EP1812638B2 - Drum for an entanglement machine for a non-woven using water jets - Google Patents

Abstract

The invention relates to a drum wherein the lateral surface thereof is provided with perforations that are separated by full parts from recessed parts and which are present on the full parts with an outer lateral surface. Application: in an entanglement machine for a nonwoven, using water jets.

Description

The present invention relates to machines for producing woven, knitted and non-woven textile products by the technique known as "jets of water" under pressure.

In documents US 3,214,819 , 3,508,308 and 4,190,695 there has been described a process for the production of nonwoven textile webs in which the cohesion and interlacing of the elementary fibers with one another is obtained by the action of a plurality of high-pressure water jets passing through a web or sail moving on a perforated support.

In the document US 5,791,028 a machine for treating textile products with water jets on suction rotary drums is described.

Whether for the production of nonwovens or the treatment of textiles, perforated rotary drums are generally thick and rigid metal tubes drilled with cylindrical or conical holes. These drums are not directly in contact with textile materials because their openings are too large. They are in particular covered by perforated supports of small holes such as metal or plastic fabrics.

In the US 5,301,401 a drum according to the preamble of claim 1 is described.

More recently in the EP 0776391 a thin sleeve has been described, the wall of which is perforated with randomly distributed micro-orifices.

More recently, it has been proposed to engrave and drill thin plastic tubes with laser to give the nonwovens three-dimensional patterns with the action of jets of water.

All these textile treatment media and nonwovens consolidation by the action of water jets, metal and plastic fabrics, micro-perforated sleeves, laser engraved sleeves have in common their small thickness and low rigidity. And especially, when dealing with pieces of industrial production of several meters in length.

Therefore, these thin supports are supported by thick and rigid perforated drums. It is known to use, for example, rotary drums of honeycomb structure. This technical solution is expensive, but has the advantage of giving a very large open area, from 75% to 90%, which results in an excellent and very uniform drainage of water jets of water with suction by air vacuum inside the drum and next to the injectors delivering the jets of water.

Another technical solution much less expensive than the honeycomb structure is to use drums drilled with cylindrical or conical holes. These less expensive drums have as their main disadvantage their open area of less than 80% and more generally of the order of 30% to 60%. When these drilled hole drums are used as support for perforated sleeves and fabrics, they generate problems of uniformity of suction and drainage of the water jets. There is a loss of efficiency of the water jets as well as appearance defects, particularly in the areas corresponding to the solid portions of the drum separating the holes of the drum. In the US 5,609,046 , metal strips are welded to the drum, while US 6,660,360 B1 they are reported there. In both cases, jet bouncing occurs, defects are observed on the sheet and punctures are closed.

To overcome these drawbacks of loss of efficiency and these defects in appearance, it is commonly interposed a coarse mesh metal fabric between the perforated drum and the outer sleeve that receives the jets of water.

If this technique provides a clear improvement in the drainage of water and a significant reduction in appearance defects, it also causes many disadvantages and in particular a fastening of the constituent materials of textiles and nonwovens such as fibers, filaments, fragments of fibers or filaments and sizing products present on the fibers. This hooking phenomenon is all the more important as the pressures used for the jets of water are high. This phenomenon of fiber attachment increases with time and requires cleaning more and more frequent. This imposes production stops, or even the replacement of parts that become unusable. It is sometimes impossible to remove the perforated sleeves and they must be destroyed and replaced with new parts.

The invention overcomes these disadvantages by a particular design of the surface of the perforated rotary drum. The drum according to the invention can receive any type of metal or plastic fabrics, thin micro-perforated metal sleeves, metal sleeves whose surface has been previously embossed as well as plastic sleeves etched by laser.

The drum according to the invention offers an excellent and uniform drainage of the water coming from the jets of water, appreciably improves the quality of the nonwovens produced, without causing the attachment of textile materials such as fibers and other constituents of the textile products and this whatever the water pressures used for the water jets.

The drum according to the invention also allows easy disassembly of the outer sleeves without damage.

Nonwovens produced with a drum according to the invention are free of marks or impression of the drum regardless of the pressure of the jets.

The invention relates to a drum according to claim 1.

The recessed portions can be easily obtained by machining.

The recessed portions of the lateral surface are obtained by machining the already cylindrical blank of the drum. Machining is in fact a cheap technique for producing recessed portions, stripes or recesses according to the preferred dimensions. The machining also allows to obtain an excellent precision on the dimensions and to weaken as much as possible the solid parts.

The ratio of the area of the perforations to the total area of the outer lateral surface is between 30% and 90%, but preferably it is between 60 and 80%, which greatly reduces the twists of the jet.

The thickness of the side wall of the drum is preferably between 1 mm and 60 mm and better still between 5 mm and 40 mm. The perforations have a diameter of between 3 and 20 mm.

The thickness of the recessed portions is preferably between 0.25 mm and 5 mm and better still between 0.5 mm and 2 mm and their width between 0.6 and 20 mm.

Preferably, the length of a non-recessed portion is from 30 to 100% of the diameter of a perforation and the width is from 0.6 to 4 mm, preferably 2 mm.

In the most preferred embodiment, the ratio of the surface area of the recessed portions to the surface of the solid portions is greater than 70 and preferably from 70 to 95. The drum is preferably made of bronze or stainless steel and has an outside diameter of between 200 mm and 1200 mm. The perforations are preferably cylindrical or conical, their circular cross section greatly facilitating the manufacture of the drum. Preferably, the water jets have a diameter of 50 to 250 microns and the pressure of the water preferably from 10 to 500 bar.

According to a very preferred embodiment allowing to have a maximum opening of the drum, a recessed portion leading to two adjacent perforations is on the line passing through the centers of these two perforations and, better still, there are only two parts. hollowed out leading to each perforation. The recessed parts are interrupted by the perforations. At diametrically opposite points of each perforation leave two recessed portions. The diameters just discussed, if they are not aligned, are parallel from one pair of perforations to another.

The invention also relates to a machine for entanglement by water jets of a nonwoven, comprising a drum, means for driving the drum in rotation, a sleeve provided with openings, threaded onto the drum and an injector system arranged so as to project jets of water on the outer lateral surface of the sleeve, characterized in that the drum is as defined according to the invention.

Preferably, the particularly cylindrical openings have a larger dimension of between 30 and 800 μm and the sleeve has a thickness of between 0.10 mm and 3 mm. The ratio of the area of the openings of the sleeve to the total area of its external lateral surface is preferably between 5% and 50%.

• la figure 1 est une vue en perspective schématique d'une machine d'enchevêtrement d'un nontissé par jets d'eau suivant l'invention,
• la figure 2 est une vue partielle en coupe de la partie entourée d'un cercle à la figure 1, et
• la figure 3 est une vue analogue à la figure 2 d'une variante.
• Les figures 4 et 5 sont des vues partielles de développées de deux modes de réalisation.

In the accompanying drawings, given solely by way of example:

• the figure 1 is a schematic perspective view of an entanglement machine of a nonwoven fabric by jets of water according to the invention,
• the figure 2 is a partial sectional view of the part surrounded by a circle at the figure 1 , and
• the figure 3 is a view similar to the figure 2 of a variant.
• The figures 4 and 5 are partial developed views of two embodiments.

The machine represented in figure 1 comprises a fixed and hollow body 1 which is pierced with slots facing injectors 2 and 3 capable of sending jets of water with a diameter of 150 microns under a pressure of 250 bar.

The body 1 is surrounded by a perforated drum 4 which is rotated about its axis by a motor 5 with the aid of a driving device 6. The drum 4 is surrounded by a perforated sleeve 7 openwork of 200 microns in diameter, which may be a fabric, a thin microperforated metal envelope, an embossed sleeve, a sleeve of plastic material etched by laser.

The injectors 2, 3 are arranged to project the jets of water on the outer lateral surface of the sleeve.

To the figure 2 , the drum 4 has non-recessed portions 8 or intact which are derived from the outer lateral surface and the recessed portions 9 machined in the surface of the drum 4 which is directed towards the sleeve 7. The portions 8 delimit through cylindrical perforations 10. The free ends of the parts 8 are in contact with the inner face of the sleeve 7.

To the figure 3 , the drum comprises non-recessed portions 11 and recesses 12, the tips 13 of the non-recessed portions pointing to the sleeve 7 are in contact with the inner face thereof.

To the figure 4 the perforations 10 are arranged in helical rows. The diameter D of the perforations 10 is 10 mm. The length L of the non-recessed portions is about 4 mm. The width of the recessed portions 9 is 2 mm. All the hollow parts 9 open on the perforations. The entire outer face of the drum is the same surface with the exception of the recessed portions 9 which are recessed.

What essentially distinguishes the embodiment of the figure 5 from that of the figure 4 is that there are only two non-recessed portions 8 of the solid parts that touch each perforation and that a non-recessed portion 8 which touches at its ends two adjacent perforations is on the line passing through the centers of these two perforations 10. The angle X of the line of these centers with a generatrix, parallel to the axis of the drum, is between 0 and 180 °. It is 90 ° to the figure 4 . The two non-recessed portions 8 which touch the same perforation do so at diametrically opposed points.

The width of the recessed portions 9 is 8 mm.

Claims (13)

1. Drum (4) the outer side face of which is provided with perforations separated by solid parts, with hollow parts which are machined on the outer surface of the solid parts, in which the whole of the side face is a same face, with the exception of the hollow parts, which are recessed, in which all the hollow parts open onto the perforations, characterised in that the ratio of the surface area of the perforations and the total surface area of the outer side face is between 30 and 90%.
2. Drum (4) according to claim 1, characterised in that the perforations are cylindrical or conical.
3. Drum according to one of the preceding claims, characterised in that the (minimum) thickness of the side wall of the drum is between 1 mm and 60 mm and preferably between 5 and 40 mm.
4. Drum according to one of the preceding claims, characterised in that the thickness of the hollow parts is between 0.25 and 5 mm, preferably between 0.5 mm and 2 mm.
5. Drum according to one of the preceding claims, characterised in that the drum is made of metal, preferably bronze or stainless steel.
6. Drum according to one of the preceding claims, characterised in that the diameter of the perforations is between 3 and 20 mm.
7. Drum according to one of the preceding claims, characterised in that the length of a non-recessed part constitutes 30 to 100% of the diameter of a perforation.
8. Drum according to one of the preceding claims, characterised in that the width of a non-hollow part is between 0.6 and 4 mm.
9. Drum according to one of the preceding claims, characterised in that a non-hollow part of a solid part, which touches two adjacent perforations at its ends, is on the line passing through the centres of these two perforations.
10. Drum according to claim 9, characterised in that there are only two non-hollow parts of the solid part touching each perforation.
11. Drum according to one of the preceding claims, characterised in that the ratio of the surface of the hollow parts to the surface of the solid parts is between 70 and 95.
12. Machine for entangling a non-woven fabric by means of water jets, comprising a drum (4), means (5, 6) for rotationally driving the drum (4), a sleeve (7) provided with openings pulled over the drum (4) and an injector system (2, 3) arranged so as to spray water jets over the outer side face of the sleeve (7), characterised in that the drum (4) is as defined in any one of the preceding claims.
13. Use of a machine according to claim 13 for manufacturing a non-woven with no marks or impressions.

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