DD261179A1 - DEVICE FOR PARALLEL STORAGE OF ELEMENTARY FAITHS IN THE MANUFACTURE OF A NON-MATERIAL BY DIRECT PROCESSING - Google Patents

Abstract

The apparatus is applicable to plants which stretch the filaments extruded from a spinneret assembly with compressed air and the web is laid down on a perforated conveyor belt. In accordance with the invention, beam apertures 5 are arranged at an angle of 5 degrees * beta * 15 degrees to the vertical. They have openings with a diameter of 1 mm * d * 3 mm, whose horizontal distance is 1.5 d * a * 3 d and whose vertical distance is 2 d * b * 6 d. Blow heads 2 are angled 15 degrees * lambda * 25 degrees opposite the beam apertures from the vertical. By means of angle blow heads / jet diaphragms and the perforation of the jet diaphragms, pulsating single air flows arise at the openings, which cause the thread spread required for a uniform filing of the filament fleece. The formation of individual air flows is favored by bulges 9 still. Likewise, exhaust air screens 10 cause an additional spreading due to air accumulation. Fig. 1.

Description

Impact point (6) of the yarn sheets to the lower edges g <100mm and the distance lower edge to the collecting device (7) 1 <800 mm and that on the guide tubes (3) mounted Blasköpfe (2) by 15 ° ^ λ <25 ° opposite the beam aperture (5) are angled from the vertical.

2. Apparatus according to claim 1, characterized in that over the openings (8) oblique bulges (9) are present, whose highest point is located in the region of the upper limit of the openings, said point the base of the jet aperture by 0.2d '< s <d, preferably projecting over 0.4 d, the length of the bulges is 0.5 d <h <2 d, preferably 1.2 d, and their width at the openings has its maximum with d.

3. Apparatus according to claim 1 or 2, characterized in that relative to the jet aperture (5) Abluftschirme (10) are arranged at an angle 8 ° <γ <20 ° to the other side of the vertical deviating and so bent at its lower end are that they run there parallel to the beam apertures to form a gap whose respective width is 2mm <ζ <10mm.

4. Apparatus according to claim 1 or 3, characterized in that the blow heads (2) rotatably mounted at an angle 10 ° <δ < 90 ° to the guide tubes and are connected via levers (4) with a translation member.

5. Apparatus according to claim 4, characterized in that the beam apertures (5) to a continuous beam aperture (5 ') are connected.

6. Apparatus according to claim 1 or 2, characterized in that the jet diaphragms (5) are arranged pivotably about its longitudinal axis.

For this 4 pages drawings

Field of application of the invention

The invention relates to a device for the uniform deposition of the filaments in the manufacture of a nonwoven fabric in the direct process. The apparatus is applicable to plants which stretch the filaments extruded from a spinneret assembly with compressed air and in which the web is deposited on a perforated conveyor belt. The filament nonwovens produced in this way meet high standards and are versatile in the consumer goods and technical sector.

Characteristic of the known state of the art

Nonwovens have been produced in direct processes for approximately 30 years, with currently still growing growth rates. After a short time, it was recognized that in addition to favorable extrusion conditions and the application of high stretching forces to achieve maximum filament strength of the nonwoven storage is of particular importance. This is reflected in the very high number of previously proposed solutions for improving storage.

By diffusers at the exit of the drawing nozzles, the air flow is greatly retarded and the filaments spread (eg, DE-OS 1635596), possibly using specific flow profiles (DD-PS 84707) or additional air flows (FR-PS 1585226). By such diffusers, the air consumption of the stretching device is not insignificantly increased and although the yarn deposit improved, but the differences in strength longitudinal / transverse in the nonwoven fabric are only partially degraded. A number of patents (eg US-PS 3338992, FR-PS 2309 654, DE-OS 1435112) are based on the electrostatic charging of the filaments, e.g. B. using a target / corona discharge, the effort justifies the achievable results only partially.

Some patents are based on the action of horizontal aerodynamic (eg DE-OS 2114854) or mechanical (FR-PS 2299438) lateral forces to spread the yarn sheet. In addition to a sometimes considerable effort, the nonwovens produced in this way have a preferred transverse orientation and thus low longitudinal strength. Some patents (eg DE-OS 2200782, GB-PS 1473270) are based on the generation of centrifugal forces by rotation of yarn guide elements at the exit of the stretching nozzles. As a result, a geometrically defined, mathematically predeterminable yarn deposit should be possible. The expense, the acoustic load and maintaining operational safety at speeds up to 2 000min ^"1 have not hitherto a implementation of these methods. Most devices utilize one below the Reckdüse arranged deflection device, which may be smooth to prevent a yarn brake or a preferred fluid deflection The spreading of the bundle of filaments may be achieved by an air jet (eg DE-OS 2220575), possibly in conjunction with the so-called COANDA effect (eg WO No. 81/02172), which states that a flowing medium exiting from a nozzle under pressure adheres to and slides over a surface arranged in front of it, the threads being able to be grasped by the fluid, padded against the deflecting device and thereby dispersed. The disadvantage here is the required use of additional air and the achievement of a strong Län gsorientierung.

In DE-OS 2211691 the arrangement of a long guide tube is described following the injector nozzle, which is angled at its end. At the output of the angled pipe section is a flat or concave deflection, even further angled in the direction of the horizontal arranged. In this way, the thread bundle is spread in two stages, which increases the overall spread. In a variant between the angled pipe section and deflecting another pipe section, which again runs more vertical direction opposite the first pipe section arranged. In this way, the spread can even be done in 3 stages. In this solution, the thread separation is influenced solely by the impact of the bundles of fibers on smooth surfaces, whereby the resolution is not achievable to monofilament. Also, a pivoting movement of the deflector can only increase the spread. In contrast, gem. US Pat. No. 4,217,387 has blown air from a distributor plate arranged below the injector and below a downstream baffle plate from slit nozzles in order to favor the disbonding of the filaments. In this way, however, the energy requirement is increased again.

Another positive aspect of this solution is that a gap is formed between the distribution plate and the deflection plate, which delays the flow of air and thus additionally favors the spreading of the threads.

Object of the invention

The aim of the invention is to propose a device for uniformly depositing the filaments in the manufacture of a nonwoven fabric in the direct process, which ensures a high thread dispersion without additional air consumption and additional noise pollution and is straightforward.

Explanation of the essence of the invention

The technical task is to design the device so that the air emerging from the guide tube can be used directly to achieve single air flows in conjunction with a deflection device.

According to the invention, this object is achieved in that the deflection device jet aperture are arranged at an angle 5 ° <β <15 ° to the vertical, the openings with a diameter 1 mm <d <3 mm, preferably 2 mm. The horizontal spacing of the openings is 1.5d <a <3d, preferably 2.3d. Their vertical distance is 2d <b <6d,

preferably 3d. The rows are offset at a distance of b <4d at least um - to each other. The length of the

Beam aperture from the point of impact of the yarn sheets to the lower edges is g <100 mm and the distance lower edge to the catcher 1 <800mm. The blow heads attached to the guide tubes are 15 ° <λ s; 25 ° angled against the beam aperture from the vertical.

Oblique bulges may be present above the apertures in the beam apertures, the highest point of which is located near the upper limit of the apertures. This point projects beyond the base area of the beam diaphragms by 0.2 d <s <d, preferably 0.4 d. The length of the bulges is 0.5d <h <2d, preferably 1.2d.

Their width has their maximum at the openings with d.

Abluftschirme can be arranged at an angle 8 ° <γ <20 ° to the other side of the vertical deviating from the beam apertures. They are bent at their lower end so that they run there parallel to the beam apertures to form a gap whose respective width is 2 mm <ζ <10 mm.

The blow heads can be rotatably mounted at an angle of 10 ° <δ <90 ° to the guide tubes and connected via levers with a translational member.

The beam apertures can be connected to form a continuous beam aperture.

The beam diaphragms can be arranged to be pivotable about their longitudinal axis.

By combining the arrangement of the blowing heads and the jet apertures to each other, d. H. the total included angle β + λ, the opposite to the vertical slope and the steep arrangement of the beam aperture at all with the specific design of the jet aperture openings with predetermined dimensions, distances and arrangement of the emerging from the guide tube air, for the stretching process of the filaments anyway is required, surprisingly directly usable to achieve spreading forces.

The air delivered from the blow heads at an acute angle to the jet diaphragms has, in the direction of flow, a pressure which is higher in relation to the environment but lower at an obtuse angle to the flow direction. The pressure difference increases after the sliding of the respective air flow to the jet aperture still. By the interaction of a direct flow component in the direction of the openings and a component produced by a negative pressure, as explained, pulsating air flows are generated at the openings, which together provide a strong splitting of the bundle of filaments.

An essential role is played by the oppositely generated movement of filament bundle / air flow through the opposite Blasrohmeigung and beam aperture inclination to the vertical. The steep arrangement of Strählblenden is especially necessary because the individual air streams not only split the group of threads, but also slow down and ein.zu strong delay affects the continuous and thus uniform thread tray. In this context, the maxima of the beam aperture length below the impact point and the distance beam aperture / collector are important.

By additionally mounted oblique bulges over the openings, the negative pressure component of the air flow can be amplified, in which case the maxima of the angles β and λ lead to optimal storage conditions. By Abluftschirme a delay of the air flow can be superimposed up to the gap, which allows a further targeted influencing the storage conditions.

By a pivoting movement of the blow heads, which can be achieved by a blow head spread can be improved. A pivoting at high frequency, as required by baffles to realize the spreading of the bundle of filaments, is not necessary here. A frequency of 70 to 150min "'is quite sufficient and does not lead to additional noise pollution.

The combination of the beam apertures is advantageous in groups or in a single beam aperture. In particular, a high pivoting range of the blow heads can then be ensured.

A possible variant for increasing the width of a web which can be operated by a blow head is also the arrangement of the jet diaphragms which can be swiveled in its longitudinal axis.

embodiments

The invention will be explained in more detail below with reference to 4 exemplary embodiments. In the accompanying drawings show:

- Fig. 1: a view of the entire storage area

- Fig. 2: the front view of a beam aperture according to the invention

- Fig. 3: a perspective view of a storage unit

4 shows a plan view of a part of the device according to the invention with a continuous jet aperture.

- Fig. 5: the front view of a beam aperture with bulges and

- Fig. 6: the associated side view.

The polymer polyamide 6 is melted in an extruder and fed to a spinning beam with several spinning stations. Each spinning station is equipped with two spinnerets each. In each spinneret there are 90 round holes 00,3mm. By means of polymer pumps, the metering of the melt takes place, the throughput amount being constant at 120 g / min and spinning position. The 4 yarn sheets pressed out of the spinnerets pass through a 320 mm long air cooling system and are taken up by 4 draw injectors and stretched to a single titer of 0.22 tex. The impressing of the stretching force on the yarn sheets is carried out substantially in guide tubes 3, at the end of blow heads 2 are arranged.

Example 1 -

The blow heads 2 with an opening dimension 015 mm are angled at λ = 15 ° from the vertical counter to the non-woven transport direction on the collecting device 7. At a distance of 60 mm to the output of the blow heads 2 beam aperture 5 are mounted.

They close with the vertical, against the bending of the blow heads an angle β = 8 °, so that the blow heads 2 and 5 beam blast total of an angle of 23 °. The beam apertures 5 have openings 8 with a diameter of 2 mm, whose spacing in the respective row is 4.6 mm and the spacing of the rows is 6 mm. The rows are each offset by 2.3 mm to each other.

The length of the beam aperture 5 is 100 mm, the impact point 6 of the yarn sheet 1 is approximately in the middle of the beam aperture.

The lower edges of the beam aperture 5 have a distance 1 = 690 mm to the collecting device. 7

Opposite the jet aperture 5 angled Abluftschirme are mounted at an angle γ = 15 ° to the vertical, which form in the region of the lower edges with the jet aperture gaps of width ζ = 5 mm.

The blow heads 2 are connected via levers 4 with a translational organ, z. B. a crank mechanism connected.

They are pivoted synchronously on the guide tubes 3 at an angle of 14 ° with a frequency of 96 min ^-1 , whereby the point of impact 6 moves the yarn sheet 1 horizontally over the respective beam aperture The spread of the guide tubes relative to each other is 140 mm .The spread suture bundles 14 are laid down uniformly in a row on the receiving device 7, a perforated conveyor belt, to form a nonwoven textile fabric 13 with a basis weight of 32 g / m ² .

The thermal fixation of the filament textile fabric 13 is then carried out by means of a calendar. The deposit on the collecting device 7 is assisted by an exhaust air suction device 12 with perforated plate 11.

The coefficient of variation of the uniformity of the mass distribution in the thus-produced filament nonwoven fabric is 4.8% against 10.2% using a known baffle plate.

By varying the variables mentioned in the range of the limits specified according to the invention, the nonwoven fabric properties can be adapted to the required parameters, in particular the longitudinal / transverse strength.

Example 2

Compared with Example 1, the beam apertures 5 are additionally provided with bulges 9. With the same opening size and arrangement, the bulges 9 protrude at their highest point s = 2 mm above the surface of the jet diaphragm. Likewise, their maximum width and length are 2mm.

The Blasköpfe 2 are inclined by 25 ° and the beam aperture 5 by 15 ° from the vertical deviating. This results in an angle of 40 ° between the two.

Due to the partial deflection of the air flows over the openings 8, even at this angle, still pulsating single air flows are achieved analogously to Example 1.

Example 3

In this variant, the beam apertures 5 are combined to form a wide beam aperture 5 '. As a result, on the one hand, the production cost is reduced, on the other hand, larger deflections of the blow heads 2, i. up to δ = 90 ° possible, whereby the coverable by a spinning station fleece width is maximized. Incidentally, as set forth in Example 1, proceed.

Example 4

In a further variant, the beam apertures 5 are arranged pivotable about their longitudinal axis. By this pivoting movement alone or in conjunction with a superimposed pivotal movement of the blow heads 2, the storage conditions beyond can be influenced in a targeted manner.

Claims (1)

1. A device for uniformly depositing the filaments in the manufacture of a nonwoven fabric in a direct process, in which arranged on the injectors guide tubes, which serve the thread guide and the impressing of the stretching force, are angled at their ends and is arranged below a planar deflecting device over a moving collecting device, characterized in that arranged as a deflecting beam aperture (5) at an angle 5 ⁰ ^ β S 15 ° to the vertical, the openings (8) having a diameter 1 mm <d <3mm, preferably 2 mm, have, whose horizontal distance , 5d <a <3 d, preferably 2.3 d and their vertical distance is 2 el <b <6d, preferably 3d, and the rows at a distance of b <4d offset at least by -§- to each other, that the length of the beam aperture (5) from the