DE2326837A1 - PROCESS FOR THE PRODUCTION OF FIBER-SHAPED STRETCHED FORMATIONS FROM POLYMER SUBSTANCES - Google Patents

Description

DH. ING. KiAVtriäSfllOKF 8 MÜXCU KN iji » DHMS.v.I'KGÜMANN S *? UW>: HjHHNTM. »SsE 2

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1A-42 868 '

B e s ο h r e i b u η g

to the patent application

AUIG S.p * A., Palermo, Via M * Stabile. 216, Italy

concerning

Process for the production of fiber-reinforced crimps Formed from polymer subetaflzaft

It is known that fibrous materials are used in industry are of particular importance. You can practically use them due to their linear dimensions into different categories, and for the sake of simplicity, the following designations are used here chosen·':

a) Threads: single-fiber, longer thread-like structures _3, optionally endless threads;

b) Staple fibers: einfaserig.e threads of much less Length as a);

c) IT glasses: short fibers, much shorter than b) that too can be in the form of aggregates of individual elements.

In the latter case, the downward length is merely because of this limits that the structure must have the profile of a fiber, which is why its length must be greater than the diameter

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its cross-section, otherwise it would be spherical.

Processes for producing the threads listed under a) are "known. They are produced by melt spinning, either dry or wet.

It is also known that the properties of fibrous structures can be improved by stretching. If one wants to achieve such excellent properties, one begins in practice with the production of the threads according to a) in any way, for example by the mentioned spinning, whereupon the thread is subjected to the drawing. Staple fibers can then also be obtained from the drawn thread. The situation is different, however, when fibrils are to be produced, for which essentially two different processes have been used. One consists in preparing a polymeric substance and dissolving it, whereupon it is allowed to coagulate under the action of strong mechanical shaking in the corresponding zone. This process is described in I ¹ R-PS 1 510 259; 1 350 455 and 84 995 · Recently it has been proposed according to LU-PS 59 586 to produce fibrils during the polymerization with the aid of a cutting reaction, taking into account the other variables that influence the process.

The method according to the invention enables production of fibrous structures of types a), b) and c) in any length to extraordinarily, simple and economical borrowed Alternatively, one or more polymeric substances are used as a starting point, as long as these products provide spinnable substances that meet the technical requirements. Preferably, but not exclusively, the invention relates, as will be explained in more detail, to wet-spun Fabrics.

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The essential feature of the process according to the invention "is that the jades during their formation with the aid of a gas or a liquid (for example the coagulant) between the zone in which the thread is formed and that in which it is collected, a pulling action or "better said, be subjected to a dragging effect. The carrier fluid is doing a velocity gradient, whereupon the stretching effect "based exerted on the yarn during its formation without damaging it. The linear Ans expansion of the yarn is as desired regulated by means of a vortex or Drallvirkung, together with the With so that eppwi rkung or instead of this is exerted by the carrier fluid.

The carrier medium, which exerts a stretching effect on the thread in the manner indicated above, can be uniform (such as e.g. the coagulant) or consist of different liquids or gases. The medium that leads to the creation the twisting effect can be the same or one of those, polygamy exert the stretching effect or it can also be a be another medium or a mixture of several media. If the threads are continuous, the twist can be be very limited. Both "the entrainment effect (stretching effect) and the twisting effect can be controlled as required Influencing the temperature of the media and / or the profiles the zones where these effects take place or others already known conditions.

According to the invention, when a low twisting effect is used, a continuous, slightly drawn thread is also obtained improved properties, but in general on Usual V / ei se must be stretched even further.

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From the continuous threads produced in this way, one can then, if the low twist is sufficient for this purpose, staple fibers can be obtained immediately or a stretching process can be carried out beforehand turn on. For this purpose, one can simply cut the infinite thread into appropriate pieces. A A much more interesting case, however, is the division of guide grooves (short threads), which are used, for example, in paper manufacture to be needed. In this case, the stretching process is always associated with a high level during the formation of the threads Twisting, whereby the threads are divided lengthways and widths into the desired dimensions.

These effects are exerted by those serving as a medium Liquids or gases, using the profiles of the zones in which they exert this effect. One can also additionally take advantage of the effect of the temperature or the speed of coagulation; E.g. you can for rapid training a cover film while the material inside is still liquid and you can do one of the above Variations or a change from other Fairtoren (e.g. by influencing the pressure if the material is in a gaseous Environment) change the cylindrical surface of the fiber so that it has many protrusions, which contributes to this able to hold the fibers together mechanically; if they are to be used for the production of structures such as paper.

It is therefore a particularly strong swirling necessary when you look at the length of the fibrous material at the same time Stretching wants to have an effect, while in the formation of continuous filaments one has a much lower vortex or twist ~ effect.

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The following statements "refer to the wet spinning process. .

It is known that in wet spinning the solution of a polymer is passed through the openings of the spinneret into an eoagulation bath, in which the single threads almost all of the solvent lose so that threads of solid polymer "form.

In this phase it is not possible with the usual methods to stretch the polymer so that the individual thread special mechanical properties. Rather, this will effected in a subsequent phase by drawing the solidified polymer yarn.

It is also known that the yarn is in a critical state when it comes into contact with the coagulant or with the precipitation bath when it emerges from the spinning head. In this phase, the individual threads in a highly plastic state, in which a stronger. Namely are "stretching could easily lead than that under its own weight to a hot. One for the" emerging from the spinneret yarn critical period is its coagulation.

With the aid of the method according to the invention, the polymer can be stretched more than was previously possible with the usual spinning baths and it therefore receives better temporary ones mechanical properties and a remarkably uniform diameter. When carrying out the method according to the invention When the polymer exits a zone that divides it into still liquid strands of thread, i.e. » so if it is still is in a highly deformable state, during the course of the coagulation a dragging and therefore a stretching effect subjected by at least one flowable substance.

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Following the pre-stretching according to the invention the threads are treated in the same way as the threads obtained at normal wet spinning.

The invention also includes an apparatus for implementation of the method in which this pre-stretching and twisting are effected by means of, for example, a device,. which consists of a tube in which a gas or liquid flows and into which the spinning head or another zone for subdivision of the polymer opens, preferably * but not necessarily, in a concentric arrangement to the Eohr itself, this zone or the spinning head always in the flow medium immersed.

The diameter of the tube is adapted to the diameter of the spinning head and can vary along the tube, so that the flow rate within the pipe changes.

The length of the tube must be chosen so that the yarn is solidified when it emerges from the tube and most of it of the solvent has released.

The flow velocity inside the pipe is a very important variable as it determines the. total degree of stretching of the polymer determined.

The nature of the medium flowing through the pipe depends on the particular system of polymer and solvent. In any event, the liquid must be viewed as a coagulant and not a solvent for the polymer in question.

Coagulation or precipitation can be effected by using a flowing liquid _s dh <, _s independent of temperature »of a true non-solvent for the in

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Question coming polymer One can also use coagulation in the Liquid "used to dissolve the polymer" by keeping it "at a low temperature or, more generally said by cooling the bypass in which the coagulation or precipitation of the polymer is to take place.

So "for example" can be used: inorganic Liquids such as water, acids and bases, either concentrated or diluted with 'fasser', organic liquids such as para-hydrocarbons, naphthenes, saturated or unsaturated aromatic compounds, halogenated hydrocarbons, alcohols, esters, amides, etherocyclic compounds etc., pure or mixed.

The temperature of the fluid flowing through the ear can vary, but it must always be a few degrees lower be than that "at which the polymer softens; them is usually about 3 "to 10 C lower than the softening temperature.

¥ enn the temperature of the liquid flowing through the pipe is about that of the surroundings, the precipitation of the polymer from the solution takes place very quickly and the stretching effect occurs the thread is less than that obtained at a higher temperature of this liquid.

Practically dispose in the latter case due to the higher Temperature the macromolecules over a greater mobility and need before the complete solidification of the polymer a longer time to orientate yourself.

The essence of the drawing obtainable according to the invention and therefore generally the orientation of the fibers was determined by measuring the bi-refraction and with the help of X-ray

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radiate or by measuring the toughness.

In attempts to work out the method according to the invention, it was surprisingly found that if the speed of the coagulating liquid within the tube is so high that a zone with a strong twist is created, the fibers obtained are torn and severely frayed; multifilament aggregates are obtained, which are usually referred to as fibrils and, due to their dimensions, are very suitable for the production of non-woven fabrics (mushrooms) or paper. For this purpose, they can be used unmixed or mixed with natural fibers, for example cellulose fibers !!, for the production of paper on the usual equipment. If one starts out from a polymeric solution of a certain consistency and uses suitable precipitation liquids from pail to pail and varies the temperature and the flow rate of these liquids in such a way that there is less movement. . If the turbulence changes to a movement with a high degree of turbulence, noticeably stretched fibers are obtained. These fibers lie within a range that extends from continuous yarn to staple fibers to various aggregates (pibrils) of various lengths, starting from solutions of various synthetic polymers and mixtures thereof ; these are: polyacrylonitrile and copolymers; Polyamides, polyesters and polyolefins such as polyethylene, polypropylene and copolymers; Polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol and other polymers known for this purpose.

In the drawing, an apparatus for performing the method according to the invention is shown in FIG. 1, wherein 1 is the End part of the storage vessel for the polymer solution to be spun

is; the vessel is provided with means for the solution to the

to subject the necessary pressure for squeezing out via the spinning head 2 (via one or more openings).

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The thermostatic jackets 3 and 6 make it possible to achieve and maintain the desired temperature. the end the spinning head 2 enter the threads in a tapered tube which is designed so that under the action of a flowable medium 5 (e.g. the coagulant) along a speed gradient is built up along the axis of the pipe. The flowable medium 5 can be introduced as in FIG Figure shown, or at any other point of the tapered tube and at any inclination and can be a be uniform or mixed medium.

According to the drawing, the pipe through which the flowable medium flows gradually tapers from section to section more and more, but the tube can also have a cylindrical shape in all of its sections or it can also be designed in this way be that the sections enlarge more and more, depending on the chosen type of "dragging along" described above.

The invention also encompasses methods for achieving different geometric shapes or structures that have a fibrous base contained in special films, sheets and the like as well as devices for carrying out such processes and the structures obtained therewith.

»In modern technology, known basic materials are often replaced by economically or technically cheaper new ones. In papermaking, for example, processes are already known which use either plastic films or fibers for the production start from synthetic pulp. Such fibers are also used for the production of non-woven or knitted textiles » Up to now, all of these methods have had to use the most varied types of devices, and this diversity is made possible by the method according to the invention largely overcome »

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According to the invention, structures of any geometric Design (e.g. also smooth foils), whose fiber structure resembles the usual paper and the non-woven Textiles corresponds without the need for the various types of devices mentioned. According to the invention one prepares simply a homogeneous or substantially homogeneous phase of a material that is used to form fibrous structures, preferably of polymer structures, which is suitable, divides them Phases, in liquid threads and then subjects these liquid threads to the action of one or more flowable Media that before,! During, or after the formation of the fibers at least in one zone where they interact with the polymer, cause turbulence; the fibrous material formed is then collected in a collection zone in relative motion with respect to the remaining parts which affect the process. the homogeneous or substantially homogeneous phase, in which the fibers are formed x ^ ground, can be represented by a solution from a polymeric substance, which may be used in another connection with a solvent and / or foaming agent function can be resolved; this phase can also consist of one Accumulation of one or more polymeric substances suitable for the formation of fibers with one or more compounds, which have the function of solvents and / or diluents and / or foaming agents.

The homogeneous phase can, however, also consist of a melt or more polymeric substances which are suitable for fiber formation, and this melt can be evenly distributed in one or more compounds that are in the liquid phase.

Among polymeric substances capable of forming fibers include the following polymers: Polyurethanes, polyacrylonitrile and its copolymers, polyamides, polyesters "

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Polyolefins such as polyethylene, polypropylene and their copolymers; Polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol, etc.

To subdivide the homogeneous or practically homogeneous phase of polymer substance capable of fiber formation, it is sufficient if this phase is passed through specifically designed zones _s have channels or distribution openings for the substance in question, as is the case with conventional spinning heads, for example, without - "Consider the number or design of the openings.

To transfer the initially subdivided polymer substance In fibrous substances, reference is made to the action of one or more flowable substances that affect the still v / calibrate threads exert a whirling or twisting effect, which -on acts on the linear and transverse dimensions of the fibers and also makes it possible to produce multifilament structures, such as those consisting of a bundle of thin fibrils fused together at one or more points.

The vortex or swirl effect mentioned also has the effect of that the fibrous structures formed have a certain stretching which improves its properties and can be easily controlled. The flowable medium that Facilitating the conversion of the segmented polymeric material into fibers, the polymer strands can be applied to virtually any one of them hit any angle, of course within the appropriate Limits of temperature, speed, pressure etc. This medium consists of a liquid, a vapor or a Gas or any combination of these states of aggregation. The occurrence and extent of the twist effect will regulated by physical provisions known to those skilled in the art; it is also known to the person skilled in the art, like that

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subdivided polymer material converted into fibrous structures will. The flowable substance used in the present invention has thereby the * unction to drive off the solvent and / or that Precipitate polymer by simple physical action (cooling) or by chemical means (coagulation).

The flowable medium can therefore also be a mixture of different liquids and / or gases, where, for example, one component is inert, another only acts on the heat state and yet another its effect not only cvx physical path, but also due to its chemical properties. According to the invention, the preferred flowable medium is a gas. The effect exerted by the media is critical for the method according to the invention for the following reasons: The Brail effect exerted on the medium influences both the dimensions of the formed fibers and, due to the more or less strong stretching effect, their properties, and the conversion of the subdivided polymer into threads or fibers also influences the nature of the structure, which is ultimately in the collecting zone, which, as boir.erJrt, is in relative motion to the rest of the system, is the action of the flow medium such that a jaserstructure is obtained that is still rich in solvent and extremely finely divided and one works in appropriate conditions for temperature, Pressure and concentration of the polymer solution and finally pushes this material into the collecting zone (which is in relative motion) with the application of force, so one finally obtains a film, because the polymer has the possibility of being shocked due to the presence of solvent and due to the shock effect according to the relative speed of the zone compared to the rest of the device in an m to be deposited more or less thin layer. In this case, the structure obtained, which is practically comparable in appearance to a film, is always more or less its origin from

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a fiber mass, even if the individual fibers can no longer be separated from each other. The on this Film obtained in this way undoubtedly has better properties than a film that does not have the aforementioned twisting effect; was obtained simply by pouring the solution onto a collecting surface. Ever after setting the concentration, temperature, pressure, etc. "for the" batch in question and depending on the regulation of the Swirl effect due to the flowable medium and according to the solvent content in the fiber structure or its plastic properties (in the case of melting or coagulation) and each depending on the force with which these fibrils are deposited and connect with one another, either fiber structures are obtained of the paper type or fila-like textile structure.

The primary purpose of the relative movement of the collection zone is to control the thickness of the deposited structure enable. I am a very simple factor influencing the system and to control the nature of the structure deposited in the collection zone consists in having one among others already Factors mentioned (temperature, pressure, chemical action of the medium) determine the distance between the zone in which the polymer is in liquid strands are divided, and the collection zone varies. This distance can vary depending on the working conditions between a few centimeters and a few meters, e.g. between 2 cm and 4 m. The starting polymer can also be dispersed Contain gas or dispersed liquids, in which case fibrous structures are then produced by interrupting the outflow special properties.

■ In practice, it is also possible to assemble in the collecting zone to obtain multilayer structures by one. in At a certain time there are multiple batches of different polymer substances or of the same but in the fiber structure different materials deposited on top of each other.

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You can also use the pasting material on other documents, e.g. deposit on non-fibrous layers, which are then coated with a or several identical or different fibers • fused will. Under a certain aspect, namely when the collection zone is stationary and instead moves the feed zone " fixed surfaces can also be formed with the aid of the method according to the invention, which is of interest, for example, for. the production of floors, walls, ceilings or in general for building elements e.

The relative movement can be continuous or discontinuous; in the first case, for example, one gets long and uniform Structures and in the second case long structures with different thicknesses or parts of structures (or in the flat case tracks).

As an example of an embodiment of a device with which one can obtain such fiber structures, reference is made to Fig. 2 of the drawing. 7 denotes an autoclave; 8 a / Shaker; 9 a heating mantle; 10 a subdivision facility for the polymer phase; 11 and 11a feeders for the Flow medium; 12 a rotating support; 15 a calender system. As substances that are suitable for the formation of fibers, are preferably called polymeric substances as defined in the textbook by Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 6, p. 463 · These polymers are capable of Creation of areas of a higher degree of lateral order (crystallites or millionelles), so that for a certain amount of time Length the molecular chains into three-dimensional net structures are divided.

To explain the invention in detail, reference is made to the production of fiber structures from materials in FIG Solution; however, the invention is not intended to be limited thereby.

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The following was found for this form of implementation; because. which exits the spinning head under a certain pressure and is "deposited on a moving support" by a gas jet which generates a high twist, which is arranged a short distance from the outlet openings of the spinning head a sheet of a polymeric substance which has a film-like structure. In another case the following was found: If the same polymeric solution was let out of a spinning head and "if it was also subjected to a strong twisting effect, it produced gas, but changed the working conditions during the collection (distance, temperature, etc.)" - so it was The result is the coagulation and simultaneous fibrillation of the polymer, which was deposited in the form of short fibers (2 to 5 mm.) on a moving Atif'Jage at a different distance from the upper spinning head openings than in the first The result was a web whose fiber structure corresponded to that of paper made from natural cellulose or from synthetic paper pulp.

The product obtained already had good mechanical properties which could then be improved by the usual chemical or thermal treatment.

To prepare a felt-like material, the following procedure was used in a third case: Under certain working conditions The polymer solution emerging from the spinning head was acted upon by a gas stream which produced less turbulence caused in such a way that the coagulation of the polymer and its simultaneous division into fibers with a Length of more than 5 mm was made into continuous fiber form; these relatively long fibers were left to stand uniformly on a running surface, which is the same distance as the second FaJ. 1 from the upper spinner head

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was arranged. The product obtained was "already good." mechanical properties due to the usual chemical and / or thermal treatment could be improved. The reasons for which three different structures were obtained although the starting point was always the same polymer solution or molten polymer and only the distance between the Support of the spinning head and / or the speed of the flowable medium as well as the concentration and / or the temperature and / or changed the pressure of the polymer solution are the following:

1st case

The short distance between the spinning head and the support prevents favors total evaporation of the solvent from the polymer solution and complete cooling of the polymer as well as the exit speed (pressure) the sticking of the. Microfibers so that a polymer film is obtained.

If the distance between the spinning head and the support is greater than in the first case and the speed of the gas is such is dosed that one by coagulation and fibrillation Receives polymer fibers 2 to 5 mm in length, they maintain their individual fiber structure when they are placed on the support unravel in such a way that a structure of short fibers is obtained, that of a paper made of natural cellulose or from synthetic pulp. The presence of a solvent in the fiber, the temperature used and the impact force together create a cohesion (fusing in places) between the fibers and therefore mechanical consolidation.

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3. Case

If the distance between the spinning head edge; the edition larger g is chosen as in case 2 and the speed of the gas is adjusted so that one coagulates from the solution © fibers that are longer than 5 mm, so they sit on the Edition in such a way that one. receives a structure that corresponds to the person corresponds to a non-woven, felt-like textile material.

In this case too, the presence of solvent in the fiber has a mechanical strengthening caused by others Variables (temperature ^ bridge, concentration us \ :.) favored can be.

As a flowable medium, nitrogen, air ,. QQq ,. Noble gases j liquids or vapors are used. temperature and the pressure of the dispersion or the melt are regulated in such a way that that the temperature is higher than the melting temperature of the Polymers, so that with the diluent a homogeneous Phase arises »If the polymer is in solution, the Temperature below the melting temperature of the polymer. The pressure is between the vapor pressure of the solution resp. Diluent and a maximum of 50 kg / cm "·

The focus is on dissolved «; or disperse Polymers preferably between 1 and 35% by weight.

The invention will be explained in more detail by way of example. In order to carry out the examples, that shown in FIG. 1 was used Device used, the outer tube? cm diameter would have.

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Example 1

Through a. Spinner head with openings from. 0.1 mm in diameter, a solution of polyacrylonitrile in TOYSiger nitric acid containing 1; 5% by weight polymer was spun ^{at 0 ° C.}

30% nitric acid was ^{pumped through the outer tube at 0 0} G at a fine flow rate

Causes stretching of the polymer in the eoagulation phase <t

(5 m see} ..,

At the end of the Kohres a continuous yarn of very uniform Durohmesser, which has a higher toughness exhibited as a yarn made from the same polymer which was obtained in the usual way by hate spinning and had not yet been drawn woi'den was *

example 2

Through a spinneret having openings of 0.1 mm diameter, a solution of high density polyethylene in decalin (50 weight fo polymer) was spun at 135 ° G. Methanol was passed through the outer tube at room temperature, the flow rate being chosen so that a vortex movement was obtained in the tube (mean raw flow rate eti ^ a 7 m see """).

Under these conditions, the liquid emerging from the spinning head polymer solution is precipitated and torn fibers and largely frayed so that vielfädige aggregates (fibrils) of _t at which the fiber diameter and fiber length were very similar to natural cellulose, Microscopic examination of the single fibers yielded a remarkable Bi fraction, which can be attributed to the stretching action to which the polymer was subjected when it was precipitated,

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Example 3

A solution of polyvinyl chloride in tetrahydrofuran (5 wt. Yi Polymer) "spun at room temperature. Through the outer tube was V / ater at room temperature under the conditions described in Example 2 Conditions pumped through (mean flow rate about 7 m see "").

In this case, too, multifilament aggregates (grooves) are obtained.

Example 4

Polymer deposition zone was charged at room temperature with a solution of 5 wt fo polymer in tetrahydrofuran through openings vonQ5 mm diameter. V / water was pumped through the outer tube at room temperature at a flow rate which resulted in the occurrence of a strong vortex movement in the tube (mean flow rate about 7 m). The speed of the water also allowed it to be around that mentioned above The polymer solution emerging from the openings was divided into thin filaments and the polymer was precipitated, so that short and strongly frayed fibers were obtained which had the appearance of multifilamentary aggregates (fibrils).

Example 5

A polymer blend of 40 £ polyvinylchloride, 30 $ polyethylene low density, IO / 0 high density polyethylene, 15p Polystyrene and 5 / £ polypropylene were used at a concentration of 5 $ dissolved in 1,2,4-trichlorobensol at 135 ° G. The solution was pushed through a spinning head with openings of 0.4 mm. By the outer tube was pumped with methanol at room temperature,

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wherein the Durohfluß Velocity was chosen so that in a strong vortex motion was obtained in the pipe (middle Duration of flow velocity about 7 m see).

Under these conditions, the polymer was precipitated from the polymer solution emerging from the spinning head and the short fibers were very frayed and had the appearance of multifilament aggregates (fibrils). They turned out to be as very suitable for making paper.

Example 6

In a series of experiments, a 5 * solution of polyethylene of high density in decalin at 1,35 ° C through a spinning head with openings of 0.1 mm diameter.

Decalin was pumped through the outer tube at a temperature of about ⁰ ° C. at various flow rates, so that a medium-strong vortex movement was obtained in the tube (average flow rate about 5 m).

Under these conditions, drawn fibers were obtained, the length of which was between 1 and 5 cm.

In the procedure described in the preceding examples, the vortices were adjusted accordingly. or twist effect obtained either endless threads or staple fibers or fibrils; the inventive method was also tested in connection with other known spinning methods.

The effects achieved between the spinning head and the collecting zone can also be related to the profiles of the Zones and / or the structures in or around which the medium flows. For example, in the one shown in FIG Device vary the profile of the spinner head in such a way that one can observe the vortex movement of the medium around it flows around, reduces or the whirling motion can also

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be reinforced. The same goes for the inner surface of the Zone 4 and for the variations of the profiles of all zones including the flow of the medium Spinning head is the handle, so either a spinning head of the usual type, as used here, is meant, or one "any other device capable of at least partially distributing the polymeric material in strands of liquid, also in sections that are many times superior to those normally used in fiber manufacture.

Example 7

An autoclave equipped with a Schützelwerk is loaded with n-heptane and high density polyethylene, = 0.6, so that a concentration of 5 & ew.-v «is obtained.

The mixture is heated to 160 G with shaking, so that a homogeneous phase of n-heptane is obtained. Contains high-density polyethylene,

The pressure existing in the autoclave was 5 kg / em "and was maintained during the entire duration of the experiment.

A dividing system was installed at the exit of the autoclave connected with 6 openings with a diameter of 1 mm. The polymer solution emerging from these openings was acted upon by a nitrogen jet under a pressure of 10 kg / cm, whereby the coagulation and the simultaneous fibrillation of the Polymers was effected.

The direction of the nitrogen jet was 90 pounds opposite the axis of the subdivision system. The fibrils formed were deposited on a moving support, the distance of which from the mouth of the openings changed can.

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Under these test conditions were changed the distance of the moving support from the openings of the distribution syst ems structure of the pilm type, fibrous structure that corresponds to the common paper and nonwoven fabrics (Mushrooms) received.

The mechanical properties of this structure have been improved by subsequent thermal treatment in a calender.

In the preceding examples, the following media were used to coagulate the pibrils: V / water, methyl alcohol, Nitric acid and deodorant. The outer tube "diameter" was 7 cffi. However, the experiments were repeated using of pipes of various shapes (e.g. from 21 cm Durohmesser).

The type of vortex or twisting motion caused was given by determining the Reynold's numbers with the help of known ones Formula:

Re = Reynold's number

Vm = mean flow rate of the coagulation

liquid (m see)
• D = pipe diameter (m)

^ = Density of the coagulation liquid (kg / m).

-ι -ι

η = viscosity of the coagulation liquid (kg / m seo).

The flow rate of the media in the above examples was in the following areas (provided that the diameter of the outer tube was constant):

3 to 5 m see "low vortex movement about 5 m see "mean vortex movement about 7 m see" strong vortex movement.

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In the case of gases or vapors, the flow rate ranges must be at least ten times, preferably Zx ^ ninety "to thirty times higher. For gases the speed ranges lie at the following values: 60 Vis 110m see low vortex movement

-1
110 "to 150 m see mean vortex motion

-1

150 "to 210 m see, - strong vortex movement» The order of magnitude of the Reynold's number en, which corresponds to the Examples of used words, i.e. low, medium and strong vortex motion, are therefore calculated from the following Table in which other media not used in the examples are listed. The values in the table were also obtained with the device described, in which the outer tube had a diameter of 7 em; the flow rates correspond to the areas listed above.

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to

Reynold number

Water methyl alcohol n-heptane methylene chloride nitrogen

slight vortex movement 24100 32200 39500 · 73000 '44500

mean vortex motion 38500 51200 64000, 118000 73000

strong whirling motion 45500 61000 75000 139000 87000

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Example 8

A mixture of high density polyethylene (MFI = 0.5 g / 10 ¹ ) and polystyrene in a ratio of "5: 1 was solubilized in n-heptane, so that a polyethylene concentration with respect to n-heptane 'of 12 G- ew .- $ was received.

The solution was ^{heated to 20O 0} G, a pressure of about 10 kg / cm was obtained. The solution was then pressed through a spinning head, the openings of which hold 1 mm Durohmeaser and 1 mm thick. Nitrogen was passed through the outer tube at a pressure of 12 kg / cm.

Under these conditions, the n-heptane evaporated and the polymer mixture coagulated to form fibrils with a mean diameter less than 10u and a length between 1 and 10 mm.

The example shows that if you think of polymer blends 'goes out and the compatibility "or incompatibility of the components correctly x ^ iles, improve the quality of the product and can increase the concentration of the starting solutions, which has a positive effect on the application.

Claims

86XXI 3098.48 / 11 BO

Claims (1)

- P a "β β ^η t claims Process for the production of fibrous or filamentary stretched structures including fiber structures, wherein a polymeric substance in the phase of fiber or thread formation is passed through a zone in which it is made into single strands is divided and the fibers or threads formed collects, characterized in that the polymeric substance between the zone in which it takes on the fiber or thread structure and the collecting zone through action a stream from a flowable medium of a vortex or. Subject to twisting effect, which also causes pre-stretching, whereupon the fibers or threads formed are in motion against the other parts of the device Underlay is deposited. 2. The method according to claim 1, characterized in that the fiber or thread formation and the Stretching is influenced by the flow rate of the fluidizing medium and by the profile of the zone in which the polymeric substance is divided into liquid single strands and / or by the profile of the zone which this distribution zone connects with the catchment and collection area. 3. The method according to claim 1 or 2, characterized in that the swirling and stretching achieved is made with the help of a flowable medium that moves with little turbulence. 309848/1150 4. The method according to claim 1 or 2, characterized in that the swirling and stretching achieved is made with the help of a flowable medium that moves with medium or strong turbulence. 5. The method according to any one of claims 1 to 4, characterized in that the swirling is effected by introducing a flowable medium, which at the same time causes the formation of the IT fiber structure from the polymeric substance, at one or more points and at any inclination with regard to the direction of flow of the fibrous Structure. 6. The method according to claim 5, characterized in that the fluidizing medium used is a medium which simultaneously causes the polymer to coagulate. · - """.. 7. The method according to any one of claims 1 to 6 _9, characterized in that the swirling is effected by one or more flowable media _9, which are different from those _{9 used} to form the fibrous structure, at one or more points and below ' any inclination with regard to the direction of flow of the fibrous structure « 8o procedure according to. Claim 5 and 7, characterized in that the stretching and swirling are carried out simultaneously is achieved with the help of 'flowable media, which cause the formation of fibrous structures and those that do not have this effect, 48/11 SUN 9. The method according to one or more of the preceding Claims, characterized in that between the zone of formation of the fibers or threads and the The catchment or collection zone maintains a gradient in terms of pressure, speed and temperature. 10. The method according to one or more of the preceding Claims, characterized in that for the purpose of producing structures from coherent fibers Collection and collection document in continuous or discontinuous Movement keeps. . 11. The method according to claim 11, characterized in that one is on the collecting and collecting pad several layers of the same or different fibers are deposited one on top of the other. 12. The method according to Ansprush 11 or 12, characterized in that the fibers on one on the Underlay arranged film deposited, with which they combine to form a multilayer structure. 13. Device for performing the method according to the preceding claims with a zone for the formation of the fiber or thread-like structure and a collecting zone as well as thermostatic Devices, characterized in that the two zones are connected by a tubular Section (4), wherein the stretching and swirling of the polymeric substance in the phase in which the fiber or forms thread-like structure takes place. 309848/11 SO 14. The device according to claim 13, characterized by one or more inlet points for one or more flowable media along the tubular section (4), wherein the supply line ^- the media inclined against the direction in which the fibrous structure flows could be. 15. The device according to claim 15 or 14 _}, characterized by a support movable with respect to the other device parts, preferably in the form of a treadmill (12) connected to a fine calender system (13). 3Q9848 / 11SG