DE485324C - Process for producing shiny hollow threads - Google Patents

Description

For the production of shiny hollow textile fibers from CeEulose solutions, it is known this before spinning emu ^ sioiisauig · with To mix air or other gases or to add substances to them, which during or after When the threads exit the spray nozzle, gas is generated inside the threads by chemical or heat effects. These hollow fibers can afterwards collapsed or degassed.

In this process, a normal Visikoselösuing, as is also used for the production full of fibers is used !, injected into a customary coagulation bath, which z. B. contains sulfuric acid and sodium sulfate. These viscose solutions usually contain 6.8 to 7.8 percent by weight of cellulose and have an alkalinity which, in

Expressed as weight units in NaOH, the cellulose weight is roughly in the ratio 6.5: 7.5. The total alkalinity of the cellulose solution · becomes here by titration with sulfuric acid using helianthin as; Indicator determined and expressed in parts by weight of NaOH.

Also the degree of maturity of the ones known to dien Process used viscose solution corresponds to that for the production of full Fibers required degree of ripeness, which is expediently expressed by the so-called salt point will, i.e. the percentage of a Sodium Chloride LöBunig, in which an incident Drops of the viscose to be examined just coagulated. The salt point determined in this way is for normal viscose solutions about 3.5 and corresponds to a maturing time of about 110 hours at a ripening temperature of 13 ° C

If one uses such viscose for the production of hollow fibers, these are often Dull and have a hollow central space made up of closely spaced bubbles. consists, which are often so interconnected that they have short pieces of fiber with tubular Form cross-section.

It has also been proposed · to spin hollow fibers from a viscose solution, which has a low degree of maturity and, accordingly, a salt point greater than 7, which corresponds to a maturation time of at most 65 hours at 13 ⁰ C. This creates a hollow and shiny artificial fiber that can be collapsed.

The subject of the invention is now a method by which the same success is also achieved when viscose solutions with a wide range of options, Degree of maturity are spun. To this

The purpose of the invention is a viscose solution applied before the addition of the necessary to form the cavities . ■ Carbonates less than a part of alkali - calculated as NaOH - to 1.2 parts of gel.

Moses contains, with a CeOMose content of 7j3 0/0 deiminach less than 6 0/0 alkali.

To a viscose with 'such a low Various ways can be used to produce health. the AlkalicelluiliOBle can be used with a smaller quantities of baking soda can be produced than normal alkali cellulose, xanthate can also be used in ordinary. Dissolved in water or in water that contains less baking soda than usual. There is also a surplus. to alkali of viscose be withdrawn by diffusion. ■ ...

Before spraying, the viscose becomes sodium carbide ONAT IN THE FOR 'THE MANUFACTURING HOLDER Fibers required amount added. Also, part or all of the required may be required Sodium carbonate in viscose anoints can be produced by adding carbonic acid to it or add bicarbonate; but in the latter case the amount of carbonic acid or bicarbonate must be used be large enough to at least one part. 0.5 0/0 of the in. The normal To implement caustic soda contained in viscose solution.

The spinning liquid thus obtained is in spun a precipitation bath which contains sodium sulphate and sulfuric acid in the usual way, and in. Concentrations, the viscose solution used for the alkalinity and the maturity condition dbr Adjusted "are. This adjustment is necessary in order to be able to use shiny fibers elongated cavities · to obtain "and can, for every viscose by simple experiments can be determined in each case. If the density of the faeces falls below a certain level lower limit, the luster of the fiber disappears, "that pronounced on the surface Aufweisit depressions. If the density of the felling bath is too high, the cave. The fiber is blistered and becomes clear. recognizable sections.

For a viscose solution with a certain Gel-Mosegehalit assumed, for example, of. 7.3 o / _o the appropriate ripening and precipitation conditions are indicated in the drawing in the form of a diagram, in which the degree of ripeness is shown as the ordinate. worn is expressed in hours of maturity; time at 13 ⁰ C, while the abscissas indicate the composition of the foul bath in three different conductors, of which the

Head 1 the density of the felling bath at 45 ° C expresses,. ".. '.

"Head 2 the amount of sodium sulfate" in a precipitation bath with 145 g sulfuric acid per liter and head 3 the amount of sodium sulfate in a precipitation bath with 125 g sulfuric acid per liter. The curves AA close the (hatched) area of associated! Ripe and sodium sulphate contents within which a viscose solution with 4% alkali (and 7.3% cellulose) can be spun into shiny hollow filaments if a precipitation bath with 145 g sulfuric acid per liter is used. So fraud z. B. the maturation time at 13 ⁰ C 48 hours, the diagram shows that · a coagulation bath must be used: whose density is between 1.200 and 1.320 and accordingly has a sodium sulfate content between 175 and 323 g per liter.

The curves BB close another region; offer, ekn, which contains the corresponding values for the precipitation of the same viscose solution with the aid of a bath of 125 g sulfuric acid per liter.

With an alkalinity of 6% (and a cellulose content of 7.3%) dissolved when using a precipitation bath with a sulfuric acid content of; Curves A'-A 'are 145 g per liter , and curves B'-B' are used when using a faecal bath with a sulfuric acid content of 125 g per liter.

It is straightforward by interpolation between the values specified in the diagram possible, for viscose solutions of a different alkalinity, the ripening times and fouling bath combinations to calculate at which the best glaze of the product is achieved. Prerequisite It goes without saying that the underlying cellulose content of 7.3% should be adhered to will. For viscose solutions · with a different gelulose content, the required Information by! Try to determine without further ado. "'.

Similar verification tests are required if further substances are added to the precipitation bath, which result in; the production have "tried and tested" artificial silk and do not affect the gloss of the product, z. B. Zünksulfat or glucose.

B eis ρ χ el ι;

A viscose solution of the following composition is prepared: ' Cellulose 7.3%, total alkalinity 4% as NaOH, which is obtained by meshing of normal xanthate with water. Sodium carbonate is added to the AlkaMtät 7.0 / 0 increase. This viscose solution is allowed to mature at 13 ° C. for 73 hours, This viscose becomes in · εΐη coagulation bath injected, which 145g acid per liter and g sodium sulfate per liter contains. It should be a synthetic silk fiber with a single thread denier of 6 den. getting produced. Nozzle

Winding speed 45m per minute, running speed of the thread in. Bath 35 cm. Bath temperature 45 ⁰ C. The thus prepared fiber is hollow and glänzenid.

Example 2

It uses the same viscose solution with an addition of carbonate and matured for 11 hours at 13 ο ⁰ C, calculated from Mischuingsbeginn on. This viscose loosening is injected into a coagulation bath which contains 125 g of acid per liter and 40 g of sodium sulfate per liter. It is said to be a silk fiber with a single thread denier of 6 denier. hedges be divided with a Düseraöffnung of ¹² mm Z ₁ Oo. The injection speed is 45 m per minute. Running speed of the thread in the bath 35 cm.

Temperature of the bath 45 ° C. The so 'produced Fiber is hollow and shiny.

Example 3

It becomes a viscose solution of the following composition prepared:

Cellulose 7.3 o / _o> total alkalinity 5 0/0 as NaOH, which is obtained by mixing normal Xanrthat 'with water. To this end, sodium carbonate is added to increase the alkalinity to 8. This Vüskoselösumg is ^{allowed to ripen for 54 hours at 13 0} C from the beginning of the mixed period. This viscose is then injected into a coagulation bath containing 125 g of sodium sulfate per liter. It is said to be a rayon fiber with a single filament titer of the. getting produced. DüsenöfSiung ¹³ Z ₁₀ O rom. Spritzgeschwihdiigkeit 45 m per miaowed, speed in the bath 35 cm, BadtemperatuT 45 ⁰ C. The thus prepared fiber is hollow and shiny.

Claims (2)

Patent claims: 1. Process for the production of shiny hollow threads by spinning viscose containing alkali carbonate in precipitation baths containing sulfuric acid and sodium sulphate, characterized by the use of viscose of varying degrees of ripeness, which before the addition of the carbonate is less than one part alkali - calculated as NaOH - per 1.2 parts cellulose , ζ. B. with a cellulose content of · 7.3% less than 6 0/0 alkali contains. 2. The method according to claim 1, characterized in that a part or the whole alkali metal carbonate required for the production of hollow fibers in the viscose solution produced even by treatment with carbonic acid or sodium bicarbonate will. 1 sheet of drawings