EP0664352B1 - Looped two component yarn, method for its production and its use as a sewing or embroidery thread - Google Patents

Description

The present invention relates to new two-component loop yarns adapted processes for their manufacture and the use of these yarns as sewing and embroidery threads.

In the field of sewing threads, loop threads have recently been made so-called stand and effect threads have become known. Loop yarns that can be used in particular as sewing threads, e.g. in the EP-A-295,601, EP-A-367,938 and EP-A-363,798.

For the production of the loop yarns described above, the most varied high tenacity and textile rovings have been described; these are directed for example, from low-oriented or partially-oriented filaments. Such filaments must be used as a roving component after Spinning are usually subjected to a drawing process.

They are also so-called fully oriented yarns yarns or FOY yarns; see chemical fibers / textile industry, 6/1985, p. 411-2) known. These yarns can be used without drawing, which means at least one process step can be saved.

The use of highly oriented polyamide yarns is known from US-A-4,069,657 known for the production of air-textured stand / effect yarns.

The use of polyester-based FOY yarns for the production of Loop yarns have not yet become known. It has now been found that such FOY yarns are used for the production of loop yarns to let. This makes a class of yarns for use in loop yarns Provided that is easy and inexpensive have it made.

i) zumindest ein Teil der Effektfilamente besteht aus Polyester,

ii) dieser Teil der Effektfilamente weist eine Höchstzugkraftdehnung von 35 bis 70 % auf, vorzugsweise von 35 bis 60 %,

iii) dieser Teil der Effektfilamente weist eine Doppelbrechung von 100 * 10^-3 bis 150 * 10^-3, insbesondere von 125 * 10^-3 bis 140 * 10^-3 auf,

iv) dieser Teil der Effektfilamente weist einen Thermoschrumpf bei 200°C von 3 bis 14 %, insbesondere von 5 bis 10 % auf, und

v) die Effektfilamente weisen einen Einzelfilamenttiter von kleiner gleich 1,5 dtex auf.

The present invention relates to a two-component loop yarn made from upright and effect filaments made from synthetic polymers, which has the following features:

i) at least some of the effect filaments consist of polyester,

ii) this part of the effect filaments has a maximum tensile elongation of 35 to 70%, preferably of 35 to 60%,

iii) this part of the effect filaments has a birefringence from 100 * 10 ^-3 to 150 * 10 ^-3 , in particular from 125 * 10 ^-3 to 140 * 10 ^-3 ,

iv) this part of the effect filaments has a thermal shrinkage at 200 ° C. of 3 to 14%, in particular 5 to 10%, and

v) the effect filaments have a single filament titer of less than or equal to 1.5 dtex.

The FOY effect component to be used according to the invention is defined by the following combination of features: maximum tensile strength elongation 35 to 60%, birefringence from 100 * 10 ^-3 to 150 * 10 ^-3 , and thermal shrinkage at 200 ° C from 6 to 14%. By presenting such effect components with low single-fiber titers in the production of the two-component loop yarn, a yarn with the properties defined above is obtained.

The maximum tensile force elongation is measured in accordance with DIN 53843, Part 1; the The birefringence is measured using the method described in Melliand Textilberichten, 1972, pp. 727-731; and measuring the Thermal shrinking is carried out according to DIN 53866, part 3.

In addition to the effect filaments characterized by the features i) to v) the two-component loop yarn according to the invention or any other Have effect filaments made of synthetic polymers. Preferably is the proportion of the effect filaments characterized by the features i) to v) more than 80% by weight, in particular 100% by weight, based on the total amount of Effect filaments.

It was also found that the two-component loop yarns according to the invention through a particularly good sewing behavior and good seam formation distinguish what is due to a soft handle of the sewn together textile Surface images is expressed; this is especially true if the Two-component loop yarns according to the invention have a relatively high proportion have effect filaments.

The invention therefore preferably relates to the two-component loop yarns defined above with a proportion of effect filaments of at least 25% by weight, preferably 30 to 50% by weight, based on the Two-component loop yarn.

Stand and effect filaments generally differ in terms of their Single titer. This can be 0.5 to 8 dtex for the upright filaments. For the Effect filaments can be 0.2 to 1.5 dtex.

Two-component loop yarns with effect and / or are preferred Standing filaments with fine single filament titers. These embodiments of the Yarns according to the invention, especially those with fine stand and Effect filaments are characterized by particularly good sewing behavior and good seam formation.

The single filament titer of the effect filaments is preferably 0.2 to 1.5 dtex, particularly preferably 0.4 to 1.5 dtex.

The single filament titer of the upright filaments is preferably less than or equal to 2 dtex, particularly preferably 0.5 to 2 dtex, and in particular 1 to 2 dtex.

The final titer of the two-component loop yarns according to the invention is usually 100 to 1000 dtex.

Two-component loop yarns with a final titer of are preferred 100 to 900 dtex.

As already stated, the two-component loop yarn according to the invention settles from standing and effect filaments together. The upright filaments are on average much more in the direction of the fiber axis aligned as the effect filaments that swirl with the upright filaments and are entangled, but additionally due to their greater length from the Form fiber loops protruding and thus the textile Properties and usage properties, such as sewing behavior, des co-determine yarns according to the invention substantially.

The total titers of standing and effect filaments of the invention Loop yarns are usually in a ratio of 40:60 to 75:25, preferably 55:45 to 70:30.

As standing components can be in the invention Two-component loop yarn made of any high-strength filaments use synthetic polymers. The strength of the upright component in the Two-component loop yarn is usually more than 30 cN / tex, such as e.g. 30 to 80 cN / tex. Stand-up filaments with a strength are preferred from about 40 to about 75 cN / tex.

The loop yarn according to the invention usually has a final strength of more than 30 cN / tex, preferably more than 40 cN / tex. Under the Final strength is the quotient of maximum tensile force and final titer at the moment understood the effect of the maximum tensile force. The ultimate strength of the loop yarns according to the invention is particularly preferably 45 to 60 cN / tex.

The loop yarn according to the invention preferably has one Thermal shrinkage at 200 ° C of less than 8%, especially less than 6%.

Two-component loop yarns, the one, are very particularly preferred Final strength of more than 40 cN / tex and thermal shrinkage at 200 ° C of less than 6%.

In principle, the upright component and part of the effect component can Two-component loop yarns according to the invention made of all synthetic spinnable polymers and polycondensation products, e.g. Polyamides such as nylon types or aramids; Polyacrylonitrile; Polyolefins, such as Polyethylene or polypropylene; Polyether ketones, such as PEK or PEEK; Polyarylene sulfides such as poly-para-phenylene sulfide; and polyesters like Polyethylene terephthalate.

The use of polyester as the starting material is particularly preferred yarns according to the invention; especially as the starting material for both Yarn components.

Particularly suitable polyesters are those which essentially consist of aromatic dicarboxylic acids, e.g. 1,4-, 1,5- or 2,6-naphthalenedicarboxylic acid, isophthalic acid or in particular terephthalic acid and aliphatic diols with 2 to 6, in particular 2 to 4, carbon atoms, such as. Ethylene glycol, 1,3-propanediol or 1,4-butanediol by cocondensation be preserved. Hydroxycarboxylic acids, such as e.g. p- (2-Hydroxyethyl) benzoic acid as starting materials for polyester.

The above polyester raw materials can also by Condensing small amounts of aliphatic dicarboxylic acids, e.g. Glutaric acid, adipic acid or sebacic acid or of polyglycols such as e.g. Diethylene glycol (2,2'-dihydroxydiethyl ether), triethylene glycol (1,2-di- (2-hydroxy-ethoxy) ethane) or of smaller proportions of higher molecular weight Polyethylene glycols are modified.

Another possibility of modification, in particular on the coloring Behavior of the two-component loop yarns according to the invention is the modification by sulfo-containing building blocks, such as by the incorporation of sulfoisophthalic acid.

Furthermore, it is also possible to use the loop yarns according to the invention flame retardant polyester materials, preferably made of phospholane modified polyethylene terephthalate. Examples of such modified polyesters are listed in DE-C-2,346,787.

The upper limit of the final strength of the loop yarns according to the invention depends also on the selected degree of condensation of the polymer material used, especially the polyester material. The degree of condensation of the polymer is expressed in its solution viscosity. A high degree of condensation, i.e. a high solution viscosity leads to particularly high final strengths.

If you want loop yarns based on polyester with a high final strength, for example, high-molecular polyester with an intrinsic viscosity is used (measured in solutions in dichloroacetic acid at 25 ° C) of larger is equal to 0.65 dl / g, in particular from 0.70 to 0.85 dl / g. This applies at least to the upright component; can also be used for stand and effect components be valid.

A preferred polyester material for the production of the invention Loop yarn is polyethylene terephthalate. These include copolyesters containing to understand recurring ethylene terephthalate units

The production of the two-component loop yarn according to the invention, consisting of upright and effect threads is made by blasting two or several fed to a texturing nozzle with different lead Roving strands. The blow texturing is carried out by a fluid, e.g. Water or in particular by a gas which is inert to the roving strands, in particular by air that may be humidified or to a previously humidified one Roving.

a) Zuführen von zwei oder mehreren sich mit unterschiedlichen Geschwindigkeiten bewegenden Vorgarnsträngen aus synthetischen Polymeren zu einer Texturierdüse, wobei mindestens einer der Vorgarnstränge aus Einzelfilamenten besteht, die aus Polyester bestehen, deren Höchstzugkraftdehnung 35 bis 60 % beträgt, deren Doppelbrechung von 100 * 10^-3 bis 150 * 10^-3, insbesondere von 125 * 10^-3 bis * 10^-3 140 beträgt, und deren Thermoschrumpf bei 200°C von 6 bis 14 %, insbesondere von 8 bis 10 % beträgt,

b) Verwirbeln der Vorgarnstränge in der Texturierdüse unter Bedingungen, daß sich ein aus Steher- und Effektfäden bestehendes Garn ausbildet, wobei sich hauptsächlich aus Effektfäden gebildete Schlaufen auf der Oberfläche dieses Garns ausbilden, und

c) Abziehen dieses primären Zweikomponenten-Schlingengarns unter Spannung, so daß sich besagtes Primärgarn unter Verringerung der Schlaufengröße mechanisch stabilisiert,

d) Erhitzen des stabilisierten Primärgarnes, um die Garnstruktur zu fixieren, und wobei vorzugsweise

e) die Gesamttiter der Vorgarnstränge, die Differenz der Zuführgeschwindigkeiten der Vorgarnstränge, die Bedingungen beim Verwirbeln, beim mechanischen Stabilisieren und beim Fixieren so gewählt werden, daß ein Zweikomponenten-Schlingengarn entsteht, dessen Anteil an Effektfilamenten mindestens 25 Gew. %, vorzugsweise mehr als 30 Gew. % beträgt.

The invention further relates to a method for producing a two-component loop yarn from stand-up and effect filaments from synthetic polymers, comprising the measures:

a) Feeding two or more roving strands of synthetic polymers moving at different speeds to a texturing nozzle, at least one of the roving strands consisting of individual filaments consisting of polyester, the maximum tensile elongation of which is 35 to 60%, the birefringence of 100 * 10 ^-3 is up to 150 * 10 ^-3 , in particular from 125 * 10 ^-3 to * 10 ^-3 140, and their thermal shrinkage at 200 ° C is from 6 to 14%, in particular from 8 to 10%,

b) intermingling the roving strands in the texturing nozzle under conditions that a yarn consisting of upright and effect threads is formed, loops formed mainly from effect threads forming on the surface of this thread, and

c) pulling off this primary two-component loop yarn under tension so that said primary yarn is mechanically stabilized while reducing the loop size,

d) heating the stabilized primary yarn to fix the yarn structure, and preferably

e) the total titer of the roving strands, the difference in the feed speeds of the roving strands, the conditions during intermingling, mechanical stabilization and fixing are selected so that a two-component loop yarn is formed, the proportion of effect filaments of which is at least 25% by weight, preferably more than 30 % By weight.

It is well known that filament material is used for the texturing of blowers in yarns fed to the blow nozzle at a higher speed than drawn from it. Of the Excess speed of feed compared to the trigger, expressed in percent, based on the take-off speed, is called the Advance. In the method according to the invention, they are now joined together mixing strands of yarn, which in the finished yarn then the stand or the Effect filaments deliver with different lead of the texturing nozzle fed. The roving strand from which the upright filaments of the yarn according to the invention emerge, the blow nozzle is usually with a lead of 3 to 10%, the roving strand from which the effect filaments of the yarn according to the invention emerge, usually with an advance fed from 10 to 60%.

Because of this different advance, longer lengths of the effect filaments are swirled with smaller lengths of the upright filaments in the blowing nozzle, which means that the effect filaments form considerably more arches and loops in the finished yarn according to the invention than the upright filaments, which essentially run in the direction of the yarn axis. With the help of the different leads it is also possible to influence the final titer of the loop yarn. The final titer T _{S of} the intermingled yarn is not simply made up of the titers of the roving, but here the leading of the two roving must be taken into account. The final titer T _{S of} the intermingled yarn results from the following formula: T S = T St * (1 + (V ST / 100)) + T E * (1 + (V E / 100)), where T _St and V _{St are} the titer and advance of the roving and T _E and V _{E are} the titer and advance of the effect roving.

Usually roving strands of different total and Single filament titer, with at least the roving for the upright filament Filaments of such strength exist that the one for the subject The desired final strength of the loop yarn is achieved can be.

Yarns in the sense of this description are yarns that are in front the inlet into the swirling nozzle and to build up the Loop yarns can be used as stand and effect components.

In the rovings for the production of the two-component loop yarns according to the invention are preferably high-strength as an upright component Multifilament yarns used, while at least as an effect component Become part of FOY multifilament yarns.

Suitable materials for the manufacture of the upright component any multifilament yarns that are either already as high tenacity Multifilament yarns are presented to the texturing device or the stretched immediately before entering the texturing nozzle. As Starting material for the production of high-strength multifilament yarns can be for example low-oriented (LOY), partially-oriented (POY) or highly-oriented Use (HOY) polyester yarns. The starting materials can the required high strength through appropriate stretching preserved (see Treptow in chemical fibers / textile industry 6/1985, p.411 ff).

Preferred polyester for the production of these high tenacity multifilament yarns have in particular intrinsic viscosities (measured as indicated above) in Range from 0.60 to 0.70 dl / g or - in the case of particularly high molecular types for the production of the roving roving, - in the range from 0.70 to 0.85 dl / g.

As roving roving for the production of the invention Two-component loop yarns are preferably high-strength and low shrinkage yarns used, e.g. from DE-AS-1,288,734 or EP-A-173,200 have become known.

Further preferred roving rovings have a thermal shrinkage at 180 ° C. of at most 9%, usually 4 to 9%, preferably 5 to 8%.

Further preferred roving rovings have a maximum tensile strength elongation of at most 15%, usually from 8 to 15%, preferably from 8.5 to 12% on.

As effect rovings - as described above - FOY known per se Multifilament yarns used. Preferred polyester for making this high-strength multifilament yarns for the production of the effect rovings especially intrinsic viscosities (measured as indicated above) in the range from 0.60 to 0.70 dl / g. The method according to the invention can also be used Effect filaments of single filament denier made above 1.5 dtex become. Usually, fancy yarns are made from fancy filaments Single filament titers of less than or equal to 4.5 dtex. Preferably come the above specified preferred ranges of the single filament titre of the effect filaments for use.

Such FOY multifilament yarns are preferably produced as in US Pat DE-A-2,117,659.

f) Schmelzspinnen von Multifilamenten in einer an sich üblichen Spinnvorrichtung, bei der sich zwischen Spinndüsen und Abzugsorgan ein Heizorgan befindet,

g) Abkühlen der ersponnenen Multifilamente vor dem Heizorgan auf die Erstarrungstemperatur oder darunter, und

h) anschließendes Erwärmen der Multifilamente auf Temperaturen oberhalb des Erstarrungspunktes unter gleichzeitiger Einwirkung der durch die Reibung am umgebenden gasförmigen Medium aufgebauten Fadenzugkraft, welche gleich der erforderlichen Streckspannung sein muß.

The invention preferably relates to a process for producing two-component loop yarns from stand-up and effect filaments, as described above, in which a FOY yarn is used as the roving strand for the effect component, which was spun by spinning at take-off speeds of over 2000 m / min. the following process steps have been carried out:

f) melt spinning of multifilaments in a conventional spinning device in which there is a heating element between the spinnerets and the take-off element,

g) cooling the spun multifilaments in front of the heating element to the solidification temperature or below, and

h) subsequent heating of the multifilaments to temperatures above the solidification point under the simultaneous action of the thread tension built up by the friction on the surrounding gaseous medium, which must be equal to the required tension.

Are high-strength and low-shrinkage two-component loop yarns if desired, the roving (s) to be used are produced for the upright component particularly preferably in an integrated, the Blow texturing immediately preceding process step in which the Roving for the upright component by stretching a partially oriented Spun and an immediately following, essentially shrink-free heat treatment is obtained. Essentially shrink-free means that the yarn is preferably on during the heat treatment is kept constant length, but that a shrinkage of up to 4%, in particular less than 2% can be approved.

The tenacity of the loop yarns obtained was found to be about Is 5 to 20% higher if the roving is stretched for the Post component integrated. It is believed that the fresh drawn individual filaments are still mobile and are particularly good i.e. with little loss of strength, let swirl.

In this preferred embodiment of the method according to the invention is therefore the roving for the upright component made from partially oriented spun fabric stretched on a drafting system that is essentially shrink-free Subjected to heat treatment and immediately afterwards Blast texturing fed. The stretching of the partially oriented spun fabric takes place at a temperature of 70 to 100 ° C, preferably over heated Godets at a drawing tension in the range of 10 to 30 cN / tex, preferably from 12 to 17 cN / tex (in each case based on the stretched Titer).

In this embodiment of the method according to the invention, therefore, only the roving intended as a stand component from a partially oriented Manufactured spun fabric, which draws on a drafting system, one in the subjected to substantially shrink-free heat treatment and immediately then the blast texturing is supplied.

Essentially the one immediately following the drawing shrink-free heat treatment of the yarn takes place, for example, at a Temperature in the range of 180 to 250 ° C, preferably from 225 to 235 ° C.

In principle, this heat treatment can be carried out in any known manner, It is particularly expedient to heat treatment directly on a heated one Deduction godet.

After leaving the texturing nozzle, the primary two-component loop yarn withdrawn under tension, so that the primary yarn under Reduced loop size mechanically stabilized. The trigger voltage is usually 0.05 to 1.0 cN / tex, preferably 0.15 to 0.4 cN / tex. The voltage should preferably be chosen so that the formed loops and loops are essentially preserved, that is do not contract or only to a small extent bud-like.

After this step, the stabilized primary yarn is heated to the Fix yarn structure. It is useful to keep the yarn of constant length hot air treatment at air temperatures of 200 to 320 ° C, preferably subject to 240 to 300 ° C.

j) Vorerwärmen eines Wärmeüberträgergases auf eine Temperatur, die oberhalb der gewünschten Garntemperatur liegt, und

k) Zuführen des vorerwärmten Wärmeüberträgergases in einen Fadenkanal, so daß dieses im wesentlichen senkrecht auf das im Fadenkanal laufende Garn entlang einer solchen Länge einströmt, daß sich das Garn innerhalb der Erhitzungsvorrichtung auf die gewünschte erhöhte Temperatur erwärmt, und wobei die Länge der Anblaszone so gewählt wird, daß durch ständiges Wegreißen der Grenzschicht durch die Anströmung des Wärmeüberträgergases das Garn direkt mit diesem in Kontakt kommt und somit eine sehr rasche Aufheizung des Garnes erfolgt.

The fixing is preferably carried out by a method which permits gentle and as uniform as possible heating of the yarn. The fixing process includes the measures:

j) preheating a heat transfer gas to a temperature which is above the desired yarn temperature, and

k) supplying the preheated heat transfer gas into a thread channel so that it flows substantially perpendicular to the yarn running in the thread channel along a length such that the yarn within the heating device heats up to the desired elevated temperature, and the length of the blowing zone is chosen so is that by continuously tearing away the boundary layer due to the flow of the heat transfer gas, the yarn comes into direct contact with it and thus the yarn heats up very quickly.

In this preferred fixing method, the yarn is of a certain length blown with evenly heated heat transfer gas so that the Heat transfer process more by moving the heat transfer gas (Convection) than by heat transfer using temperature gradients. Through this type of blowing, the adhering air boundary layer, which counteracts heat transfer due to its insulating effect on a longer yarn stretch blown away and the heated heat transfer gas can give off its heat quickly and evenly to the yarn. The temperature of the Heat transfer gas only needs to be a little above the yarn temperature, because most of the heat is transported by convective air movement and only a small part is caused by temperature gradients. This convective type of Heat transfer is very efficient and it will also overheat the Yarn material avoided, so that a gentle and uniform heating is realized.

The heat transfer gas can be preheated in any conventional manner become; for example by contact with a heat exchanger, Pass through heated pipes or by direct heating over Heating coils. The temperature of the preheated heat transfer gas is above the yarn temperature required in individual cases; it is preferably heated Heat transfer gas to temperatures up to 20 ° C above and contributes to it Make sure that between the preheating and the actual heating of the Yarn no significant temperature drop occurs.

The heated heat transfer gas can be anywhere in the Thread run channel are introduced. This is preferably done Heat transfer gas to the thread run channel in such a way that this can come into contact with the yarn along the entire thread run channel.

The heat transfer gas is preferably passed in perpendicular to the direction of the yarn the thread run channel, the heat transfer gas on the one hand from the current Yarn is carried away and the heating device over the Leaves yarn outlet along with the running yarn, and on the other hand moves against the direction of yarn and the Leaves heating device through the yarn inlet opening.

In a preferred embodiment, the heat transfer gas is in the middle part of the thread running channel on a length of about 1/4 to 1/2 of Channel length blown from small openings perpendicular to the yarn and escapes in and against the thread running direction from the thread running channel. In a another preferred modification of this embodiment is a Cross-blowing with suction on the opposite side.

Contacting the heat transfer gas in the heating device with the running yarn has to take place under such conditions that the Yarn raised to the desired level within the heater Temperature warms up and the heat transfer gas in the Heating device cools practically only very little.

A number of measures are available to the expert with the help of which these specifications can be set. For example possible, compared to the yarn mass, which is divided by the time unit Thread channel moves, relatively large masses of heat transfer gas per Let unit of time flow through the thread channel, so that despite the effective and rapid heat transfer to the yarn only a little Cooling of the heat transfer gas results. In contrast to the blowing at practically one point of the moving yarn, blowing results a particularly intensive interaction of the Heating gas with the yarn, since the boundary layer between the yarn and the surrounding Medium in this zone is constantly being torn away. That way it is possible, even with only a slight change in the temperature of the gas to achieve effective heating of the yarn. The control of the The temperature profile of the heat transfer gas can also be determined by Selection of the heat capacity of the gas or by the Control the flow rate of the gas in a manner known per se.

With the usual fixing methods for yarns with protruding capillary ends or loops become irons, heating rails or heated godets used, which one heats up considerably higher than the fixing temperature to generate sufficiently rapid heat transfer. This is limited Procedure in that projecting capillary ends or loops are in direct contact with the heater and melt because they are much faster Take the temperature of the heating element as the compact yarn that itself warms up much more slowly because of its larger mass. The melting of the Capillary ends or loops cause sticking or deposits on the Heater surface that affect the yarn run. In addition, through the relatively strong shrink and melt effect the number of loops per Unit of length. Melted capillaries become brittle and this can happen with further processing, e.g. when sewing, cause excessive abrasion. Fixation of the compact yarn at higher speeds while maintaining the The number of loops is therefore limited with these methods. Also at non-contact heat treatment of the yarn, for example in one Heating tube, the walls must be significantly overheated to pass through a sufficient heat transfer the desired fixing temperature in To achieve compact yarn. Essentially the same effects and Disadvantages described above for contact heating.

It has now been found that these difficulties are significantly reduced can if you apply hot gas by forced convection to the moving yarn can flow. This gives the yarn heat quickly enough introduced to the desired fixing temperatures in the compact yarn to reach. A particularly great advantage is that the hot gas only needs to be warmed slightly above the fixing temperature, since the Heat transfer depends not only on the temperature gradient, but in is essentially determined by the flowing hot gas. The little one Overheating of the hot gas prevents premature melting of the protruding capillary ends or loops, so that the fixing temperature in Compact yarn is reached without the heat sensitive capillary ends or loops are impaired too much. As the upper limit of the temperature the hot gas is the melting temperature of the protruding Capillary ends or loops to choose. In the case of yarns based on Polyethylene terephthalate, this upper limit is about 270 ° C.

The two-component loop yarns according to the invention have the advantages the known two-component loop yarns. So they stay Loops of the individual filaments full after leaving the blowing texturing nozzle maintain and provide good sewing properties due to the entrained air at high sewing speeds. This advantage is reflected in high values for the so-called sewing length to break, which according to that from DE-A-3,431,832 known methods can be determined. Furthermore, the invention Two-component loop yarns ensure an even dyeing along the Fadens, especially the variants, the filaments with fine single titer exhibit.

A particular advantage is that the invention Two-component loop yarn does not have to be twisted. It can can be used for example as a sewing thread.

However, it is also possible, for example, in the course of further processing optical reasons to apply a desired twist to the yarn, for example a rotation of about 100 to 300 T / m.

The two-component loop yarns according to the invention can be use for example as embroidery threads or in particular as sewing threads. The Invention also relates to these uses of the yarns.

The following examples illustrate the invention without limiting it. A device for producing the two-component loop yarn according to the invention can be made up of the following elements, for example: a creel for the bobbins of the stand and effect roving, one Drafting system with heatable inlet and outlet godets for the production of the Stand roving, the speed of which can be adjusted separately, one Blower nozzle, a take-off unit for the defined take-off of the blown yarn, if desired, a conventional hot air fixation as described above and one Take-up spool.

Example 1:

On the creel is a bobbin with partially oriented spun fabric from the titer 490f32 as the starting material for the production of the upright roving and a spool presented with effect roving titer 76f128. Both rovings consisted of Polyethylene terephthalate with an intrinsic viscosity of 0.74 dl / g (roving for Upright component) or 0.63 dl / g (roving for effect component) (measured as defined above).

• Höchstzugkraftdehnung von 35 %
• Schrumpf bei 200°C von 10 %

The effect roving was a FOY yarn with the following properties:

• Maximum tensile strength expansion of 35%
• Shrinkage at 200 ° C of 10%

The effect roving was passed directly over a pair of godets to the texturing nozzle, the inlet and outlet godets moving at practically the same speed turned. The starting material for the production of the roving was fed to a drafting unit and there in relation with the help of godets 1: 3.25 stretched. The temperatures of the inlet godets were 85 ° C and the outlet godet 232 ° C. The drawn yarn was heated around the Discharge godet of the drafting system. The single filament titer of the roving before running into the blow nozzle was 4.71 dtex for the main yarn and 0.57 dtex for fancy yarn. The blown yarn became like this behind the blow nozzle deducted that a tradition of 7% for the main yarn and 18% resulted for the fancy yarn.

After leaving the blow nozzle, the loop yarn was pulled off mechanically stabilized, the tension in the yarn being 0.46 cN / tex. The yarn was then fixed by heating it to 260 ° C Convection oven was passed.

The raw yarn thus obtained was wound up and then dyed.

The following characteristics were obtained before dyeing the raw yarn: Final titer: 249.4 dtex Final strength: 48.2 cN / tex, Heat shrinkage at 200 ° C: 6.4% Maximum tensile strength expansion 12.8%

The raw yarn obtained could be dyed evenly.

Example 2:

The procedure was analogous to that in Example 1, with a partially oriented Spun goods with titer 256f48 as starting material for the production of the Stand roving and a bobbin with effect roving with titer 50f32 become. Both rovings were made of intrinsic viscosity polyethylene terephthalate 0.73 dl / g (roving for upright thread) or 0.63 dl / g (roving for Effect thread) (measured as defined above).

• Höchstzugkraftdehnung von 43 %
• Schrumpf bei 200°C von 8,8 %

The effect roving was a FOY yarn with the following properties:

• Maximum tensile strength expansion of 43%
• 8.8% shrinkage at 200 ° C

The effect roving was passed directly over a pair of godets to the texturing nozzle, the inlet and outlet godets moving at practically the same speed (speed difference between the inlet and outlet godet is e.g. up to 5%). The starting material for the production of the roving was fed to a drafting unit and there with the help of godets in the Ratio 1: 2.20 stretched. The temperatures of the inlet godets were 85 ° C and the outlet godet 232 ° C. The drawn yarn became around that heated outlet godet of the drafting system. The single filament titer of Rovings before entering the blow nozzle were 2.42 dtex for the main yarn and 1.49 dtex for the fancy yarn. The blown yarn was behind the Blower nozzle deducted so that a tradition of 7% for the main yarn and of 17% for the fancy yarn resulted.

After leaving the blow nozzle, the loop yarn was pulled off mechanically stabilized. The yarn was then fixed by passing it through a was heated to 260 ° C convection oven.

The raw yarn thus obtained was wound up and then dyed.

The following characteristics were obtained before dyeing the raw yarn: Final titer 183.6 dtex Final strength 46.1 cN / tex Heat shrink at 200 ° C 4.0% Maximum tensile strength expansion 15.4%.

The raw yarn obtained could be dyed evenly.

Claims (21)

1. A two-component loop yarn composed of core and effect filaments made of synthetic polymers, characterized in that:

   i) at least a part of the effect filaments consists of polyester,

   ii) this part of the effect filaments has a breaking extension of from 35 to 70%, preferably from 35 to 60%,

   iii) this part of the effect filaments has a birefringence of from 100 * 10^-3 to 150 * 10^-3, in particular from 125 * 10^-3 to 140 * 10^-3,

   iv) this part of the effect filaments has a hot air shrinkage at 200°C of from 3 to 14%, in particular from 5 to 10%, and

   v) the effect filaments have a filament linear density of not greater than 1.5 dtex.
2. The two-component loop yarn of claim 1, characterized in that the proportion of effect filaments is at least 25% by weight, based on the two-component loop yarn.
3. The two-component loop yarn of either of claims 1 and 2, characterized in that the core filaments have a filament linear density of not greater than 2 dtex.
4. The two-component loop yarn of claim 1, characterized in that it has a final linear density of from 100 to 1000 dtex.
5. The two-component loop yarn of claim 1, characterized in that it comprises core filaments having a tenacity of from about 30 to about 80 cN/tex.
6. The two-component loop yarn of claim 1, characterized in that it has a final tenacity of more than 30 cN/tex, preferably of more than 40 cN/tex.
7. The two-component loop yarn of claim 1, characterized in that it has a hot air shrinkage at 200°C of below 8%.
8. The two-component loop yarn of claim 1, characterized in that the core and effect filaments consist of polyethylene terephthalate.
9. The two-component loop yarn of claim 1, characterized in that the core filaments, preferably the core and the effect filaments, consist of polyester which has an intrinsic viscosity (measured in solutions in dichloroacetic acid at 25°C) of greater than 0.65 dl/g.
10. The two-component loop yarn of claim '1, characterized in that the core and effect filaments consist of low-flammability polyester, in particular phospholane-modified polyethylene terephthalate.
11. The two-component loop yarn of claim 1 composed of core and effect filaments composed of synthetic polymers wherein at least a part of the effect filaments consists of polyester and is obtainable by a process comprising the following measures:

    f) melt spinning multifilaments in a conventional spinning apparatus with a heating element between the spinning jets and the take-off element,

    g) cooling the spun multifilaments upstream of the heating element to the solidification temperature or below, and

    h) subsequently heating the multifilaments to temperatures above the solidification point under the simultaneous action of the thread tension resulting from the friction against the surrounding gaseous medium, which thread tension must be equal to the necessary drawing tension.
12. A process for producing a two-component loop yarn composed of core and effect filaments composed of synthetic polymers, characterized in that comprises the following measures:

    a) feeding two or more feed yarn strands made of synthetic polymers at different speeds into a texturing jet, at least one of said feed yarn strands consisting of polyester filaments whose breaking extension is from 35 to 60%, whose birefringence is from 100 * 10^-3 to 150 * 10^-3, in particular from 125 * 10^-3 to 140 * 10^-3, and whose hot air shrinkage at 200°C is from 6 to 14%, in particular from 8 to 10%,

    b) intermingling the feed yarn strands in the texturing jet under conditions to form a yarn consisting of core and effect filaments and having loops formed chiefly of effect filaments on its surface,

    c) withdrawing this primary two-component loop yarn under tension so that, through reduction in the loop size, said primary yarn becomes mechanically stabilized,

    d) heating the stabilized primary yarn to set the yarn structure, and preferably

    e) choosing the strand linear densities of the feed yarn strands, the difference in the transport speeds of the feed yarn strands and the intermingling, mechanical stabilization and setting conditions in such a way as to produce a two-component loop yarn whose proportion of effect filaments is at least 25% by weight.
13. The process of claim 12, characterized in that the feed yarn strand used for the effect component is an FOY yarn produced by spinning at take-off speeds of above 2000 m/min, the following process steps having been passed through:

    f) melt spinning multifilaments in a conventional spinning apparatus with a heating element between the spinning jets and the take-off element,

    g) cooling the spun multifilaments upstream of the heating element to the solidification temperature or below, and

    h) subsequently heating the multifilaments to temperatures above the solidification point under the simultaneous action of the thread tension resulting from the friction against the surrounding gaseous medium, which thread tension must be equal to the necessary drawing tension.
14. The process of claim 12, characterized in that the number of feed yarn strands fed into the texturing jet at different speeds is two.
15. The process of claim 12, characterized in that the feed yarn strands have different strand and filament linear densities and the feed yarn for the core filament consist of filaments which have a breaking strength, based on the final linear density, of at least 60 cN/tex, a hot air shrinkage at 200°C of from 4 to 9% and a breaking extension of from 8 to 15%.
16. The process of claim 12, characterized in that the core feed yarn strand fed to the texturing jet is obtainable immediately upstream of the texturing jet by drawing a partially oriented yarn material and an immediately subsequent, essentially shrinkage-free heat treatment.
17. The process of claim 15, characterized in that the drawing of the core feed yarn strand is carried out at from 70 to 100°C under a drawing tension of from 10 to 30 cN/tex, based on the drawn linear density.
18. The process of claim 16, characterized in that the essentially shrinkage-free heat treatment carried out immediately following the drawing is carried out at a temperature of from 180 to 250°C.
19. The process of claim 12, characterized in that the withdrawal of the primary two-component loop yarn after the intermingling step is effected under a tension of from 0.05 to 1.0 cN/tex.
20. The process of claim 12, characterized in that the setting is carried out by a process comprising the following measures:

    j) preheating a heat transfer gas to a temperature which is above the desired yarn temperature, and

    k) feeding the preheated heat transfer gas into a yarn duct so that it flows into the yarn duct essentially perpendicularly to the yarn moving within the yarn duct and along such a length that the yarn heats up to the desired elevated temperature within the heating apparatus, the length of the zone of impingement of the gas on the yarn being such that, as a result of continuous removal of the boundary layer by the impinging heat transfer gas, the yarn comes into direct contact with the heat transfer gas and thus heats up very rapidly.
21. The use of two-component loop yarns composed of core and effect filaments as claimed in claim 1 as sewing yarns and/or as embroidery yarns.