EP0290926B1 - False-twist textured bulky multifilamentary yarn, method for making it, and its use - Google Patents

Description

The invention relates to a false twist textured voluminous synthetic multifilament yarn made of a uniform raw material, consisting of at least two filament groups with different, but essentially identical individual titers ET 1 and ET 2. The invention further relates to a method for producing and the use of such a multifilament yarn.

Titer 55f46

unverwirbelt ist generell einsetzbar.

Titer 55f46 x 2

kann wegen zu geringer Fadenreinheit nur verwirbelt als Kettgarn für Hochleistungswebstühle eingesetzt werden.

Titer 55f46 x 3

ist auch verwirbelt zu flusig für den Einsatz als Kettgarn in der Weberei.

Titer 55f46 x 4

ist nur für besonders unempfindliche Bereiche einsetzbar.

Multifilamentgarne höheren Gesamttiters, also beispielsweise 150 dtex f 250, werden vorzugsweise nach dem Lufttexturierverfahren gebauscht. Gewebe, Wirk- und Strickwaren, die ausschließlich aus feinen ungedrehten Multifilamentgarnen mit kleinerem Einzeltiter als 1 dtex bestehen, haben zu wenig Stand und sind im Griff zu "lappig". Deshalb wird beispielsweise in wildlederartigen Geweben die Kette bevorzugt aus gröberen und nur der Schuß aus feineren Einzelkapillaren hergestellt. Ähnliches gilt für die Unter- und Oberkette bei Wirkwaren.The false twist texturing has proven to be the most cost-effective construction method for endless multifilament yarns with a total titer of less than 200 dtex. With this method, however, it has so far not been possible to produce a lint-free yarn that contains more than about 100 individual capillaries. The finest multifilament yarn made of polyethylene terephthalate (PET), which has previously been commercially manufactured using the false twist process, has the titer 56 dtex f 100. In practice, the following experience applies to fine capillary textured yarns for use in fabrics and knits:

Titles 55f46

Unwired is generally usable.

Titre 55f46 x 2

can only be used as a warp yarn for high-performance looms when interlaced due to insufficient thread purity.

Titre 55f46 x 3

is also tangled too fluffy for use as a warp yarn in the weaving mill.

Titre 55f46 x 4

can only be used for particularly insensitive areas.

Multifilament yarns with a higher total denier, for example 150 dtex f 250, are preferably bulked using the air texturing method. Fabrics, knitwear and knitwear made exclusively from fine untwisted multifilament yarns with a smaller single titer than 1 dtex, have too little stance and are too "lobed" in the handle. For this reason, for example, in suede-like fabrics, the chain is preferably made from coarser and only the weft from finer individual capillaries. The same applies to the lower and upper chain for knitwear.

EP-OS 0 124 869 discloses a water-repellent, high-density textile fabric in which, according to some exemplary embodiments, a synthetic multifilament yarn made from two filament groups of different individual deniers is used, the individual denier of one filament group being extremely fine and the individual denier of the other filament group being significantly coarser . However, this is not a false twist textured multifilament yarn. Rather, the unification of the finer and coarser filament groups takes place, among other things. when triggering their different shrinkages. This process is therefore complex, both in its implementation and in the finishing of the fabrics made from these yarns, since they have a minimal shrinking force.

Furthermore, numerous methods for producing a synthetic multifilament yarn from a uniform raw material, consisting of at least two filament groups with different, but essentially identical, individual titer are already known. In this process, the two filament groups are jointly stretch-textured after spinning using the false twist process. The two filament groups are pre-oriented differently so that the draw ratio of the filament group with coarser single titer is smaller than that of the filament group with finer single titer. The draw ratio is to be understood as the draw ratio in which a draw texturing of each of the individual filament groups has a maximum tensile strength extension of 25% (compare e.g. DE-OS 23 08 031, Lenzinger reports, issue 47, 1979, p. 67f, EP-OS 0 022 065, man-made fibers / textile industry, 37th / 89th year, Febr. 1987, p. 107f). In these methods, however, filament groups of very different draw ratios are combined, with the aim of creating loops or protruding fiber ends by under or over drawing a filament group during texturing in order to impart fiber yarn character to the multifilament yarn.

Finally, methods are known in which a false-twist textured yarn, which preferably consists of bundles with different capillary thicknesses, is given a fiber-yarn-like character in that it is rotated alternately in the S and Z directions due to the extremely low outlet tension during texturing and the associated slipping of the twist (see DE-OS 29 34 762 and EP-OS 0 022 065). However, similar to staple fiber yarns, these yarns have only a small volume due to their high twist and are unsuitable for the intended use.

The invention has for its object to provide a false twist textured voluminous synthetic fine capillary, lint and loop free and inexpensive to manufacture multifilament yarn and a method for producing such a multifilament yarn.

gilt.To solve this problem, a false twist textured voluminous synthetic multifilament yarn made of a uniform raw material, consisting of at least two filament groups with different, but essentially the same single titer ET₁ and ET₂ according to the invention characterized in that for the finer single titer ET₂ <1 dtex and for the total titer T. of the textured yarn $\text{T> 100 x ET₂}$

applies.

By selecting the individual titer of the two filament groups, it is possible to overcome the "lobed" grip of fabrics that consist only of multifilament yarns with a single titer smaller than 1 dtex. Preferably, only two different spun filament groups are presented for joint simultaneous stretch texturing. The filament yarns according to the invention are bulky. They have no alternating S and Z filament groups or core and sheath filament groups. Preferably (but not necessarily) the filament yarns according to the invention are twist-free.

. Hierdurch ist trotz des feinen Einzeltiters ET₂ < 1 dtex gemäß der vorliegenden Erfindung eine ausreichende Steifigkeit des aus diesem Multifilamentgarn herzustellenden Flächengebildes erzielbar.If the individual capillaries of both filament groups have a round cross-section, the following applies expediently for the individual titers ET 1 and ET 2: $\text{3 <ET₁ / ET₂ <8}$

. As a result, despite the fine single titer ET₂ <1 dtex according to the present invention, sufficient stiffness of the fabric to be produced from this multifilament yarn can be achieved.

gewählt werden.According to a special embodiment of the present invention, a round cross section is used for the individual capillaries of the finer filament group and a profiled cross section for the individual capillaries of the coarser filament group, for example in the form of a pronounced Y. Since the profiled cross section already gives the multifilament yarn increased rigidity, the titer ratio should be in this case $\text{1.5 <ET₁ / ET₂ <4}$

to get voted.

The synthetic polymers used can be pure or modified polyesters or polyamides. The polyesters can be subjected to direct esterification or transesterification and subsequent Condensation have been produced. Instead of ethylene glycol, other diols, such as 1,3-propanediol, 1,4-butanediol, etc., and other dicarboxylic acids, such as isophthalic acid, adipic acid, etc., can also be used instead of terephthalic acid. The polyamides can be either type 6 or 6.6 or their copolymers.

• a) die Spinntiter der beiden Filamentgruppen so gewählt werden, daß für den feineren Einzeltiter ET₂ des streck-texturierten Garnes ET₂ < 1 dtex und den Gesamttiter T des strecktexturierten Garnes $\text{T > 100 x ET₂}$
  
  
  gilt,
• b) die Verstreckverhältnisse VE₁ und VE₂ so gewählt werden, daß $\text{VE₂ - VE₁ < 0,1}$
  
  gilt,
• c) das gemeinsame Strecktexturieren bei dem Streckverhältnis VE₁ der Filamentgruppe mit gröberem Einzeltiter durchgeführt wird,
• d) und daß die Spannung des Garns nach Verlassen der Texturierspindel größer als 0,3 cN/dtex gewählt wird.

A process for producing a synthetic multifilament yarn from a uniform raw material, consisting of at least two filament groups with different, but essentially the same individual titer, in which process the two filament groups are spun and then stretch-textured together in the false twist process, the spinning take-off speeds of the two filament groups between 2500 and 5000 m / min are selected and the two filament groups are differently pre-oriented so that the draw ratio VE₁ of the filament group with coarser single titer is smaller than the draw ratio VE₂ of the filament group with finer single titer, with the draw ratio being understood as the draw ratio in which a draw texturing each of the individual filament groups would give a maximum tensile strength extension of 25%, is characterized according to the invention in that

• a) the spin titer of the two filament groups are chosen so that ET₂ <1 dtex for the finer single titer ET₂ of the stretch-textured yarn and the total titer T of the stretch-textured yarn $\text{T> 100 x ET₂}$
  
  
  applies
• b) the draw ratios VE₁ and VE₂ are chosen so that $\text{VE₂ - VE₁ <0.1}$
  
  applies
• c) the joint stretch texturing is carried out at the stretch ratio VE 1 of the filament group with coarser single titer,
• d) and that the tension of the yarn after leaving the texturing spindle is chosen to be greater than 0.3 cN / dtex.

In the method according to the invention, the degree of orientation of the two filament groups and the draw ratio when stretch texturing together (co-texturing) are selected so that the co-texturing involves drawing the two filament groups under essentially the same tension. In this way, in contrast to the previously known cotexturing processes which aim to produce loops or protruding fiber ends, it has been possible to produce a false-twist textured, fine-capillary, lint-free and loop-free multifilament yarn. In addition, the method according to the invention is characterized by low manufacturing costs.

To spin the two filament groups, the raw material granules are dried, melted, filtered and pressed through spinnerets in accordance with the generally customary yarn production process. The resulting multifilament yarns are cooled by an air stream, provided with a spin finish, swirled and wound up.

The different pre-orientation of the two filament groups can be achieved by spinning at different spinning take-off speeds on different spinning systems. In this case, the two filament groups are only combined during stretch texturing.

According to a preferred embodiment of the invention the different pre-orientation of the two filament groups by means of suitable procedural measures at adjacent spinning positions, that is to say with the same spinning take-off speed, so that the two filament groups are combined after preparation and then swirled and wound up together. These procedural measures for a higher pre-orientation of the coarser filament group can consist in profiling the cross-section of the individual capillary. Another possibility is an additional heat treatment of the filament group in question in a tube heated to 80 ° C to 150 ° C, which is attached in the area between the blowing and preparation, such as in EP-OS 0 013 101, examples 5 and 6 and figure 2 described.

Preferred areas of application of the multifilament yarn according to the invention are water-repellent fabrics, clean room clothing and the conductive component in sports clothing. If only one heater is heated during stretch texturing, high-shrinking multifilament yarns are created, which are particularly suitable for the production of fine-pored textile fabrics for rainwear and cleanroom clothing. A yarn according to the invention with a shrinkage <10% at 130 ° C. is suitable for use in double-surface articles which contain a conductive and a sorptive component for reasons of clothing physiology, which is obtained by additionally heating the second heater during stretch texturing.

The procedure for carrying out the method according to the invention will now be explained on the basis of the single figure which shows the relationship between the spinning titer and the draw ratio.

In the figure, the individual titer of the Spinning thread (spinning titer), measured in dtex, applied on a logarithmic scale. The ordinate shows the draw ratio of the filament, starting at 1: 1.0 in the origin.

As is known, a measure of the degree of orientation of a spun fabric is the stretching ratio VE used in the stretch texturing of the outlet speed at the delivery unit 2 to the inlet speed at the delivery unit 1 on the stretch texturing machine. The draw ratio is to be understood as the draw ratio which leads to a maximum tensile force elongation of the draw textured yarn of approximately 25%.

The curves a, b, c shown in the diagram represent the relationship between the draw ratio and the spinning titer, curve a for a spinning yarn with a spinning take-off speed of 4000 m / min with a round cross-section of the individual capillary, curve b for a spinning yarn with a spinning take-off speed of 3000 m / min with a round cross section of the individual capillaries and curve c for a spinning yarn with a spinning take-off speed of 3000 m / min with a Y cross section of the individual capillaries.

It is not surprising that all curves for constant spinning take-off speed meet at the origin of this coordinate system ET = 0.01 → 0 and VE 1: 1.0. It is surprising, however, that the curves for constant spinning take-off speeds prove to be a straight line. This facilitates the selection of suitable filament groups (spun threads) for carrying out the method according to the invention.

erfüllen.As can easily be seen, the diagram allows the spin filament for the two filament groups To choose the respective pre-orientation of the filament groups so that their draw ratios are the condition $\text{VE₂ - VE₁ <0.1}$

fulfill.

The method according to the invention is now explained in more detail with the aid of examples.

Example I

A spinning thread 1 made of PET is produced with a conveyance of 28 g / min by spinning from 22 round bores at a spinning take-off speed of 4000 m / min. This spinning thread 1 with the titer 70f22 is presented as a trial to a stretch texturing machine, the stretching ratio of which is set to 1: 1.28 and the iron temperature of which is set to 195 ° C., and stretch textured at 400 m / min winding speed. The tensile force of the yarn after leaving the texturing spindle is 24 cN. In the subsequent tear test, the following measured values were obtained: tenacity 36 cN / tex, maximum tensile elongation 24%.

In an analogous manner, a spinning thread 2 is produced from the same raw material with a conveyance of 20 g / min, a number of round bores of 88 and a spinning take-off speed of 3000 m / min. After the drawing texturing of the spinning thread 2 on the same drawing texturing machine, at the same temperature and winding speed as the spinning thread 1, but with a drawing ratio of 1: 1.34, the tensile force of the yarn being 23 cN after leaving the texturing spindle, the following measured values result : Fineness 37 cN / tex, maximum tensile elongation 25%.

The draw ratio of the two spun threads 1 and 2 differs by 5%, so the difference is less than 0.1.

To produce a yarn according to the invention, both spun threads 1 and 2 (filament groups) are used together on one Texturing point under the conditions of the filament 1 stretch textured. The tensile force of the yarn after leaving the texturing spindle is 51 cN. This creates a loop-free, lint-free, voluminous multifilament yarn with the following properties:
Fineness 37 cN / tex, maximum tensile elongation 22%, shrinkage of 41% at 130 ° C. The multifilament yarn has a total titer of 116 dtex and contains 88 single capillaries with a single titer ET₂ of 0.6 dtex and 22 single capillaries with a single titer ET₁ of 2.5 dtex.

For illustrative purposes, the data of the filaments 1 and 2 are entered as points A and B in the diagram of the single figure. For all other spinning threads with a round cross-section, which are spun on similar lines at 3000 or 4000 m / min, the stretching ratios for the individual titers can be found from lines a and b.

Example II

In this example, single capillaries with a round cross section are used for the spinning thread 2 with a finer single titer and single capillaries with a profiled cross section, for example in the form of a Y, for the spinning thread 1 with a coarser single titer. The data for the two strands 1 (corresponding to point C of the diagram) and 2 are as follows:

The two spinning threads 1 and 2 are spun on side by side spinnerets of the same spinning system, that is to say with the same spinning take-off speed. After this Cooling and preparation of the two previously running spun threads are brought together and swirled together before winding. The combined spun thread thus obtained is stretch-textured under the conditions of the spinning thread 1. The tensile force of the yarn after leaving the texturing spindle is 51 cN. The yarn thus obtained is lint and loop free and has the following properties: tenacity 35 cN / tex, maximum tensile elongation 20%, shrinkage of 45% at 130 ° C. The multifilament yarn has a total titer of 122 dtex and contains 88 single capillaries with a round cross section with a single titer ET₂ of 0.6 dtex and 60 single capillaries with a Y cross section with a single titer ET₁ of 0.9 dtex.

In this embodiment it is also possible to vary the stiffness of the yarn. This will be illustrated using an example III.

Example III

In this example, the stiffness of the yarn is increased according to the points B 'and C' in the figure. For this purpose, spinning pumps with different feed per revolution are used for the spun threads 1 and 2 spun next to one another. The data for the two strands are as follows:

The swirled combined spun thread 1 + 2 is textured with the draw ratio 1: 1.36 and otherwise at the same temperature and speed as in Example I. The tensile force of the yarn after leaving the texture spindle is 52 cN. The voluminous multifilament yarn thus obtained is lint and loop free and has the following data: tenacity 36 cN / tex, maximum tensile elongation 23%, shrinkage 42% at 130 ° C. The titer is 118 dtex. The multifilament yarn contains 40 individual capillaries with a round cross section with a single titer ET₂ of 0.8 dtex and 48 individual capillaries with a Y cross section with a single titer ET₁ of 1.3 dtex.

• 1) durch Fachen der feinkapillarigen Spinnware vor dem Texturieren nicht möglich ist, ein flusenfreies Garn herzustellen;
• 2) auch durch Fachen von fein- und grobkapillarigem texturierten Garn nicht möglich ist, ein für die vorgesehenen Einsatzgebiete geeignetes Garn herzustellen. Dieses Ziel wird somit nur durch die vorliegende Erfindung erreicht.

The following comparative examples show that it

• 1) it is not possible to produce a lint-free yarn by folding the fine capillary spun fabric before texturing;
• 2) it is also not possible to produce a yarn suitable for the intended areas of application by weaving fine and coarse capillary textured yarn. This aim is therefore only achieved by the present invention.

Comparative Example 1

Two spinning bobbins of the spinning thread 2 from Example I with the titer 67f88 are textured together with the draw ratio 1: 1.34 and, moreover, under the conditions described there. A fluffy yarn is created. This result is also obtained when the stretching texture ratio is gradually reduced to 1: 1.28, 1: 1.24 or 1: 1.20, i.e. no suitable texturing conditions can be found for this yarn.

Comparative Example 2

The spun threads 1 and 2 described in Example I are simultaneously on two adjacent texturing points under the texturing conditions specified in Example I, namely with the stretching ratios 1: 1.28 or 1: 1.34 textured. This ensures that both capillary bundles are fed with the same tension from the texturing zone of the winding. Despite these optimal conditions, it was not possible to mix both yarns as intensely as required for a suitable warp yarn by swirling in an air stream. Already after the texturing process, the yarn 2 with the fine single titer 0.6 dtex is mixed so intensively that it can no longer be opened in the air stream to the extent necessary for a thorough mixing of the two yarns.

As the examples given show, it is only possible according to the teaching of the present invention to produce flawless, false-twist textured, voluminous (preferably twist-free) yarns with ET₂ less than 1 dtex and a total titre greater than 100 x ET₂.

Claims (9)

1. A false twist textured bulky synthetic multifilament yarn made of a single raw material and consisting of at least two groups of filaments, the filaments of the one group having the same filament linear density FLD1 and the filaments of the other group having the same filament linear density FLD2, FLD1 being different from FLD2, characterized in that the finer filament linear density FLD2 is subject to the relation FLD2 < 1 dtex, the total linear density TLD of the textured yarn is subject to the relation $\text{TLD > 100 × FLD2}$

   

   

   , and the filament linear densities FLD1 and FLD2, given a round cross-section for the individual filaments of the two groups of filaments, are subject to the relation $\text{3 < FLD1/FLD2 < 8}$

   

   .
2. A false twist textured bulky synthetic multifilament yarn made of a single raw material and consisting of at least two groups of filaments, the filaments of the one group having the same filament linear density FLD1 and the filaments of the other group having the same filament linear density FLD2, FLD1 being different from FLD2, characterized in that the finer filament linear density FLD2 is subject to the relation FLD2 < 1 dtex, the total linear density TLD of the textured yarn is subject to the relation $\text{TLD > 100 × FLD2}$

   

   

   and in that the filament linear densities FLD1 and FLD2, given a round cross-section for the individual filaments of a group of filaments having the finer filament linear density and a profiled cross-section for the individual filaments of the group of filaments having the coarser filament linear density, are subject to the relation $\text{1.5 < FLD1/FLD2 < 4}$

   

   .
3. The false twist textured bulky synthetic multifilament yarn of claim 1 or 2, characterized in that the total linear densities TLD1 and TLD2 of the two groups of filaments are subject to the relation $\text{3/7 < TLD1/TLD2 < 7/3}$

   

   

   .
4. A process for producing a synthetic multifilament yarn of a single raw material and consisting of at least two groups of filaments having different, but within each group essentially the same, filament linear densities, in particular as claimed in any one of the preceding claims, in which process the two groups of filaments are spun and then jointly draw textured by false twisting, the spinning take-off speeds for both the groups of filaments being between 2500 and 5000 m/min and the two groups of filaments being differently oriented in such a way that the draw ratio DR1 of the group of filaments having the coarser filament linear density is smaller than the draw ratio DR2 of the group of filaments having the finer filament linear density, the draw ratio being that draw ratio which, if each of the individual groups of filaments were subjected to draw texturing, would produce a breaking extension of 25%, characterized in that

   a) the as-spun linear densities of the two groups of filaments are chosen in such a way that the finer filament linear density FLD2 of the draw textured yarn is subject to the relation FLD2 < 1 dtex and the total linear density TLD of the draw textured yarn is subject to the relation $\text{TLD > 100 × FLD2}$

   

   ,

   b) the draw ratios DR1 and DR2 are chosen in such a way that $\text{DR2 - DR1 < 0.1}$

   

   holds,

   c) the joint draw texturing is carried out at the draw ratio DR1 of the group of filaments having the coarser filament linear density,

   d) and the tension of the yarn on leaving the texturing spindle is chosen to be greater than 0.3 cN/dtex.
5. The process of claim 4, characterized in that the two groups of filaments are produced at different spinning take-off speeds in order to achieve a difference in orientation and are only combined at the draw texturing stage.
6. The process of claim 4, characterized in that the two groups of filaments are spun at the same spinning take-off speed with different orientations and are wound up together prior to draw texturing.
7. The use of the yarn of any one of claims 1 to 3 having a shrinkage of > 10% at 130°C for manufacturing waterproof woven or knitted fabric.
8. The use of the yarn of any one of claims 1 to 3 having a shrinkage > 10% at 130°C for manufacturing finely pored woven or knitted fabric for clean room clothing.
9. The use of the yarn of any one of claims 1 to 3 having a shrinkage < 10% at 130°C as a conductive component in the manufacture of sportswear.

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