SK278606B6 - Yarn made from coated fibres and process for producing the yarn - Google Patents

Abstract

Yarn created based on the fibres consists of the core and coating, while the core and the coating are created with use of the spinning procedure closed to polymers being able of spinning, however all of two component fibres are equipped with a complete coating, in most cases. All of the fibres equipped with coating in yarn have a share of these fibres A in percents related to the coating material share (M +/- 0,1M) in a total volume of these fibres so that it corresponds with the condition represented by the formula A is less or equal than 100, M is more or equal than 0,5 and A is more or equal than 30 + (0,1 M)exp(8).

Description

Technical field

The present invention relates to a coated fiber yarn whose core and coating are formed by spinning and to a process for their production. 5

BACKGROUND OF THE INVENTION

Yarn of coated fibers is known. 10 For example, in European patent no. It is described that special spinning devices are necessary in order to prevent the formation of so-called homogeneous fibers even in the case of a small proportion of packaging material. Although the formation of homogeneous fibers can be avoided by means of known devices, it is not possible to prevent fibers which contain a very fluctuating proportion of packaging material from being present in the yarn obtained, so that there are also sections completely free of packaging material, and moreover it varies greatly even during the same fiber.

Experiments have shown that using a spinning device according to European patent specification no. 11,954, while using a core material / packaging material ratio of 85:15 by volume (as described in the example), 25 contains no more than 15%, but typically less fiber in the yarn, the packaging material content is 15%, even when taken a variation of ± 10%. The remaining fibers in the obtained yarn have a larger (up to 30% by volume) or lower (up to 5% by volume) wrapping material. 30

Also, the known process does not allow obtaining individual homogeneous fibers in the yarn or a larger number thereof. The formation of homogeneous fibers is quite random and it is also not possible to ensure that the fiber which appears on the yarn cross-section without the wrapping material also remains in the yarn direction without this material. More often, the homogeneous fiber changes in the direction of the yarn to the fiber containing the wrapping material and vice versa.

The large variation in the proportion of packaging material causes each of the fibers in the yarn to have different properties. This means that the fibers during the yarn have great fluctuating properties, which is undesirable.

In principle, the coated yarns should have the desired core material properties, i.e. strength, shrinkage, ductility, birefringence, and the like, wherein the wrapping material should improve the other properties of the yarn, such as adhesion to other materials, chemical or mechanical stability and the like. . In carrying out the known processes, it is necessary to use an average of at least 20% by volume of the wrapping material in order to maintain said 50 variation in the thickness of the wrapper within acceptable limits and to maintain uniformity of the desired material properties relative to the overall fiber cross-section.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a new, higher quality yarn of coated fibers, optionally containing homogeneous fibers, by spinning the spinnable polymers to ensure a uniform coating of all the fibers that are coated. The yarns should allow better use of the properties of the core material without compromising the properties of the wrapping material. 60

It is also an object of the present invention to provide a method for producing these yarns while at the same time providing better yarn uniformity with a pre-selectable proportion of homogeneous fibers and coated fibers (bicomponent fibers). The proportion of packaging material in the 65 coated fibers should give the desired result even at less than 20%.

This problem is solved by the invention such that all fibers coated in the yarn have a proportion of these fibers A in% with a proportion of packaging material (M ± 0.1 M) in the total volume of these fibers such that it satisfies the following conditions:

A <100 M> 0.5 A> 30+ (0.1 M) ⁸ .

The expression M ± 0.1 M means that for the determination of A all the coated fibers containing M% by volume of the wrapping material, based on the total volume of the coated fiber, are taken into account, where variation of ± 10%. Since these conditions must be met simultaneously, it is clear that M can only have values at which A is at most 100%.

In particular, the yarns according to the invention in which the yarns have excellent properties

A> 40+ 7 (0.1 M) ⁸ , preferably

A> 50+ 100 (0.1M) ⁸ .

Depending on the application, yarns in which at least 60% of the coated fibers comprise a proportion of the wrapping material are preferred

M ± 0,1 M% by volume, where M <9% by volume, or yarn in which at least 70% of the fibers covered by the wrapping material contain a proportion of that material

M ± 0,1 M, where 1% vol <M <7% vol or yarn in which at least 75% of the fibers covered by the packaging material contain a proportion of that material

M ± 0.1 M, where 3% by weight <M <6% by weight.

It is surprising that yarns of this type have substantially improved specific properties. For example, the specific strength (cN / dtex) of these new yarns is considerably higher than that of the known yarn of coated fibers and also higher than that of homogeneous fibers made of core material.

The yarns forming the yarn according to the invention can have virtually any cross-section. For example, circular cross-section fibers are suitable for the tire cord, while trilobal cross-section fibers are particularly suitable for underlining the light effect in carpet yarns.

Certain yarn properties, such as adherence, are especially expressed for fibers with trilobal cross-section.

Among the polymer combinations, the following polymers have proven to be particularly suitable for forming the coating:

the core container Polyethylene terephthalate (PET) Polyethylene terephthalate (PET) Polyamide 46 (PA 46) High viscosity polyethylene terephthalate (PET) Polyethylene terephthalate (PET) Polyethylene Naphthalate (PEN) Polyethylene Naphthalate (PEN) Polyamide 66 (PA 66) Mixture of polyamide 66 (PA 66) and poly (m-xylylene adipamide) Polyamide 66 (PA 66) Polyethylene terephthalate (PET) low viscosity Mixture of polyethylene terephthalate (PET) and polyvinylene difluoride (PVDF) Polyamide 66 (PA 66) Polyamide 46 (PA 46)

Further advantageous combinations of core material and sheath are given below:

core cover

Polyethylene terephthalate (PET) Polyamide 66 (PA 66) with higher viscosity Polyamide 6 (PA 6) with higher viscosity

Polyethylene terephthalate (PET) Polyethylene terephthalate (PET) Polyethylene terephthalate (PET) Polyethylene terephthalate (PET) Polyethylene terephthalate (PET)

Polyethylene terephthalate (PET)

Polyamide 6 (PA 6)

Polyamide 6 (PA 6)

Polyethersulfone (PES)

Polyamide 66 (PA 66) with lower viscosity

Polyamide 6 (PA 6) with lower viscosity

Polytetrafluoroethylene (PTFE) Polyimide

Polyphenylene sulphide (PPS) Polypropylene (PP)

Mixture of polyethylene terephthalate (PET) and polytetrafluoroethylene (PTFE)

Mixture of polyethylene terephthalate (PET) and poly (m-xylylene adipamide)

Polypropylene (PP)

Polyvinylenedifluoride (PVDF)

The yarns of the invention can be used in various fields of technology.

Sewing threads from suitable core polymers (PET, PA 66, PA 6) can be coated with high temperature stable polymers and are therefore suitable for use at high sewing speeds. material with high chemical stability, resistance to ultraviolet light or to high temperature.

In the case of yarns used to reinforce elastomeric products, for example, in the case of a tire cord used to reinforce tires, drive belts or conveyors, a better adhesion between the core and the elastomer can be achieved by selecting the packaging material. This also applies in the case of plastics reinforced with fibrous materials.

In the case of carpet yarns, the choice of packaging material can improve fiber dyeing even if the core material is a good conductive material to reduce antistatic properties, the color of which is often dark and difficult to overlap by other colors. By choosing different high-shrinkable materials, it is possible to ensure a strong fiber shrinkage under the effect of heat when making carpets from such yarns. Profiled fibers improve light scattering. By selecting special materials to form the inner and outer layers of the fibers, it is possible to obtain yarns that are low flammable, low soiling and the like, thereby further improving the properties of the carpets and fabrics made of these yarns. In the same way, it is also possible to prevent slight molding or rotting of these materials.

By using a hydrophobic coating material, it is also possible to substantially reduce the water uptake of fibers. This feature is particularly desirable in the use of the yarns of the invention in the textile industry. It is also possible to spin the coating material with the addition of a colored pigment to obtain a dyed fiber.

By using the yarns according to the invention for the production of nonwoven fabrics, it is possible to improve the chemical stability, for example, of materials intended for the manufacture of filters by suitable polymer selection. It is also possible to achieve ion exchange or flame retardant properties.

The invention also relates to a method for producing said type of yarn, in which the core material is fed in a known manner (according to EP 11 954) through a first spinneret plate in a plurality of individual streams to a second spinneret plate, between the first and second spinneret plates. In each case, each material stream of the core material is fed to the casing layer, the two components being spun together, elongated and wound, wherein at least in the region of the individual streams of core material the casing material fed is exposed to flow resistance.

The process according to the invention can be carried out as a single stage (without winding between stages) or as a multi-stage (with winding between stages).

In particular, a mesh having a hole for each individual material flow may be used as the flow resistance element of the packaging material. In a preferred embodiment, the mesh with the meshes fills the entire space between the first and second spinneret plates, with the exception of openings for individual spokes of the material. Other resistive elements, such as porous plates, may also be used. However, by using the mesh with the mesh, it is possible to maintain the same distance between the two plates even with the large dimensions of the spinneret plates, since the mesh with the mesh also acts as a spacer plate.

Thus, it is possible in a simple manner to obtain fibers with a core and a wrapping material, where each fiber has a different proportion of the wrapping material. For this purpose, different resistors are selected for the individual streams of packaging material. If such a high resistance is chosen that the flow of the wrapping material around some of the core material flow is completely interrupted, a homogeneous fiber can be obtained in a simple manner.

Of the nets with meshes, nets which are commonly available under the designation R.V.S. X mesh, the X value being in the range of 30-500. means that the net is made of stainless steel, X mesh means that the net contains x wires per 2.54 cm in both directions of the net, the wires intertwined together and having a diameter in the range of 0.5 to 0.025 mm.

The flow resistance can also be determined by the permeability of the element that is used as the resistance. Permeability is defined by a relationship,

K = -_ ^ δ _ρ / δ _χ where η is the viscosity of the material used in Pa.s, V is the speed of the material used when passing the resistance element in m / s, δ _ρ / δ _χ is the pressure gradient in N / m3 in the flow direction.

In this way, the permeability value in m ² is obtained.

The permeability K of the resistance element used is preferably in the range of 10-11 to 3.10-10 m 2.

It is surprising that the process according to the invention can be used in the spinning of molten material as well as in the spinning from a solution, and it is possible to combine both processes. For example, it is possible to spin-melt or solution-spun both, but it is also possible to obtain a core component, for example, by melt-melt spinning and a solution-spinning casing. Solution spinning means that the solution consists of a polymer dissolved in a solvent, while the latter uses a molten polymer.

If only one aperture is provided in the first and second spinneret plates at a time, it is possible to obtain a single bicomponent fiber by the method according to the invention, the envelope of which has a very uniform thickness over the entire periphery of the fiber and its entire length.

BRIEF DESCRIPTION OF THE DRAWINGS

In FIG. 1 is a graphical representation of the result of the method of the invention compared to the result which can be achieved using known methods.

In FIG. 2 is a schematic illustration of how the yarn production method of the invention can be practiced practically.

In FIG. 3 schematically shows the structure of a spinnerette previously used.

In FIG. 4 is a schematic illustration of a nozzle for carrying out the method of the invention.

In FIG. 5 and 6, the nozzle construction of FIG. 4th

In FIG. 7 is a partial cross-sectional view of a known type of yarn.

In FIG. 8 is a partial cross-sectional view of the novel yarn of the present invention.

The invention will be further explained by way of example with reference to the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1, it is clear which region of the yarn is obtained by the process according to the invention. In FIG. 1 is a diagram showing the percent by volume of the packaging material on the x-axis and the percent A by the y axis for the bicomponent fibers with an M ± 0.1 M sheath. It is apparent that the known state allows the shredded portion desktop diagram. Thus, it is possible to make yarns from fibers with a coating material content of 25% or more, while the yarn according to the invention allows the use of less than 10% of the packaging material, even only 5% of this material. It is therefore clear that yarns with a much more uniform distribution of the proportion of packaging material can be obtained in a new way. Curve A corresponds to the conditions set forth in the main claim of the invention, curve B corresponds to the preferred embodiment according to claim 2 and curve C to the preferred embodiment according to claim 3 of the claims.

In FIG. 2 schematically shows an embodiment of the method according to the invention. The material supply apparatus 1 to the spinnerets 2, which are connected to the machine 1 by means of a flange, is shown, this section being described in more detail in FIG. 3, 4, 5 and 6. The device 1 comprises the usual inlets for molten or dissolved material, which are not shown. After spinning the bicomponent fibers or homogeneous fibers 8, the fibers pass through a cooling chamber 7 into which cooling air 9 is guided. Through the roller 5, the fibers are joined and fed to the drawing unit 3, 4 and finally the elongated fibers are wound up as a finished yarn.

In FIG. 3 shows a section of a spinneret according to the prior art. The first plate 10 and the second plate 11 are shown, the core stream being passed through the spinnerets 12 through the first plate 10 to the second plate 11a orifice into the cup 13. The flow of packaging material flows instead of rom between the first plate 10 and the second plate 11a. In this way, a sheath component is fed to each individual core material stream, and then both components flow together through the cup 13 into the opening 14 where they are extruded. In the region in which the sheath material flows around the core material, elevations 15 are formed on the second plate 11.

In FIG. 4 is a schematic representation of a spinnerette structure for use in carrying out the method of the invention. The first plate 20 and the second plate 21 of the spinneret are shown. The core material is fed through the orifice 26 into the nozzle channel 22 which continues into the second plate 21 as a channel 23. The packaging component is evenly distributed between the first plate 20 and the second plate 21 by the annular channels 28, the space between the first plate 20 and the second plate 21 being filled. a metal wire mesh 27 such that the channels 22 and 23 remain free. Thus, the sheath component is fed to the core component through the annular channel 28 through the mesh 27. The mesh 27 thus creates a flow resistance of the sheath material. The two components are then fed together into the nozzle 24.

In FIG. 5 and 6 illustrate one embodiment of a spinneret for carrying out the method of the invention, wherein FIG. 5 shows a longitudinal section and FIG. 6 cross section. Channel 32 feeds the core component to the first plate 20, while channel 33 feeds the packaging component (the continuation is shown in broken line as channel 33 then extends out of the plane), and then continuation 34 through the first plate 20 into the annular channels between the first plate 20 and A mesh 27 is placed between the first plate 20 and the second plate 21, which also maintains a constant distance between the first plate 20 and the second plate 21. The centering pins 31, the gasket 30 and the inserts 35 are also shown in the drawing to prevent leakage of the packaging. the components between the plate 29 already pass through the channels and the first plate 20.

In FIG. 7 shows a partial cross-section of a yarn of known type, the wrapper 37 appears to vary in thickness, as is the core 36. The same variations can be observed in the length of the individual fibers.

In FIG. 8 shows a partial straight section through the yarn according to the invention. The uniformity of distribution of the cores 38 and shells 39 is evident.

Examples 1 to 9

Examples 1 to 9 show the variation width in which the yarn according to the invention can be produced.

In Examples 1 to 3, a polyester with a viscosity typical of textile yarn (1 g of polymer in 100 g m-cresol measured at 25 ° C) was chosen as the core material; in Examples 4 to 6 a low viscosity polyester suitable for technical yarns and in Examples 7 to 9, a high viscosity polyester, for example applicable to a tire cord or sewing yarn. In all cases, polyamide 66 (PA 66) was used as the packaging material.

In each example, the rate of material feed to both the core and the sheath was varied. R.V.S. mesh was used as a resistance element. 60 mesh, which will be described in more detail in Examples 10 to 15. The spinneret of FIG. 4 to 6.

The bicomponent fibers were made in the manner shown in FIG. 2. The processing conditions are given in Table 1 below. Table 1 below shows how many percent A of the bicomponent fibers contained M volume percent of wrapping material based on the total fiber volume. Percentage A is the mean of 10 cross-sectional measurements at different points in the yarn.

Table 1

Example 1 2 3 4 5 6 7 8 9 The core polymer PET PET PET PET PET PET PET PET PET Relative viscosity 1.60 1.60 1.60 1.85 1.85 1.85 2.04 2.04 2.04 Flow rate (ml / min) 58.0 62.0 96.0 58.0 62.0 96.0 58.0 62.0 96.0 Pressure (MPa) 6.0 6.2 6.4 8.8 9.2 11.6 13.6 14.7 22.5 Temperature (° C) 299 299 299 299 299 299 299 299 299 container polymer PA66 PA66 PA66 PA66 PA66 PA66 PA66 PA66 PA66 Relative viscosity 3.12 3.12 3.12 3.12 3.12 3.12 3.12 3.12 3.12 Flow rate (ml / min) 9.0 6.6 6.1 9.0 6.6 6.1 9.0 6.6 6.1 Pressure (MPa) 5.2 4.1 3.9 5.0 4.8 4.3 5.0 4.8 4.4 Temperature (° C) 299 299 299 299 299 299 299 299 299 Flow through the mantle (% vol.) Core flow rate 15.2 11.0 6.9 15.2 11.0 6.9 15.2 11.0 6.9 Number of nozzle holes Diameter of holes 36 36 36 36 36 36 36 36 36 in veneer (pm) Speed 500 500 500 500 500 500 500 500 500 spinning (m / min) 500 500 500 500 500 500 500 500 500 A (%) 94 97 96 98 95 95 97 99 94 B (%) 15.2 11.0 6.9 15.2 11.0 6.9 15.2 11.0 6.9

The value A expresses the uniformity with which the yarn according to the invention can be produced, while at the same time the yarn can be produced with a very uniform ratio of the individual bicomponent fibers. This diameter D is usually in the range D ± 0.1 D.

Examples 10 to 15

Various tire cords were manufactured and their properties determined by the method of Examples 10-15.

In this case, a polyester with a relative viscosity of 2.04 was chosen as the core polymer. Polyamide 66 (PA66) was used as packaging material in Examples 10 and 11, and a mixture of polyamide 66 and 0.3% by weight of poly (m-xylylene adipamide), which is indicated as an additive in the following table, was used in Examples 12-15. Said mixture adheres very well to the polyester and also to the elastomeric materials, in particular rubber.

Each core-wrapping combination was wound without stretching in one case at a speed of 900 m / min and in the other case at 500 m / min, otherwise the method of FIG. 2. A 5V mesh was used as a resistance element. S. 60 mesh. This mesh was made of stainless steel wires. In both the longitudinal and transverse directions, the mesh always contained 60 wires per 2.54 cm in length. The mesh, commercially available, was made of 0.16 10 mm diameter steel wires.

The spinneret of FIG. 4 to 6.

In Examples 14 and 15, a 0.4 m long heating tube was used directly below the nozzle to achieve 15 slowed cooling of the material. Otherwise, the processing conditions are given in Table 2 below.

Table 2

Example 10 11 12 13 14 15 The core polymer PET PET PET PET PET PET Relative viscosity 2.04 2.04 2.04 2.04 2.04 2.04 Flow rate (ml / min) 96.0 96.0 96.0 96.0 96.0 96.0 Pressure (MPa) 17.5 12.2 17.5 17.5 14.5 14.5 Temperature (° C) 293 296 295 295 295 295 container polymer PA66 PA66 PA66 + PA66 + PA66 + PA66 + additive additive additive additive Relative viscosity 3.12 3.12 3.12 3.12 3.12 3.12 Flow rate (ml / min) 6.1 6.1 6.1 6.1 6.1 6.1 Pressure (MPa) 7.5 5.2 7.3 7.3 5.0 5.0 Temperature (° C) 293 296 295 295 295 295 Flow through the mantle (% vol.) Core flow rate 6.9 6.9 6.9 6.9 6.9 6.9 Number of nozzle holes Diameter of holes 36 36 36 36 36 36 in veneer (pm) 500 500 500 500 500 500 Heating tube length (m) 0.4 0.4 Heating tube temperature (° C) 290 290 Spinning speed (m / min) 900 500 900 500 900 500

The yarns obtained were finally drawn on a drawing machine. In this experiment, the yarn was fed from the take-up spool to the first spindle and then through a septum to the second spindle and then through a 10 m steaming path in which the yarn was steam treated at 250 ° C 5 to the third spindle and then wound. while maintaining the rate of debt. The septet was maintained at 75 ° C. The yarn elongation ratios of Examples 10-15 and the respective speeds are shown in Table 3. The elongation ratio in the septum means the ratio in which the yarn is elongated during the passing of the septet. The overall debt ratio is apparent from the speed difference between the first and third triads.

Table 3

example 10 11 12 13 14 15 length ratio in September 2.48 3.30 2.51 3.10 3.21 3.70 total elongation ratio 3.80 5.45 3.80 5.10 5.15 6.50 speed at length (m / min) 185 138 144 185 184

The properties of the yarn produced by this method are included in the following Table 4 in the Yarn paragraph. A LASE of 1% (N) means the strength of 25 yarns in N at a predetermined elongation of 1% (load at specific elongation. The same applies to the stated LASE values of 2% and LASE of 5%.

The HAS value of 47160 ° C (hot air precipitation for 4 minutes at 160 ° C) indicates the hot air coagulation of the yarn when the yarn is exposed to 160 ° C for 4 minutes with a load of 5 mN / tex.

The yarns obtained were processed into a 1100 (Z 472) x 2 (S 472) tire cord. The cord properties of this construction are also summarized in the following table 4 under the designation cord.

The cord thus obtained was conventionally provided with an adhesive layer. For this purpose, the cord was guided for 120 seconds through a 150 ° C oven under a 5 N bath, and then for 45 seconds through a 240 ° C oven under a 5 N bath. The bath contained the following components: demineralized water, sodium hydroxide, resorcin , VP-latex, ammonia.

The properties of the cord prepared in this way are also included in Table 4 below in the soaked cord paragraph.

The A and M values were identical for the yarn as well as for the dipped cord. Therefore, the values in the following Table 4 were given only in the yarn paragraph.

Table 4

Example 10 11 12 13 14 15 yarn Titer (dtex) 1384 1073 1382 1108 1029 874 Strength (mN / dtex) 717 803 723 816 837 933 Ductility (%) 9.3 10.9 9.4 9.5 11.5 9.4 1% (N) 13.2 11.1 13.5 11.3 10.8 9.8 LASE 3% (N) 21.4 17.4 21.6 18.2 17.0 15.0 LASE 5% 53.0 43.3 53.3 45.4 43.4 39.0 HAS 47160 ° C 3.3 4.6 3.3 4.3 4.5 5.6 A (%) 96 98 94 97 96 97 M (%) 6.9 6.9 6.9 6.9 6.9 6.9 cord Titer (dtex) 3141 2376 3120 2467 2247 1893 Strength (mN / dtex) 541 631 551 646 672 758 Ductility (%) 16.5 15.0 16.5 14.9 15.0 12.6 1% (N) 8.1 8.7 8.3 8.9 9.6 9.6 LASE 3% (N) 15.8 16.4 16.2 17.0 17.8 17.4 LASE 5% 34.7 33.9 35.5 35.7 37.9 36.9 HAS 47160 ° C 4.6 6.3 4.7 5.8 6.1 7.3 Pressed cord Titer (dtex) 3360 2533 3353 2633 2420 2035 Strength (mN / dtex) 498 583 501 578 617 645 Ductility (%) 16.3 15.6 16.5 15.1 16.0 13.2 1% (N) 12.5 12.3 12.2 12.0 12.5 11.8 LASE 3% (N) 22.8 21.5 22.4 21.4 21.6 20.5 LASE 5% 46.5 44.8 44.9 44.2 44.8 43.9 HAS 47160 ° C L5 2.0 1.4 1.8 2.0 2.3

PATENT CLAIMS

Claims (19)

A yarn of fibers consisting of a core and a coating, wherein the core and the coating are formed by spinning of spinnable polymers and at least almost all bicomponent fibers are provided with a complete coating, characterized in that all fibers coated in the yarn are A the percentage by weight of the packaging material (M ± 0,1 M) in the total volume of these fibers is such that it satisfies the following conditions: A <100 M> 0.5 A> 30 + (0.1 M) 8. Yarn according to claim 1, characterized in that A> 40+ 7 (0.1M) 8. 3. Yarn according to claim 1, characterized in that A> 50+ 100 (0.1M) 8. Yarn according to claim 1, characterized in that at least 60% of the coated fibers comprise a proportion of wrapping material (M ± 0.1 M), where M <9% by volume. Yarn according to claim 1, characterized in that at least 70% of the coated fibers comprise a proportion of wrapping material (M ± 0.1 M), wherein 1% by volume < M < 7% by volume. Yarn according to claim 1, characterized in that at least 75% of the coated fibers comprise a proportion of wrapping material (M ± 0.1 M), wherein 3% by volume < M < 6% by volume. 5 Yarn according to claims 1 to 6, characterized in that in the case of bicomponent fibers, the core is made of polyethylene terephthalate and the polyamide 66 sheath. Yarn according to claims 1 to 6, characterized by: 10, characterized in that, in the case of bicomponent fibers, the core is made of polyethylene terephthalate and the sheath is a mixture of polyamide 66 and poly (m-xylene adipamide). Yarn according to claims 1 to 6, characterized in that for bicomponent fibers 15, the core is made of polyamide 66 and the casing is also made of polyamide 66. Yarn according to claims 1 to 6, characterized in that, in the case of bicomponent fibers, the core is made of high viscosity polyethylene terephthalate. 20 low-viscosity polyethylene terephthalate packaging. Yarn according to claims 1 to 6, characterized in that, in the case of bicomponent fibers, the core is made of polyethylene terephthalate and the sheath is made of polyethylene terephthalate. 25 polyvinyllenedifluoride. A yarn production method according to claims 1 to 11, wherein the material is fed through the first spinner plate in a plurality of individual streams to a second spinneret plate, wherein between each of the first and second plates, material is supplied to the sheath layer. The two components are spun, lengthened and coiled together, characterized in that at least in the region of the individual streams of the core material, the packaging material supplied is subjected to flow resistance. Method according to claim 12, characterized in that a mesh is used as a resistance to the packaging material, which comprises a separate opening for each individual 10 stream. Method according to claim 12 or 13, characterized in that a resistance at a permeability in the range of 10 to 3 x 10 ¹⁰ m ² is selected. The method of claim 13, wherein the mesh comprises 30 to 500 wires per 2.54 cm. 16. A method according to any one of Claims 12 to 15, characterized in that such a high resistance is selected for the production of homogeneous substances that the flow of the wrapping material is stopped to the individual streams of the core material. The method according to claims 12 to 16, characterized in that the casing and / or core material is spun in the molten state. The method according to claims 12 to 16, characterized in that the coating material and / or the core material is spun from solution in a solvent, Method according to one of Claims 12 to 18, for the production of individual bicomponent fibers, characterized in that a first and a second spinneret plate equipped with only one aperture are used.