Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H18/00—Needling machines
  • D04H18/04—Needling machines with water jets

Definitions

• the invention relates to an improved process for the manufacture of a light non-woven textile sheet without pattern, by the technique known under the name of "water jets" under pressure; the invention also relates to an installation for implementing this method.
• this technique consists first of all in making a base ply formed of elementary fibers, then in tangling the fibers of this moving ply on an endless perforated canvas, by means of a ramp of contiguous jets d water under high pressure (50 to 200 bars).
• a ramp of contiguous jets d water under high pressure (50 to 200 bars).
• the water coming from the injectors crosses the sheet then rebounds on the fabric.
• the combination of incident and reflected jets creates turbulence which displaces and arranges the elementary fibers.
• the endless fabric is a metallic or polyester fabric having porosities between 15 and 25%
• the invention consists in using a rotary drum, support of the sheet, having a multitude of micro-orifices distributed in a random and no longer orderly manner.
• randomly means a random arrangement of the orifices over the entire surface of the drum.
• the interval between the edges of contiguous orifices must be at least 0.3 millimeter and, in practice, at most two millimeters. .
• the dimensions of the orifices are identical, it is also possible to use orifices the dimensions of which vary randomly within the range defined below. Similarly, if more generally the section of these orifices is cylindrical, it can also be of frustoconical or parabolic shape, or even in the shape of a trumpet. It could not have been foreseen that the simple random arrangement of the micro-orifices of the rotary drum would allow, on the one hand, as will be seen in the comparative examples below, to improve substantially (of the order of 30% and more) the mechanical properties of the plies obtained, and on the other hand, of increasing the pressure of the water jets, also of the order of 30% and more. In fact, when the rotary drum has regularly ordered micro-orifices, this increase in pressure is not possible, because it would inevitably lead to destruction of the sheet.
• micro-orifices are arranged randomly, optimizes the rebound of the water jets in all directions and prevents the appearance of "shadow-marking".
• the vacuum (vacuum) which prevails inside the drum is between 100 and 1000 mm of water column, preferably in the vicinity of 500 mm of water column and the diameter of this rotary drum is included between 300 and 1000 millimeters, advantageously near 500.
• the diameter of the micro-orifices is between one tenth (0.1) and one half (0.5) millimeter.
• the porosity (ratio between the solid surfaces and the empty surfaces) of the characteristic rotary drum is between (one) 1 and (fifteen) 15%, preferably in the vicinity of (three) 3 to (twelve) 12%, to allow good water evacuation, while remaining compatible with the desired hydraulic binding.
• the base sheet is previously compressed, then pre-wetted on an endless perforated fabric before being tangled by the ramp of high-pressure water jets, as described in the application for Patent FR 95.01473 filed by the Applicant on February 3, 1995.
• the invention also relates to an installation for manufacturing a non-woven textile sheet without a pattern by pressurized water jets, which comprises:
• an endless porous support conveyor intended to receive a basic fibrous web formed of elementary fibers
• a perforated rotary cylindrical drum having on the surface a plurality of micro-orifices, comprising drive means in synchronism with the speed of advance of the porous support, arranged tangentially by one of its generators to the porous support;
• a fixed hollow cylindrical drum coaxial with the rotary cylindrical drum, connected to a vacuum source and having on one of its generators a first slot intended to be positioned in the vicinity of the point of tangency of the rotary drum with the porous support;
• a first ramp of water jets disposed on the other side of the porous support with respect to the rotary drum, and in alignment with the slot so as to form a curtain of wetting water;
• means for receiving the obtained entangled compressed compressed web characterized in that the micro-orifices of the rotary drum are distributed randomly on the surface of said drum.
• the randomly perforated rotary drum is produced by the screen printing technique by electrolytic deposition of nickel or another metal on a conductive matrix.
• appropriate software makes it possible to obtain a random distribution of the micro-orifices on a photographic film.
• This film is then placed on a matrix having very exactly the inside diameter of the drum to be produced.
• This matrix is previously coated with a photosensitive layer. After exposure of the photosensitive layer, the matrix is immersed in an electrolysis bath. After about eight hours, the deposit has reached its optimum thickness. The cylinder is then removed from the mold.
• the software is directly associated with an engraving laser.
• Figure 1 is a schematic representation of an installation according to the invention.
• Figure 2 is a photographic representation of a part of the drum characteristic of the invention, that is to say in which the micro ⁇ orifices are arranged randomly.
• FIG. 3 is a photographic representation seen from above of a nonwoven web obtained by the method of the invention.
• FIG. 4 is a photographic representation, on the same scale as in FIG. 2, of a part of a drum in which the micro- holes are distributed in an orderly and staggered fashion, commonly used for this application.
• FIG. 5 is a photographic representation seen from above of part of the nonwoven web obtained by the implementation of this drum according to FIG. 4.
• the installation according to the invention comprises an endless porous conveyor (1), formed by a canvas of polyester monofilaments having a porosity close to 50%, that is to say having a ratio between the solid surfaces and the empty surfaces close to half.
• This endless fabric (1) is driven in movement by a driving roller (2), actuated for example by an asynchro motor, and passes over return rollers (3,4,5).
• the tensioning of the fabric (1) is carried out by a tension cylinder not shown.
• a base ply referenced (10) from a card or a conventional tabler not shown is deposited.
• This layer (10) advances in the direction indicated by the arrow (FI).
• the installation also includes a perforated rotary cylindrical drum (20) disposed in the immediate vicinity and in contact with the fabric (1) on the descending portion, disposed between the driving roller (2) and the guide roller (3).
• This perforated rotary drum (20) is rotated by an asynchronous motor not shown, at the same linear peripheral speed as the speed of movement of the fabric (1).
• This rotary drum (20) made of nickel 0.4 mm thick and 500 mm in diameter has on the surface a plurality of micro-orifices (21) distributed randomly, produced by the known technique of screen printing and electrolytic deposition described below. above and shown in Figure 2.
• Each micro-orifice (21) has an average diameter of 0.40 millimeter, a slightly frustoconical cut and an edge-to-edge spacing of 0.8 millimeter.
• the porosity of the drum (20) is thus about ten percent (10%).
• the perforated rotary drum (20) is in contact with the fabric (1), which travels over a portion of an arc.
• the vacuum inside the drum (25) is about 500 millimeters of water column.
• the installation also includes a first ramp (30) of water jets, arranged to the left of the fabric (1) relative to the area (A), so as to form a water curtain (31) directed orthogonally to (AT).
• the water comes out of the ramp (30) under a pressure of 5 bars.
• the fixed hollow drum (25) forming a suction box has, in alignment with the water curtain (31), a slot (32) of twenty millimeters in width disposed over the entire generator of the cylinder (25), so as to suck excess water from the water curtain (31).
• the sheet (10) which advances on the porous support (1) is gradually compressed by pinching between the porous support (1) and the rotary perforated drum (20), which both advance at the same linear speed, then is wetted by the curtain of water (31) and the excess water not retained by the compressed base ply, is sucked into the central box (25).
• the obtained wet compressed web (40) is held on the periphery of the perforated rotary roller (20) due to the vacuum in (25).
• This ply (40) which advances in the direction of arrow F2 is then subjected to the action of three injector ramps, respectively (41,42,43), directing on this ply (40) a plurality of jets of contiguous water at a pressure of 40 bars.
• the hollow fixed central cylinder (25) has slots (45,46,47) similar to (32) and also arranged on generators, for suctioning and remove the intermingling water.
• the jets of water under high pressure (41,42,43) cooperate with the micro-orifices (21) distributed randomly on the surface of the rotary drum (20) to entangle and entangle the elementary fibers of the tablecloth.
• the tangled spunlace sheet obtained (50) is detached from the rotary cylinder (20) by passing over a detour roller (51), then from there is conveyed at (52) to the rest of the installation.
• the reference 60 (FIG. 3) designates the final ply obtained without pattern.
• the base sheet (10) is a 50 g / m2 sheet, made of viscose fibers 38 mm long and 1.7 dtex. This compacted and pre-wetted sheet advances at a linear speed of 50 meters per minute.
• the surface of the perforated rotary roller (20), illustrated in FIG. 2 has on average approximately eighty holes per square centimeter distributed according to the invention in a completely random manner (porosity close to 10%).
• the sheet (50) obtained, illustrated in FIG. 3 has the following characteristics measured according to the EDANA standard 20.2.89.
• Example 1 is repeated, replacing the perforated rotary drum with random distribution by a rotary drum according to the prior state comprising micro-orifices (22) of the same dimensions (0.4 millimeters), but distributed in staggered rows in a regular manner ( according to the teachings of document US-A-3 485 706 referred to in the preamble), with a density of micro-orifices of eighty (80) holes per square centimeter (see FIG. 4).
• the sheet obtained (60), shown in FIG. 5, has the following mechanical characteristics:
• this sheet (60) has crippling appearance defects and an effect of "shadow marking” (61) accentuated (see Figure 5), so that it is unsuitable for all uses.
• Example 3
• Example 1 is repeated (random distribution), but replacing the viscose sheet with a polyester fiber sheet of 40 g / m2, formed of elementary fibers 38 mm in length and 1.7 dtex in title.
• the sheet (50) obtained has the following characteristics:
• this sheet does not have any "shadow marking" effect.
• Example 2 is repeated (regular distribution) with the same polyester web as in Example 3. The following characteristics are obtained:
• the sheet obtained has an aspect bordering on the acceptable, with significant "shadow marking" effects.
• Example 3 is repeated (random distribution), but by increasing the pressure of the injectors to 70 bars.
• the sheet obtained still does not have a "shadow marking" effect, but on the contrary a very regular surface appearance.
• This sheet meets the following mechanical characteristics:
• the method of the invention which consists in randomly distributing the micro-orifices on the surface of the rotary drum, unexpectedly eliminates the unacceptable shortcoming of "shadow marking", which makes it possible to increase the pressure of the jets of water from the injectors, and thereby the effectiveness of the entanglement. In addition, this process increases by thirty percent (30%) and more the mechanical characteristics of the plies obtained.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Nonwoven Fabrics (AREA)
• Treatment Of Fiber Materials (AREA)
• Chemical Or Physical Treatment Of Fibers (AREA)
• Cleaning Implements For Floors, Carpets, Furniture, Walls, And The Like (AREA)

Priority Applications (1)

Applications Claiming Priority (3)

Publications (2)

Family

ID=9479258

Family Applications (1)

Country Status (11)

Cited By (3)

Families Citing this family (41)

Family Cites Families (9)

• 1995
  • 1995-05-17 FR FR9506079A patent/FR2734285B1/fr not_active Expired - Lifetime
• 1996
  • 1996-04-30 EP EP96914262A patent/EP0776391B1/de not_active Expired - Lifetime
  • 1996-04-30 DE DE69600146T patent/DE69600146T2/de not_active Expired - Lifetime
  • 1996-04-30 KR KR1019960707621A patent/KR100387448B1/ko not_active Expired - Lifetime
  • 1996-04-30 ES ES96914262T patent/ES2112080T3/es not_active Expired - Lifetime
  • 1996-04-30 US US08/765,319 patent/US5768756A/en not_active Expired - Lifetime
  • 1996-04-30 CN CN96190519A patent/CN1077165C/zh not_active Expired - Lifetime
  • 1996-04-30 WO PCT/FR1996/000654 patent/WO1996036756A1/fr not_active Ceased
  • 1996-04-30 JP JP53459496A patent/JP3677049B2/ja not_active Expired - Fee Related
  • 1996-04-30 AT AT96914262T patent/ATE162238T1/de not_active IP Right Cessation
  • 1996-05-15 IL IL11826696A patent/IL118266A/xx not_active IP Right Cessation

Non-Patent Citations (1)

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