 min for the melt flow index and / or less than 1 but greater than 0.3 for the degree of dispersion Yes, and / or the flexural modulus ranges from 300 MPa to 50 MPa; the relative difference in melt flow index is 100 g / 10 min or less, the relative difference in dispersity is less than 1, and the flexural modulus The relative difference is 300 MPa or less. The crimp rate of the fiber is at least 5 per 20 mm of fiber.

Description

  The present invention relates to a bat made of crimped bicomponent or multicomponent fibers composed of at least two materials, which comprises a polymer as a main component and is suitable for promoting fiber crimp in the setting process. The main polymer components have a difference in heat of crystallization (dHc). In particular, the type of bat described herein is primarily intended for the manufacture of nonwoven fabrics for use in the hygiene industry.

  For several reasons, the bulkiness of nonwovens is considered important. Nonwoven fabrics are often used as part of sanitary products and have the functionality (eg as part of a loop part of a fastening system composed of hook-and-loop fasteners or for the purpose of improving the liquid distribution in the core of an absorbent product, for example). ) And perceptual reasons—particularly because of the bulkiness of the material, which gives it more flexibility and makes it possible to comfortably contact the skin. In certain cases, non-woven fabrics can be used as part of cleaning articles such as cloths and dusters. If the bulkiness of such a non-woven fabric is improved, the effect is enhanced as a cleaning element.

  In some cases, efforts have been deliberately expanded to create or improve specific properties of nonwoven materials with the goal of improving the nonwoven materials. These efforts consisted of selection and / or improvement of various chemical compositions of fibers, basis weight, fiber lamination method, fiber density, various patterns of extrusion, use of various adhesive types, and the like.

  The bulkiness of a nonwoven fabric is directly related to the properties of the fibers that form it. Homogeneous and continuous fibers are typical of spunmelt nonwovens. The bulk height can then be increased using an adhesion method. One method consists of the use of such a thermal bonding method, which maximizes the proportion of loose fiber fragments between the individual bonding points used to obtain the desired strength of the final material. Is. Another method consists of subjecting the nonwoven fabric to jet water flow (hydraulic increase or hydroentanglement) after calendering in order to fluff the fiber and increase its specific thickness.

  Another method consists of the production of nonwovens from “two-component” polymer fibers, in which these fibers are formed under a spinneret, laminated to form a bat, and then typified. Bonding using an embossing calendar selected to achieve the desired effect. Such bicomponent fibers can be manufactured using a spinneret with two adjacent regions, where the first polymer is introduced into the first region, the second polymer is introduced into the second region, A fiber is formed having one region of the cross section formed by the polymer and a second region of the cross section formed by the second polymer (ie, the term “two component”). Each polymer can be selected to have different properties, thereby allowing the bicomponent fibers to curl in the side-by-side or asymmetric core / sheath arrangement composites during the spinning process as they are cooled and pulled from under the spinneret It becomes. It is known that there are various documents dealing with different applications individually to enable fiber curl formation. For example, European Patent EP 0 658 579 by Kimberly Clark describes a composite of polypropylene and polyethylene. Another European patent EP 1129247 by the company describes different polypropylene composites. The important point here is the degree of difference between the characteristics described.

  The resulting curled fibers can then be laminated to form a bat and then bonded using a variety of methods to form a bulky nonwoven.

The vat according to the present invention is composed of at least two polymer components and is arranged to cross the cross sections of the fibers to promote the crimping of the fibers during the setting process, with a difference in heat of crystallization (dHc). The content of the present invention is that the difference in heat of crystallization (dHc) is in the range of 30 J / g to 5 J / g, and the polymer component is a group of melt flow index, polydispersity and flexural modulus. There is a difference in at least one of the other parameters more selected, and the relative differences in the polymer components are:
Melt flow index ranges from 100 g / 10 min to 5 g / 10 min and / or
In polydispersity, it ranges from 1 to 0.3 and / or
The flexural modulus is in the range of 300 MPa to 50 MPa;
The relative difference in melt flow index is 100 g / 10 min or less, the relative difference in polydispersity is less than 1, the relative difference in flexural modulus is 300 MPa or less; and the crimp rate of the fiber is , At least 5 per 20 mm of fiber.

  Preferred and / or specific embodiments of the invention are defined in the dependent claims. In a further aspect, the present invention relates to a method for manufacturing such a bat.

An example of an asymmetrical arrangement (promoting crimping) of component regions across the cross-section of a multicomponent fiber. The example of symmetrical arrangement | positioning of the component area | region in the cross section of a multicomponent fiber. An example of a spun melt production line.

Definitions The term “bat” as used herein refers to a material in the form of fibers found in the pre-bonding state, for example, performed during the calendar process described in patent application WO201203414. “Batts” are usually made up of individual fibers that are not yet fixed together, even if the fibers are pre-bonded in a specific way. Can be carried out during or immediately after the lamination of the fibers. However, even with this pre-bonding, a considerable number of fibers can still move freely, thus allowing the fibers to be rearranged. The “bat” described herein can be composed of several layers formed by the precipitation of fibers from several spinning beams in a spunlay process.

The terms “fiber” and “filament” are interchangeable in this case.

  The term “monocomponent fiber” means a fiber formed from a single polymer or polymer blend and is distinguished from bicomponent or multicomponent fibers.

  “Bicomponent” means a fiber having a cross-section comprised of two distinct polymer regions, two distinct polymer blend regions, or one distinct polymer region and one distinct polymer blend region. The term “bicomponent fiber” is encompassed by the term “multicomponent fiber”. The entire cross section of the bicomponent fiber can also be divided into two or more regions composed of different regions taking any shape or arrangement, such as coaxial arrangement, core / sheath arrangement, side-by-side arrangement, radial arrangement, etc. .

  The term “multicomponent” means a fiber having a cross-section comprised of a plurality of distinct polymer regions, a plurality of polymer blend regions, or at least one distinct polymer component and at least one polymer blend region. Thus, the term “multicomponent fiber” includes “bicomponent fiber”, but is not limited thereto. The entire cross section of the multicomponent fiber can also be divided into parts composed of different regions having any shape or arrangement such as coaxial arrangement, core / sheath arrangement, side-by-side arrangement, radial arrangement, sea-island arrangement, and the like.

  As used herein, the term “nonwoven” means a structure in the form of a fleece or webbing formed from fibers oriented in a given direction or randomly, from which the bat is first formed and then And the fiber is formed by friction, cohesive effect, adhesion, or by crimping and / or effect of pressure, heat, ultrasonic or thermal energy, or a combination of these effects as required. Adhere to each other by a similar method of forming single or multiple bond patterns composed of indentations. The term does not mean a fabric formed from weaving or knitting, or a fabric that uses yarns or fibers to form a stitch bond. The fibers can be of natural or synthetic origin and can be staple fibers, continuous fibers or fibers formed directly at the processing site. Commonly available fiber diameters range from about 0.0001 mm to about 0.2 mm in several forms: short fibers (also known as staples or chopped fibers), continuous monofilaments (filaments or monofilaments), It is provided in the form of untwisted yarn continuous fibers (also known as tows) and twisted fiber bundles (yarns). Non-woven fabrics are known in the art such as melt blow, spun bond, spun melt, solvent spinning, electrospinning (electrospinning), carding, film fibrillation, melt film fibrillation, air lay, dry lay, wet lay using staple fibers. And many methods including techniques such as various combinations of these processes. The basis weight of a nonwoven fabric is generally expressed in grams per square meter (gsm).

  The term “asymmetric” as used with respect to the vertical plane of the fiber cross section means that the fiber cross section is not symmetrical, especially with respect to central symmetry, when the center is considered the center of the fiber cross section. The term is also related to axial symmetry, and the evaluation here must be performed with at least as many fiber cross-section center pass axes as the existing polymer cross-sections.

  The term “heat” means “heat of fusion” or “heat of crystallization” and is understood to mean “latent heat”.

  In accordance with the present invention, the bat can be composed of continuous multicomponent fibers made, for example, from a spunmelt process. The fiber is extruded under a spinneret, then refined, cooled, and laminated onto a belt to form a fiber vat. During the process, these fibers are automatically curled. The vat can be converted to a non-woven fabric.

  Each fiber is composed of at least two polymer components A and B, the polymer components are separately introduced into the spinneret, and the resulting fiber has a region rich in A polymer component and a region rich in B polymer component. , Areas in the cross section of the fiber are arranged in a manner that assists in crimping the fiber in advance during the fiber setting process. These regions are found, for example, on the opposite side of the fiber cross-section and thus form the arrangement known for bicomponent fibers named side-by-side, or for example one region surrounds the second region and thus as a core-sheath Form a known arrangement. Here, the cross-section of the overall arrangement of both regions of the main polymer components A and B is asymmetric to ensure fiber crimp. In another arrangement, the fiber includes three polymer regions having major polymer components A, B, C arranged in an arrangement known as, for example, “segment pie” or “sea island”, where In order to ensure crimping, the overall arrangement of the two regions with the main material components A and B is asymmetric in cross section.

  There is no theoretical intent to adhere, and the interposition of the major polymer component regions in the fiber cross-section modified to support fiber crimping during fiber setting is, for example, the result of final crimping. Although it has already been reported by the symmetry rate of the polymer component that has a great influence, it cannot be easily estimated that the crimp is further strengthened due to the remarkable asymmetry of the fiber arrangement. On the other hand, it is also necessary to take into account the characteristics of the individual components that the synergistic effect of the arrangement arises and that the fibers with less asymmetric arrangement crimp more strongly than the fibers with a significant asymmetry rate. Those skilled in the art are well aware that the optimal placement of the region with the major polymer component in the fiber can be determined, for example, by experimental testing using a small experimental spinneret. An example of an arrangement that supports individual asymmetric arrangements and fiber crimps is shown in FIG. 1A, but is not limited to the arrangements shown herein. Based on the definitions provided above, an arrangement that is not asymmetric or generally does not support fiber crimp is shown in FIG. 1B.

  The formation of crimped fibers due to significant differences in the properties of individual polymer components, generally expressed using the so-called shrinkage of the individual components, is well known in the industry. The fibers thus produced are known by the name of chemically formed fibers. It is well understood by those skilled in the art that the term “component shrinkage” mainly refers to a change in volume during the transition from liquid to solid, influenced by various properties of the polymer. For example, for bicomponent fibers, a combination of two polymers, for example, a combination of one polymer with another polymer (polypropylene + polyethylene), a copolymer (polypropylene + polypropylene copolymer) or a mixture (polypropylene + polypropylene blend and polypropylene copolymer) Can also be used. When using two types of polymers, the materials used and their mutual miscibility must always be considered very carefully. The greater the difference between these materials, the lower the adhesion level between the two regions including the main polymer component in the fiber, and the possibility of fiber breakage. Especially in hygiene applications, even if the fiber cutting is low, it appears clearly as “flood weaving” on the surface of the fabric, appears on the surface of the product, and is viewed by the end customer as a mark of low quality product, which is very inconvenient. is there. The same type of polymer with different properties (eg, melt flow index, polydispersity, material crystallinity or its elasticity) may be used, and there is a significant difference in at least one of the parameters for success here. It is also known that it is essential.

  For example, according to European Patent EP 0 655 579 by Kimberly Clark, in the case of polydispersity, a difference of at least 0.5 is necessary in the accurately measured region-in this document the polydispersity of one main component is <2.5, the second major component is> 3, and for crystallinity, the major component in one region must be non-crystalline and the other crystalline. The difference in heat of fusion should be at least 40 J / g, and the melt flow index suitable for spun melt applications is in the range of several g / 10 minutes to several thousand g / 10 minutes. Need to be combined.

  The subject of the present invention is a crimped multicomponent fiber in which the polymers used for the most part in the region are very similar to each other. Preferably the polymer can be a chemically similar and slightly different physical property, for example a polypropylene-polypropylene composite. For example, polypropylene (a polymer formed with propylene monomer units) has basic characteristics, but it can be used to produce fibers and non-woven fabrics, for example due to the stereoregularity of a single unit or the polymer chain length or dispersibility of different polymer chains in the polymer. Those skilled in the art are well aware that the physical properties that are important to varieties vary. The person skilled in the art is also well aware that there are a wide range of commercially available polymers available on the market and that they are available in various quantities in individual forms. Due to the demand for dispersibility, applications are concentrated especially on polymers with a relatively narrow range of properties. A number of advantages obtained by using very similar polymers are also that they are relatively readily available on the market.

  It is important to note that the polymer region described above may be formed using a single polymer or a mixture of various components. It is well known in the industry that some fibers are composed of multicomponent fibers based on the same type of polymer and differ only in the addition of the mixture between the components. For example, US Application No. 6,203,905 by Kimberly Clark describes the addition of a nucleation additive to one region of a bicomponent fiber.

  The principle of the present invention may consist of the main polymer component alone or of the main component and additives.

  While the principles of the present invention may include the addition of additives (eg, dyes), the addition of such additives does not affect the crimp of the fiber to the left. For example, the additive may be added symmetrically to both regions.

  As is known in the industry, just prior to spinning, several functional additives directly induce chemical reactions in the polymer melt and are effective for example at the temperature of the melt (eg, BASF IRGATEC CR76). Sex can also be affected. Thus, due to the effect of the various temperatures of the melts of both polymer components per region, the properties obtained (eg, melt flow index, A significant difference appears in polydispersity. The principle of the present invention includes the addition of a functional additive, but this addition does not affect the crimp of the fiber to the left.

  As is clear from the above description, it is well known in the industry that if there is a sufficient difference in the shrinkability of the major components in each region, the fibers will crimp under the spinneret due to tension. The crimping of the fibers according to the invention occurs by combining slight differences in at least two, preferably three, parameters of the polymer.

  An important variable is the latent heat of crystallization (dHc), which is a measure of the amount of energy that must be taken from the system to cause crystallization of the polymer component. A well-known theory is that if the temperature difference is sufficient, the main component of one region begins to harden first, and is thus formed in the form of the main component that is still liquid in the second region. It is thought that the fiber is curled because the tension has no reaction force. It is always necessary that there is a sufficient difference between the two polymer components, otherwise there is no effect.

  Kimberly Clark's known document EP 0 655 579 describes the minimum difference in heat of fusion, which is approximately equal to the heat of crystallization of 40 J / g. In contrast, according to the present invention, fiber crimping occurs even if the difference in heat of fusion is small, if other differences between the major components of the region obtain a surprisingly large synergistic advantage. The curling or crimping of the fibers according to the present invention is obtained by combining a slight difference in the heat of crystallization (dHc) and at least one, preferably a plurality of polymer parameters.

  Each main component has a difference in heat of crystallization (dHc), and the difference in value is 30 J / g to 5 J / g, more desirably 30 J / g to 10 J / g, preferably 30 J / g to 20 J / g. It is a range. In the case of reducing the degree of crimping, the difference in heat of crystallization (dHc) is 24 J / g to 5 J / g, more desirably 24 J / g to 10 J / g, preferably 24 J / g to 20 J / g. . In addition, individual major components may differ in melt flow index (MFI) levels, the difference between values being about 100 g / 10 min to 5 g / 10 min, more desirably 80 g / 10 min; preferably 60 g. / 10 minutes to 10 g / 10 minutes.

  In addition, the individual main components may have a difference in the polydispersity of the material, the value difference being in the range of 1 to 0.3, more desirably 1 to 0.5, preferably 1 to 0.75. is there.

  Furthermore, the individual principal components may have a difference in the flexural modulus of the material, and the difference in values is in the range of 300 MPa to 50 MPa, more desirably 250 MPa to 80 MPa, preferably 200 MPa to 80 MPa.

Theoretically, if one region is already crystalline and the other remains liquid, or if its crystallinity is relatively low at some point, the fiber tension causes the fiber to curl. The present inventors have predicted without thinking. In general, during the crystallization process, the volume of a given area decreases, but if other areas are still malleable at some point, the level of resistance and fiber curl will not become too high. From the above, it is clear that the temperature at which crystallization is initiated and the crystallization rate also affect the degree of curl formation, except for the value of latent heat (dHc) of crystallization itself. Given that the subject of the invention is a combination of two very similar polymers, they may also approximate the crystallization temperature. Examples of various commercially available polypropylene homopolymers are shown in the table.

  Differences in crystallization time within about a few minutes are not enough force to cause them to curl fibers, but to the extent of curl formation due to the above differences, ie, differences in latent heat of crystallization (dHc). The present inventors have predicted that they have contributed without thinking theoretically.

  The individual main components of the region may have different crystallization temperatures, with the difference in values ranging from about 5 to 30 ° C, more desirably 5 to 25 ° C, preferably 8 to 25 ° C.

  The individual main components of the region may have different crystallization rates, the difference in values being at least 20 seconds, more preferably 50 seconds, more preferably 120 seconds, preferably 150 seconds.

  Divide the polymer components into appropriate amounts (1), place them in a separate extrusion system (2), melt them, heat them to a suitable operating temperature, separate them and introduce them into the spinneret (4), where the multicomponent fibers are Form. The process of preparing polymers for spinning in the form of multicomponent fibers includes additional specific steps depending on the type of technology, and various additives designed for this purpose can be used, for example Added to the polymer component for the purpose of changing the color (dye) of the fiber or the properties of the fiber (eg hydrophilic, hydrophobic, flammable), and according to the invention, these additives may be added to the fiber It is understood by those skilled in the art that it is important for the material that it does not affect the crimps of and / or is symmetrically distributed in the resulting fiber. The fibers (5) formed under the spinneret (8) are subjected to a cooling flow and a finer air flow (6, 7), so that they crimp the fibers before they fall (8) onto the recovery mat (10). Formed on top. The cooling air flow and the fine air flow (6, 7) are at about room temperature, preferably 10 to 30 ° C, more preferably 15 to 25 ° C. The recovery mat (10) may be, for example, a moving belt that carries the formed fiber bat (11). During the process, there is no excess heat or mechanical energy inflow on the recovery mat (10) to promote crimping.

  In this way, several spinning beams are aligned, either all forming crimped fibers or different layers (eg simple spunmelt fibers—eg spunbond or meltblown, nanofibers, films, etc.) Can be laminated. In a configuration according to the present invention, it is advantageous that the crimped fiber layer (s) is laminated to other layers, thereby preventing unnecessary compression of the crimped fibers. In other applications, the crimped fibers are ejected from the first and last spinning beams so that the resulting material has an outer surface composed of crimped fibers, and the inner surface has different properties (eg, obtained It is advantageous to have the combination of having the mechanical strength of the nonwoven fabric to be produced.

  The fiber layer (s) is then reinforced (12), where several known methods may be used (eg, thermal bonding, thermal calendar bonding, needle punch, hydroentanglement, etc.). Individual bonding methods have a significant effect on the properties of the resulting material, and those skilled in the art can easily determine which method is appropriate for the material. Similarly, choosing an adhesion method with high strength or density of adhesion points will result in an overall bulk difference between the non-woven fabric containing fibers according to the present invention and a standard material containing uncrimped fibers. Those skilled in the art also understand that it will even be invalid.

  The final nonwoven web can be used in a variety of applications on the non-limiting list of the following examples: cleaning cloths and sanitary cloths, including wet types; furniture pieces; eg tablecloths, bedspreads, etc. Part of household goods; cover material; eg forming or part of a non-woven landing zone, ADL (uptake distribution layer), back sheet, top sheet, side panel, core wrap, leg cuff, etc. A part of hygiene absorbent products for all infants, women's care and adult urinary incontinence.

繊維をスパンメルト不織布用のReicofil3の製造ラインで製造し，材料の接着に先立って，積層するバットから外した。 Examples Example 1: Construction according to the invention The vat is a continuous bicomponent fiber in which one component is composed of Total Petrochemicals polypropylene MR2002 and the second component is Unipetrol polypropylene Mosten NB425. It is configured. Both polypropylene homopolymer materials are readily available on the market, are inelastic and crystalline.

The fiber was produced on a production line for Reicofil3 for spunmelt nonwoven and removed from the vat for lamination prior to material bonding.

Example 1A:
The continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 40:60. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Mosten NB425.
The average crimp rate obtained was 13.4 pieces / 20 mm.

Example 1B:
Continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 30:70. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Mosten NB425.
The average crimp rate obtained was 15.8 pieces / 20 mm.

Example 1C:
Continuous bicomponent fibers were side-by-side, with individual regions formed at a weight ratio of 65:35. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Mosten NB425.
The average crimp rate obtained was 8.2 pieces / 20 mm.

Example 1D:
The continuous bicomponent fibers were side-by-side and the individual regions were formed with a weight ratio of 50:50. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Mosten NB425.
The average crimp rate obtained was 11.7 pieces / 20 mm.

繊維をスパンメルト不織布用のReicofil3の製造ラインで製造し，材料の接着に先立って，積層するバットから外した。 Example 2: Construction Based on the Invention The vat is composed of continuous bicomponent fibers in which one component is composed of Total Petrochemicals polypropylene MR2002 and the second component is composed of Slovnaft polypropylene Tatren HT2511. Yes. Both polypropylene homopolymer materials are readily available on the market, are inelastic and crystalline.

The fiber was produced on a production line for Reicofil3 for spunmelt nonwoven and removed from the vat for lamination prior to material bonding.

Example 2A:
Continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 30:70. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Tatren HT2511.
The average crimp rate obtained was 15.9 pieces / 20 mm.

Example 2B:
The continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 40:60. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Tatren HT2511.
The average crimp rate obtained was 12.8 pieces / 20 mm.

Example 2C:
The continuous bicomponent fibers were side-by-side and the individual regions were formed with a weight ratio of 50:50. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Tatren HT2511.
The average crimp rate obtained was 12.0 pieces / 20 mm.

Example 2D:
Continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 70:30. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Tatren HT2511.
The average crimp rate obtained was 7.3 pieces / 20 mm.

Example 3: Construction Based on Invention—Experimental Line The bat is composed of continuous bicomponent fibers, which are 12 mm in diameter 0.5 mm and 0.8 mm in length by filament finening of compressed air up to 0.9 MPa. It was manufactured on an experimental spinning line using a spinning die having holes. Extrusion system with two independent extruders (16 mm diameter). A line throughput of 0.5 grams per hole per minute. The line is available, for example, at the research institute "VUCHV as Svit" (Republic of Slovakia) for artificial fibers.

Example 3A
The continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 40:60. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Tatren HT2511. The air pressure to be reduced was 0.85 MPa.

Example 3B
The continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 40:60. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Mosten NB425. The air pressure to be reduced was 0.85 MPa.

繊維をスパンメルト不織布用のReicofil4SSS製造ラインで製造した。
繊細化する空気の温度は１５〜２５℃，領域内のキャビン圧力は２８００〜３２００Paであった。１対の滑面グラビアロールを使用し，Ungricht社の様式U2888M（標準的な楕円形）によりバットを熱接着した。滑面ロール温度は１７０〜１８０℃，グラビアロール温度は１６０〜１７０℃，ニップは１２０〜１２５daN/cmであった。
材料の接着に先立って，積層したバットから外した繊維の平均捲縮率は
１５．７個／２０mmであった。

Example 4: Construction Based on Invention—Calendaring etc. Continuous bicomponent fibers were side-by-side and individual regions were formed at a weight ratio of 40:60. The first region is composed of polypropylene MR2002, and the second region is composed of polypropylene Tatren HT2511. Both polypropylene homopolymer materials are readily available on the market, are inelastic and crystalline.

Fibers were produced on the Reicofil 4SSS production line for spunmelt nonwovens.
The temperature of the air to be refined was 15 to 25 ° C., and the cabin pressure in the region was 2800 to 3200 Pa. A pair of smooth gravure rolls was used and the bats were thermally bonded by Ungricht style U2888M (standard oval). The smooth surface roll temperature was 170 to 180 ° C, the gravure roll temperature was 160 to 170 ° C, and the nip was 120 to 125 daN / cm.
Prior to material bonding, the average crimp rate of the fibers removed from the laminated bat was 15.7 pieces / 20 mm.

Test Method The “crimp rate” of the fiber is measured by the method described in CSN 80 0202 standard from 1969. Measurements are made on individual fibers under standard conditions (individual fibers placed loose on the mat for 24 hours at a temperature of 20 ° C. and a relative humidity of 65%). Thereafter, the fibers are hung vertically and a heavy pressure of 0.0076 g is applied (for one fiber having a fineness of 1 to 5 den). Count the number of crimps per 20 mm length.

  The “polydispersity” or “polydispersity coefficient (PDI)” of a polymer represents the non-uniformity of the material. It is identified by calculation of the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the polymer, where PDI = Mw as described, for example, in Modern Physical Organic Chemistry by Eric V. Anslyn and Dennis A. Dougherty. / Mn.

  The “melt flow index (MFI)” of a polymer is measured by a test method according to the German ASTM D1238-95 standard; the specific test conditions (eg temperature) vary with the individual polymer—for example the test conditions for polypropylene are 230 /2.16, and the polyethylene condition is 190 / 2.16.

  “Polymer's flexural modulus” is measured by the test method described in ISO178: 2010.

  “Crystallinity”, “Latent heat of crystallization”, “Temperature of crystallization” and “Melting point” were measured by the test method described in ASTM D3417 using DSC. It is 2 ° C./min and the amount of the sample is 7 to 7.4 g.

  The “crystallization rate” of the polymer was measured by ISO11357-7-measurement-isothermal crystallization method for crystallization kinetics, where the sample was first held at a melting point of 210 ° C. for 8 minutes and then cooled to 120 ° C.

INDUSTRIAL APPLICABILITY OF THE INVENTION The vat manufactured according to the present invention can be simply used for the production of non-woven fabrics and can form a manufacturing process on an online manufacturing line. Nonwoven fabrics made from bats made in accordance with the present invention can be widely used in various fields, such as baby diapers, female absorbent products or incontinence products. Crimped fibers create a soft feel to the fabric, which can be soft and silky smooth (for example, some absorbent products that are in direct contact with the user's skin) and bulky Means that the material can be used advantageously in both applications where fabrics are needed (cloth width, loop side of "loop fastener" system, etc.).

Claims (15)

It consists of a polymer or polymer blend as the main component and is arranged to cross the cross section of the fiber in a manner suitable for promoting fiber crimping during the setting process, and the main component has a difference in heat of crystallization (dHc). A vat made of crimped bicomponent or multicomponent fibers composed of at least two regions, the difference in heat of crystallization (dHc) being in the range of 30 J / g to 5 J / g, Has a difference in at least one of the other parameters selected from the group of melt flow index, polydispersity and flexural modulus, the relative differences of the main components are:
Melt flow index ranges from 100 g / 10 min to 5 g / 10 min and / or
In polydispersity, it is less than 1 but greater than 0.3 and / or
The flexural modulus is in the range of 300 MPa to 50 MPa;
The relative difference in melt flow index is 100 g / 10 min or less, the relative difference in polydispersity is less than 1, the relative difference in flexural modulus is 300 MPa or less; A bat characterized in that there are at least five per 20 mm of fiber.   2. The relative difference between the main components with respect to the melt flow index is in the range of 80 g / 10 min to 5 g / 10 min, preferably 60 g / 10 min to 10 g / 10 min. Bat made of crimped fiber.   From crimped fibers according to claim 1 or 2, characterized in that the relative difference between the main components in terms of polydispersity is in the range of 1 to 0.5, preferably 1 to 0.7. The bat that consists.   4. The relative difference between the main components with respect to heat of crystallization (dHc) is in the range of 30 J / g to 10 J / g, preferably 30 J / g to 20 J / g. A vat comprising crimped fibers according to any one of the preceding claims.   A crimped fiber according to any one of claims 1 to 4, characterized in that the relative difference between the main components in terms of flexural modulus is in the range of 250 MPa to 80 MPa, preferably 200 MPa to 80 MPa. The bat that consists.   The vat comprising crimped fibers according to any one of claims 1 to 5, wherein the fibers are side-by-side bicomponent fibers.   7. A vat comprising crimped fibers according to claim 6, wherein both main components of the bicomponent fibers are propylene homopolymers.   The main component is arranged to cross the cross section of the fiber in a central and / or axial asymmetry with respect to several axes passing through the same number of fiber cross-sectional centers as the number of polymer regions in the fiber. A vat comprising crimped fibers according to any one of claims 1 to 7.   The vat according to any one of claims 1 to 8, wherein the fiber contains an additive, and the additive is present in the component so as not to affect the crimping of the fiber to the left.   A non-woven fabric comprising the bat according to any one of claims 1 to 9.   The nonwoven fabric according to claim 10, wherein the nonwoven fabric is a spun melt type. A method for producing a vat comprising multicomponent fibers, comprising the following steps:
i. preparing at least two materials suitable for the formation of fibers comprising a polymer or polymer mixture as major components;
ii. forming a multicomponent fiber from the material prepared under the spinneret, ie forming a multicomponent fiber containing said material arranged in the region, which is suitable for promoting fiber crimping during the setting process Placing the fiber across the fiber cross-section in a method, cooling the fiber with a cooling air flow and a fine air flow, and defibrating; and
iii. forming a vat from the multicomponent fiber;
Including
The difference in heat of crystallization (dHc) is in the range of 30 J / g to 5 J / g, and there is a difference in at least one of the other parameters selected from the group of melt flow index, polydispersity and flexural modulus, The relative differences in polymer components are:
Melt flow index ranges from 100 g / 10 min to 5 g / 10 min and / or
In polydispersity, it ranges from 1 to 0.3 and / or
The flexural modulus is in the range of 300 MPa to 50 MPa;
The relative difference in melt flow index is 100 g / 10 min or less, the relative difference in polydispersity is 1 or less, and the relative difference in flexural modulus is 300 MPa or less;
The production method according to claim 1, wherein the crimp rate of the fibers is at least 5 per 20 mm of fibers.   The regions of the main component are arranged to traverse the cross section of the fiber in a centrally and / or axially asymmetric manner with respect to several axes passing through the same number of fiber cross-sectional centers as there are regions in the fiber. 13. The method of claim 12, wherein:   The method according to claim 12, wherein the multicomponent fiber is a side-by-side type bicomponent fiber. The method of claim 12, wherein the polymer region comprises a polypropylene homopolymer as a major component.

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