DE2338359C2 - Process for the production of nonwoven fabric - Google Patents

Description

U- invention relates to a method for the production of nonwovens according to the preamble of the claim.

Such a method is described in the earlier '964 patent. A wet spinning-drawing process is known per se from BE-PS 6 74809, in which immediately after the spinning process the thread sheet flowing off the spinneret is deposited in a random fiber layer after drawing. By the patent 2242964, the object is achieved in such a method the Fiiden / u distributed in a substantially uniform manner and with each other to cross direction, so that the nonwoven fabric in the longitudinal direction and in transverse direction of the web has approximately the same good strength. Although the nonwovens produced by this method correspond to knitted fabrics in terms of their strength properties, they do not have the same grip due to the smooth surface of the nonwovens.

The present invention is based on the object to provide a process for producing such a nonwoven fabric that is not only good and uniform Has strength in the longitudinal and transverse direction, but also the characteristic of textile knitted fabrics Structure and a correspondingly good grip.

To solve this problem, those specified in the characterizing part of the claim are in the case of the invention Design features provided.

The method according to the invention has the advantage that instead of a more or less direction-specific Random filing of the drawn continuous thread immediately following the funnel draw spinning in im substantially uniform structure in the manner of a knitted fabric or woven fabric over the entire nonwoven web surface Let them cross evenly distributed, with an equally good strength on all sides being achieved, and at the same time nodular, uniformly distributed elevations are generated on one of the surfaces, which also the grip characteristic of knitted fabrics is achieved.

In the following description and the drawing, the invention is explained and illustrated by way of example.

Show it:

Fig. La and b depositing pattern, as they are after the Tricnterstreckspinnverfahren on a running conveyor in a random order.

2a to c schematically illustrated depositing patterns of different types of thread looping with two, three and six endless sets of filaments, as they are on a running and after the funnel stretching method at the same time laterally swinging, permeable conveyor result.

3 shows a diagram of the longitudinal tensile strength of a nonwoven fabric which has been deposited on a conveyor running in the longitudinal direction and vibrating in the transverse direction, with the vibration amplitude α of the conveyor being changed at constant al.

4 shows a diagram of the ratio of the longitudinal strength to the transverse strength, the ratio ti I being changed with a constant oscillation amplitude 11.

5 shows a schematically represented illustration of successive steps of the invention Manufacturing process.

6 shows a schematic top view of a device, in the method according to the invention for generating the lateral oscillatory movement of the current, permeable conveyor can be used.

7a to c in a greatly simplified, clear representation different types of combined curve or loop arrangements, which can be combined with one or four Endless thread sheets on a running and laterally swinging conveyor result, as well as a Vlicsstoffbahnst ruktur.

8a and b schematically simplified representations to explain a method step according to the invention for opening or perforating the Nonwoven, with the web structure in Fig. 8a is shown before and in Fig. 8b after the process step has been carried out.

9 is a schematic, perspective view of a elongated, rectangular spinning unit, as in the method according to the invention can be used.

FIG. 10 shows a schematic cross section of the spinning unit shown in FIG. 9.

11 is a microscope photograph of part of FIG Top or front of one according to the invention Process produced nonwoven fabric.

FIG. 12 is a view corresponding to FIG. 11 Part of the back of the same nonwoven fabric.

13 is a sketch of a plan view of a nonwoven fabric protected according to the invention on an enlarged scale, and

14 shows a cross section along the line AA in FIG.

In Fig. La three threads are shown as they are from one Hopper draw spinning unit on a running, permeable Conveyors are usually deposited when the thread speed is higher than the conveyor speed. The lateral amplitude is quite limited and irregular. The lateral deviations and Deflection ™ can be very different, especially when the threads are melt spun are formed. Thread patterns of the type shown in FIG. 1b can develop. Low side Interpretations result in a relatively elongated zigzag shape, which is a comparatively weak one Structure of the fiber web. To avoid this, the filing pattern of the threads can be determined by adjusting the thread take-off speed and the Conveyor running speed can be regulated so that an approximately linear arrangement arises on the conveyor. In this case, although the elongation becomes extremely high in the longitudinal direction, the elongation is or Tear strength in the transverse direction extremely low

In the process according to the invention, on the other hand, the spun continuous filaments which, after being ejected from the spinnerets, run through the coagulation bath in the form of a curtain-like thread array, are deposited below the outlet of the draw funnel as a continuous web that is continuously subjected to lateral vibrations at right angles to the direction of travel of the conveyor. As a result, the threads of the web are deposited evenly in the longitudinal and transverse directions, as shown in FIGS. 2a to c. The wave-shaped thread arrangements illustrated there have been obtained using three, four and six spools, respectively. The sinusoidal wavy lines preferably each have a phase shift of In η . whereby /; indicates the number of spinning units used. In the illustrations shown, the representation of the wave pattern is shown in a very simple way: each thread length, which for example consists of about 90 (XX) threads supplied by one spinning unit, is only shown as a single line.

The amplitude and frequency of the lateral vibrations to which the conveyor is subjected can be combined in one wide range can be changed to c'em to be manufactured To give nonwoven the desired advantageous properties. The following general dependencies apply :

If the ratio t <I . where ti is the oscillation amplitude and / means half the wavelength, is constant. and the amplitude is changed, the elongation strength of the obtained nonwoven fabric changes as illustrated in FIG. 3. The abscissa is the amplitude i / in mm and the ordinate is the longitudinal tensile strength in j; tin worn away. A nonwoven fabric with a surface weight of 40 gm ² at a constant value for u I of 0.4 was investigated. It was determined. that the nonwoven fabric has sufficient strength. \\ ςηη dwr value son _s / is selected in the range from 5 to 50 mm.

When the conveyor is running at constant speed is driven, the deflection of the sinusoidal curve at the thread deflection can be changed change the number of oscillations per unit of time.

When the amplitude is </ constant. while ti I is changed, the relation Jic shown in FIG. 4 is obtained. In Fiu.4 the value u I is plotted on the abscissa and the ratio of longitudinal to transverse strength is plotted on the ordinate; the values were determined on a nonwoven fabric with a basis weight of 40 g / m ² with a constant value for the amplitude of 20 mm. As can be seen from Fig. 4, a nonwoven fabric with balanced longitudinal and transverse strength can be produced when the ratio of all is set to about 0.3. The difference between the longitudinal and transverse strength of the nonwoven increases all the more than the value for all

to deviates from 0.5. Within the scope of the present invention, depending on the intended use for the nonwoven fabric to be produced, the value for al can be selected differently in a very large range.

In the method according to the invention, it is also important. _{that the ratio of the thread withdrawal speed I "F} to the conveying speed v _{s is} appropriately adjusted so that the depositing structure of the thread sheet emerging from the drawing funnel is such that the material web transported on the conveyor can then be hydraulically perforated. It was found that then, Weiwi the ratio Yfii-χ is chosen to be greater than 3, a remarkably clean and fairly clearly defined formation of perforations is achieved by means of jets of liquid directed onto the material web from above. as the parts rested on the openings of the permeable conveyor

lowing threads are hydraulically flushed down into these openings. Those parts of the nonwoven web, which rest on the conveyor base are therefore with holes or perforations formed while the parts of the nonwoven fabric flushed into the openings in the conveyor are down out of the plane are pressed out of the nonwoven web and form protruding elevations in the finished nonwoven.

If the conveyor, which runs at a certain constant speed r _v , is made to vibrate sideways, for example with the aid of a cam, crank or other eccentric drive, its total movement can be expressed by the following mathematical equations

χ = ν-η-1.

where the distance ν is assumed in the running direction of the conveyor. and

ι = ti ■ sir \ 2nnl.

where the distance r is assumed in the transverse direction.

The corresponding speeds then result from / u

and r, = 2jt ι. / ι ca-, 2nnt.

where η represents the lateral vibrations of the conveyor per minute, α the vibration amplitude, / half the wavelength of the vibration and ι the time in minutes.

The resulting speed K _{v of} the longitudinal and transverse speeds of the conveyor is:

I γ = eil + '\ κ ² α ² ΐΓ ■ cos ² 2niit

, /, 4 π ² «V

= rsl I + cos * 2πιιΙ

= νI ', t + (π ") ² ■ cos ² 2Jt / ir}

The conveyor speed Γ _ν . how it is measured at the source of the to-and-fro movement results in:

¹ '.V · «ut ='" .V 1 '+ [tf) ²

and becomes at a top or valley:

'V min - ^r , V

The ratio of the thread speed to the conveyor speed is then always:

'V mn.'', V min ' .V

Hence a greater accumulation of threads appears at a point or valley than at the source of the back and forth Float appears to be by a factor on the order of:

or, alternatively, the thread degree of freedom at a tip or sink is higher than it appears at the source of the reciprocation by the same factor:

If it is now assumed that IV / ''. _v "" = I is. the value \ on r _f / i _v changes with a change in u I. as shown in the following table:

Ί I 'Vv 0 1 0.2 1.18 0.4 1.61 0.6 2.13 0.8 2.70 1.0 3.30 1.2 3.90 1.4 4.51 1.6 5.12 2.0 6.36

The correctness of the above considerations has been confirmed in the practical tests carried out. This means that when a number of threads are spun in a wet spinning process and hit a constant speed conveyor under the action of gravity. which is simultaneously subjected to a lateral oscillation, a nonwoven web is created, whose Threads are partially arranged relatively linearly and partially have a high degree of freedom. this also means that if such a path is formed is subjected to a hydraulic perforation process of the type mentioned above, a nonwoven fabric is produced that has high longitudinal and transverse strength and at the same time good knitted-like grip owns.

When the method according to the invention is carried out using a plurality of spinning units is, the ratio I> / I '% ·. "" should be set to 1 to 5 for at least three of these spinning units. The reason for this is that this measure ensures the formation of a thread skeleton can be. When this ratio is greater than 5. cannot achieve satisfactory tensile strength will.

In the present invention, at least one of the spinning units used must have the value of the ratio f'V / ''. ν must be greater than 3. By this measure it is ensured that in some cases threads with a high degree of freedom are actually present around a tight to realize mutual intertwining of the threads with each other.

In order to meet the various requirements mentioned above, various types of combinations of V _F and al come into consideration. Some of these combinations are shown below for a better understanding of the invention.

1. Three spinning units are used, where Vf = 30 m min, r _v = 8 m min and a I = I.

In this embodiment, for each spinning unit J, <t _v ^ s 1.1 and Γ, r _v s3.8.

2. There are vior spinning units used. For three of these units i, ■ = 30 m min, r _v = i5 in min and «/ = 0.4.

For the remaining unit, I ', - = 60 m min. Then for the three units V _F V _x "", = 1.25 and V _F ι _v = 2. For the remaining fourth unit, \' _f <\ = 4 .

The same work results can also be used in the hydraulic process step for the perforation a perforated metal sheet or a fabric can be achieved instead of that in the case of the permeable conveyor Wire mesh provided for the fiber fleece is used can be. The permeable conveyor is arranged immediately below the spinning units, so that the appropriate number of continuous threads can be poured, and it is for the Conveyor preferably uses an endless smooth wire mesh with 40-60 people. The infused continuous Rail can be made using multiple fluid

J5 jets of liquid directly onto the conveyor 'Subjected to a hydraulic perforation process will. On the other hand, it is also possible to transport the web on another permeable conveyor, to perform the hydraulic perforation. In the latter case can be advantageous a wire mesh with 10-60 meshes can be used.

Instead of a plain-woven wire netting, any three-ply, body-bound or a other such wire mesh or any combination thereof can be used in the same way to create a to achieve a correspondingly modified design effect of the end products. Instead of a wire network, it is too possible to use a perforated or openwork non-woven cloth or fleece.

Very advantageously and preferably water can be used as the liquid medium for the formation of the liquid jet flows for performing the hydraulic perforation. It should be noted here that when the method according to the invention is carried out, water is very suitable for carrying out the fiber rearrangement. the application being advantageously easy, safe, reliable and also very inexpensive.
Various known types can be used as spray nozzles in the method according to the invention. Spray nozzles of the round or ring type and of the flat type have already been used with good success.
The liquid pressure at the outlets of the spray nozzles depends on the ratios of V _F ! C _s and V _F l K _v . ^ ₁ and of the total flow rate of the spun and infused continuous threads. With higher values of F _F , r _v and V _F jV _{! L} _ _max and a

lower / ulühriingsrate of continuous threads is the Outlet liquid wedge pressure smaller. The perforated or perforated thus produced according to the invention The woven fabric tap has geometrically arranged perforations or holes and a large number 5 son surveys on. the perforations with the kL'.Krlichen or non-perforated parts of the Network or the perforated carrier web and the elevations with the holes or openings of the carrier web correspond. The surveys b: slehen from debts of the interconnected parts of the continuous loading. Furthermore, the bumps are made of string-like or cord-like parts of thread ties connected with each other.

At each of these elevations, threads with high freedom are closely intertwined with threads with low Degree of freedom, arranged in a latticed skeicii. so uj'ü get a well-articulated GssaiKtsiruk'.ur der not practiced in the course.

In the following in connection with FIG. 5, several Process steps of the process according to the invention described in detail.

In 1 ig. 5 is denoted by t an endless wire mesh conveyor, which in the present exemplary embodiment circulates in your own sense, as if through a small one Arrow is indicated. The conveyor moves over rollers 2. 3. 4 and 5. whereby, for example, rollers 2 and 3 can be drive rollers that are driven by one not shown main drive are driven.

O half of the net conveyor ΐ are near his jo at the left end a plurality of, for example three, spinning units 31, which are generally designated by.-I.

Between the two ends of the conveyor I, various washing or rinsing units 33 to 35 are arranged immediately above them, which are generally summarized under B as washing a s'.uffe. With C a piercing or perforation step and with D a drying step is shown. The perforation stage C and the drying stage D are assigned to a further net conveyor 15 which revolves along a number of rollers or cylinders 6 to 14, the cylinders 11 to 14 at the same time forming a cylinder drying device. In a practical embodiment, the rollers 6 and 7 are, for example, guide rollers, and the cylinder rollers 11 to 14 are driven by a suitable drive, not shown. In this way, the net conveyor 15 can rotate clockwise, as indicated in Fig. 5 by a small arrow.

The reference numeral 16 denotes a machine frame which carries the components of the spinning and washing stages.-1 and B. The frame 16 is supported by columns 17-19 which are pivotally connected to the upper parts of stationary uprights 23-25 carried by the support blocks 20-22. The roller 2 is rotatably arranged at the top of a column 26, the lower end of which is pivotably connected to the upper part of a stationary stand 28. which is arranged on a Slützblock 27.

According to FIG. 6, the roller 2 and the frame 16 are mechanically connected to a mechanical oscillator unit E. Reference numeral 29 denotes an electric motor, while 30 denotes a housing in which a crank or other eccentric mechanism is contained. When the motor 29 is switched on, the oscillator unit E is put into operation, so that the roller 2, the net conveyor 1 and the frame 16 are moved horizontally back and forth together.

In Fig. 5, each of the three spinning units designated 31 has a funnel with a horizontally oriented one rectangular shape, see also Figs. 9 and 10. The main axis of each of these spinning funnels is aligned transversely to the running net conveyor 1.

A plurality of suction boxes arranged directly below the net conveyor and vertically aligned with the spinning units 31 are designated by 32. The reference numerals 33 to 35 designate troughs or containers arranged above the net conveyor 1 for receiving a washing liquid which pours downwards in showers onto the net conveyor. These troughs illustrate the washing stage B.

Several water jet nozzles 36 are arranged above the next net conveyor 15 and form the perforation stage C. in which the above-described perforation of the nonwoven web is carried out with the aid of water jet streams directed thereon. Also under the net conveyor 15 are vertically aligned with the nozzle group ^ 36 Suction box 37 is provided. With 38 a pair of pull-off rollers and 39 with a take-up roller for the cast and for the hydraulically perforated non-woven web.

In connection with FIGS. 9 and 10 the details of the spinning units designated by 31 in FIG.

In Figs. 9 and 10, 40 denotes a spinning liquid supply line, 41 an outer case. 42 a nozzle box or a nozzle plate with a large An / .ihl of spinning orifices, not shown, which are generally arranged in a horizontal plane and in an elongated, rectangular or elliptical pattern are. An upper funnel element for defining an upper coagulation liquid bath is at 43 and a Lower funnel element for a lower coagulation liquid bath denoted by 44. In Fig. IO is also an intermediate partition wall 45. an inlet opening 46 for Supply of the first coagulation bath liquid. one Inlet opening 47 for supplying a second coagulation bath liquid and deflection plates 48 to 51 are shown. A slot-shaped outlet opening is at the lowest end of the lower stage of the coagulating liquid bath arranged.

In the illustrated embodiment, the spinning liquid is supplied through the input line 40 and through a number of outlet openings formed in the nozzle slit 42 are ejected vertically downward.

The outlet openings can for example have an opening diameter of 0.8 mm. These openings can be spaced from one another by 1.5 mm, and they can, for example, in the running direction of the net conveyor 1 seen in 90 rows and transversely to be arranged in 1000 rows, so that per Unit a total of 90,000 openings are provided.

The bath liquid introduced through inlets 46 meets the deflection plates 49 and fills the container space above the intermediate plate 45 so that the bath liquid enters the upper bath funnel 43, in which it, together with the from the nozzle openings ejected threads flow downwards. As can be seen. if necessary, the cross-section of the coagulation bath decreases gradually downwards to the outlet of the bathroom. Therefore, the speed of the downward flow of the bath liquid becomes gradual greater.

The inlet temperature of the coagulation bath liquid is set at such a value that as well as in earlier procedures through contact with the bath

liquid a real degree of kougulaiion of the expelled results in continuous threads.

The threads are then washed with the second coagulation bath liquid brought into contact in the lower Koaguhitionsbad 44, so that they a further coagulation and be subjected to stretching to the correct extent. The threads then get to the slot-shaped one Auslaßöffnunj 52 and are then completely in one formed by the bath liquid flowing downwards Liquid curtain delivered wrapped. to

The liquid voihiing emerging from the opening 52 Is called with unchanged lateral length in the form of a liquid film or a liquid layer downwards, with a curtain-like core inside, that of the so ejected coagulate and stretched continuous filaments, and has a substantially constant thickness. In Fig. 5 are formed in this or similar manner three liquid curtains are shown in a greatly simplified manner by parallel vertical lines 53. These liquid curtains or layers contain a curtain-like thread core inside and fall without damage or destruction of the aligned curtain of liquid under the action of gravity down to where they are on top of the running net / conveyor 1 hit. In a practical example of the copper rayon spinning process, there are three spinning units Arranged at a distance of one meter above the net conveyor 1.

While the net conveyor I is running, it becomes one of the side jo borrowed vibratory motion, as explained in connection with FIG. The sponsor 1 becomes for example at a speed of 10m min driven and shaken sideways at 250 cycles per minute and an amplitude of 20 mm.

When the emerging continuous threads hit the upper side of the net conveyor 1 running in the longitudinal direction and oscillating transversely thereto. they are poured onto this, describing a sinusoidal curve combined out of phase. as explained above in connection with FIG. 2a. After the continuous threads encased in a liquid curtain have hit the conveyor, the liquid is sucked off with the aid of the suction box 32. For this operation, the thread speed, the conveyor running speed and the conveyor oscillation frequency are suitably set such that the values of l ' _F l \. “,, and i ' _F : v _{s are} within the reasonable range mentioned above.

By setting correct values of l ' _F ll \ "" and w l'fi'v and by selecting three, four or six spinning units, nonwovens with different patterns of the infused threads result, as shown in FIGS. 2a to c. At the peaks and valleys of the sinusoidal curve, the threads are poured into a more dense cluster on the permeable carrier web 1, while they are arranged fairly linearly on the carrier web at the transition parts between the peaks and the valleys of the sinusoidal curves. As a result, a path is formed in this way. that it contains thread parts which generally form a lattice-shaped skeleton, and that it also contains thread parts in which the threads are folded or superimposed quite densely and finely. These two different types of parts are intertwined in a mixed manner and form the nonwoven web of the invention.

The nonwoven web formed in this way is transported on the running conveyor and a Subject to washing process. In spinning copper rayon, the first trough became the purpose of the door 33 released a dilute sulfuric acid aqueous solution with an acid concentration of 5%. For the same Purpose, the troughs 34 and 35 from fresh and clean water. In this way they became the nonwoven fabric forming threads regenerated and washed.

After this water cleaning, the non-woven web runs from the first conveyor 1 for further processing on the second conveyor 15. On the second conveyor, the web is then subjected to the hydraulic perforation process subject as explained above.

During this process step, water jets from flat spray nozzles 36. the immediate are arranged above the second conveyor, sprayed onto the conveyed tissue, see Fig. Sa. Gleichze!: ig the suction boxes 37 below the / wide conveyor are in operation to suck in the water from below, In Fig. 5, 54 denotes the ViicNsioiT in iiit.-i.ci process stage.

At this stage, the threads forming the nonwoven web are in a state in which they are under the action of the fluid pressure are displaceable in their mutual position. The threads are therefore under the action the influence of fluid energies in their location rearranged. The effect of this alignment is shown in Fig. 8b. Part of that shown in Fig. Sa Panel 54 was shifted and pressed into the mesh openings of the carrier fabric. These parts of the nonwoven fabric were thereby increased in their density. Even if in this case parts of the lattice-shaped Skeleton can be moved in a similar way, but it is not possible to change the overall structure of the skeleton to destroy. The liquid energy can therefore be used for this. Parts of the suture bundle skeleton to shift and to concentrate the threads locally.

Adverse damage to or destruction of the Skeleton is not possible when the water jet energic is not that big. that the threads forming the nonwoven fabric tear.

The change in position of the zigzag trained Parts of the thread can be carried out with relatively little energy. The water jet energy is under Taking these facts into account. Favorable results were obtained in the case of a nonwoven fabric Copper rayon with a water jet inflow rate of 10 1 min and at a pressure of 20 kg cnr per spin set obtained, the nozzles were arranged 150 mm above the nonwoven web.

The nonwoven web perforated hydraulically in this way forms a regular arrangement of elongated ones Breakthroughs and downward elevations, the thread parts maintaining the latticework tightly and closely with zigzag thread parts are entwined. It is clear from this that the grid-like basic structure is essentially retained remains, but loses its original planar arrangement and becomes bundled together.

The track produced in this way with regular perforations and elevations runs on the second conveyor through a hot roll type drying zone and is finally withdrawn from the conveyor and rolled up.

The nonwoven fabric produced in this way naturally consists of a large number of continuous threads that are closely connected to one another are intertwined, but have retained the original strength structure in their substance, whereby Compared to woven products, high values for tensile strength or tensile-tear strength in both

iu! as well as in (.Hierrivhuing achieved and guarantee been emphasized as a particular advantage i> l. d'.ilJ the production without the use of Binder took place.

Since the non-woven fabric according to the invention has a regular Arrangement of a large number of small elongated openworks and small ones directed downwards Has elevations and the advantageous maintenance of the connection of the tightly entwined threads is guaranteed without any special adhesive. i> t an advantageously pleasant grip ensured, similar to that of gauze fabrics for sanitary purposes. The invention is due to its superior properties i.iü manufactured nonwovens can be used in a wide range for different purposes and can be used, for example, for sanitary ware, for cleaning tables and used for disposable items.

The nonwovens produced according to the invention can instead of Kupi'rikuiisisciui- or Viscose Scidc as well uui can also be made from Akr \ lniirii threads.

The following are detailed numerical examples given for the invention:

Example I.

With the aid of the schematic representation in I ig. 5, a nonwoven fabric was used Manufactured using / ellulose threads regenerated with copper oxide ammonia. It had three wet spinning units of the TV shown schematically in FIGS. 9 and 10 ends. These units were in the running direction de> permeable conveyor belt arranged one behind the other at intervals of one meter.

The \ expended copper hydroxide ammonia cellulose spinning liquid was prepared in the usual manner and contained a composition of cellulose in one concentration before. ! 0.0 Gev ..-%. Ammonia in one concentration of 7.0% by weight and copper in a concentration of 3.6% by weight. The liquid was out a large number of 90 × 1000 outlet openings of a nozzle plate, see reference number 42 in FIG. 10. pushed out. In this way the funnel spinning step was carried out. The bath liquid was deaerated, soft or lime-free, fresh water, which fed to the bath funnels in two successive vertical stages in an overcurrent inflow process became. The outlet oil openings each had a bore of 0.8 mm and were rectangular Matrix arranged with a regular spacing of 1.5 mm.

The bath liquid consisting of deaerated, fresh water was with flow rates of 100 1min with a temperature of 34 C or 110 l / min with a Temperature of 46 C for the two stages of the coagulation bath supplied.

In this way, the streams of the ejected fines were coagulated and entrained with that Bath liquid flow discharged through the outlet slot openings with a width of 5.0 mm, namely in the form of a composite liquid curtain with a parallel layer-like thread core.

The composite curtain of essentially constant thickness flowed 500 mm freely down through the open atmosphere and then encountered a _{400 mesh stainless steel wire mesh running at I 'F} = 40 m / min, the constant speed of which was 10 m min. The conveyor was vibrated violently sideways at 125 cycles per minute and an amplitude of 20 mm. _{If / I v} “ _iot = 2.2 and V _f ; v _s = 4 were set for each of the three spinning units.

After meeting the composite pre

The bath liquid was hanging on the conveyor through whose mesh openings are sucked off with the help of the suction boxes provided, which slot-like suction openings possessed, which faced the spinning units and the size of which was adapted to the spinning units.

The so deposited nonwoven web was transported further through the running carrier net and during it washed with aqueous acidic solution and fresh water for the purpose of regeneration known per se beef then on to another conveyor with a corrosion resistant one Steel mesh of 30 meshes transferred. This transferred nonwoven web was then put into use of water jets subjected to a perforation process, whereby for the water jets coming from above use several flat-type sprinklers!

which were arranged at a distance of 150 mm above the second net conveyor. The flow of the water supply for these spray nozzles was set at 10 1 min per spinning unit and at a pressure of 20 kg cm ^: .

A similar suction box was provided below the net conveyor to suck in the water which was ejected while performing the hydraulic perforation process. A suction pressure of 74mmHg adjusted to the liquid through the mesh openings suction of the conveyor. Such a suction pressure could also be used with the first, with the spinning units cooperating suction box can be used.

As the second conveyor continued to run, the perforated web ran through a tunnel dryer to dry, to make the final product.

The openwork fleece membrane produced in this way has a high elongation and tensile strength in the longitudinal and transverse direction, similar to that of fabrics for Surgical purposes and a very comfortable grip compared to woven cloths.

In the following Table 1, the tensile strengths and the hanging or draping property <3os obtained in this way Non-woven fabric shown:

Tabel

Dry strength * Wet strength wedge * Hanging property **

lengthways across lengthways across

24.4 17.3 16.6 11.8 3.6

* in (g cm) (g cirr)
** in cm. Measurement using the cantilever method

Enlarged photographs of a portion of the nonwoven perforated web are available through the reproductions in FIG Figs. 11 and 12 are shown. 11 shows the front or top side, taken with a magnification factor of 10, while FIG. 12 shows the rear side shows the same web taken with a magnification factor of 3.

Example 2

Here four spinning units were used, which arranged one behind the other at a mutual distance of 1 m in the running direction of the first conveyor was. The spinning and driving conditions of the

Promoters were the same as above. The number of side swings and the speed of walking of the conveyor were selected so that the continuous thread groups of these one after the other with a mutual thread displacement of 1/4 oscillation period were poured onto the conveyor.

The base web thus prepared was transferred to a second conveyor or carrier web made of a 28 mesh plain woven mesh made of corrosion-resistant steel, and then subjected to a hydraulic perforation process. Again, the spray nozzles were of the flat type. The feed rate of the water jet was 5 l / min, and the feed was carried out at a pressure of 13 kg / cm ² . The properties of the perforated nonwoven web thus prepared or produced were similar to those of the previous example 1.

Example 3

There were six spinning units of the same TVps as previously used. The distance for the threaded curtains to fall freely was for the first and fourth spinning unit 700 mm. For the second, third, fifth and sixth spinning units this distance was 400 mm set. The spinning speed for the first case wa * · 56 nvmin. while the speed for the second case was 31 m min.

The running speed of the carrier web was set at 15 m min with 180 lateral oscillations per minute with an amplitude of 20 mm.

For the first and fourth spinning unit was:

V, ¹ Kv. ", = 2.0
and V _F r _v = 3.7.

For the second, third, fourth and fifth spinning units was:

and Yv r.

= 2.2.

The so deposited nonwoven web was on a second Carrier sheet made of a flat-woven, corrosion-resistant wire mesh with 30 meshes and transferred as in subjected to a hydraulic perforation process in the previous cases. The spray nozzles were again of the flat type.

The water was supplied at 10 l / min at 20 kg cm ² .

The dried web showed that in the following table characteristic properties shown.

Table 2

Dryness lengthways across

Moisture strengthening kit lengthways across

Hanging property

21.7

19.5

14.8

4.3

Example 4

A viscose spinning liquid was produced in the usual way with a cellulose concentration of 8.4% by weight. one Alkali concentration of 6.5% by weight. an average degree of polymerization of 290. a gamma value of 55 and a viscosity of 53 seconds and used to spin the continuous filaments. the The spinning device was the same as that shown in FIG. Three spinning units were used. The orifice plate was 30x200 orifices with a Hole diameter of 0.1 mm and spacing of 1.5 mm.

The composite curtain of liquid thus formed impinged on a net conveyor which was 500 mm was arranged below the outlet, the running speed of which was 5 m / min, and that of a wire mesh Made of corrosion-resistant steel with 40 meshes

ίο existed. V ₁₁ was 26 m | min. The sponsor was with

50 vibrations per minute and an amplitude of 30 mm moved sideways. Furthermore, V _f / V _s . "" = 24 and y _F lv "= 5X

The web thus poured on was transferred to a second conveyor and then subjected to a hydraulic perforation process as above. The second conveyor was made from a 30 mesh stainless steel wire mesh. The water was supplied for 101 min at 20 kg cm ² . The results were essentially the same as above.

Example 5

The coagulation bath liquid contained 130 g of 1 sulfuric acid. 300 g / l sodium sulphate and 20 g / l zinc sulphate. In the first stage, the bath liquid was 100 l min at a temperature of 40 C and in the second stage at the same speed, but one temperature of 60 C supplied.

The width of the slot-shaped outlets of the double judge was 2.0 mm. The coagulated and somewhat stretched continuous filaments thus expelled became released through the outlets and flow encased in a curtain of threads into the bath liquid curtain downward.

94 parts by weight of acrylonitrile. 5.5 parts by weight of acrylamide. 0.5 part by weight of acrylic sulfonate. 4 parts by weight of ammonium persulfate and 0.2 parts by weight of thioglycol were dissolved in 1000 parts by weight of water, which by adding a small amount of sulfuric acid a pH value of 3 was set. and left alone for five hours at 60 C. The polymer thus formed was dissolved in 70% nitric acid at 0 C to obtain a Prepare spinning fluid, the 12 Ge \ v .-% of the polymer contained.

Using this spinning fluid were continuous filaments expelled, coagulated, stretched and placed on a running, permeable conveyor, using the on-order shown in FIG. The spinning units were the same as at previous example 1. However, there were four used instead of three spinning units. Each unit had an orifice plate with an array of 20 χ 150 outlet openings with 1.0 mm bore diameter and intervals of 2 mm.

The coagulation bath fluid was a 37% nitric acid aqueous solution. The ratio of the inflow rates of the first and / or second stage of the two-stage bath was set to 1: 1. The bath temperature was set to 3 ^J C for both baths.

The width of the lower outlet opening was set to 2.0 mm, and the net conveyor was 300 mm below This opening was arranged and was driven at a speed of 7 m / min. The promotion

b5 consisted of a corrosion-resistant steel wire net / with 40 stitches. Furthermore was:

l ' _v = 27 m / min.

The lateral oscillation was 75 cycles per minute with an amplitude of 20 mm. For all four units was:

I'f'I'v ..., * = 2.1 and V _r r _v = 3.9.

The nonwoven web thus laid was subjected to a hydraulic perforation process using ½ 'on spray nozzles of the flat type with a water supply rate of 6.4 l'min per spinning unit and a supply pressure of 15 kg cm ² . The suction boxes were operated at 740 mm Hg. The thread entanglement and attachment to each other was performed without using any adhesive.

The results were better than before. The main structure of one according to the method of the invention The perforated non-woven fabric produced is shown schematically in FIGS. 13 and 14 in a plan view and a cross-section shown.

In these figures are regularly arranged with iöi elongated perforations, while the downwardly protruding elevations, which are also regular are arranged, denoted by 102. In the general view of FIG. 13, the perforations are 101 and the elevations 102 arranged alternately with one another in the horizontal direction.

The elevations 102 form a compacted accumulation of threads intertwined closely with one another. the end Fig. 13 is / u can see that these elevations 102 in the transverse direction (in Fig. 13 horizontally) and in the longitudinal direction (perpendicular in Fig. 13) to each other by relative thin band-like connecting parts 103 are connected. Form seen in the horizontal two elevations 120 each at one end of the elongated opening or opening 101. In the vertical seen, the subsequent pair of elevations 102 lay the opposite end of the next opening or opening 101 fixed. The four elevations 102 mentioned here are crosswise connected by two transversely Band parts! 07 connected. When viewed in the vertical direction of FIG. 13, there are two elevations in each case 102 connected to one another by a thread strip 106 running essentially in parallel. Two surveys 102 are interconnected in the transverse direction by a

ίο essentially parallel thread strips 108 connected. This strip has a generally convex curvature. see Fig. 14. Loops of thread are denoted by 10, which protrude from each elevation 102, and which the advantageous possibility of an intertwining with similar

! 5 borrowed thread loops of other similar paths offers, if several identical or similar strips are laid on top of one another, a composite strip is more desirable Generate thickness.

The above explanation of FIGS. 13 and 14 relates essentially only to the appearance or visual inspection of the web of the invention. The true structure of the entire entity is based on the combination effect of a uniform lattice structure with interconnections, as they are in particular in connection with FIG. 1 and also otherwise in the preceding one Description has been explained.

A nonwoven fabric produced according to the invention is therefore superior to conventional products Strength in both the longitudinal and transverse directions, and another advantage is that it feels much more pleasant than the previous ones Products.

It is also possible according to the invention to use a nonwoven fabric with these advantages in an advantageously simple manufacturing process to create.

In addition 5 sheets of drawings

Claims (1)

Claim: Process for the production of nonwoven fabric from drawn endless threads in direct connection with their spinning from an aqueous one. Electrolyte-containing spinning solution after the funnel stretch spinning process using a plurality of bores having rectangular nozzles, the coagulating threads aligned in the form of a multi-thread curtain and then crossed over one another to form sheet-like structures and the nonwoven web thus formed is then washed, dried and fed to a fabric tree, the Crossing and sticking of the coagulating threads, which are still in the self-adhesive state, takes place on a liquid-permeable, horizontally arranged conveyor belt, which is continuously moved at a constant speed perpendicular to the direction of flow of the precipitation bath and is simultaneously subjected to lateral oscillating movements, characterized in that at least three multi-thread curtains in Conveying direction are successively ejected onto the conveyor belt that the lateral oscillating movement is adjusted so that the ratio ' Fi ^ m max can be set between 1 and 5 and the ratio l ', r _v for at least one of these multi-thread curtains to be greater than 3, where V _{f is} the speed of impact of the multi-thread curtains on the conveyor belt. \ \ , ", The maximum value of the speed of the lateral oscillations measured at the oscillation source. Conveyor belt and r _v mean the speed of the vonvärlsbcw movement of the conveyor belt, and that finally the nonwoven web prepared in this way is exposed to the direct action of jets of liquid directed vertically from above and is perforated hydraulically in the process. 40