EP3296438B1 - Spunbond nonwoven fabrics made from continuous fibres - Google Patents

Description

The invention relates to a spunbonded nonwoven made of continuous filaments made of thermoplastic, the continuous filaments being designed as multi-component filaments with a core-sheath configuration, in particular as bicomponent filaments with a core-sheath configuration. - According to the invention, the spunbonded webs have continuous filaments. Such endless filaments differ because of their quasi-endless length from staple fibers, which have much shorter lengths, for example 10 to 60 mm.

Spunbonded nonwovens of the type mentioned are known in practice in different versions. With such spunbonded fabrics, high strength or high tensile strength is generally desirable. For many applications, the spunbonded fabrics should also have a smooth, soft handle. A soft grip of the spunbonded fabrics on the one hand and a high strength or tensile strength of the spunbonded fabrics on the other hand can often not be achieved satisfactorily in the combination. Above all, a soft grip cannot be achieved at the same time as high productivity or system productivity.

Spunbonded fabrics made of polypropylene have been known for a long time and are characterized by good running behavior on the associated system. In particular, there is relatively little contamination. However, these spunbonded webs are not particularly soft and the possibilities for improving the softness - for example by using finer fibers - are limited and often not economical. The use of a lubricant to increase the softness of the spunbonded nonwoven is possible, but does not change the relatively high flexural strength of the filaments and can therefore not result in a satisfactory soft spunbonded nonwoven. The use of such a lubricant has the disadvantage that the lubricant diffuses out of the filament melt or from the initially hot filaments during the spinning process and contaminates the system, so that productivity is ultimately reduced.

To improve the softness, polypropylene mixtures were introduced, for example mixtures of homo-polypropylene and copolymers based on polypropylene, such as "Random CoPP". These mixtures result in flexible filaments, which, however, are usually characterized by a rather blunt handle, which in turn requires the use of additional lubricants. These soft polypropylene blends have a disadvantageously reduced strength. In addition, the problems with contamination described above are also present here. - When using certain bicomponent filaments with a core-sheath configuration, a compromise between acceptable softness and sufficient strength can be achieved. A homo-polypropylene in the core improves the strength and soft polypropylene blends or the use of polypropylene copolymer in the sheath increases the softness of the filaments or the spunbond. However, the filament surfaces in question are also relatively blunt. This requires the use of a lubricant, which in turn brings with it the problems described above in connection with soiling.

At the high production speeds of modern plants for the production of spunbonded fabrics, a combination of a so-called jumbo roll winder and a rewinding cutting machine is used, since at these high production speeds it is no longer possible to wind up directly. Between the production of the spunbonded fabric and the associated production of the jumbo roll on the one hand and the time of the rewind cutting process on the other hand, the jumbo rolls are temporarily stored, which can take several hours. During this time, a lubricant that has been used can migrate to the surface of the filaments, so that the filaments or the spunbonded nonwovens become smoother and the rewind behavior deteriorates. - There is thus a need to adjust the filaments or spunbonded nonwovens so that on the one hand positive end properties are maintained, on the other hand the system is contaminated as little as possible and furthermore the production speed, the winding ability and the process reliability remain optimized or can be optimized .

In the production of spunbonded nonwovens from continuous filaments, it is fundamentally already known to mix plasticizing additives or lubricants into the thermoplastic plastic of the filaments. At the same time, the lubricant is introduced homogeneously into the filaments. However, these known measures have the disadvantage that the additives can evaporate from the filaments in the course of the production of spunbonded fabric and contaminate the system or, in particular, are reflected in the air-carrying components of the system. These negative effects are of course undesirable.

Out US 2011/0165470 A1 a spunbonded fabric made of bicomponent filaments is known, which can have a core-sheath configuration. In particular, a polyethylene-based material is to be used for the jacket component. The measures described in this document lead to spunbonded webs, the properties of which leave something to be desired. In contrast, the invention is based on the technical problem of specifying a spunbonded nonwoven of the type mentioned that can is characterized by a smooth, soft handle and also by sufficient strength, which is simple and efficient to produce and in which, in particular, evaporation of softening additives or evaporation of lubricants can largely be avoided.

To solve the technical problem, the invention teaches a spunbonded fabric made of continuous filaments made of thermoplastic, the continuous filaments being designed as multi-component filaments with a core-sheath configuration, in particular as bicomponent filaments with a core-sheath configuration, the core component and the sheath component each having at least 90% by weight .-% have at least one component from the group "polypropylene, polypropylene copolymer, mixture of polypropylene and polypropylene copolymer", the filaments containing at least one lubricant, the proportion of the lubricant - based on the entire filament - 250 to 5500 ppm , preferably 500 to 5000 ppm, preferably 700 to 3000 ppm and particularly preferably 700 to 2500 ppm, wherein lubricant is present in the jacket component and wherein in the jacket component furthermore at least one additive reducing the migration rate of the lubricant through the jacket component f is included.

The mass ratio between the core component and the cladding component is expediently 40:60 to 90:10, preferably 60:40 to 85:15, in particular 65:35 to 80:20, preferably 65:35 to 75:25 and very preferably 67:33 until 73:27.

Raw material mixtures can be used in the core component and / or in the jacket component, which are preferably compatible in each case. Core-shell configuration means within the scope of the invention that the sheath component completely or essentially completely surrounds the core component. The continuous filaments of the spunbonded nonwoven preferably have a titer of 1.0 to 2.5 denier and particularly preferably a titer of 1.2 to 2.2 denier for all embodiments of the invention.

It is within the scope of the invention that the core-shell configuration can be an eccentric core-shell configuration. A spiral-crimped filament is then preferably obtained by suitable selection of the raw materials or the plastic components.

The core component and / or the sheath component particularly preferably has at least 95% by weight, and preferably at least 96% by weight, of at least one component from the group consisting of polypropylene, polypropylene copolymer, mixture of polypropylene and polypropylene copolymer In an embodiment variant, the core component and / or the sheath component essentially consist of a polypropylene and / or essentially of a polypropylene copolymer and / or essentially of a mixture of a polypropylene and a polypropylene copolymer. The restriction "essentially" in The embodiment variants described above take into account the fact that additives, in particular the lubricant and, if appropriate, an additive which reduces the migration speed of the lubricant, are / are contained in the core component and / or sheath component. The proportion of additives (lubricants, if appropriate the Migration speed of the lubricant-reducing additive and any other additives, such as color additives) - based on the total Filament - at most 10% by weight, advantageously at most 8% by weight, preferably at most 6% by weight and very preferably at most 5% by weight. - The polypropylene copolymer used in the invention is, moreover, designed according to an expedient embodiment as an ethylene-propylene copolymer. The ethylene-propylene copolymer used preferably has an ethylene content of 1 to 6%, preferably 2 to 6%. It is recommended that the polypropylene copolymer preferably used has a melt flow rate (MFI) of 19 to 70 g / min, in particular 20 to 70 g / min, preferably 25 to 50 g / min. It has proven useful that the polypropylene copolymer has a molecular weight distribution or molecular weight distribution (M _w / M _n ) of 2.5 to 6, preferably 3 to 5.5 and very preferably 3.5 to 5.

A recommended embodiment of the invention is characterized in that the core component consists essentially of a homo-polypropylene. It has proven useful that the core component has at least 90% by weight and particularly preferably at least 95% by weight of homopolypropylene. A recommended embodiment is further characterized in that the jacket component consists essentially of a polypropylene copolymer and / or essentially of a mixture of a polypropylene or homo-polypropylene with a polypropylene copolymer.

The substances specified below are preferably used as lubricants. At least one fatty acid derivative and preferably at least one substance from the group "fatty acid esters, fatty acid alcohol, fatty acid amide" is expediently used as the lubricant. A recommended variant The invention is characterized in that at least one stearate - in particular glycerol monostearate - and / or a fatty acid amide such as. B. erucic acid amide and / or an oleic acid amide. For example, the use of distearylethylenediamide is also possible. According to a tried-and-tested variant, the erucic acid amide product SL05068PP from Constab is used as the lubricant masterbatch.

The melt flow rate (MFI) is measured within the scope of the invention, in particular according to ISO 1133, specifically for polypropylene and polypropylene copolymer at 230 ° C. and 2.16 kg. The polypropylene copolymer preferably has an ethylene content of 2 to 20%, preferably 4 to 20%. The polypropylene copolymer of this embodiment is preferably characterized in terms of the carbon atoms by an average C2 content in the range from 2 to 6%. Exxon Vistamaxx 3588 and / or Exxon Vistamaxx 6202 or a polypropylene with similar properties are preferably used as the polypropylene copolymer. The polypropylene copolymer is mixed according to the above information with the homo-polyolefin or homo-polypropylene for the shell component. Preferred details for homo-polypropylene are listed below.

According to the invention, lubricant is present in the casing component and, according to one embodiment of the invention, is only contained in the casing component. In principle, however, lubricant can also be present in the core component. According to one embodiment, the lubricant can only be contained in the jacket component. In principle, lubricants can also be present in the core component in this embodiment.

The core component can consist or essentially consist of a homo-polypropylene. A recommended embodiment of the invention is characterized in that the jacket component or the jacket component containing the lubricant consists or essentially consists of a polypropylene copolymer. It must be taken into account that the jacket component contains lubricant and (in addition) the additive that reduces the migration rate of the lubricant. In one embodiment, a polypropylene copolymer is preferably chosen for the jacket component, which has a melt flow rate (MFI) of 20 to 70 g / 10 min, preferably 25 to 50 g / 10 min. An ethylene-propylene copolymer with an ethylene content of 1 to 6%, preferably 2 to 6%, is expediently used. The polypropylene copolymer selected for the shell component is preferably distinguished by a narrow molecular weight distribution and preferably by a molecular weight distribution or molecular weight distribution (M _w / M _n ) from 2.5 to 6, preferably from 3 to 5.5 and very preferably from 3 , 5 to 5. In the context of the invention, the molecular weight distribution M _w / M _n is determined according to gel permeation chromatography (GPC) in accordance with ISO 16014-1: 2003, ISO 16014-2: 2003, ISO 16014-4: 2003 and ASTM D 6474-12. - It is recommended to use a random polypropylene copolymer which has a nucleating agent or is otherwise modified for a high crystallization rate, such as Borealis RJ377MO or Basell Moplen RP24R. This latter random polypropylene copolymer has, for. B. a melt flow rate of 30 g / 10 min and a Vicat temperature of 120 ° C (ISO 306 / A50, 10 N).

In the context of the invention, at least one additive reducing the migration speed of the lubricant is used in the sheath component of the continuous filaments. This additive is at least one nucleating agent and / or at least one filler. According to a particularly preferred embodiment of the invention, at least one nucleating agent is used. The nucleating agent is expediently present in the filaments in a proportion of 500 to 2500 ppm, based on the entire filament. A nucleating agent from the group "aromatic carboxylic acid, salt of an aromatic carboxylic acid, sorbitol derivative, talc, kaolin, quinacridone, pimelic acid salt, suberic acid salt, dicyclohexyl-naphthalenedicarboxamide, organophosphate, triphenyl compound, triphenyldithiazine" has proven particularly useful. used. A sorbitol such as dibenzyl sorbitol (DBS) or 1,3: 2,4-bis (p-methylbenzylidenes) sorbitol (MDBS) or 1,3: 2,4-bis- (3, 4-Dimethylbenzylidene) sorbitol (DMDBS) can be used. A preferred nucleating agent is a salt of an aromatic carboxylic acid, in particular an alkali salt of benzoic acid and, for example, sodium benzoate.

By nucleating the jacket component, in particular the polypropylene copolymer of the jacket component with at least one nucleating agent, the migration rate of the lubricant in the jacket is reduced and, in view of solving the technical problem, the problem-free use of lubricants in the jacket component is made possible. - At least one filler in the jacket component can also reduce the migration rate of the lubricant. At least one metal salt is preferably used as the filler, and at least one is particularly preferred a substance from the group "titanium dioxide", calcium carbonate, talcum "used.

In the context of the invention, random polypropylene copolymers with a narrow molar mass distribution can advantageously be used as polypropylene copolymers for the shell component. Polypropylene copolymers which are known from the injection molding sector and often contain antistatic agents and nucleating agents are particularly suitable here. Such antistatic agents (e.g. fatty acid esters such as glycerol monostearate or also ethoxylated fatty amines or alkylamines) can often already be sufficient as lubricants and would fall under the amount of lubricant claimed according to the invention. - Optionally, additional lubricant can be metered into the core component and / or jacket component if the already existing proportion of the copolymer is insufficient. The copolymer of the shell component can be mixed with homo-polypropylene. It is within the scope of the invention that the viscosity of these mixtures is lower than the viscosity of a homopolypropylene. If a homo-polypropylene is used, it is preferably a homo-polypropylene with the following properties. The melt flow rate (MFI) is advantageously 17 to 37 g / 10 min, preferably 19 to 35 g / 10 min. The homopolypropylene is recommended to have a narrow molar mass distribution in the range from 3.6 to 5.2, in particular in the range from 3.8 to 5. The measurement of the molecular weight distribution has already been specified above. According to a preferred embodiment of the invention, at least one of the following products is used as homopolypropylene: Borealis HF420FB (MFI19), HG455FB (MFI25), HG475FB (MFI25), Basell Moplen HP561R (MFI25) and Exxon 3155 PP (MFI35).

According to the invention, homo-polypropylene and / or polypropylene copolymer, in particular ethylene-propylene copolymer and / or mixtures thereof, is used for the jacket component.
It is within the scope of the invention that a spunbonded fabric according to the invention is produced using a spunbond process. First, multi-component filaments or bicomponent filaments with a core-sheath configuration are spun as continuous filaments by means of at least one spinnerette, and then these continuous filaments are cooled in at least one cooling device and then the continuous filaments pass through a drawing device for drawing the filaments. The drawn filaments are deposited as a spunbonded fabric on a tray, in particular on a tray screen belt.

A particularly recommended embodiment of the invention is characterized in this context in that the assembly of the cooling device and the stretching device is designed as a closed assembly, with no further air supply into the closed assembly except for the supply of the cooling air in the cooling device. This closed design has proven particularly useful in the production of a spunbonded nonwoven according to the invention.

At least one diffuser is expediently arranged between the stretching device and the deposit or the deposit screen belt. The continuous filaments emerging from the drawing device are passed through this diffuser and then placed on the tray or on the deposit screen belt. A recommended embodiment of the invention is characterized in that at least two between the stretching device and the storage Diffusers, preferably two diffusers are arranged one behind the other in the filament flow direction. At least one secondary air inlet gap for the entry of ambient air is expediently present between the two diffusers. The embodiment with the at least one diffuser or with the at least two diffusers and the secondary air inlet gap has also proven particularly useful with regard to the production of the spunbonded fabrics according to the invention.

After the filaments have been deposited in the spunbond, this spunbond is consolidated, pre-consolidated in a preferred embodiment and then finally consolidated. The pre-consolidation or consolidation of the spunbonded fabric is advantageously carried out with at least one calender. Two interacting calender rolls are preferably used. According to a recommended embodiment, at least one of these calender rolls is heated. The embossing area of the calender is advantageously 8 to 20%, for example 12%. If, within the scope of the invention, the degree of softness is determined on the one hand in a spunbonded nonwoven according to the invention and on the other hand in the case of a comparative nonwoven, the same pre-consolidation or consolidation of the spunbonded nonwoven takes place in both nonwovens.

The invention is based on the knowledge that the spunbonded nonwovens according to the invention have an optimal smooth, soft feel and nevertheless have a high strength. The result is soft spunbonded fabrics with good tensile strength. This applies above all to the use of the polypropylenes or polypropylene copolymers for the core component and / or sheath component of the continuous filaments of the spunbonded fabric according to the invention. It is also essential that the evaporation compared to known solutions of lubricant from the filaments can be effectively reduced, thereby avoiding unwanted deposits in the system. In this way, the cleanliness of the system can be increased compared to the known measures and thereby the efficiency and availability of the system can be increased. In particular, the system runtime can be increased. In this respect, the invention is also based on the knowledge that an inhomogeneous introduction of the lubricant into the filaments effectively contributes to solving the technical problem according to the invention. - As will be demonstrated with the following exemplary embodiments, a comparable strength of the nonwovens can be achieved in comparison with the measures known from practice in the production of the spunbonded nonwovens according to the invention and in particular in the consolidation of the spunbonded nonwovens with less energy expenditure - especially at lower calender temperatures. Due to the high strength of the spunbonded webs achieved according to the invention, material can also be saved in the production of the continuous filaments, in particular in comparison to other raw material combinations, such as PP / PE. Furthermore, a simple recycling of the components into the manufacturing process can take place in the manufacture of the spunbonded fabrics according to the invention. Due to the compatibility of the raw materials used, it is possible to recycle recyclate with high proportions without any problems. This also results in a significant cost advantage over z. B. a PP / PE combination. The result is soft, smooth and tensile spunbonded nonwovens that can be realized at relatively low cost.

The invention is explained in more detail using exemplary embodiments:
Spunbonded nonwovens were subsequently produced from bicomponent filaments with a core-sheath configuration using the spunbond process described above. Homo-polypropylenes and polypropylene copolymers were used as the material for the two components (core and jacket). In all of the exemplary embodiments, the spunbonded fabric deposited on the deposit screen belt was consolidated with a calender which had an U5714A engraving (12% embossing area, round engraving points, 25 fig / cm ² ). The fineness of the filaments of all examples was approximately 1.6 to 1.8 denier. All samples were produced with a spinning system with the same or similar throughputs.

Comparative example:

Monocomponent filaments were made from homo-polypropylene (Borealis HG455FB with MFI25). The calendering was carried out at a surface temperature of the calender rolls of approx. 148 ° C. The spunbond fabric produced has good strength, but in comparison to the following exemplary embodiments it does not have a satisfactory soft feel.

Example 1:

A spunbonded fabric made of bicomponent filaments was produced, both the core component and the sheath component being made of homo-polypropylene (Borealis HG455FB with MFI25) with 8% of a polypropylene from Idemitsu "L-MODU X901S" as a soft additional polypropylene. The mass ratio between the core component and the cladding component was 70:30. Only in the core was the lubricant SL05068PP from Constab based on erucic acid amide. The lubricant content was 2000 ppm with respect to the entire filament. The spunbonded fabric was calendered at a surface temperature of the calender rolls of approximately 142 ° C.

The spunbonded fabric produced from these continuous filaments had a smooth, soft feel after one day of storage.

Example 2:

The bicomponent filaments of this spunbonded fabric contained homo-polypropylene (Basell Moplen HP561R with MFI25) in the core component as well as in the sheath component with 10% by weight of a soft additional co-polypropylene (Exxon Vistamaxx VM 6202). The mass ratio between the core component and the cladding component was also 70:30 here. SL05068PP from Constab based on erucic acid amide was again used as the lubricant. This lubricant was contained only in the core and the content of the lubricant was 2500 ppm, based on the entire filament. The spunbond was calendered at a surface temperature of the calender rolls of 132 ° C. The handle of the filament produced had to be classified as blunt at first, after a day of storage a smooth, soft handle appeared. This shows the delayed migration of the lubricant.

Example 3:

The bicomponent filaments of the spunbonded fabric produced here contained homo-polypropylene (Borealis HG475FB) in the core and polypropylene copolymer (Basell Moplen RP248R with MFI 30) in the jacket. The mass ratio between the core component and the cladding component was 70:30. A nucleating agent and an antistatic agent were contained in the polypropylene copolymer of the jacket. The spunbond was calendered at a surface temperature of the calender rolls of 121 ° C. The handle of the spunbond fabric produced initially had to be blunt can be classified, after a day of storage a smooth, soft feel of the fleece appeared. This in turn shows a delayed migration of the lubricant or here the antistatic.

Example 4:

The core component of the bicomponent filaments of this spunbond fabric produced consisted of homo-polypropylene (Borealis HG475FW with MFI25) and the sheath component consisted of polypropylene copolymer (Basell Moplen RP248R with MFI30). The mass ratio between the core component and the cladding component was 50:50. A nucleating agent and an antistatic agent were contained in the polypropylene copolymer. The consolidation took place with calender rolls with a surface temperature of 121 ° C. The handle of the spunbond fabric produced was initially blunt and after a day's storage period, a smooth, soft handle appeared. This in turn shows the delayed migration of the stearate used as a lubricant. In comparison to embodiment 3, the strength of the nonwoven is reduced (see table below), which is due to the larger proportion of polypropylene copolymer in comparison to homopolypropylene.

Example 5:

The bicomponent filaments of this spunbonded fabric had homo-polypropylene (Borealis HG475FB with MFI25) in the core and polypropylene copolymer in the jacket. The mass ratio of the core component to the shell component was 70:30. The polypropylene copolymer used is comparable to the Moplen RP248R copolymer, but has no nucleating agent and no antistatic. A consolidation of the spunbond was carried out with calender rolls carried out a surface temperature of 121 ° C. Even after three days of deposition, the spunbonded fabric produced in this way did not achieve the smooth, soft feel of embodiment 3. This shows that the use of polypropylene copolymer alone is not sufficient and that a migrating lubricant is required to achieve the properties according to the invention.

The following table shows the basis weights of the spunbonded nonwovens in g / m ² and the strengths in the machine direction (MD) and crosswise to the machine direction (CD) in N / 5cm. The strengths were measured in accordance with EDANA ERT 20.2-89 with a clamping length of 100 mm and a take-off speed of 200 mm / min. Comparative example V is compared here with examples 1 to 5: example Basis weight Strength MD Strength CD "V" 22 49 35 1 22 44 28 2nd 22 39 31 3rd 20th 55 31 4th 20th 48 30th 5 20th 55 35

It should be emphasized that the spunbonded fabrics of exemplary embodiments 3 to 5 were consolidated at a significantly lower calender temperature than in comparative example V. Nevertheless, comparable strengths can be observed, so that the energy expenditure in the production of the spunbonded fabrics according to exemplary embodiments 3 to 5 could be reduced. The lower calender temperature supports the soft grip and thus enables the additional lubricants to be added to be reduced.

Example 6:

This embodiment relates to the difference in the degree of hardness or in relation to the degree of hardness. Measurements of the degree of hardness were carried out on a spunbonded nonwoven S1 according to the invention and on a comparative nonwoven V1 using a commercially available measuring device TSA (tissue softness analyzer) from Emtec, Leipzig, Germany. The measuring head was pressed onto the fleece surface with a force of 100 mN. It was measured here on the spunbond surface facing away from the deposit screen belt. The measuring head was equipped with eight rotating or rotatable measuring sheets and the speed during the measurement was 2 / sec. - With the measuring device, the spunbond fabric according to the invention and for the comparative nonwoven fabric each a volume / frequency spectrum was recorded, and the volume of the peak maximum (TS7 value) at 6550 Hz was determined in each case. 5 individual measurements were averaged in each case. The two spunbonded fabrics were produced with the same spunbond device, pre-consolidated or solidified in the same way (ie under the same conditions of calender bonding) and both spunbonded fabrics had filaments with the same titer of 1.8 denier. The difference between the filaments of the two spunbonded nonwovens was the distribution of the lubricant in the polymer melt when it emerged from the spinning plate before spinning to the respective filament. In the spunbonded nonwoven S1 according to the invention, the filaments consisted of a homogeneous mixture of homo-polypropylene and polypropylene copolymer. The raw materials for the bicomponent filaments were analogous to the above Embodiment 2 selected, the lubricant content based on the entire filament was 2000 ppm and a calender engraving "U2888" with 19% area ratio was used. The proportion of the core was 50% (mass ratio between core component and shell component 50:50). Corresponding 4000 ppm of lubricant were added to the core component of the bicomponent filaments. A spunbonded nonwoven with filaments of the same components was used as the comparative nonwoven V1, but the lubricant was homogeneously distributed over the filament cross section at 2000 ppm. The volume values (TS7 values) were determined for both nonwovens S1 and V1, specifically for three points in time, namely 15 minutes, 2 hours and 96 hours after the filaments had been deposited on a deposit screen belt. Volume values for the spunbonded nonwoven S1 according to the invention and for the comparative nonwoven V1 are shown in the table below: L (dBV ² rms) in % S1 V1 S1 V1 15 minutes 4.31 3.98 108.2 100 2 hours. 4.42 4.16 106.3 100 96 h 3.93 3.84 102.2 100

The single figure shows the volume values TS7 (in dBV ² rms) of the peak maximum at 6550 Hz depending on the time of measurement. On the far left is the TS7 value that was determined 15 minutes after filament deposition and on the right is the TS7 value that was determined 2 hours after filament deposition. On the far right, the TS7 value is shown, which is determined 4 days or 96 hours after filament deposition has been. The solid line characterizes the TS7 values for the spunbonded nonwoven S1 according to the invention and the dashed line shows the TS7 values for the comparative nonwoven V1. It can be seen here that the spunbonded fabric S1 according to the invention initially (after 15 minutes and after 2 hours) has a significantly higher volume value and thus a lower degree of softness or higher degree of hardness than the comparative nonwoven fabric V1. The result of this is that the lubricant in the filaments of the spunbonded nonwoven S1 according to the invention migrates or migrates to the filament surface much more slowly. In contrast, the comparative nonwoven undergoes a relatively rapid migration, so that high degrees of softness or low degrees of hardness are achieved relatively early. The increase in the curve between 15 minutes and 2 hours for both spunbonded fabrics is explained by the first post-crystallization of the polypropylene mixture, which stiffens the filaments. This shape of the curves may be considered typical for this combination of raw materials. As expected, both migration of the lubricant and recrystallization affect the softness at the same time. Since migration speeds can also change depending on the respective crystallinity, there is no general curve here, this is specific to the raw material. After 96 hours, the volume values and thus the degrees of softness or hardness of the spunbonded nonwoven S1 according to the invention on the one hand and of the comparative nonwoven V1 on the other hand match or quasi match. The delayed migration of the lubricant to the filament surface in the spunbonded nonwovens according to the invention has the advantage that in the course of the production of the filaments there is a significantly lower outgassing of lubricant from the filaments and the system components are accordingly less contaminated. At the same time, the winding behavior is positively influenced. - The percentages in the table can also be seen that the volume value of the invention Spunbonded fabric is more than 3% higher than the volume value of the comparative nonwoven fabric V1 within the first 150 minutes after filament deposition and accordingly the degree of hardness of the inventive spunbonded fabric S1 is more than 3% higher than the hardness level of the comparative nonwoven fabric V1. It can also be seen that the finished spunbonded nonwovens have become softer, regardless of the recrystallization that takes place, which demonstrates the effect and sense of the lubricant.

Example 7:

With the same system and solidification as in embodiment 6, the raw material combination was chosen according to embodiment 5, but with a lubricant. A homopolypropylene Moplen HP561R was used in the core and the random CoPP with MFR 30 from embodiment 5 was used in the jacket. A core-jacket ratio of 70:30 was set and the same calender temperature was used as in embodiment 6 In the spunbonded nonwoven S2 according to the invention, 2900 ppm of lubricant were only metered into the core. In comparison fleece V2, 2000 ppm of lubricant were metered in both in the core and in the jacket. Here, too, there is a similar relationship of the TS7 values as in embodiment 6, although the shell raw material used here, with its different basic softness and rate of crystallization or migration, results in a different course over time. The TS7 difference is particularly noticeable after 2 hours. L (dBV ² rms) S2 V2 15 minutes 5.03 4.91 2 hours. 5.64 4.86 96 h 4.3 4.19

Here, too, the deposited spunbond is softer (lower in TS7 value) than the freshly produced spunbond.

The table below shows the TS7 relation of spunbonded nonwovens S according to the invention to the comparative nonwovens V (exemplary embodiments 6 and 7) after 15 minutes, 2 hours and 96 hours, as well as the strength values after production and the basis weights of the spunbonded nonwovens. Strengths and basis weights were determined according to the methods explained above, a pull-off speed of 200 mm / min being used for the strength measurement. template V1 S1 V2 S2 TS7 (15 min) [%] 100 108.2 100 102.4 TS7 (2 hours) [%] 100 106.3 100 116.1 TS7 (96 hours) [%] 100 102.2 100 102.5 Strength MD [N / 5cm] 41.6 39.4 44.2 42.3 Strength CD [N / 5cm] 23.7 23 28.1 28.4 Basis weight [gr / m ² ] 20.6 20.3 20.6 20.3

A strength advantage of embodiment 7 compared to embodiment 6 is shown. It shows the advantage and the possibilities of bicomponent technology.

Claims (11)

1. A spunbonded nonwoven made of continuous filaments of thermoplastic material, wherein the continuous filaments are configured as multicomponent filaments having a core-sheath configuration, in particular as bicomponent filaments having a core-sheath configuration,
   wherein the core component and the sheath component each have at least 90 wt.% of at least one component from the group "polypropylene, polypropylene copolymerizate, mixture of polypropylene and polypropylene copolymerizate,
   wherein the filaments contain at least one lubricant, wherein the proportion of the lubricant, relative to the overall filament, is 250 to 5500 ppm, preferably 500 to 5000 ppm, preferably 700 to 3000 ppm and particularly preferably 700 to 2500 ppm,
   wherein lubricant is present in the sheath component and wherein furthermore at least one additive that reduces the migration speed of the lubricant through the sheath component is also included in the sheath component.
2. The spunbonded nonwoven according to claim 1, wherein the core component has at least 95 wt.% and preferably at least 96 wt.% of at least one component from the group "polypropylene, polypropylene copolymerizate, mixture of polypropylene and polypropylene copolymerizate".
3. The spunbonded nonwoven according to one of claims 1 or 2, wherein the core component consists or substantially consists of a homo-polypropylene or wherein the core component has at least 80 wt.%, preferably at least 85 wt.%, preferably at least 90 wt.% and particularly preferably at least 95 wt.% of the homo-polypropylene.
4. The spunbonded nonwoven according to one of claims 1 to 3, wherein the sheath component consists of or substantially consists of a polypropylene copolymerizate and/or a mixture of a polypropylene with a polypropylene copolymerizate.
5. The spunbonded nonwoven according to one of claims 1 to 4, wherein the polypropylene copolymerizate has a molecular weight distribution or molar mass distribution (M_w/M_n) of 2.5 to 6, preferably of 3 to 5.5 and very preferably of 3.5 to 5.
6. The spunbonded nonwoven according to one of claims 1 to 5, wherein at least one fatty acid derivative and preferably at least one substance from the group "fatty acid ester, fatty acid alcohol, fatty acid amide" is used as lubricant.
7. The spunbonded nonwoven according to one of claims 1 to 6, wherein at least one stearate and/or at least one erucic acid amide and/or at least one oleamide is used as lubricant.
8. The spunbonded nonwoven according to one of claims 1 to 7, wherein the lubricant is contained only in the sheath component.
9. The spunbonded nonwoven according to one of claims 1 to 8, wherein at least one nucleating agent and/or at least one filler, preferably at least one nucleating agent is contained in the sheath component as an additive that reduces the migration speed of the lubricant.
10. The spunbonded nonwoven according to one of claims 1 to 9, wherein at least one additive from the group "aromatic carboxylic acid, salt of an aromatic carboxylic acid, sorbitol derivative, talc, kaolin, quinacridone, pimelic acid salt, suberic acid salt, dicyclohexyl naphthalene dicarboxamide, organophosphate, triphenyl compound, triphenyl dithiazine" is used as the additive that reduces the migration speed of the lubricant.
11. The spunbonded nonwoven according to one of claims 9 to 10, wherein at least one metal salt or at least one substance from the group "titanium dioxide, calcium carbonate, talc" is used as filler.

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