DE1251464B - Process for treating flax fibers - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

DOIf

German class: 29 b -2/01

Number:
File number:
Registration date:
Display day:

1251464
U8048IVc / 29b
May 25, 1961
5th October 1967

3) ο * C-

The invention relates to a method for treating flax fibers with aqueous sodium hypochlorite solutions and acids on the one hand and alkalis on the other hand, flooding the fiber mass.

The pectin substances (pectin, pectose, pectic acid) of the flax form the bast lamellas into which the fibers The central lamellae of the elementary fibers are embedded in the plant stem in the form of a bundle Way cemented together to form the technical fibers or fiber strips, as well as a small part of the Cellulose that makes up the fibers.

The pectin substances consist mainly of the neutral, in warm water, especially in bases and basic solutions soluble pectin, the neutral and insoluble pectose and the pectic acid, the Can form pectates.

The most widespread and so far best means of removing the pectin substances is the roasting water or the Dew roast, d. H. bacteriological roasting and roasting by mold. Roasting is supposed to be the bast remove, but must not attack the central lamellae between the elementary fibers, otherwise the fiber ridges to be divided further and further and finally split up.

The biological roasting is cumbersome, lengthy and inefficient, so that the linen, in particular under the competition of synthetic fibers, is becoming less and less important. It is therefore a economic problem to modernize the flax industry and restore its competitiveness. In addition, it is of considerable technical importance to use the flax fibers in such To gain shape and length that they can be spun together with synthetic fibers, as they are through such Allow mixed fibers to achieve particularly valuable properties.

Numerous attempts to perfect organic roasting and especially to replace it by a chemical process have been made. So one has z. B. special bacterial cultures in the Roasting bath introduced, but if you want to accelerate the roasting, you have a more virulent and as a result, achieved harmful effects.

Another attempt is the addition of very small amounts of hydrogen peroxide to the roasted water, however no real improvement could be achieved in this way either.

It is known that acids partially hydrolyze pectin substances and, under pressure, degrade them at the same time but the cellulose of the fibers attack with the formation of hydro-cellulose that bases and basic substances Process for treating flax fibers react more effectively than acids to pectin substances

Applicant:

Union Financiere d'Anvers B. U. F. A. S. A .;

Fincancieverbond van Antwerp

B. U. F. A. N. V.,

Antwerp (Belgium)

Representative:

Dipl.-Ing. H. Kosel, patent attorney,

Bad Gandersheim, Braunschweiger Str. 22

Named as inventor:

Walter Theophiel Florent Hennion,

Gand (Belgium)

Claimed priority:

Belgium of June 3, 1960 (469 860)

by eliminating their methoxyl groups without to be sufficient per se, and that the bleaching agents customary for textile fibers attack the pectin substances, especially if the fibers have previously been treated with bases. Bleaching works almost without exception the central lamella and is generally associated with the formation of oxycellulose.

In other words, the chemical treatments are either inadequate or detrimental the fiber too much.

The classic process of flax extraction is therefore usually as follows:

1. Bacteriological roasting (in water) or roasting through mold (on the meadow).

2. If necessary, if white goods are desired, boiling the threads, fabrics and, more rarely, the fibers with sodium carbonate, sodium bicarbonate, caustic soda or a mixture these chemicals result in bleaching. So bleaching is done on raw materials, which contain only a few pectins as a result of roasting.

In this way you get a usable linen, but, as I said, neither with the technical one

709 650/373

3 4

still kept pace with the division in a controllable manner in that can. desired degrees and according to the intended use

The green flax can therefore be produced without roasting or other fibers.
Digestion by mechanical treatment only. The above-mentioned substances must now be chemically treated without chemical aftertreatment and / or physically reshaped in such a way that they are only suitable for yarns for ropes, packaging and other coarse fabrics that can be easily removed without damaging the cellulose. The well-known finishing are. With the removal of these substances, natural processes occur through chemical aftertreatment or, accordingly, a lightening of the fibers.
Water digestion lead at most to yarns of medium size. The object set is according to the invention there number, and is not achieved with considerable losses by binding the fibers with a sodium hypochlorite solution for 1 to 4 hours at room temperature only in terms of fiber weight, but also in terms of fiber length. For example, the unpressurized treatment with 2 to 5 g / l of active chlorine is known, whereby the green flax is boiled in a lye containing 10% per liter of 0.5 to 10 ml hydrochloric acid of 22 ° B6 sodium hydroxide of the bast or yarn weight or 0.1 to 2 ml of sulfuric acid at 50 ° Βέ added in a flotene ratio of about 1:10, as well as 15 and then a customary dechlorination treatment in a water connection below 2 atm. Performs pressure at 4 hours lurg and alkaline cooking.
Cooking time with circulation of the liquor. The treatment with bases, e.g. B. caustic soda, be-Shabbcn must be removed on special equipment, most of the soluble pectin, is removed. Green processing is therefore also not a practicable way of solving the problems described at the beginning and softening them and removing them from the insoluble problems described. Pectose the methoxyl groups. It forms in the

This also applies to the building structure (cotton-molecular structure of the pectosis, a gap which

sicrung, flax fiber production) of the flax fiber. Since lead of substances permitted by reaction

For a long time, attempts have been made again and again to get rid of the methoxyl groups from pectosis

inferior stalks and tows form high quality 35 soluble derivative.

To make fiber products and the domestic raw material. Every aftertreatment by using basic cooking

flax for cotton-like products brings about agents that act in molecular form

to draw. Despite all the problems, the flake problem is only a partial reduction of the pectosis,

Efforts not yet resolved even today. The simplest one yields lower quality fibers and splits them

and methods practiced over and over again for the production of fiber ridges in elementary fibers or at least in lots

of flake bast is the cutting or tearing of shorter fibers.

von Röstwergcn and the spinning of this material If you add the boiled fibers in

on its own or together with cotton or rayon. the manner according to the invention carefully and gently

The digestion process was pre-treated in Germany, whereby the active substances "in statu nascendi"

predominantly simple or multi-stage liquor digestions 35 act, they form a soluble and thus removable

or combined chlorine-alkali processes are used. bare connection with what is after the pectosis

The ozonization has besides the mechanical elimination of the methoxyl groups by the bases

and chemical weakening of the fiber and what is left over.

considerable technical effort has the disadvantage that it is better to use the treatments (boiling and

deliberately repeating the valuable length of natural flax 40 degumming) twice or more than

fibers in favor of an inferior short- to extend the duration of action or the concentration

Fibrous cotton-like product is sacrificed. increase the tration of the baths. Incidentally, this

The modern spinning of synthetic fibers calls for easier draining of the residues,

However, as already mentioned above, the method of treatment according to the invention is destroyed for as long as possible

Fibers, so that a mixed spinning with flax a 45 likewise the straw and the wood pulp.

Treatment process requires which fiber is obtained by the method of the invention

length not affected. compared to biological roasting, the following important

The invention solves the problem of such tend advantages:

To create a process that is at the same time economical> _ßei , _{calibrated capacity of the} used

.st and linen very high quality, particularly 50 _Beh | _{ter kötmen in the} ⁵ _cl f _{emischea equipment}

special wakefulness and firmness, leads. Γη first _{larger M item to be treated} introduced

Lime sol this process the biological rust ^ _na , _{g in} ^s _{the Rö} Sonders at loading

this can, however, also complement and further act of peeled fibers,

preferably used for bleaching. °

The invention is based on the consideration that 55 b) The treatment time is shorter than in the

green fibers, no matter in which form, organic roasting.

contain a lot of pectins. This great pectinic substance. . , ...

quantity is one of the reasons for the failure of numerous ^c > ^Die . ^{Men s of the} chemicals to be used

Try to get one that reduces organic roasting.

replacing chemical degumming process to 60 d) The treatment costs are lower than for the

Find. So, through the chemical treatment of biological roasting,

of bast fibers or their waste on the fibers _N ^ ~, ■, ·. ., ".,

on the one hand any straw or wood still ^{clinging to it and e} ) ^ drying is easier and faster to

on the other hand pectin substances, lignins, impurities.

and to a large extent the natural coloring agents to 65 f) The possibility to control the processing sequence

Removal, regardless of the influence, allows fibers to be obtained

Form these fibers accumulate. In doing so, if desired, with different, very different

the condition of the fiber ridges are retained or the properties appropriate for use.

The process of the invention provides industrially advantageous form:

Fiber ridges (long fibers), tow, etc. for spinning linen;

Fibers with a length suitable for intimate mixing with other, natural, semi-synthetic or synthetic fibers are suitable;

Fibers for Fiechel yarn spinning;

very short, fine and completely white fibers for paper manufacture and other uses.

The method is applicable to peeled or unpeeled, organically roasted or unroasted Fibers, no matter in which form they are presented e.g. B .:

Flocked goods (fiber ridges or shorter fibers before spinning),

Flax fiber waste,

Card slivers, comb slivers or stretch slivers, spindle bench roving,

finished yarns,

Cords, ropes, ropes,

Woven and knitted fabrics, etc.

However, the treatment according to the invention is of particular importance in the case of green flax fibers it provides all of the advantages described here.

The method is e.g. B. feasible in the following way:

a) A filling of peeled or non-peeled flax fibers is cooked by adding suitable Way an alkali, z. B. caustic soda circulate or, conversely, the material to be treated in constant motion in the alkali holds to remove the soluble pectin, soften the cockroaches and wood pulp and the To prepare fibers for "the hypochlorite treatment, on the one hand the total or partial Removal of remaining components, such as pectose and softened wood pulp, and on the other hand if necessary, the more or less driven, accompanied by a refinement Allows splitting of the fibers.

b) Rinse and neutralize if necessary.

c) One sends through the filling of boiled, rinsed and optionally neutralized fibers an aqueous solution of sodium hypochlorite under the conditions given above, to which one slowly adds hydrochloric or sulfuric acid in such a way that the fibers with the sodium hypochlorite or the products of the reaction between the sodium hypochlorite and the acid come into intimate contact. Even if the The chemistry of the process according to the invention has not yet been fully clarified, so it is but it can be assumed that the reaction proceeds via active intermediates or nascent chlorine and that the pectose and the wood pulp of the fibers through this in by washing, z. B. With an alkaline solution, removable substances can be converted.

d) The filling is subjected to a dechlorination treatment.

e) The reaction product formed according to c) is removed by washing out as at the end of the Paragraph c).

JF) f) If necessary, repeat steps a) to e) until the desired results are achieved. The number and sequence of operations is determined by necessity a rational process, which the fibers systematically and without degradation of the cellulose controllably freed from all substances to be removed and at the same time the fibers their softness, Maintains strength and spinnability and them

ίο gives the desired properties and the Saving of chemicals in order to lower the production costs.

The decoction can be done with the following chemicals,. take place:

sodium

z. B. about 2 to 25 g per liter of water sodium bicarbonate

z. B. about 20 to 50 g per liter of water ^ao sodium perborate

z. B. about 2 to 20 g per liter of water sodium sulfite

z. B. about 5 to 10 g per liter of water a ₅ sodium hydroxide

z. B. about 10 to 50 g per liter of water potassium hydroxide

z. B. about 10 to 80 g per liter of water sodium hydrosulfite

z. B. about 2 to 10 g per liter of water sodium acetate

ζ. B. about 2 to 10 g per liter of water borax. z. B. about 2 to 10 g per liter of water Marseille soap

z. B. about 5 to 25 g per liter of water

Detergents (synth.)

z. B. about 1 to 10 g per liter of water

These chemicals differ somewhat from one another in their effects, so that the person skilled in the art can select the most favorable substances for the individual case, alone or in a mixture with one another. Various chemicals can be used when repeating the decoction. The decoction advantageously takes about 1 to 4 hours. The liquor ratio is the same as that used in textile technology in dyeing or bleaching machines.
The hypochlorite treatment takes place with constant circulation of the bath or with constant movement of the material to be treated. The treatment time is about ¹ 1 to 4 hours and the shorter the smaller the amount of the processed material. The usual liquor ratios are also used here.

example 1

21 peeled green flax is boiled gently in a conventional manner by being moved l 2 hours in approximately ° / soda lye cent of 70 ⁰ C. After thorough rinsing with plenty of water and any careful neutralization with very dilute acid of the flax is moved I ¹ I ₂ hours at room temperature in a sodium hypochlorite solution of 2 g / l active chlorine. Over this period

_{0.1 ml H 2} SO ₄ of 50 ⁰ Be (expediently in dilute form) are added while avoiding local overconcentrations which could lead to the evolution of chlorine.

After rinsing again with plenty of running water and, if necessary, dechlorinating in the usual way With bisulfite, boil again with sodium hydroxide solution, rinse carefully and then carry out the hypochlorite treatment and repeat the alkaline decoction under the same conditions.

Ultimately, about 1.5 tons of very white, soft fibers are obtained, the length of which is practically that of the fibers used Green flax fiber corresponds to and which can be found without difficulty with z. B. polyterephthalate fibers mixed spinning into a solid yarn. A made from it Fabric is pleasant to the touch and combines the properties of natural fibers in an advantageous manner Flax with those of synthetic fiber.

Example 2

11 peeled unroasted flax fibers with a shives content of 20% are boiled for 1 hour at 85 ° C by flooding them with a solution of 100 kg 100% caustic soda in 10 m ³ water, then the bath is drained and rinsed with cold water Water until neutralized. 2401 of a technical sodium hypochlorite solution of 25 to 26 ° Βέ (with 149 to 150 g of active chlorine per liter) is then dissolved in 10 m ^{3 of} water at room temperature and this liquid is allowed to flow through the fibers for 1 hour, hydrochloric acid of 22 ° with at a rate of 750 ml / min. The bath is then drained. At this stage, the fibers give off a slight smell of chlorine, and the adherent cockroaches have a reddish-yellow: color. It is rinsed with plenty of water and then carried out a customary dechlorination treatment with bisulfite, rinsed with water, boiled in the usual way, rinsed again with water and dried.

You get 70% white fibers, which are characterized by a soft hand and practically the original Have fiber length. They contain about 1.4% cockroaches and 95% α-cellulose, while the biologically roasted fibers (classic treatment) are yellow and about 5% cockroaches and a maximum of 80% contain α-cellulose.

Claims (2)

Patent claims: 1. Process for the treatment of flax fibers with aqueous sodium hypochlorite solutions and Acids on the one hand and alkalis on the other hand, with flooding of the fiber mass, characterized in that that the fibers 1 to 4 hours at room temperature with a sodium hypochlorite solution Treated with 2 to 5 g / l of active chlorine, gradually adding 0.5 to 10 ml of hydrochloric acid of 22 ° Βέ or 0.1 to per liter Add 2ml sulfuric acid at 50 ° Βέ, and then by performing ordinary dechlorination treatment and alkaline cooking. 2. The method according to claim 1, characterized in that the treatment is repeated several times performs. Considered publications:
German patent specifications No. 328 034, 696 892, 430. 709 650/373 9.67 © Bundesdruckerei Berlin