AU2008200702B2

AU2008200702B2 - A method and a device for the production of splittable fibres and their use

Info

Publication number: AU2008200702B2
Application number: AU2008200702A
Authority: AU
Inventors: Ararad Dr Emirze; Norbert Goffing; Klaus Klein; Engelbert Loecher
Original assignee: Carl Freudenberg KG
Current assignee: Carl Freudenberg KG
Priority date: 2007-02-12
Filing date: 2008-02-12
Publication date: 2010-12-02
Anticipated expiration: 2028-02-12
Also published as: TW200914656A; TWI354719B; DE502008000166D1; AU2008200702A1; AR065293A1; KR101053019B1; DE102007034687A1; ATE447634T1; US20090004943A1; BRPI0801120A2; KR20080075451A

Description

Australian Patents Act 1990 - Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title A method and a device for the production of splittable fibres and their use The following statement is a full description of this invention, including the best method of perfonning it known to me/us: P/0/011 5102 P PvOXOCSWMM"pf*, r e~bknbn rgspeeI dec-I2/f2J200t A method and a device for the production of splittable fibres and their use Description 5 Field of the invention The invention relates to a method and a device for the production of splittable fibres by means of a melt spinning process using at least two mutually incompatible polymer 10 components, splittable fibres produced in accordance with this method and their use. Background of the invention From documents EP 0 413 688, US 5,562,930 and FR 2 647 815 methods and devices for 15 the production of splittable fibres by a melt spinning operation using at least two mutually incompatible polymer components are known. In accordance with these methods and devices, the individual polymer melt streams are passed through distribution plates within a spinning head so that each fibre coming out of the spinning head is made up of a plurality of elementary fibres of the particular polymer, which are arranged in alternation as viewed 20 in the cross section of the fibre. In particular the use of polyamide 6.6, as one of the polymers, is associated with a high cost for the starting material. This starting material also necessitates drying of the raw material, causes an electrostatic charge build-up during the spinning operation, and tends 25 to yellow under the influence of light and heat. Therefore there is the need for greatly reducing the proportion of one polymer component, in particular that of the polyamide proportion in the splittable fibres.

-2 However, with the prior art methods, the weight ratio of the polymers to one another may be varied predominantly in a ratio of 30:70 to 70:30, since otherwise no separate polymer segments are obtained which makes splitting into microfibers difficult or even impossible. 5 Document DE 101 15 185 Al describes a method for producing splittable fibres from mutually incompatible polymer component A and B, wherein a reduction of the proportion of polymer component B is reduced to between 5 and 25 % by weight, by introducing the polymer components A and B in molten form into a spinning head, where they are distributed into groups of elementary filaments, every second elementary filament being at 10 least partially sheathed with polymer component B, combined in spinnerets to form the splittable fibres and then drawn. The polymer component B as the component with the lower weight proportion remains behind as a thin film or separator sheath where later on the separation will be performed. 15 The division of the polymer melt streams into components with lower weight proportion (minor component) and components with higher weight proportion (major components) into a plurality of individual streams which together form the multicomponent fibre, is generally undertaken directly upstream of the spinneret capillaries. 20 Where in conventional spinneret arrangements the weight ratio of two components greatly differs, the major component, whilst still in the molten state, frequently tends to flow around the other component (minor component) still within the spinneret and therefore forms a closed outer sheath. 25 Due to the surrounding /sheathing of one of the components and/or the flowing together of the two components, the tendency of the otherwise incompatible polymers for splitting is greatly reduced. In extreme cases it can occur that fibres of actually non compatible polymers can no longer be mechanically split, in particular by hydrodynamic needling with water jets. In such an event, the sheathing component can at best be removed by means of 30 a solvent.

C WR rbl\CC\AKW\190|531 DOC-4A9/2010 -3 Summary of the invention The present invention seeks to make available a method and a device for the production of splittable fibres by means of a melt spinning process by virtue of which it is possible to 5 direct the melt streams of the two or more mutually incompatible polymer components during the melt spinning process in such a manner that a surrounding of an individual polymer stream by another polymer stream or a flowing together of the different polymer streams is prevented, in particular in cases where greatly varying weight ratios of the polymer components exist. 10 In accordance with the method for the production of splittable fibres by means of a melt spinning process using at least two mutually incompatible polymer components, the problem set is solved in accordance with the invention in that distribution orifices are provided upstream of the at least one spinneret capillary, wherein the cross-sectional area 15 of the at least one distribution orifice assigned to a respective polymer component is adjusted in dependence of the volume flow of the respective polymer component. Fibres are understood to be staple fibres, continuous fibres or filaments. 20 Fibres spun into yams are also included. The fibres can also be combined to form fleeces, in particular bonded fleeces, the nonwoven fabrics. The dependent claims describe advantageous further developments of the subject of the invention. 25 In a preferred embodiment of the invention, the cross-sectional area of the distribution orifice assigned to each respective polymer component is designed such that the flow P:'WD"81F4MNpwA-mfrm #car tcc'12l A12I200 -4 velocity of all polymer components concerned is equal with a deviation of between 0 and less or equal to 20 %, preferably of equal or less than 10 %, For this purpose, the ratio of the total sum of the cross-sectional areas of the distribution 5 orifices assigned to a respective polymer component vis a vis the total sum of the cross sectional areas of the distribution orifices assigned to another polymer component is adjusted such that it corresponds to the volume flow ratio amongst the polymer components used, with a deviation of between 0 and less or equal to 20 %, preferably of between equal or less than 10 %. In this instance, the volume flow ratio is preferably 10 unequal. Thereby the flow velocities of all polymer streams concerned are at least approximately equally set or adjusted so that clearly separated segments are created, preferably of segments of cross-sectional areas of equal size, which are even particularly easily splittable 15 in the event of weight ratios preferably selected for the method, namely of between 80:20 and 97:3 for the two mutually incompatible polymer components, even by mechanical methods, in particular by water jet treatment. Due to the minimal proportion of equal to or lower than 20 % by weight, preferably of 20 equal to or lower than 15, 10 or 5 % by weight or down to 3 % by weight of one component, in particular of comparatively expensive polymers, such as for instance polyamide 6.6, the costs for the initial materials and the end products of multicomponent fibres can be reduced. Furthermore, the undesired properties of a component, such as for instance yellowing, can be reduced by the use of only a minimal proportion of this 25 component. In addition the marked reduction of a polymer proportion and/or the clear segmentation of the polymer components in the fibres may enhance recyclability. Where a minor component has a very minimal proportion it is possible in a subsequent dyeing process of the nonwoven fabric to forego dyeing the minor component and restrict 30 the process to the major component.

-5 In a preferred embodiment, the method is also particularly designed for a desired even melt distribution of polymers, where the viscosity ratio of the polymer components is between 1:1 and 10:1, preferably of between 1:1 and 7:1, and particularly preferred of between 1:1 and 4:1. 5 The method is also suited for the production of a great variety of cross-sectional shapes of the multicomponent fibres. For the distribution orifices, cross-sectional shapes are used which are advantageously 10 round, bow-shaped, slot-shaped, star-shaped and/or angular, in particular triangular and rectangular. Preferably the distribution orifices are arranged in a circle, in particular for the production of hollow fibres. Also distribution orifices arranged in a star-shape or in a row are preferably selected. 15 In these instances, the arrangements and the cross-sectional shapes of the distribution orifices are preferably adjusted to those of the spinneret capillaries. For the purpose of an optimal melt flow distribution, the mutually incompatible polymer components are assigned to the respective distribution orifices preferably in single 20 alternation or in block alternation and in this instance the polymer components of one type are assigned to the respective distribution orifices preferably in blocks of equal size. For the production of splittable multicomponent fibres, the preferred use as components are thermoplastic polymers, selected from polyester, preferably polyethylene terephthalate 25 (PET), from polyolefins, preferably polyethylene (PE) and /or polypropylene (PP), from polylactates and/or from polyamides (PA). As bicomponent fibres combinations of mutually incompatible polymer components are selected, preferably of PET and PP, of PET and PA6, of PET and PA6.6 or of PP and PE. 30 C W-\ blCC KW\1901 1-.DOC-14A09/2010 - 6 -6 Due to the low weight proportion of in particular comparatively expensive polymers, such as polyamide 6.6, costs may be saved. Furthermore, due to the use of specific weight proportions of employed polymers the 5 desired properties of the multicomponent fibre can be accurately controlled. In a preferred embodiment of the method, a polymer component with a lower melting point is selected as the polymer component with a lower weight proportion. 10 In a further preferred embodiment of the method, a polymer component with a lower weight proportion is used as adhesive or binder component. By virtue of this measure, the properties of the nonwoven fabric thus produced can be influenced; in particular its degree of consolidation or softness can be selectively determined without the necessity of a consolidation by water jets. 15 The cross-sectional area of the respective distribution orifices is advantageously varied by the exchange and/or addition of components. According to another example aspect, a form of the invention further relates to splittable 20 fibres produced by means of the method described above. Advantageously, the splittable fibres in particular produced by means of the above method, which have at least two mutually incompatible polymer components, wherein the minimal proportion of one polymer component is equal to or lower than 20 % by weight, preferably 25 equal to or lower than 10 % by weight, more preferred equal to or lower than 5 % by weight, particularly preferred up to 3 % by weight, and where the individual polymer components are built up of clearly separated segments, preferably of segments of cross sectional shapes of equal size for each particular type of polymer component. In this way particularly preferred PIE fibres are produced. 30 C :NRPo.bI\DCC\AK WV190153l DOC-14M9I20O -7 The splittable fibres produced in accordance with the above method are used for the production of nonwoven fabrics, in particular for filters, clothing, and hygiene or cleaning products or tufting products, in particular carpet backings. 5 In another example form the present invention seeks to make available a device for the production of splittable fibres by virtue of which it is possible to direct the melt streams of the two or more mutually incompatible polymer components during the melt spinning process in such a manner that a surrounding of an individual polymer stream by another polymer stream or a flowing together of the different polymer streams is prevented even in 10 cases where greatly varying weight ratios of the polymer components exist. In this case, the minimal proportion of one polymer component is proposed to be equal to or lower than 20 % by weight, preferably equal to or lower than 10 % by weight, preferred to be equal or lower than 5 % by weight or particularly preferred up to 3 % by weight. 15 To provide a solution to the problem, the device has distribution orifices upstream of the spinneret capillaries, wherein the cross-sectional area of the at least one distribution orifice assigned to each respective polymer component is adjusted to the volume flow of the respective polymer component. 20 Preferably, the ratio of the total sums of the cross-sectional areas of the distribution orifices assigned to a respective polymer component corresponds at least approximately to the volume flow ratio amongst the polymer components used with a deviation of between 0 and less or equal to 20 %, preferably of between equal to or less than 10 %. 25 In a preferred embodiment of the device, the number of the distribution orifices assigned to a respective polymer component and the size of the cross-sectional areas of the distribution orifices assigned to a respective polymer component are adjusted to the volume flow ratio amongst the polymer components concerned in such a way that the flow velocity of all polymer components is substantially equal, i.e. with a deviation of between 0 and less or 30 equal to 20 %, preferably equal to or less than 10 %.

-8 Dependent on the desired cross-sectional shapes of the splittable fibres to be produced, the distribution orifices have correspondingly round, bow-shaped, slot-shaped, star-shaped and/or angular, in particular triangular and rectangular, in particular triangular and rectangular cross-sectional shapes. 5 For the production of hollow fibres or filaments, the distribution orifices are advantageously arranged in a circle. Also distribution orifices arranged in a star-shape or in a line are proposed depending on the desired cross-sectional form of the splittable fibres. 10 In a preferred embodiment of the device the distribution orifices are assigned to the respective polymer components in single alternation or in block alternation, wherein the distribution orifices for the polymer components of one type are particularly preferred to be arranged in blocks of equal size. 15 Advantageously, the cross-sectional areas of each respective distribution orifice can be varied by exchange of and/or addition of components. 20 Detailed description of the embodiments of the invention The subject of the invention is explained in greater detail by reference to some examples which do not narrow the scope of the invention. 25 The invention is described by reference to preferred embodiment examples illustrated in the drawings of distribution orifices arranged upstream of the spinneret capillaries by comparison with a known prior art arrangement of a distribution plate for a spinneret capillary, which orifices are provided for the passage of two mutually incompatible polymer components A and B with a weight ratio of 20:80 to 3:97. The drawing shows: 30 MWPP0CSKMfl~peelneauonmhanbrspcidoc-I22h2?21 -9 Fig. I A top view of a known arrangement and design of a distribution plate with distribution orifices for a spinneret capillary for the passage of polymer components A (grey) and B (black); Fig. 2 flow path of polymer component A (continuous arrow) and B (dotted arrow) using a prior art method and a prior art device for the production of splittable fibres as per Fig. 1; Fig. 3 flow path of said polymer components A (continuous arrow) and B (dotted arrow) using the method according to the present invention and the device for the production of splittable fibres according to the present invention; Fig. 4 a top view of a preferred embodiment of a circular arrangement of distribution orifices having round cross-sectional shapes, with different numbers of orifices for the passage of said polymer components A (grey) and B (black) with equally sized cross-sectional areas for the respective passage of said polymer components A and 13 as well as differently sized respective cross-sectional areas in the total sum; Fig. 5 a top view of a preferred embodiment of a circular arrangement of distribution orifices, with angular cross-sectional shapes, with different numbers of orifices for the passage of said polymer component A and B differently sized respective cross-sectional areas in the total sum; Fig. 6 a top view of a preferred embodiment of a circular arrangement of distribution orifices with round cross-sectional shapes, with equal numbers for the passage of the said polymer component A (grey) and B (black) and with individually als also in the total sum of differently sized cross sectional areas for the passage of the said polymer components A and B.

Fig. 7 A top view of a preferred embodiment of a circular arrangement of distribution orifices with round cross-sectional shapes for the passage of said polymer component A (grey) and B (black), as well as with combined slot- and bow shaped cross-sectional shapes for the passage of said polymer component B (black), with the same number of orifices for the passage of said polymer components A and B and with individually and also in the total sum differently sized cross sectional areas for the passage of the said polymer components A and B. Fig. 8 a lateral view in perspective of a device in accordance with the invention for the production of splittable fibres from at least two mutually incompatible polymer components A (grey) and B (black), where distribution orifices are arranged upstream of the spinneret capillaries; Fig. 9 Cross- section of a fibre with the said polymer component A (grey) and B (white) produced by the method according to the invention and the device according to the invention, and Fig. 10 Cross- section of a fibre with the said polymer component A (grey) and B (white) produced by a known prior art method and a known prior art device. Splittable multicomponent fibres are conventionally produced in that from one spinneret two or more polymers are spun from capillaries. At the boundary areas of two polymer 5 components, the fibres of the individual two polymer components can be separated from each other following spinning out and cooling of the fibres. In Figure 1, known circularly arranged round distribution orifices 6 with equal cross sectional areas for the passage of mutually incompatible polymer components, for instance 10 for the polymer components A and B, are shown, where the polymer components A and B V-%W'OOC' NiMA pecicaumnO9rmdenbespe .du122005 - 11 are distributed onto the distribution orifices 6 individually in alternation as per arrangement (AB)n, where n is an integer of equal to or greater than 1. The polymer component B, due to its greater flow velocity, flows out and spreads out and 5 consequently displaces or surrounds polymer component A. This flow path of polymer component B (dotted arrow) and of polymer component A (continuous arrow) is diagrammatically shown in Figure 2. This can lead, in particular in the given weight ratios of 20:80 to 3:97, that the fibres from 10 the polymer components A and B may no longer be capable of being mechanically split but, if at all, only by using a solvent. The splitting by means of solvents is however particularly disadvantageous, since the solvent is subsequently required to be removed and, depending on the circumstances, may need to be recycled. 15 To facilitate a mechanical splitting, in particular a splitting by means of water jets, even for fibres with a greatly different weight ratio, a melt spinning method and/or a melt spinning device 2 are provided, in which distribution orifices 6 are provided upstream of the spinneret capillaries 4, whose configuration and design is specifically adjusted to the polymer components used. 20 For this purpose the cross-sectional areas of the distribution orifices 6 assigned to a respective polymer component are adjusted to the volume flow ratio amongst the polymer component concerned. 25 The flow velocity of all polymer components concerned is at least approximately equally adjusted by a corresponding adjustment of the distribution orifices 6 with regard to the number of distribution orifices 6 assigned to a respective polymer component und with regard to the size of the cross-sectional areas of the distribution orifices 6 assigned to a respective polymer component. This flow pattern is shown diagrammatically in Figure 3 30 example for polymer component B (dotted arrow) and polymer component A (continuous arrow).

P tWPOOSUCMH4fpti~nndrutlobri .pectdor'ILCnSSa -12 In a preferred embodiment, the ratio of the total sums of the cross-sectional areas of the distribution orifices 6 assigned to a respective polymer component to the total sum of the cross-sectional areas of the distribution orifices 6 assigned to another polymer component is adjusted such that it corresponds at least approximately to the volume flow ratio 5 amongst the polymer components conceded, i.e. with a deviation of between 0 and less or equal to 20%, preferably equal to or less than 10 %. In a volume flow ratio of two polymer components A and B of 1:4, for instance, equally sized distribution orifices 6, i.e. with equally sized cross-sectional areas, with a number of 10 the orifices in the ratio 1:4 with the alternating arrangement in blocks A BBBB A BBBB ... an optimum selection for an even flow velocity of polymer components A and B through the assigned distribution orifices 6. In the instance of circularly arranged distribution orifices 6 with round cross-sectional 15 shapes such an arrangement is shown in Figure 4. Here also the ratio of the total sums of the cross-sectional areas of the distribution orifices 6 assigned to polymer components A (grey) and B (black) is 1:4 in accordance with the volume flow ratio of the polymer components A and B. In this case the polymer components A and B are assigned to the respective distribution orifices 6 in particular in block alternation. 20 Alternatively to the round cross-sectional shapes of the distribution orifices 6 also other geometries are feasible, such as for instance bow-shaped, slot-shaped, starshaped and/or angular cross-sectional shapes. 25 In the case of circularly arranged distribution orifices 6 with angular cross-sectional shapes for the distribution orifices 6 assigned to the polymer components A (grey) and B (black), such a configuration is shown in Figure 5. Alternatively, at a volume flow ratio of two polymer components A and B of 1:4, also 30 distribution orifices 6 of different sizes can be used. In this instance, the number of the distribution orifices 6 assigned to the polymer components A and B is the same, and the -13 size of the cross sectional areas of the distribution orifices 6 assigned to the polymer component B is 4 time the size of the cross sectional areas of the distribution orifices assigned to the polymer component A. In this case the polymer components A and B are assigned to the respective distribution orifices 6 singly in alternation in particular. 5 In the case of circularly arranged distribution orifices 6 with round cross-sectional shapes such a configuration is shown in Figure 6. Figure 7 shows a top view of a preferred embodiment of circularly arranged distribution 10 orifices 6 with round cross-sectional areas for polymer component A as well as combined slot-shaped and bow-shaped cross-sectional shapes for polymer component B. It is understood that also any other configurations with combinations of any volume flow ratios with correspondingly adjusted distribution orifices 6 with regard to the number and 15 the size of the cross-sectional areas in any cross-sectional shape are proposed. Figure 8 shows a lateral perspective view of a device 2 in accordance with the invention for the production of splittable fibres 1 from two mutually incompatible polymer components A and B, where the distribution orifices 6 are provided upstream of the 20 spinneret capillary 4. In this embodiment example, the ratio of the total sums of the cross sectional areas of the distribution orifices 6 assigned to the polymer component streams A (grey) and B (black) at a volume flow ratio of the polymer component A (grey) and B (black) of 1 : 3 is correspondingly 1 : 3. 25 The distribution orifices 6 shown in Figures 4 to 8 are optimal for an even flow velocity of the polymer components A and B (see Figure 3). By virtue of these configurations, the polymer components flow in at least approximately equal flow velocity through the aforementioned distribution orifices 6 so that 30 multicomponent fibres 1 produced therein with a minimal proportion of one polymer component of equal to or lower than 20 % by weight, preferably of equal to or lower than CWRPortblDCC\KW\2190153_ .DOC-14C102010 -14 10 % by weight, particularly preferred of equal to or lower than 5 % by weight or to 3 % by weight, have segments 8, 10 clearly separated from one another, in particular with equally sized cross-sectional shapes as is shown in Figure 9 by example of the said polymer component A (grey) and B ( white). 5 These cross-sectional shapes are particularly well suited for splitting even by mechanical methods, such as in particular by water jets. By contrast, for instance the cross section shown in Figure 10 of a fibre 12 with the said 10 polymer component A (grey) and B (white), produced by a known prior art method and device, does not show segments which are clearly separated from one another, in particular with regard to the polymer component B (white). Throughout this specification and the claims which follow, unless the context requires 15 otherwise, the word "comprise", and variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. The reference in this specification to any prior publication (or information derived from it), 20 or to any matter which is known, is not, and should not be taken as, an acknowledgement or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 25 Whilst the present invention has been hereinbefore described with reference to a particular embodiment, it will be understood that numerous variations and modifications will be envisaged by persons skilled in art. All such variations and modifications should be considered to fall within the scope of the invention as broadly hereinbefore described and as hereinafter claimed. 30

Claims

1. A method of forming splittable fibres by a melt-spinning process using at least two mutually incompatible polymeric components, which method comprises the at least 5 one spinning capillary having distributing bores placed upstream of it and the cross-sectional area of the at least one distributing bore assigned to any one particular polymeric component being adjusted such that the ratio of the sum totals of the cross-sectional areas of the distributing bores assigned to any one particular polymeric component corresponds approximately to or equals the volume flow 10 ratio between the polymeric components used, with a deviation of 0 to less than or equal to 20%, preferably of equal or less than 10%, the volume flow ratio not being equal to 1.

2. The method according to claim 1, wherein the minimum proportion of any one 15 polymeric component used is a proportion of equal to or less than 20% by weight, preferably of equal to or less than 10% by weight, more preferably of equal to or less than 5% by weight and most preferably of up to 3% by weight.

3. The method according to any one of the preceding claims, wherein the distributing 20 bores are used in round, arc-shaped, slot-shaped, star-shaped and/or angular, in particular tri- or rectangular, cross-sectional shapes.

4. The method according to any one of the preceding claims, wherein the distributing bores are arranged in the shape of a circle, in the shape of a star and/or in a row. 25

5. The method according to any one of the preceding claims, wherein the mutually incompatible polymeric components are assigned to the respective distributing bores alternating on a one-to-one basis or alternating in blocks. 30

6. The method according to claim 5, wherein the polymeric components of any one species are assigned to the respective distributing bores in blocks of equal size. C :NRPorbl\DCC\AKW\2190153_1 DOC-14A9/2010 - 16

7. The method according to any one of the preceding claims, wherein the polymeric components are selected from thermoplastic polymers, particularly from polyesters, from polyolefins, preferably polyethylene and/or polypropylene, from polylactates 5 and/or from polyamides.

8. The method according to any one of the preceding claims, wherein at least one polymeric component which has a lower weight fraction is used as polymeric component having a lower melting temperature. 10

9. The method according to any one of the preceding claims, wherein at least one polymeric component which has a lower weight fraction is used as bonding or binding component to form splittable fibres or filaments. 15

10. The method according to any one of the preceding claims, wherein the cross sectional area of any one particular distributing bore is varied by exchanging and/or adding structural components.

11. Splittable fibres, produced by the method according to any one of claims I to 10. 20

12. Splittable fibres, produced by the method according to any one of claims I to 10, which have at least two mutually incompatible polymer components, wherein at least one polymer component has a proportion of equal to or lower than 20 % by weight, preferably of equal to or lower than 10 % by weight, particularly preferred 25 of equal to or lower than 5 % by weight, even more particularly preferred up to 3 % by weight, and where the individual polymer components are built up of segments clearly separated from one another, preferably of segments with an equally sized cross-sectional shape for each respective type of polymer component. C \RPorbI\DCC\AKW\2 9I53_1 DOC-14A/)f21010 - 17

13. Use of splittable fibres as per either claim II or 12, for the production of nonwoven fabrics, in particular of filters, clothing, hygiene or cleaning products, or tufting products, in particular for carpet backings. 5

14. Apparatus, particularly for the method according to any one of claims 1 to 10, for forming splittable fibres from at least two mutually incompatible polymeric components by a melt-spinning process, wherein at least one spinning capillary has distributing bores placed upstream of it and the cross-sectional area of the at least one distributing bore assigned to any one particular polymeric component is 10 adjusted such that the ratio of the sum totals of the cross-sectional areas of the distributing bores assigned to any one particular polymeric component corresponds approximately to or equals, the volume flow ratio between the polymeric components used with a deviation of 0 to less than or equal to 20%, preferably of equal to or less than 10%. 15

15. Apparatus according to claim 14, wherein the distributing bores have round, arc shaped, slot-shaped, star-shaped and/or angular, in particular tri- or rectangular, cross-sectional shapes. 20

16. Apparatus according to either of claims 14 and 15, wherein the distributing bores are arranged in the shape of a circle, in the shape of a star and/or in a row.

17. Apparatus according to any one of claims 14 to 16, wherein the distributing bores are assigned to the respective polymeric components alternating on a one-to-one 25 basis or alternating in blocks.

18. Apparatus according to claim 17, wherein the distributing bores for any one species of polymeric components are arranged in blocks of equal size. C\NRPorblDCC\AKW\2190153_ .DOC-14//9/2010 - 18

19. Apparatus according to any one of claims 14 to 18, wherein the cross-sectional area of any one particular distributing bore is variable by exchange and/or addition of structural components. 5

20. A method of forming splittable fibres, substantially as hereinbefore described with reference to the accompanying figures.

21. Splittable fibres, substantially as hereinbefore described with reference to the accompanying figures. 10

22. Apparatus for forming splittable fibres, substantially as hereinbefore described with reference to the accompanying figures.