EP1877601B1

EP1877601B1 - Melt spinning method for producing a composite yarn as well as a composite yarn

Info

Publication number: EP1877601B1
Application number: EP05797782A
Authority: EP
Inventors: Suprit School of Textile Design & Fashion SINGH; Markus Reichwein; Ulrich Enders; Klaus Schäfer
Original assignee: Oerlikon Textile GmbH and Co KG
Current assignee: Oerlikon Textile GmbH and Co KG
Priority date: 2005-03-09
Filing date: 2005-09-23
Publication date: 2012-04-25
Anticipated expiration: 2025-09-23
Also published as: KR20070110342A; WO2006094538A1; EP1877601A1; CN101137775B; CN101137775A

Abstract

The invention relates to a melt spinning method for producing a composite yarn as well as a composite yarn. The production of the composite yarn occurs by two parallel spun filament bundles, with one of the filament bundles being cooled to a POY yarn with a partially oriented molecular structure, and the second filament bundle being cooled to an HOY yarn with a highly oriented molecular structure. The POY yarn and the HOY yarn are jointly withdrawn and combined to the composite yarn. To ensure the physical properties that are required for textile applications, and the desired yarn effects, the invention provides for combining the filaments of the POY yarn and the filaments of the HOY yarn to a mass ratio in the composite yarn of MPOY/MHOY ≤ 2.5, with the filaments of the POY yarn having a denier ≥ 2.0 deniers, and the filament bundles of the HOY yarn having a denier ≤ 4.0, preferably ≤ 1.5 deniers.

Description

The invention relates to a melt spinning method for producing a composite yarn as defined in the preamble of claim 1, as well as a composite yarn as defined in the preamble of claim 15.
A generic method of melt spinning as well as a generic composite yarn are disclosed in DE 101 16 294 A1 .
For textile applications of synthetic fibers it is common to use in part so-called effect yarns, which exhibit special yarn effects, such as, for example structure effects, glaze effects, or color effects. Such yarn effects can be produced by blending dissimilar synthetic fibers. In this connection, one distinguishes in the art between a two-stage method, wherein the synthetic fibers are produced separately from one another and wound to packages in a first process stage. In a second process stage, the yarns are unwound from feed yarn packages and combined to a composite yarn. A method of this type is disclosed, for example, in US 5,980,355 or US 5,943,852 .
In a second variant, the dissimilar fibers are extruded in a spinning process and combined to a composite yarn in a single stage. The invention proceeds from this variant of producing a composite yarn. In the melt spinning method disclosed in DE 101 16 294 , two filament bundles are extruded side by side from a polymer melt, for example, a polyester. After extruding, one of the filament bundles is cooled and drawn in such a manner that a POY yarn with a preoriented molecular structure is formed. The parallel extruded second filament bundle is cooled and drawn in such a manner that an HOY yarn forms with a highly oriented molecular structure. After cooling and drawing, the two yarns are combined to a composite yarn. Composite yarns of this type distinguish themselves by a high shrinkage difference in the fibers, since a POY yarn has a high boiling water shrinkage, and an HOY yarn has a relatively low boiling water shrinkage in the fibers. These composite yarns are especially suited for producing structure effects, such as, for example, bulkiness.
In practice, however, it is desired to make such composite yarns accessible to a wide spectrum of applications with different yarn effects.
US 5,858,290 discloses a melt spinning method for producing a composite yarn, wherein two filament bundles are extruded parallel in side-by-side relationship, and cooled under identical conditions, so that after cooling two POY yarns form with a preoriented molecular structure. Before combining the two yarns, one of the yarns is fully drawn, so that an FOY yarn forms. The POY yarn and the FOY yarn are then combined to the composite yarn. However, the fiber differences which originate from drawing, have the disadvantage that the limited withdrawal speed of a POY yarn permits producing only very limited differences in the physical properties of the fibers.
In comparison therewith, DD 266 598 A1 discloses a method of producing a composite yarn, wherein the filament bundles advance through different setting zones directly after extruding and before cooling. In this process, the action of a so-called.afterheater is used to attain a delayed crystallization in one of the filament bundles. After a joint cooling, the filament bundles are combined and wound as a composite yarn to a package. Likewise, this process permits producing different physical properties in the individual fibers only within relatively narrow limits. Thus, the composite yarns disclosed in US 5,858,290 and DD 266 598 A1 are limited to a maximum shrinkage difference in the fibers of at most 30%.
H. TREPTOW: "LOY-MOY-POY-HOY-FOY", CHEMIEFASERN/TEXTILINDUS-TRIE, June 1985 (1985-06), pages 411-412 in particularly defines the term POY yarn as a polyester yarn produced at a spinning speed between 3.000 to 4.000 meter per minute and the term HOY yarn as a polyester yarn produced at a spinning speed between 4.200 to 6.000 meter per minute.
EP-A-1 361 300 discloses a method for manufacturing polyester mixed fiber yarn by melt-extruding a polyester composition A which comprises a substrate polymer comprising a polyester and 0,5 to 5,0 percent by weight of a polymer P being different from the substrate polymer. The object of said document is to provide a method for stably producing a polyester blended yarn which comprises two or more filament groups having different elongations, giving a woven or knitted fabric exhibiting a higher-grade texture than those of conventional fabrics and being excellent in post processability.
US-B1-6 723 265 relates to a method for producing polyester-based combined filament yarn, wherein a polymer different from a base polymer comprising a polyester component in an amount within the range of 0,3 to 5,0 percent by weight based on the base polymer is added to the base polymer. The filaments of the yarn are taken off at a speed of 2.500 m/min or above, wherein a spinneret hole diameter of a filament group without being subjected to a heat treatment is 1,5 times or above a spinneret hole diameter of a filament group in a open state subjected to a heat treatment.
JP-A-10 298839 discloses a method for producing a yarn for a fabric having light weight and spun-like fuzzy feeling although having high density. The combined filament yarn is composed of a HOY yarn A and a polyester-based slightly shrinkable yarn B having a lower hot water shrinkage percentage than yarn A.
WO-A1-93 10292 relates to a process for improving the properties of a mixed shrinkage yarn of spin-oriented polyester filaments of elongation-to-break 40 to 120 percent comprising polyester filaments of high boil-off shrinkage greater than 15 percent and of low shringage polyester filaments. The mixed shrinkage yarn is cold-drawn without heat-setting to provide drawn filaments of elongation-to break less than 30 percent from drawing said filaments of high boil-off shrinkage, and wherein said low shrinkage filaments are of tenacity at 7 percent elongation at least 0,7 grams/denier, boil-off shrinkage less than 10 percent, thermal stability as shown by an value less than +1 percent, net shrinkage less than 8 percent, maximum shrinkage tension less than 0,3 grams/denier, density 1,35 to 1,39 grams/cubic centimeter, and crystal size 55 to 90 Angstroms and also at least (250p - 282,5) Angstroms.
It is therefore an object of the invention to further develop the generic melt spinning method for producing a composite yarn as well as the composite yarn such that a widest possible spectrum for producing yarn effects is created while maintaining a highest possible shrinkage difference.
A special object of the invention consists in attaining as much as possible for each desired yarn effect an optimum of the fiber blend in the composite yarn.
In accordance with the invention, this object is accomplished by a melt spinning method with the steps of claim 1, as well as by a composite yarn with the features of claim 15.
Advantageous further developments of the invention are defined by the features and feature combinations of the respective dependent claims.
The invention is based on the knowledge that the blending ratio of the fibers in the composite yarn as well as the fiber cross sections are decisive for defining the characteristic and thus the possible application of the composite yarn. In this connection, limit values have crystallized for the application in the textile field, which are to be maintained for adjusting the yarn effects that are common for textile applications. The filaments of the POY yarns and the filaments of the HOY yarns are thus combined in the composite yarn at a mass ratio of M_POY/M_HOY ≤ 2.5. In this combination, the filaments of the POY yarn have a denier ≥ 2.0 deniers, and the filaments of the HOY yarn have a denier of ≤ 4.0 deniers, preferably ≤ 1.5 deniers. This guarantees on the one hand the required strengths which are largely defined by the POY yarn. On the other hand, a bulkiness of a shrunk yarn which is produced by loops and curls, is advantageously formed by the filaments of the HOY yarn. In this case, it is possible to obtain an open loop structure by the mass ratio.
Depending on the case of application and the therewith connected yarn effect, it is possible to produce the composite yarn with different mass percentages of the POY yarn and HOY yarn. Thus, the ranges of the mass ratio of M_POY/M_HOY from 1.0 to 2.5 are especially suited for producing structure effects and color effects in the composite yarn. To produce color effects, a range of the mass ratio of M_POY/M_HOY from 0.5 to 0.75 has also been found very advantageous.
To be able to still better influence the possibility of combination and the characteristic of the composite yarn, the further development of the method according to the invention is especially preferred, wherein the POY yarn and the HOY yarn are each formed from a different number of filaments in the filament bundle with different deniers of the filaments. With that, it is possible to realize individual combinations between the POY yarns and the HOY yarns.
An essential aspect in the melt spinning process of a composite yarn is the combination of the POY yarn and the HOY yarn. In this connection, the variant of the method has shown especially useful, wherein the composite is produced by a multistage entanglement, with a first stage occurring in an initial entanglement after cooling, and a second stage by a main entanglement before winding the composite yarn. The initial entanglement occurring after cooling has the advantage that the POY yarn and the HOY yarn can jointly advance in the spinning process for their further treatment, without producing an overly intensive yarn cohesion. Only before winding, will a main entanglement take place, which causes the two yarns to combine by means of entanglement knots.
In this process, an adequate yarn cohesion will advantageously be reached, when the main entanglement is performed under an overpressure of the air, which permits producing in the composite yarn at least a number of 25 entanglement knots per meter.
In the case that the main entanglement is carried out between two godets, it is possible to perform as an alternative a third entanglement of the composite yarn for purposes of causing the filaments to intermingle as is needed for the further treatment of the composite yarn.
To combine the filaments of the POY yarn and the filaments of the HOY yarn, the filaments of the POY yarn are lubricated after cooling and advancing through a spin zone ≥ 800 mm. In this process, a greater spin zone of the POY yarn enables a slower cooling, which is accompanied by an increase of the withdrawal speed. In so doing, the filament bundle of the POY yarn and the filament bundle of the HOY yarn are withdrawn at the same withdrawal speed.
In the case that the POY yarn is cooled by a cooling air stream that is generated in the direction of the advancing yarn, withdrawal speeds in range above 3,500 m/min. and higher are possible.
To be able to attain yet maximal shrinkage differences in the composite yarn, an advantageous further development provides for adjusting cooling and withdrawal of the filament bundle of the POY yarn such that a boiling water shrinkage results of at least 50%, preferably in ranges from 50% to 70%. In comparison therewith, the cooling and withdrawal of the filament bundle of the HOY yarn are adjusted such that a boiling water shrinkage results in the yarn of at most 10%, preferably in a range from 4% to 10%. With that, it is possible to realize boiling water shrinkage differences in the composite yarn of ≥40%, preferably ≥45%.
Despite the common withdrawal of the two filament bundles, it is possible to ensure a great individual adjustability while extruding and cooling the filament bundles, in that the method steps are performed by separately controllable processing units.
At the end of the process, the composite yarn is wound to a package, with the takeup speed being adjusted only insignificantly higher than the withdrawal speed. To be able to attain the characteristic of the POY yarn and the HOY yarn, the takeup speed differs from the withdrawal speed only by a factor in a range from 0.95 to 1.2.
The composite yarn of the invention distinguishes itself as effect yarn for textile applications. The composition of the POY yarn and the HOY yarn in accordance with the invention permits generating in the composite yarn both structure effects and color effects in a particularly intensive way. The similar crystalline structure of the POY yarn and the HOY yarn is especially advantageous during a subsequent dyeing of the composite yarn. The filaments of the composite yarn absorb dyes with the same intensity, so that no color differences develop within the composite yarn.
It has been found that as a function of the desired yarn effects, certain ranges of the mass ratios are considered especially suited for attaining between the POY yarn and the HOY yarn, effects that are directed in particular to the yarn effects. In this connection, mass ratios of 1.0 to 2.5 or 0.5 to 0.75 have crystallized as advantageous ranges.
It is thus possible to produce structure effects in particular at a mass ratio in a range from 1.0 to 1.5, at which the broken filaments of the HOY yarn are produced in a subsequent texturing process, to obtain, for example, a wooly effect or a spun-like effect. The filament deniers of the HOY yarn are in a range of ≤ 1.5 deniers.
Color effects, such as, for example, a mixed color effect, can be very advantageously produced by the mass ratio M_POPY/M_HOY in a range from 1.5 to 2.0 or, alternatively, also in a range from 0.5 to 0.75.
The composite yarn of the invention distinguishes itself in particular by the high shrinkage difference in the filament, so that so-called flat effects can be produced with high shrinkage differences of more than 40%. The composite yarn of the invention opens totally new possibilities for textile applications, which have so far been reserved only to composite yarns that were produced by the two-stage process.
To guarantee the yarn cohesion that is required for further processing the composite yarn, the filaments of the POY yarn and the HOY yarn are interconnected by a high number of entanglement knots. In this connection, it is absolutely necessary to maintain a lower limit value of 25 entanglement knots per meter.
In the following, the method for producing the composite yarn is described in greater detail by means of an embodiment with reference to Figure 1.
Figure 1 is a schematic view of the setup of a spinning apparatus. The spinning apparatus comprises a POY spinning position 1 as well as an HOY spinning position 2, which are arranged side by side with no space inbetween. The spinning position 1 includes a driven spin pump 1.1 which connects to a source of melt not shown. The spin pump 1.1 connects to a spinneret 1.2. The spinneret 1.2 which experts also name spin pack is arranged in a heatable spin head 1.3. On its underside, the spinneret 1.2 comprises a plurality of spin holes (not shown). Downstream of the spin head 1.3, a cooling device 1.4 extends. The construction of the cooling device 1.4 within the POY spinning position is basically disclosed in DE 101 16 294 A1 , so that this publication is herewith incorporated by reference. The special feature of the cooling device 1.4 is that the filament strands are cooled by means of a cooling tube, in which a cooling air stream generated in the direction of the advancing yarn cools the filament bundle as much as possible free of stress. At the outlet end of the cooling device 1.4, a yarn lubrication device 1.5 is provided for combining the cooled filaments to a POY yarn 3.
The HOY spinning position 2 comprises likewise a driven spin pump 2.1, which connects to a source of melt. In the production of the composite yarn from a polymer melt, it is common to connect the spin pumps 1.1 and 2.1 to an extruder.
The spin pump 2.1 connects to a spinneret 2.2, which comprises on its underside a plurality of spin holes for extruding a plurality of filament strands. The spinneret 2.2 is arranged in a heatable spin head 2.3. Downstream of the spin head 2.3, a cooling device 2.4 extends, and at the outlet end of the cooling device 2.4, a yarn lubrication device 2.5 follows. The construction of the cooling device is likewise disclosed in DE 101 16 294 A1 , so that for the description of the cooling device, the foregoing publication is herewith incorporated by reference. Essential is that the cooling device 2.4 is operated separately and independently from the cooling device 1.4, so that the filaments produced in the HOY spinning position 2 are differently cooled than the filaments spun in the POY spinning position 1. In this connection, it is essential that the spin zone, in which the filaments are cooled, is made, because of process conditions, substantially shorter in the HOY spinning position 2 than in the POY spinning position 1. In this connection, the spin zone is identified by the distance of the yarn lubrication devices 1.5 and 2.5 from the respective undersides of spinnerets 1.2 and 2.2. In the case of the POY spinning position 1, the spin zone has a length of at least 800 mm. Preferably, it is made longer than the spin zone of the HOY spinning position 2, which has a maximum length of 900 mm.
In the HOY spinning position 2, the yarn lubrication device 2.5 combines the filaments to an HOY yarn 4.
The POY yarn 3 and the HOY yarn 4 are withdrawn by a godet unit 7, which comprises a driven withdrawal godet 8 and a guide roll 9. In so doing, the HOY yarn 4 advances downstream of the yarn lubrication device 2.5 over deflection rolls 5.1 and 5.2 into the path of the advancing POY yarn 3. As deflection rolls 5.1 and 5.2, it is preferred to use freely rotatable rolls, preferably supported in air bearings, to generate the least possible yarn frictions. Downstream of the deflection roll 5.2 is a first entanglement unit 6. The first entanglement unit 6 comprises a yarn channel, through which the POY yarn 3 and the HOY yarn 4 advance jointly. The yarn channel receives compressed air for entangling the filaments of the two yarns, so that in a first stage, a yarn cohesion occurs for forming a composite yarn 10. After looping the godet unit 7 several times, the composite yarn 10. advances over a subsequent draw godet 12 by partially looping same. Between the draw godet 12 and the godet unit 7, a main entanglement unit 11 extends, in which the filaments of the composite yarn 10 receive a final yarn cohesion.
At the end, the composite yarn 10 enters a takeup device 13, and is wound to a package 14. The takeup device 13 is constructed as a winding machine with a turret, as is disclosed, for example, in EP 0 937 008 B1 . With this type of takeup, it is possible to wind the composite yarn to packages in a continuous operation. For a description in greater detail of the takeup device 13, the foregoing publication is herewith incorporated by reference.
To carry out the method of the invention, the spinnerets 1.2 and 2.2 are selected with respect to the number of their spin holes and choice of the capillary diameters of the spin holes such that a defined mass ratio of the mass of the POY yarn M_POY to the mass of the HOY yarn M_HOY adjusts in the composite yarn. The spin holes of the spinneret 1.2 have a capillary diameter of at least 0.25 mm to be able to produce a filament denier in the POY yarn of ≥ 2 deniers. In comparison therewith, the spin holes of the spinneret 2.2 are made smaller to be able to produce, for example a filament denier in the HOY yarn of 1.5 deniers. Both the mass of the POY yarn 3 and the mass of the HOY yarn 4 are determined by the denier that results after withdrawing the filaments, and the number of the respective filaments. Thus, the spinnerets 1.2 and 2.2 may be made different both with respect to their number of spin holes and the size of the capillary diameters. In this connection, the mass ratio that is decisive for the composite yarn is selected as a function of the yarn effect that is to be produced in the composite yarn.
To produce the composite yarn, a source of melt supplies a polymer melt, which is delivered by the spin pump 1.1 to the spinneret 1.2 and by the spin pump 2.1 to the spinneret 2.2. In their deliveries, the spin pumps 1.1 and 1.2 are adapted to the respective constellation of the spin holes in the spinnerets 1.2 and 2.2 as well as the selected withdrawal speed. Thus, it is possible to adjust in the POY spinning position 1 and the HOY spinning position 2 the deliveries of the spin pumps 1.1 and 1.2 each individually.
After extruding the filament strands through the spinneret 1.2, same are cooled in the cooling device 1.4 by a cooling air stream that is largely directed in the direction of the advancing yarn. At the end of the spin zone, the filaments are combined by the yarn lubrication device 1.5 to a POY yarn 3. To be able to adjust a highest possible withdrawal speed, the method of the invention requires maintaining a spin zone of at least 800 mm during the cooling of the POY yarn. It is preferred to select a still longer spin zone for a stressfree cooling of the filaments of the POY yarn.
In comparison therewith, the filament strands of the HOY yarn are cooled in a spin zone that is shorter than 900 mm. Preferably the spin zone for producing the HOY yarn 4 is shorter than the spin zone of the POY yarn 3. These differences in lengths of the yarn path make it possible to deflect the HOY yarn, preferably downstream of the lubrication device, directly into the path of the POY yarn, so as to enable a joint advance and a joint withdrawal by a withdrawal godet unit. To ensure the advance of the yarn on the withdrawal godet unit 7, the POY yarn 3 and the HOY yarn 4 are entangled in a first stage. The entanglement by the first entanglement unit 6 is adjusted such that the filaments undergo a slight entanglement, so as to not impede the formation of the POY yarn with a partially oriented molecular structure, and the formation of the HOY yarn with a highly oriented molecular structure. In this connection, the withdrawal speed of the withdrawal godet unit 7 is adjusted to values above 3,500 m/min. With a corresponding cooling of the POY yarn, it is possible to achieve withdrawal speeds greater than 5,000 m/min.
The final combination of the filaments of the POY yarn and the HOY yarn to the composite yarn proceeds in the main entanglement unit 11 after withdrawal by the godet unit 7. In this process, the compressed air entering the yarn channel of the main entanglement unit 11 is adjusted to an overpressure, which leads to an intensive knot formation. It is thus possible to produce in the composite yarn a minimum number of 25 knots per running meter. The main entanglement of the composite yarn 10 occurs between the godet unit 7 and the draw godet 12. In this process, the draw godet 12 is driven at a somewhat higher circumferential speed than the withdrawal godet 8, so that a predefined yarn tension can be adjusted for the entanglement. Finally, the composite yarn 10 is wound by the takeup device 13 to a package 14.
In this process, the composite yarn 10 is wound at a takeup speed, which is only insignificantly higher than the withdrawal speed, so as to prevent unacceptable drawing. Preferably, the takeup speed is adjusted to differ from the withdrawal speed by a factor of 0.95 to 1.2.
The construction of the apparatus for carrying out the method of the invention as shown in Figure 1 is exemplary. Basically, the cooling devices 1.4 and 2.4 may include modifications, in which the filaments strands first advance through a first uncooled heating zone. In particular in the HOY spinning position 2, so-called annealers may be arranged between the cooling device 2.4 and the spin head 2.3 in order to produce an especially low-shrinkage HOY yarn.
Furthermore, the combination of the composite yarn 10 can be further improved before the takeup by arranging a third entanglement unit between the draw godet 12 and the takeup device 12. With that, it is possible to achieve in a third stage a further entanglement of the filaments that is directed in particular to the yarn lengths forming between the knots.
The composite yarn of the invention that is produced by the method of the invention is thus especially suited for use in textile applications as a effect yarn with a structure effect or a color effect. As a function of the desired yarn effect, a mass ratio of the filaments of the POY yarn and the HOY yarn is selected. In so doing, it is necessary to maintain certain filament deniers of the POY yarn and the HOY yarn respectively, to ensure on the one hand a strength of the yarn as is required for its application, and to obtain on the other hand the desired effects in structure or color. The composite yarn of the invention is therefore defined by limit ranges of the filament deniers. Thus, when combining the filaments, it is necessary to see that the filaments of the POY yarn have a denier ≥ 2.0 deniers, and the filaments of the HOY yarn a denier ≤ 4.0 deniers, preferably < 1.0 denier. In so doing, it is necessary to maintain a mass ratio of the filaments of the POY yarn to the filaments of the HOY yarn of M_POY/M_HOY ≥ 2.5. In the case of larger mass ratios, there is no adequate guarantee for the properties as are required for textile yarns.
To produce conventional bulked synthetic composite yarns with a high shrinkage difference, a combination of the POY yarn and the HOY yarn has been found especially advantageous, wherein the mass ratio is in a range from 1.2 to 2.5. Table 1 lists a plurality of typical composite yarns, which were produced by the method of the invention. The composite yarns are within a total denier range from 135 denier to 450 denier, with the number of filaments being at least 60 and at most 168. The composite yarns listed in Table 1 were extruded from polyester. They are especially suited for producing a so-called flat effect with a high shrinkage difference. In all combinations, the boiling water shrinkage measured on the filaments of the POY yarn ranged from 50 to 70%. In comparison therewith, it was possible to produce the HOY yarn with a low boiling water shrinkage in a range from 4 to 10%, so that it was possible to adjust shrinkage differences of more than 60%. The takeup speeds were set in a range from 4,500 to 6,500 m/min.
Tables 2 and 3 show further embodiments of the composite yarn according to the invention, which were likewise extruded from a polyester material. The composite yarns listed in Table 2 are preferred and suited to produce a so-called wooly effect. In this instance, the composite yarn is textured in a further processing step, wherein individual breaks of the filaments of the HOY yarn occur. With that, a surface is created, which is similar to a wool yarn. For such structure effects, it is desired that the mass ratio M_POY/M_HOY be preferably in a range from 1.0 to 1.5. In this case, the filament deniers of the HOY yarn are preferably ≤ 1.5 deniers.
Similar effects can be achieved with the composite yarns shown in Table 3. The composite yarns listed in Table 3 are preferably used for producing so-called spun-like effects. Likewise in this case the mass ratio M_POY/M_HOY is in a range from 1.0 to 1.5.
The composite yarn of the invention is also particularly suited for dyeing. Because of similar crystallinity of the POY yarn and the HOY yarn, it is possible to achieve an intensive coloring. It is likewise possible to adjust special color effects, such as, for example, a mixed color effect. To do so, it has been found that the mass ratio M_POY/M_HOY should be in a range from 1.5 to 2.0, or alternatively in a range from 0.5 to 0.75. In this respect, the composite yarn can be used for textile applications in many ways. The combination between a POY yarn and an HOY yarn can be realized by the use of one polymer type, or also by the use of different modifications of a base polymer or a plurality of polymer types.
The method of the invention distinguishes itself in particular by high withdrawal speeds and a thus accompanying high productivity in the production of a composite yarn in a single stage process. Likewise, the expenditure for processing units is advantageous, in particular in the takeup region, since both parallel spun yarns are jointly withdrawn at the same withdrawal speed.

NOMENCLATURE

1: POY spinning position
1.1: Spin pump
1.2: Spinneret
1.3: Spin head
1.4: Cooling device
1.5: Yarn lubrication device
2: HOY spinning position
2.1: Spin pump
2.2: Spinneret
2.3: Spin head
2.4: Cooling device
2.5: Yarn lubrication device
3: POY yarn
4: HOY yarn
5.1, 5.2: Deflection rolls
6: First entanglement unit
7: Withdrawal godet unit
8: Withdrawal godet
9: Guide roll
10: Composite yarn
11: Main entanglement unit
12: Draw godet
13: Takeup device
14: Package

Claims

Melt spinning method for producing a composite yarn, wherein two filament bundles are separately extruded from a polymer melt of the same source of melt, wherein one of the filament bundles is cooled to a POY yarn with a partially oriented molecular structure, wherein the second filament bundle is cooled to an HOY yarn with a highly oriented molecular structure, wherein the POY yarn and the HOY are jointly withdrawn, combined, and wound as a composite yarn to a package, and wherein the POY yarn is less orientated than the HOY yarn,
characterized in that
the filaments of the POY yarn and the filaments of the HOY yarn are combined at a mass ratio in the composite yarn of 1.0 ≤ M_POY/M_HOY ≤ 2.5 or 0.5 ≤ M_POY/R_HOY ≤ 0.75, wherein the filaments of the POY yarn have a denier ≥ 2.0 deniers (2.22 dtex) and the filaments of the HOY yarn have a denier of ≤ 4.0 deniers (4.44 dtex), preferably ≤ 1.5 deniers (1.66 dtex),
wherein the mixture of the filaments of the POY yarn and the HOY yarn is generated by a multistage entanglement, with a first stage occurring by an initial entanglement after cooling, and a second stage by a main entanglement before winding the composite yarn, and
wherein the main entanglement is carried out with an overpressure of the air, which permits producing in the composite yarn at least a number of at least 25 knots per meter.
Method of claim 1,
characterized in that
the POY yarn and the HOY yarn are each formed from different numbers of filaments in the filament bundles with different filament deniers of the filaments.
Method of claim 1,
characterized in that
the main entanglement of the composite yarn is performed on a yarn length advancing between two godets, and that the composite yarn undergoes a subsequent entanglement in a third stage.
Method of one of claims 1-3, characterized in that
the filaments of the POY yarn are combined, after cooling and advancing through a spin zone of > 800 mm, by applying a yarn lubricant.
Method of one of claims 1-4,
characterized in that
the filaments of the HOY yarn are combined, after cooling and advancing through a spin zone of ≤ 900 mm, by applying a yarn lubricant.
Method of one of claims 1-5,
characterized in that
after extruding, the filament bundle of the POY yarn and the filament bundle of the HOY yarn are withdrawn at the same withdrawal speed.
Method of claim 6,
characterized in that
the withdrawal speed is in a range above 3,500 m/min, with the POY yarn being cooled by a cooling air stream that is generated in the direction of the advancing yarn.
Method of one of claims 1-7,
characterized in that
the extruding and cooling of the filament bundles is performed by separately controllable processing units.
Method of one of the foregoing claims,
characterized in that
the composite yarn is wound to a package at a winding speed, which differs from the withdrawal speed by a factor in a range from 0.95 to 1.2.
Composite yarn consisting of two
filament bundles that are produced parallel in a melt spinning process and that are separately extruded from a polymer melt of the same source of melt, with one of the filament bundles being a POY yarn with a partially oriented molecular structure, and the second filament bundle being an HOY yarn with a highly oriented molecular structure, and wherein the POY yarn is less orientated than the HOY yarn,
characterized in that
the filaments of the POY yarn have a denier ≥ 2.0 deniers (2.22 detex), and the filament bundles of the HOY yarn have a denier ≤ 4.0 (4.44 dtex), preferably ≤ 1.5 deniers (1.66 dtex), and that the filaments of the POY yarn and of the HOY yarn are present at a mass ratio of 1.0 ≤ M_POY/M_HOY ≤ 2.5 or 0.5 ≤ M_POY/M_HOY ≤ 0.75,
wherein the filaments of the POY yarns and of the HOY yarn are joined by entanglement knots by at least 25 knots per meter.
Composite yarn of claim 10,
characterized in that
for producing a wooly effect or a spun-like effect, the mass ratio M_POY/M_HOY is in a range from 1.0 to 1.5.
Composite yarn of claim 10,
characterized in that
for producing a flat effect with a shrinkage difference > 40%, the mass ratio M_POY/MHOY is in a range from 1.2 to 2.5.
Composite yarn of claim 10,
characterized in that
for producing a mixed color effect, the mass ratio M_POY/M_HOY is in a range from 1.5 to 2.0 or 0.5 to 0.75.
Composite yarn of one of claims 10-13,
characterized in that
the POY yarn and the HOY yarn are each formed from a different number of filaments in the filament bundles with different filament deniers of the filaments.