DE1435619A1 - Process for the production of high density threads - Google Patents

Description

Patent attorney

DR.-ING. WALTER ABITZ ^liJJÖN

Munich

22c March 1962 A-480

E. I. DU PONT DE NEMORS AND COMPANY 10th and Market Streets, Wilmington 98, Delaware,

Process for the production of high density threads

The invention relates to a method for producing high-density threads from acrylonitrile polymers, in particular under simultaneous washing and drawing of the threads in a cascading water bath.

Filaments of acrylonitrile polymers formed by dry spinning emerge from the spinning cell generally in a solvent-laden state, ie. with a solvent content of about 15 to 40 $> of suitable ° to achieve textile yarns have to significantly reduce the Lbsungsmittelgehalt, such as _e stretch to about 5 $> or less, and the filaments to improve their physical properties :. While washing

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In general, the use of carefully controlled chemical baths and / or the application of complicated procedures are necessary. Attempts to simplify such procedures have led to threads of low density with numerous micro-headed cavities, at least in part »Could be the cause of poor retention of finishes and excessive" flying "in yarn production. In general, the threads obtained are also slack and "soggy".

The present invention provides a new washing-stretching process for the production of thick threads from acrylonitrile polymers, which is particularly easy directs and delivers high-density threads with high residual shrinkage. It enables the production of threads from acrylonitrile polymers »which can be easily processed and in the finished textile goods a desired crisp and a lively grip «.

The objectives of the invention are achieved with a method » in which a continuous thread bundle loaded in a number of reservoirs of a cascade-like flowing water bath washed concurrently and washed by a predetermined Amount to be stretched «For easier description of the

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In each case the reservoirs are considered separately

In lcum who belong to the lower Reeervoirfluoht " de · anter Tell dee laekadenbadee-forming reservoirs tt & i on the other hand in the form of the upper Reeervoirfluoht adjacent to the upper part of the bath forming reservoirs. During the procedure according to the invention, the thread bundle Bit rorbeetlmmter Ckfoohylndigkeit in at least one lower Reservoir dee Badee introduced, which can be heated to a temperature of about 90 ° to 100 ° O ^. The threads are inserted one after the other at the previously directed speed into the lower reservoirs provided for furthermore or taken from them » drawn »that they will be given about £ 40 or £ 70 of the desired total execution. Clay will be the lower reservoirs the threads are fed to the upper reservoirs, which are heated to a temperature of around 90 to 88 ° C. The speed »kit that the threads pass through the upper reservoirs, is set in such a way »that the remaining amount of the desired scattering is given to the threads · When leaving the The upper reservoir is placed on the threads at a temperature from 50 to 60 ° G heated water, or the. Threads are immersed in a watery bath that is on a Temperature is heated up in the range mentioned. That fasser becomes the cascade-like Durohstrom of the bath supplied to the uppermost reservoir. By controlling the speed of passage through the bath and the number of reservoirs the solvent content of the threads is adjusted to the desired level

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.Value ₉ preferably 5 ί> or less, lowered, and »earth the threads apf that. about 2 to 10 or more times »preferably 2 to 8 times their original length stretched out ·

In the drawing, which serves to further illustrate the invention, a schematic representation of a device suitable for carrying out the invention is shown;

The bundle 1 of threads made of acrylonitrile polymer is sswisohen Pinch rollers 2, 5 and 4 inserted through into the lowest reservoir of the cascade-like flowing water structure · It runs under the roller 6 and then out of the reservoir 5 again - and then through during its successive passage the rising reservoirs 9 »12, 15, 18, 21 and 24 alternate over or under the rollers 7, 8, 10, 11, 13, 14, 16, 17t 19t 20, 22 and 23 away or through «» After leaving the Reservoir 24 the bundle is passed through a second set of nip rollers 25 »26 and 27; on the bundle at this point 28 water is sprayed on from a nozzle. The water not held by the threads flows onto the

inclined part 29 of the housing 30 and from there into the reservoir 24. The water flows through the bath like a cascade: from the top reservoir 24 to the bottom reservoir 5 an outlet 38 is constantly drawn off washing liquid. All reservoirs can be heated using steam loops 31 to 37 ο 909 SW 0 97 3.

The number that make up the cascading bath Reservoirs can, depending on the amount of solvent, which is to be removed from the filaments can be very different. At z. B. relatively low solvent content a very small number of reservoirs, such as 3 lower and 2 upper reservoirs, can be used. With a higher solvent content can ? up to 12 reservoirs may be required. Generally 9 or 10 reservoirs are appropriate » The lower part of the bath preferably has the greater number of reservoirs.

The number of reservoirs can vary, but it is important to keep the lower reservoirs at a temperature within the range from 90 to 100 ° C, preferably 95 to 100 ° C, and the Maintain upper reservoirs at a temperature of 50 to 88 ° C. The temperature profile should preferably be in the the lowest reservoir approach the upper limit value for the temperature and in the lower part of the bath to a value close to the decrease progressively lower limit value. In the same way, there is a temperature gradient for the upper part of the bath preferred towards the exit point of the threads.

The threads can be drawn in each of the reservoirs. However, it is important to have 40 to 70 $ of stretching of the threads during their passage through the reservoirs of the lower part of the bath, while the rest of the stretching is carried out when passing through the upper part of the bath

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Dae following example serves to further illustrate the invention, "rope and percentages βloh _f nioht when otherwise indicated, αenloht on dae.

example

There are threads made of acrylonitrile polymer Trocfcenverspinnen prepared a solution of a terpolymer of about 93t5 # acrylonitrile, 6.0 and 0.5 # Aorylsäuremethylester f Natrlumstyrolsulfonat in dimethylformamide duroh · the threads containing 25 £ of the solvent, on cables are in the form ▼ υ < .λ about 185,000 den (20,550 tex), total titre collected; the single thread denier in the state i ** retained during spinning is about 10 den (1 »1 tex). The various cables collected are carried out at a speed of 59.4 m / * n. A washing-stretching device of the type shown in the drawing

supplied type shown, with certain individual cables be guided side by side through the device »

The cascade bath here has nine separate reservoirs, with certain upper rollers being driven in such a way that the cable is stretched in four stages on the distance to be covered in the device. Working conditions:

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Temperature « ⁰ O Scattering never beta tar-. laseen de Reaervoir 9β 1.55X 98 0 98 O.29X 98 0 94 0 90 0.81X 87 0 85 0 85 1.89X; 4.52 times total

Bat "Hindurohtrltt through the outlet squeegee whales is on the cable frlaohaa Extraktionewaeeer of 50 ° C with about 1179 ke / Btd. aafceapritst. The exact and representative ones contain 2 % solvent

The cables are then passed through a steam chamber to increase their temperature to about 70 ° C. and then passed through a conventional storage chamber ripple, which is held by O ₉ H atU while the hinged floodplain is kept at about 4-2 atU will. The crimped cables are anaohlleaeend cut into stacks, dried and opened. The staple fiber has a Reatach body of around 17 % and a density of 1.183 · Dae yarn has a crisp, lively feel and excellent antistatic properties «

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The process according to the invention is explained above.an hand from an "aorylnitrile terpolymerisate, but you can also use threads as homopolymers of aorylnitrile and copolymers with a content of ntindeetene Θ5 t of poly?" merized acrylonitrile inserts, see e.g. acrylonitrile polymers, with a content τοη Ms su 15 £ of mispolymerizable, ethylene-like unsaturated monomers (such as those according to US Patents 2,436,926 and 2,743,994) as well as a content of a small amount , β. B. from up to about 5 % t βineβ sulfur-containing monomers of the type described in US Patents 2,527,300, 2,837,500 and 2,837,501. The treatment according to the invention can also be used to subject threads which have been mixed using them Polymers were prepared, one of the polymers of the mixture containing at least 85 pounds of acrylonitrile. The polymers from which the threads are produced should preferably have an average molecular weight in the range from about 40,000 to 150,000.

The term "cascading water bath" means No restrictions on the use of water alone as Wasohmedium. Bern fasohmedium can also provide suitable aids, such as non-proprietary dyes, extraction aids and the like, so be set. These auxiliaries can be used on the threads ▼ enact the Endreeerroire sprayed on or a separate one or more of the reservoirs are added.

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The threads treated according to the invention can be subjected to various aftertreatments in order to reduce certain properties. A staple fiber, for example, which is produced in the manner described in your Beißpiel, has when treated in a storage chamber curler without prior steam treatment and without steam supply to the storage chamber and while maintaining a druoke of 3.9 atU. at the outlet flap essentially the same physical properties as the staple fiber in the example, but a slightly lower crimp frequency and amplitude. Such a fiber also has a higher residual shrinkage, e.g. B. in the range of about $ 20 to $ 24 after cutting and drying.

The pied vegetables of the invention have a high density. They are also easier to process, especially on cotton spinning devices and even after long, z. B. six months of storage. The obtained paser also gives a significantly improved mass cohesion and a lower "Flying" during processing. You can use this fiber alone or in a mixture with other artificial and use natural fibers for numerous textile purposes.

Numerous other embodiments are within the scope of the invention.

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Claims (1)

Ί56 Λ ίβΟ { ί, Ι ancestors aur producing hoohdiehu »parts from The drying process is carried out with washing and washing and drying of the dry piidon in a number of pictures, characterized in that the loaungamifcfcelboladenen threads are passed through at least one lower reservoir of a water structure flowing in a cascade-like manner About 40 to 70 $> of the degree of stretching and then, while being carried out through at least one upper reservoir of the water bath kept at a temperature of about 50 to £ 8 ° C, stretched by the remainder of the total degree of stretch and then to a temperature of about 50 to 60 ° C heated water is directed at the threads and fed to the uppermost reservoir for a cascade-like flow through the bath reservoirs 2ο Method according to claim 1, characterized in that the threads are stretched to about 2 to 8 times their original length. 3. The method according to claim 1 or 2, characterized in that a progressively decreasing temperature profile of the cascading water bath from the first lower reservoir to the last upper reservoir is used » - 10 - 909815/0873 U35619 4 · Ttrfatiren aaoh one of the recommendations 1 bie.3, thereby keaastloluwt »4mm ground the lower beeerroire to a« ββ-from 95 to 100 ° 0 aofgehelst ". - 11 - 909815/0873