DE2049413A1 - Method and device for producing an elastic crimped yarn from synthetic continuous filaments with low, irreversible shrinkage - Google Patents

Description

2049413 FARBENFABRIKEN BAYER AG

LEVEJUCU S EN-Beyerwerk "7. OKI. Patent department

Reu / it

Method and device for the production of an elastic crimped yarn from synthetic continuous filaments with low, irreversible shrinkage.

The invention relates to a method for producing a stabilized, developable, elastic Crimped yarn with low, irreversible shrinkage according to the false twist method with continuous thermal mixer Post-treatment and a device for carrying out the process.

It is known to produce highly elastic crimped yarns by a discontinuous or continuous work process under the action of heat and variable voltage ratios to stabilize or set the amount required for the respective purpose.

For example, a crimped yarn sewing treatment device is known which in its entirety has a complete, represents a machine specially built for this purpose. Furthermore, a machine combination is described, which also a thermal post-treatment of the thread makes possible with great mechanical engineering effort.

A method for balancing out the internal tension of textured synthetic textile yarns is also already in progress been pointed out, in which the yarn is turned up and

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is fixed and counter-rotated wrongly by downstream devices and thermally stabilized. There are , furthermore known processes according to which both heat treatments of the thread is carried out with the same heating device. The thread tension differs here not very significant between the two heatings. All previously known processes for the thermal aftertreatment of Krauselgarneri usually require complex mechanical engineering to carry out the procedure.

The crimping of bulked continuous yarns is based on the change in the fine fiber structure caused by the texturing process. at the fixing of the yarn deformation results in a certain one Constellation of intermolar bonds in the deformed individual threads. The quality of fixation depends on the energy content of the intermolecular bonds.

If energy is invested in the form of mechanical work and heat in stretch texturing, the energy content increases of intermolecular bonds.

A process has now been found for the production of a stabilized, developable elastic crimped yarn from synthetic continuous filaments with low irreversible shrinkage, in which the continuous filaments are crimped and fixed according to the false twist method with continuous thermal aftertreatment and at high thread speeds according to the stretch texturing process, with and in the same operation at the same fusing temperatures, the continuous filaments are guided over the same contact heating bar. The method is characterized in is performed AAI the second heat treatment in the Kontaktheizzone the turnback yarn with a lower by 50 to 99f5 i "thread tension as the thread tension in the first heat treatment. Advantageously, the heat treatment is carried out in two stages at temperatures of 130-210 ⁰ C.

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The synthetic continuous filaments used are those made from polyamides and linear polyesters. Another object of the invention is a textured yarn made of synthetic continuous filaments, characterized by a latent curl value of 80-200 J & eirniig & ft / aÄ »·, a boiling shrinkage of 4 - 5 f, a crimp contraction of 6J f and a latent Ecgen number / cm of 8- 15-

To Lerabsetzuijg the thread tension control units For example, continuously variable drive units can be used, but also tyrister-controlled DC drives.

The surface of the contact heating rail over which the pad runs is advantageously roughened. In the second heat treatment, the thread is preferably guided over part, for example half, of the contact surface. This allows the shrinkage and the extensibility to be varied. The method according to the invention gives a yarn which differs from the known elastic yarns in that it has a latent crimp and is also characterized by a low irreversible shrinkage. This crimp is fully developed again when the yarn is processed. For this purpose, polyamide and polyester threads with a Fräuselkontraktion of 4t to 79 # and a curl value of approx. 6G - 300 turn / meter are suitable, the cooking shrinkage is 6 %, the elastic stretchability of the knitted fabric is 130-20 % in length - and cross direction. In addition, the processing reliability, for example on circular knitting machines, is significantly increased due to the lower climatic sensitivity of the threads. In contrast, the unstabilized f-.ateriai has a Kringex rotation of 500 - 700 rotations / m. , a boiling shrinkage of 1o - 12 ji for polyamide 6, or of 7 - 8 λ for polyamide 66. Cross-longitudinal elasticity: from 80 - 110 · / ... The crimp contraction and crimp resistance

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speed were determined by the Wegener method (Meliand Textile Reports, No. 5, 1966, pages 495-495). In contrast to conventional knitted goods, which are characterized by their extremely fine mesh, this yarn has a larger-meshed character, which can be influenced by equipment methods, e.g. high-temperature automatic dyeing machines.

The inventive yarn has the following advantages: During processing to active or knitwear a downstream Iiochtemperaturausrüstung at temperatures of about 12O ⁰ C is possible without the elasticity of the knitted fabric is adversely affected.

The loss of goods, especially with hosiery, is larger meshed. In addition, the yarn according to the invention makes the static friction between the skin surface and the knitted fabric clear reduced.

The method for determining the curl values is characterized in that 1 m of thread is halved and loaded with 0.1 g / denier and the thread is allowed to twist freely due to the given tendency to twist. The thread is untwisted in a measuring device and the number of turns / m is determined. The yarn according to the invention has a number of sheets of 8-15 per cm and can be brought to 20 to 30 sheets per cm by thermal aftertreatment. The figure shows an apparatus for carrying out the method. The thread coming from bobbin A is fed to the delivery cylinder (1) via deflection elements and is pre-stretched between the delivery cylinder and godet (2), then passes the contact heating rail (j5) over the entire contact surface (equal to 400 mm), passes through the false twist generator (4) to

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Stretching godet (5). The thread is not opened immediately on the head, but is led to the pulley (6) and passes the contact heating rail (3) a second time, but with 200 mm Contact surface is prepared using the preparation section (7) and then twisted onto the controllable cop (8) at a lower controlled thread tension.

Example 1:

A polyamide 6 thread - 44 t 10 dtex - (nultifil raw titer 135 dtex) is pre-drawn in a ratio of 1: 2.10 between the delivery cylinder (1) and godet (2) at a web speed of the godet (5) of 400 m / min and a total draw ratio of 1: 3.10, wherein the high thread rotated by a twisting element (4) and is fixed at 175 ⁰ C on a Kontaktheizschiene (3) of 400 mm length.

The thread textured in this way is now guided a second time over deflection elements 6 over the same rail and now touches it 200 mm, then it is opened on cop (8) at a thread tension of 2.8 g (5 $> the stretch texturing tension). The yarn treated in this way has a crimp contraction of 60 % and an irreversible shrinkage of only 4 - 5 i>, the final denier is 44/10 dtex.

The double edge of a women's stocking produced from this yarn under defined knitting conditions has 480 rows of stitches with a normal production setting on the Schröder device and a width of 36.5-37 cm.

Example 2;

1 polyamide 66 thread - 22 f 3 dtex - raw titer 73 t 7 dtex, is pre-drawn in a ratio of 1: 2.05 between the delivery cylinder (1) and godet (2) at a web speed of the godet (5) of 350 m / min, and a total distance. ratio of 1: 3.65. wherein the filament high rotated by a twisting element (4) and is fixed at 195 ⁰ C. The final titre is 22 f 3 dtex. The thread textured in this way is now over the deflection element (6) a second time over the same rail (200 mm)

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'guided. It is then wound through and opened on a cop with a thread tension of 1.7 g (8.5 i- the stretch texturing tension).
Crimp contraction: = 6, f irreversible shrinkage 3 ^c / ..

Example 3;

A polyester yarn (multifilament 167 dtex f 1E) is in the ratio 1: 3.05 prestretched between delivery cylinders (1) and godet (2) at a temperature of 120 ⁰ C. The temperature of the contact heater in the fixing and stabilizing zone is 185 ⁰ C. The fabric speed (godet 5) is 5OU m / min. The total drawing is set to 1: 4.25. The textured thread is guided a second time over the deflection element (6) over the contact heating rail, which has a length of 400 mm, with a contact surface of 125 mm over the rail. The yarn treated in this way has a KK of 70 ^c /., An irreversible shrinkage of 2-3 f. The final denier is 44 f 10 dtex. The thread tension is 2.5 g (5.5 i- the stretching tension).

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6A0 ORIGINAL

Claims (4)

Claims 1) Process for the production of a stabilized, developable, elastic thermoplastic crimped yarn from synthetic endless yarns with low irreversible shrinkage according to the false twist method with continuous thermal aftertreatment at high thread speeds between 500 and 800 m / min., In which a crimped and fixed thread after the stretching process is performed in the same operation and at the same fixing temperature in a fully continuous procedure over the same contact heating bar, characterized in that the second heat treatment of the twisted back thread is carried out with a 50 to 9915 f lower thread tension than the thread tension in the first heat treatment. 2) Method according to claim 1, characterized in that the heat treatment is carried out in two stages at temperatures of 150 ° to 210 ⁰ C. 3) Device for performing the method according to claim 1 and 2, characterized in that above the contact heating rail (5) the deflecting element (6) and below the heating rail the impact generator (4) and the delay godet (5), the speed-controlled twisting spindle (8) under the delay godet (5) is arranged. 4) Textured yarn made from synthetic continuous filaments, characterized by a latent curl value of 80 - 200 Le A 13,332 - 7 - 209816/1241 Twists / meter, a boiling shrinkage of 4 - 5 %> a curl contraction of 60 % and a latent number of arcs / cm of 8 - 15, Le A 13 332 -8- 209816/1241