ES2210190T3 - PROCEDURE AND DEVICE FOR THE MANUFACTURE OF NON-WOVEN FABRIC. - Google Patents

Abstract

The aim of the invention is to provide a method and device with which the distribution of binders (2) and/or other additives in a nonwoven material layer (5) for the production of nonwovens can be homogenized. To this end, a binder (additive) gas flow (6) is blown onto and/or into a supplied nonwoven material layer (5) at high flow speed. Once the components of this mixture have interlaced to a certain extent, the mixture is deposited as a strip (7) on a transport device (4) and is then fed to a compaction station.

Description

Procedure and device for manufacturing of non-woven fabric.

The invention deals with a method and a device for manufacturing nonwoven fabric of the genre indicated in the preambles of claims 1 and 6.

Procedures and devices of this type (documents US-A-5 569 489 and US-A-4 971 742). In these you mix the fibers of the nonwoven material in free fall with help of a gas stream with the binder also fed in Free fall and extend into a transport organ. In case of be made of non-woven material first a mat by compressing the fibers of the nonwoven fabric, before mixing with the binder takes place another separation of the different fibers of the nonwoven layer.

In addition, it is known (document US-A-4 018 646) try fabrics no woven made from fibers of different lengths subsequently with binders, which is done, for example, by spraying the binder. In this procedure a very irregular distribution of the binder takes place inside of the mat of non-woven material.

The invention aims to achieve the simplest possible nonwoven fabrics of one embodiment uniform, that is, respecting very low tolerances, for example of the weight per square meter or other fabric properties not woven manufactured. In addition, it is desirable to be able to control the properties of this type easily by adjusting the part of the binder or other additives in the material no tissue.

The invention is characterized in claims 1 and 6 and in the other subordinate claims advantageous embodiments are claimed. In addition, below is will explain with the help of drawing especially advantageous of the invention.

In the invention, the nonwoven material is made move forward in the form of a layer. The gas stream mixes before to reach the mixing zone proper with the binder to form a binder-gas stream, which is blow on and / or inside the layer of nonwoven material. For this, the speed of circulation of the binder current and gas is chosen high enough for the binder to be dragged hard inside the layer of material not fabric, thus increasing the transport speed of the non woven material.

It is advisable to blow the current of binder and gas by one or preferably several nozzles in The layer of non-woven material. The angle of attack of the current of binder and gas should be up to 60º, in particular of up to 20º with respect to the transport direction of the layer of non woven material.

In addition, it is recommended that the material layer non-woven present in the shock area of the current of binder and gas a layer thickness of approximately 0.1 to 30 cm. It is also recommended that the pressure can be reduced at the point of shock in a mixing chamber whose section widens, being able to perform in this way an even better mixture of binder made in particular in granular form and as granulated with the non-woven material that has another structure, specifically in the form of fibers. From this mixing chamber, the mixture should fall in particular through an advancing organ performed as a screening drum in the transport organ or the advancing body should move it towards it. The mixture forms there a band, in particular of a width between 1 and 3 m.

Instead of a nozzle, they can also be several nozzles distributed along the width of the layer of non-woven material, since the mixing chamber indicated above contributes to greater uniformity of fluidized materials. However, in many application cases it is advisable to use a single nozzle with an internal width of approximately 0.9 to 3.5 m along the entire width of the nonwoven layer fed.

The invention allows to respect minimum tolerances of compressed and, if necessary, shaped nonwoven fabric. May up to 35% binder and additives have been introduced, for to be able to offer certain physical properties, in particular for Soundproofing technique applications, and stability of shape of the nonwoven fabric used, even in case of large temperature differences Weights can be achieved per meter square of non-woven fabric between approximately 400 and 2500 g / m 2 and a specific weight between 50 and 300 kg / m 3, per example in nonwoven fabrics that absorb sound and weights well specific between 300 and 1500 kg / m 3 for preformed parts that they serve, for example, for the inner lining of vehicles.

As non-woven material they are used in particular previously torn cotton and plastic fibers thermoplastics, as well as two component fibers. How binder is preferably used in particular resin Phenolic

The part of the binder or other additives It can be controlled very easily by dosing previous of these materials, for example with the help of screws without end of dosing or measuring scales for tapes conveyors, as well as by the corresponding pressure, with the one that can adjust the speed of feeding of the current from binder and gas to the nonwoven layer.

In the drawings they show:

Figure 1, a schematic cross section to through a device according to the invention;

Figure 2, a schematic partial cut of the Figure 1 in the area of the mixing chamber 13;

Figure 3, a cutout in scale view enlarged area of the power supply of the current binder and gas 6 in and within the nonwoven layer 5 Y

Figure 4, a schematic view of the pre-dosing of the binder and the propellant gas.

According to figures 1, 2 and 3, fibers are fed of torn cotton or other non-woven material through a loading hopper that serves as the feeding element 11, which narrow at the bottom in the form of a slotted nozzle to the surface of a conveyor cylinder that serves as an organ of transport, also called "card", whose surface it presents elevations in the form of nerves, so the material does not fabric 1 pressed on top of it is transported in the form of a layer of nonwoven material 5 in the direction of transport F towards the left. The conveyor cylinder also serves as a call "opening cylinder", which pulls fibers from the nozzle grooved

There is a nozzle 8 with the width 10-25 mm inside as the lower end of the organ feed 12 for binder 2. To the nozzle 8 leads the channel supply 9, through which a gas, in particular air, ejects with a velocity of v = 20 to 70 m / s binder 2 with the main component of current A of the feeding member 12 with a circulation speed of, for example, 50 m / s. In this point of collision of the binder and gas current 6 in y partially inside the nonwoven layer 5, this It has a thickness of D = 1 cm. The angle of attack? Between the current component A and the transport direction F of the layer of nonwoven material 5 in the crash zone is placed preferably between about 0 and 5 °. Here, the grains of binder crawl practically hard entering between the fibers of the nonwoven material 1, so that the speed of Fiber transport increases considerably. Since the interior width of the mixer group 13 increases considerably into the mixing chamber 10, there the speed of circulation is greatly reduced, so that the components fluidized material mix binder-additive fibers se drag by means of the advancing member 14 made as a drum screener under depression to the surface of it and is pushed from the same inside a channel formed by deflector plates 15. Next, the advancing member 14 transports the layer of the mixing to a conveyor belt made as an organ of transport 4 presenting the layer a width of, for example, 2.5 m and a thickness of, for example, 5 cm. The transport organ 4 transports the band 7 of the mixture layer to a station of Pressing not shown. There the binder is heated until the fusion. Since the binder powder or granulate of binder is already well mixed with the fibers of the non-material fabric, short sections of non-woven material are enough, for achieve a good union in pressing and consolidation uniform between the particles of nonwoven material and, given case, other additives.

On or behind the pressing station, the band 7 can undergo a subsequent conformation and / or cut to Get nonwoven mats.

According to figure 4, a phenolic resin thermoplastic, which serves as binder 2, drains from a container manifold 16 down, to reach through a screw without end of transport 17 to a dosing screw 18, in which takes place a previous dosage. Binder 2 comes out of the dosing worm 18 through a hopper to a dosing scale for conveyor belts 19, in which fine dosing takes place, to feed from there in free fall to a cyclone 20, to which air is fed with a high speed up to 70 m / s. Here the current of binder and gas 6, to be fed next through connection channels to the feeding member 12 of the device according to the invention. Instead of a slotted nozzle 8 wide, also several individual nozzles can be distributed along the width of the nonwoven layer 5; in the example according to Figure 4 seven nozzles are provided.

Claims (10)

1. Process for the manufacture of nonwoven fabrics, in which nonwoven material (1) is in particular in the form of fibers, in particular with granulated binder (2) and, where appropriate, with other additives in an organ of transport (4), in particular in the form of a tape, and can be fed to a pressing station, in which the mixture of nonwoven material (1) and binder (2) and, if necessary, additives are pressed, in particular in a heated state, to form a nonwoven web or a nonwoven mat, in which the nonwoven material (1) and the binder (2) are mixed in the presence of a gas stream, which has a component of current (A) in the same direction as the movement of the nonwoven material (1), characterized in that the nonwoven material (1) is advanced in the form of a layer (5), because the gas stream is mixed with the binder (2) to form a binder and gas stream (6), because the binder stream and gas (6) is blown into and / or inside the layer of nonwoven material (5), and because the speed of circulation of the binder and gas stream (6) is chosen high enough for the binder ( 2) be dragged hard inside the layer of nonwoven material (5) thereby raising the transport speed of the nonwoven material (1). 2. Method according to claim 1, characterized in that the binder and gas stream (6) is blown under high pressure in an area of the extended nonwoven layer (5) having a reduced layer thickness (D) between approximately 0.1 and 30 cm and because, then, the pressure is fundamentally reduced, before spreading the mixture of binder (2) and nonwoven material (1) in a transport member (4). 3. Method according to claim 1 or 2, characterized in that the circulation speed of the binder and gas stream (6) is chosen between 20 and 70 m / s. Method according to one of the preceding claims, characterized in that the angle of attack? Between the direction of transport (F) of the layer of nonwoven material (5) and the binder and gas stream (6) is chosen from up to 20º at the point of shock thereof in the layer of nonwoven material (5). Method according to one of the preceding claims, characterized in that the part of the binder (2) with respect to the non-woven material (1) is dosed by controlling the addition of binder to the gas stream. Device for the manufacture of nonwoven fabrics with a method according to one of the preceding claims with a feeding member (11) for nonwoven material (1), with a feeding member (12) for binder (2) and, where appropriate, other additives, with a nozzle (8) for feeding a gas stream and with a transport member (4), with which the mixture of nonwoven material (1) and binder (2) and, where appropriate, other additives can be fed, in particular in the form of a band, to a pressing station, in which the mixture can be pressed to form a nonwoven web or a nonwoven web mat, characterized in that an organ of transport (3) transports a layer (5) of the nonwoven material (1) towards the nozzle (8), because the nozzle (8) blows a binder and gas stream (6) with a current component (A) with a angle of attack α up to 60 ° with respect to the transport direction (F) of the matte layer Nonwoven rial (5) in a mixing group (13) for mixing with the nonwoven material (1) inside the nonwoven layer (5). 7. Device according to claim 6, characterized in that the transport member (3) is made as a transport cylinder. Device according to claim 6 or 7, characterized in that the nozzle (8) is arranged in the inlet zone of a mixing chamber (10), the section of which widens starting from the nozzle area, in particular continuously up to an advancing member (14), because the mixture of nonwoven material (1) and binder (2) and, if necessary, other additives extend as a band (7) in the transport member (4). Device according to one of claims 6 to 8, characterized in that the binder (2) can be mixed by means of an endless screw for dosing (18) and / or a dosing scale for conveyor belts (19) dosed in a group of cyclone (20) with the gas under pressure, coming from there under pressure to the feed channel (9). Device according to one of claims 6 to 9, characterized in that several nozzles (8) are distributed along the width of the layer of nonwoven material (5).